Medical decision-making among Hispanics and non-Hispanic Whites with chronic back and knee pain: A qualitative study

Jeffrey N Katz
Nancy Lyons
Lisa S Wolff
Jodie Silverman
Parastu Emrani
Holly L Holt
Kelly L Corbett
Agustin Escalante
Elena Losina
Medical decision-making among Hispanics and non-Hispanic Whites with chronic back and knee pain: A qualitative study
R E S E A R C H A R T I C L E Open Access
Background: Musculoskeletal disorders affect all racial and ethnic groups, including Hispanics. Because these disorders are not life-threatening, decision-making is generally preference-based. Little is known about whether Hispanics in the U.S. differ from non-Hispanic Whites with respect to key decision making preferences.Methods:We assembled six focus groups of Hispanic and non-Hispanic White patients with chronic back or knee pain at an urban medical center to discuss management of their conditions and the roles they preferred in medical decision-making. Hispanic groups were further stratified by socioeconomic status, using neighborhood characteristics as proxy measures. Discussions were led by a moderator, taped, transcribed and analyzed using a grounded theory approach.Results: The analysis revealed ethnic differences in several areas pertinent to medical decision-making. Specifically, Hispanic participants were more likely to permit their physician to take the predominant role in making health decisions. Also, Hispanics of lower socioeconomic status generally preferred to use non-internet sources of health information to make medical decisions and to rely on advice obtained by word of mouth. Hispanics emphasized the role of faith and religion in coping with musculoskeletal disability. The analysis also revealed broad areas of concordance across ethnic strata including the primary role that pain and achieving pain relief play in patients' experiences and decisions.Conclusions: These findings suggest differences between Hispanics and non-Hispanic Whites in preferred information sources and decision-making roles. These findings are hypothesis-generating. If confirmed in further research, they may inform the development of interventions to enhance preference-based decision-making among Hispanics.

Background

Musculoskeletal problems are prevalent, disabling and resource-intensive [1]. Utilization of health care services for these disorders differs across racial and ethnic groups. For example, Hispanic utilization of total hip and knee replacement in the United States is as low as half that of non-Hispanic Whites [2][3][4][5]. As one in eight U.S. residents was either born in a Spanish-speaking country or is related to someone who was [6][7][8], understanding these differences merits high priority.

The lower rates of total joint replacement among Hispanics do not appear to be attributable to ethnic differences in prevalence of arthritis, health insurance status, income or geographic location [2,3]. Possible explanations for the disparity include differences in the treatments that physicians recommend to Hispanic patients, and differences between Hispanic and non-Hispanic patients in their preferences for treatment. Since musculoskeletal disorders are not life-threatening, treatment decisions are sensitive to patient preferences. Shared decision-making (SDM) -a process that enables patients to make fully informed, preference-consonant decisions -has been proposed as an ideal process for making therapeutic decisions in such preference-sensitive situations [9][10][11][12][13][14]. These concepts of shared decisionmaking are embodied in the Ottawa Framework for Decision making, a well established paradigm used to evaluate the decision making process [15,16].

The shared decision-making process calls for patients to be offered descriptions of available treatment options and informed of the favorable and adverse outcomes associated with each one. The clinician also helps patients to assess their preferences for these outcomes. This process may be especially challenging for many Hispanics, who do not share the predominant culture and language and often have less formal education and lower health literacy than the general population [6]. Prior literature suggests that Hispanics may differ from non-Hispanic whites in the type of health information they seek, the extent of decision-making authority they wish to exercise and the role of religion and faith in decision-making [17][18][19].

These considerations led us to pose a series of questions: Do Hispanics obtain knowledge about treatment options in a fashion that is similar to Whites? Do Hispanics prefer to defer important health care decisions to their physicians or to the advice of family and friends? Given the substantial socioeconomic differences that exist among Hispanics in the U.S., we also ask whether the answers to these research questions differ according to socioeconomic indicators. Because our research questions have been largely unexamined in the arthritis and pain literatures, we chose to use qualitative methods to develop hypotheses that could then be tested quantitatively in subsequent research.

Methods

Design overview

We conducted six focus groups for Hispanic and non-Hispanic White subjects with chronic back or knee pain. The Hispanic and non-Hispanic White subjects were matched with respect to the socioeconomic features of their zip codes of residence. The groups were led by a professional moderator who used a semi-structured moderator's guide. We transcribed the focus group discussions and analyzed the transcripts using a grounded theory approach [17,[20][21][22].

Patient sample Eligibility criteria

To be eligible for this study, subjects had to be older than eighteen and had to be seen at least twice in 2006 at Brigham and Women's Hospital for back or knee pain. We excluded subjects that lived outside of Route 95, a beltway around the Boston metropolitan area with radius of approximately ten to fifteen miles. This exclusion enhanced comparability of Hispanics and non-Hispanic Whites, as eligible Hispanic subjects rarely lived far outside of the city. Hispanic ethnicity was confirmed by self-report using the 2000 U.S. Census criterion. We first asked the subjects' ethnicity (Hispanic or non-Hispanic), then asked the subjects' race. We excluded subjects who identified themselves as African American, Asian, Pacific Islander and Native American so that the two groups would be composed of Hispanics and non-Hispanic Whites.

Socioeconomic stratification

We obtained zip codes on all eligible subjects from the administrative database. The zip codes were grouped according to a variable we termed "vulnerability index," which was constructed as follows. First, we used 2000 U. S. Census data to characterize each zip code with respect to four variables: the proportion of residents in the subjects' zip code who had attained less than high school education; the proportion of residents in the zip code whose income was below the poverty line; the proportion who were foreign-born; and the proportion of racial and ethnic minorities. For each of these variables, we created a threshold value on distributional grounds. These included: >25% with income less than poverty; >28% with education less than high school; >26% foreign born and >64% non-white. If a zip code exceeded the threshold we regarded residents of that zip code as "vulnerable" with respect to that factor. We then stratified patients according to whether their zip code had one or fewer of these vulnerability factors ('less vulnerable') or two or more vulnerability factors ('most vulnerable').

Recruitment procedures Hispanic subjects

We identified our sample using the hospital's Research Patient Data Repository, a database that integrates information from diverse hospital electronic databases for research purposes. We performed a search within the Repository database for patients seen in outpatient practices for back or knee pain. Hispanic ethnicity was provisionally identified using the race/ethnicity indicator in the database. (We subsequently confirmed ethnicity in direct conversations with patients, as described above. ) We stratified Hispanic patients first into those with back versus knee pain. We further stratified according to whether their zip code had 0-1 vulnerability factors versus 2 or more. We attempted to recruit sufficient patients to conduct four focus groups among Hispanic subjects: two among Hispanics with two or more vulnerability factors (one of patients with knee pain, one with back pain) and two among Hispanics with two or more vulnerability factors. We envisioned, correctly, that we would reach saturation with four groups: that is, four groups were sufficient to elicit a wide range of responses, with few new pieces of information encountered in the latter groups. Ultimately, we did not receive enough responses from Hispanics with 0-1 vulnerability factors and knee pain. Therefore, we created a combined knee and back pain group of Hispanics with vulnerability score of 0-1. We sent a letter to patients (written in both Spanish and English to Hispanic patients) inviting them to participate. Patients could refuse by returning an opt-out letter. We called those who did not refuse to determine whether they were interested in participating. A research associate fluent in Spanish made the calls.

Non-Hispanic White Subjects

Each time a Hispanic subject agreed to participate, we selected three potential non-Hispanic White patients matched on clinical condition (back pain vs. knee pain) and the zip code-based vulnerability index. We invited these patients to participate. Our goal was to recruit one non-Hispanic White focus group with knee pain and one with back pain. The vulnerability groupings were admixed among non-Hispanic Whites, as resources precluded our including both high and low vulnerability White groups.

Focus group protocol

Experienced moderators led the focus groups. A native Spanish speaker moderated groups comprised of Hispanic subjects. The moderators adhered to standard focus group procedures. These included maintaining neutrality; ensuring that concepts were understood before they were discussed; maintaining an environment in which all participants felt comfortable sharing their thoughts and experiences; eliciting comments from all participants; and ensuring confidentiality.

The focus groups were held in the evening. Participants completed a brief questionnaire upon arrival, including their level of educational attainment. Dinner was provided, along with travel expenses and a $40 honorarium. None of the subjects' health care providers attended the focus groups. The Spanish language focus group transcripts were transcribed in English by a bilingual speaker with substantial experience in Spanish-to-English transcription.

Moderator's guide

We developed a semi-structured moderator's guide to ensure that all focus groups covered the same material and that the conversations covered the same key domains. The broad areas covered by the moderator's guide included knowledge of treatment options; the treatment decision-making process; discussions between patients and physicians about treatments; preferences for information resources and for roles in the decision process; and attitudes about strong or invasive treatment.

Analysis

The analysis proceeded in two stages. In the first stage, one co-investigator (LW) read the transcripts and prepared a report identifying key themes. The report also emphasized differences among the Hispanic and non-Hispanic participants with respect to these themes. The research team then performed a second analysis that used a content analysis approach to identify themes and provide a semi-quantitative assessment of the differences across focus groups.

Accordingly, two investigators (KC, HLH) who did not attend the focus groups and were not involved in the development of the project proposal or moderator's guide analyzed the transcripts. These investigators read the transcripts to identify content areas without specific hypotheses guiding the identification of these areas. In this way, theory could be developed based upon observation of the data and not on prior assumptions [23,24]. After statements made by the subjects were allocated to content areas, the investigators reviewed the statements and identified specific research themes suggested by the statements. Each theme was framed directionally so that statements in the transcripts could be coded as either supporting the theme, refuting it, or neither supporting nor refuting the theme. The investigators coded all transcripts in this fashion. Two researchers (KC, HLH) coded two of these transcripts independently as described above. They then compared the results of their coding of these transcripts and discussed and resolved areas in which they disagreed. In this fashion, the two investigators developed a common approach. They then coded the remainder of the transcripts individually.

We tallied the number of statements supporting the theme, the number refuting and the number neutral with respect to the theme. We compared these data across the six focus groups. We used these data to produce summary tables and we supported the trends noted in the tables with representative quotations from the transcripts. We recognize that these tallies do not account for the possibility that a singe participant or two can contribute a large number of statements. We use the tallies as a rough gauge (rather than a precise estimate) of the comparative importance of themes arising in the focus groups.

The study was approved by the Brigham and Women's Institutional Review Board.

Results

Recruitment

Six focus groups were assembled, as shown in Table 1. Ninety percent of all participants were female. The median age of non-Hispanic White patients (back and knee groups) was 60 (range 47-80). Among Hispanics, the median age of subjects with knee pain was 60 (range 40 -83) and median age of subjects with back pain was 49 (range 32 -65). Eighty-six percent of non-Hispanic Whites had attended college as compared with 24% of Hispanics.

Themes

The coding produced 36 distinct themes, though many of them were mentioned only rarely. We concentrated the analysis on the 21 themes that were noted more than nine times across the six groups. These are shown in Table 2, which documents the number times each theme was mentioned in each of the six focus groups.

Role of Pain in Function and Decisions regarding Care-Seeking

Participants across all six focus groups made numerous statements indicating that pain was the primary reason they sought care for their musculoskeletal problem. They expressed frustration with pain and with treatments that did not manage pain adequately.

-"I feel more, more, more nervous, frustrated, more desperate because of the pain."-Hispanic participant -"I've told the doctor, that when the pain is too strong, I drink more pills than what they prescribe. When I can't bear the pain anymore, I drink more

Decision-making

Numerous statements in each of the six focus groups indicated that the participants were aware of the pros and cons of various treatments. However, differences emerged in the role of prior experiences on decisions to seek care or choose treatments. As compared with Non-Hispanic Whites, Hispanic subjects made more statements indicating that fear of negative treatment outcomes inhibited them from seeking care. Similarly, Hispanics were more likely to comment that adverse prior treatment experiences of friends and family made them less inclined to choose a particular treatment.

"I worked with a person who had arthritis and she was going to get cortisone and the last time she went to get it at the hospital, she didn't return home. Instead, she went to the cemetery."-Hispanic participant "I know of a few people who have had the surgery and they've had to have it three and four times."-Hispanic participant "I see the results friends have. I had a friend who got the shots and it didn't work at all." -Hispanic participant "I know of my sister-in-law, who had it done [knee replacement surgery] and she's heavier than I am, and it didn't work for her. So I said I [would] rather cope with my pain before subjecting myself to surgery."-Hispanic participant.

"My sister had an injection and the doctor didn't apply it correctly. It seems he was a resident and he didn't do it correctly... I was never going to get the injection because of her experience, and I won't let them do it to me. Not even if I were crazy would I let them do it."-Hispanic participant

There was considerable discussion in all groups about who made health care decisions -the patient, the physician or others. Most of these comments (72% across all groups) supported the theme that the primary decision maker in the doctor-patient relationship is the physician.

"The doctor's recommendation is very important to me because I think that we should respect each professional in their field. He's the one with the knowledge in the field. So, if as a doctor, he recommends you can have surgery, it's because he's very sure within his professional field, about what he's recommending. He has read. He has studied, and knows what the advantages and disadvantages are..."-Hispanic participant "The pain doctor. I've only seen him once, but I felt great confidence. He took his time with me and he made me feel like I was important to him. With a doctor like that, I think I would take the risk to get the injection or try something else because I feel confident." -Hispanic participant "I have a lot of physicians in my family. So I listen to them fairly routinely. But I also question them quite seriously." -non-Hispanic White participant.

Doctor-patient relationship

There was considerable discussion in each focus group about patients' trust of these physicians and about the extent of satisfaction or dissatisfaction with the physician's advice, the physician's manner and rapport and the service provided by the physician's practice. In general, patients trusted their physicians. This theme recurred consistently across the six groups. The non-Hispanic White back pain group made many more statements expressing dissatisfaction with the physician's advice than statements expressing satisfaction with the physician's advice ( Table 2). "I don't want to be talked down to. Don't throw out a bunch of medical jargon at me... to be dismissed because you're just a patient, and I'm the doctor and I'm the god, doesn't work for me. I think I was more afraid of having him do the surgery than I was, actually, of having the surgery." -Non-Hispanic participant "I went to see him. He stayed with me maybe all of five or eight minutes. 'Do this, do that. Bop bop bop. Can you do this? Can you do that? Bend over. Looked at my MRI. Three minutes longer and he was out of there.

After four months. That was my experience." Non-Hispanic White participant

This pattern was not seen in knee pain groups or in Hispanic groups. Across all clinical and ethnic groups, there was a fairly even distribution of statements expressing satisfaction with the physician's manner and rapport as compared with dissatisfaction.

Finally, subjects were more likely to comment on their dissatisfaction than their satisfaction with the service provided by the medical practice. This pattern was roughly similar across all groups.

-"With my spine doctor, I am disillusioned because I have to wait an hour, an hour and a half to be seen. Therefore, that's a bit discouraging, and secondly, everything is in a rush."-Hispanic participant "What makes me angry is you wait about 45 minutes for the doctor to see you for five minutes. By the time you open your mouth to say something, your time is up, and he goes Patients dissatisfied with physician's manner and rapport 5 6 3 0 6 5

Patients satisfied with physician's manner and rapport 9 9 1 0 7 2

Coping resources

A positive attitude helps patients cope with pain before and after treatment 0 0 3 1 8 0

Faith and religion helps patients cope with pain before and after treatment 0 0 5 2 8 1

Family members will care for a patient recovering from surgery 0 1 1 0 3 1 to see another patient, and then another. He doesn't spend enough time with me. I want to let him know that I am in pain."-Hispanic participant

Coping resources

The Hispanic focus group participants were considerably more likely to discuss the ways in which they cope with their musculoskeletal problem than the non-Hispanic Whites (33 comments among Hispanics vs. 1 among non-Hispanic Whites). The issue of coping came up more frequently among Hispanics with back pain than among those with knee pain. Subjects noted a number of different coping strategies including having a positive attitude, faith and religion and having family members care for patients in the event they have surgery. "When I went for the first shot in my back, I had the chance to see the size of the needle. I put myself in God's hands."-Hispanic participant "Well, we have to count on Him up there. We have to rely on the one up there first, and then, on the doctors."-Hispanic participant "Surgery? It would be in the name of the Lord because many people tell me not to have surgery because I can remain handicap[ped], or something."-Hispanic participant

Information sources

Subjects provided a range of comments about the types of media they prefer for receiving health information. By far the most preferred source of information, across all focus groups, was the physician. Print media were less frequently preferred and DVD even less frequently. Preference for internet-based approaches differed across focus groups. Non-Hispanic whites and the less vulnerable Hispanics commented that the internet was an important source of health information.

"You know with the Internet everybody just goes online...Before you even get to the doctor you can do a lot of research ahead of time."-Non-Hispanic White participant "I would be very likely to [go to the website], and I would read a pamphlet. If it presented both sides, it would be very useful, if it presented alternatives."-Non-Hispanic White participant

On the other hand, Hispanics with vulnerability sores of two or greater reported much lower use of the Internet.

"I'm kind of old-fashioned and I don't [use the Internet]."-Hispanic participant"

Discussion

We conducted focus groups among Hispanics and non-Hispanic Whites with chronic back and knee pain.

We chose these conditions because management decisions are typically preference-based and because patients with these conditions must discuss a range of potentially risky decisions with their providers including corticosteroid injections and surgical procedures. We analyzed the focus group data using a content analysis approach, permitting the data to drive hypothesis generation.

The research highlighted several important differences between Hispanics and non-Hispanic Whites in regard to health-related decision-making. Hispanics were more likely to be influenced by word-of-mouth communication of bad experiences with certain treatments, making them disinclined to seek or choose those treatments. Hispanics were more likely than Whites to comment on strategies for coping with musculoskeletal problems including a positive outlook, faith, religion, and family support. Finally, the internet served as a source of health information for Whites and Hispanics with low vulnerability scores but not for Hispanics with high vulnerability scores.

Our findings also point to important commonalities. The data suggest that pain and functional limitation are the central experiences of these musculoskeletal disorders, shared across ethnic groups. In addition, across all strata subjects indicated that, in general, they trust their physicians. Across all strata, subjects provided mixed reviews of their physicians' manner and rapport and they provided largely negative assessments of office practices.

These findings are largely consistent with prior literature. In a population-based survey, Levinson and colleagues noted that Hispanics are more likely than non-Hispanic Whites to prefer that their physicians make health-related decisions [19]. Similarly, Xu et al noted that Hispanics were less likely to report a participatory relationship with their physicians than non-Hispanic Whites [25]. Our data demonstrate that across all ethnic groups in this study, about three quarters of patients see themselves as primary decision-makers. In a study of decision-making surrounding total knee replacement, Kroll and colleagues found that Hispanic patients developed trust in the physician in part based on word-ofmouth testimonials of friends and family. This echoes our finding of the importance of word of mouth in the Latino community [17].

Our findings can be viewed from the perspective of the Ottawa Decision Support Framework, which emphasizes patients' needs for knowledge, resolution of decisional conflict, involvement in the decision process and sources of support for their decisions as well as the importance of value consonant decisions [15,16]. We identified differences in strategies for seeking knowledge, with Hispanics more likely to use word of mouth and less likely to use the internet. Differences surfaced as well in sources of support with Hispanics more likely to seek support from family and religion.

These data have implications for efforts to improve preference-based decision-making. Patients across all groups view their physicians as trusted sources, highlighting the important role of physicians in efforts to promote optimal decision-making. Word of mouth is a powerful source of information among Hispanics; decision support should target this potential source of misinformation. Faith, religion and family appear to be especially important among Hispanics, suggesting that these sources of support could be integrated into decision support among Hispanics. Finally, Hispanics who are likely less acculturated (those with two or more vulnerability factors) are much less likely to respond to internet-based strategies for providing health information.

Our study has several noteworthy limitations. Our budget did not permit multiple focus groups within each combination of condition and ethnicity. While we observed saturation of comments, we acknowledge that more focus groups might have provided additional insights. We note that the neighborhood-level socioeconomic information that we used for socioeconomic stratification may not reflect individual characteristics accurately. In fact, 86% of non-Hispanic Whites had attended college as compared with 24% of Hispanics. These imbalances require that differences we observed be attributed cautiously to Hispanic ethnicity. The inclusion of two clinical conditions (back and knee pain) may improve generalizability but also introduces an element of heterogeneity to the analysis with respect to clinical features and age that makes interpretation less incisive. Finally, we recognize that the Hispanic community in the U.S. is highly heterogeneous. Our Boston-based sample of Hispanics (comprised largely of patients of Dominican and Puerto Rican descent) cannot account for the variability in the U.S. Hispanic population with respect to nation of origin, duration of residence in the U.S., facility with English, acculturation or educational attainment. For all these reasons, the findings should be confirmed in further research and generalized cautiously.

Conclusion

In conclusion, patients with musculoskeletal problems share a core of concerns revolving around the primacy of pain and pain relief. However, Hispanic patients with knee and back pain appear to differ from non-Hispanic Whites in areas pertinent to shared decision-making, including the role of adverse experiences in shaping treatment preferences, the importance of family and religion in the decision process, and preferences for use of internet sources of health information as the foundation for health decisions. These findings should be confirmed, as they may help to shape strategies for refining the health-related decision-making process among Hispanics.

[medication], because it's just unbearable."-Hispanic participant -"You can't walk any distances [with the pain], you can't stand in line at Wal-Mart...it overtakes your life like that. And I was to the point where I just, I felt old...."-Non-Hispanic White participant

Table 1
1Number of subjects in each focus group (N = 39)Non Hispanic Whites
Hispanics

Mixed SES
Low vulnerability High Vulnerability

Knee
6
6*
3

Back
8
9
7

*mixed knee and back.

Katz et al. BMC Musculoskeletal Disorders 2011, 12:78
http://www.biomedcentral.com/1471-2474/12/78

Table 2
2Number of mentions of key research themes, stratified by ethnicity, vulnerability group, and clinical conditionEthnicity

AcknowledgementsSupported by the Foundation for Informed Medical Decision-Making and NIH grants K24 AR 02123 and P60 AR 47782. The funding organizations had no role in the study design, analysis or decision to submit the paper for publication.(Authors' contributions JNK wrote the grant and paper and led all aspects of the research. NL and JS led in the development of the moderator's guide, assisted in leading the focus groups and edited the manuscript. LSW moderated the non-Hispanic focus groups, assisted in development of the moderator's guide, performed the fist level analysis of transcripts, drafted many paragraphs of the manuscript and edited all of it. PE recruited patients into the study, assisted in drafting the moderator's guide and edited the mansucript critically. HLH and KLC performed the quantitative coding of the transcript data and edited the final manuscript critically. AE provided expertise on Hispanic health and performing research studies involving Hispanics and also edited the final manuscript critically. EL oversaw all methodologic aspects of the study including the development of vulnerability factors using zip code data and also edited the final manuscript critically. All authors read and approved the final manuscript.Competing interestsThe authors declare that they have no competing interests.
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The value of shoe size for prediction of the timing of the pubertal growth spurt

Iris Busscher
Idsart Kingma
Frits Hein Wapstra
Sjoerd K Bulstra
Gijsbertus J Verkerke
Albert G Veldhuizen
The value of shoe size for prediction of the timing of the pubertal growth spurt
R E S E A R C H
Background: Knowing the timing of the pubertal growth spurt of the spine, represented by sitting height, is essential for the prognosis and therapy of adolescent idiopathic scoliosis. There are several indicators that reflect growth or remaining growth of the patient. For example, distal body parts have their growth spurt earlier in adolescence, and therefore the growth of the foot can be an early indicator for the growth spurt of sitting height. Shoe size is a good alternative for foot length, since patients can remember when they bought new shoes and what size these shoes were. Therefore the clinician already has access to some longitudinal data at the first visit of the patient to the outpatient clinic. The aim of this study was to describe the increase in shoe size during adolescence and to determine whether the timing of the peak increase could be an early indicator for the timing of the peak growth velocity of sitting height.Methods: Data concerning shoe sizes of girls and boys were acquired from two large shoe shops from 1991 to 2008. The longitudinal series of 242 girls and 104 boys were analysed for the age of the "peak increase" in shoe size, as well as the age of cessation of foot growth based on shoe size. Results: The average peak increase in shoe size occurred at 10.4 years (SD 1.1) in girls and 11.5 years (SD 1.5) in boys. This was on average 1.3 years earlier than the average peak growth velocity of sitting height in girls, and 2.5 years earlier in boys. The increase in shoe size diminishes when the average peak growth velocity of sitting height takes place at respectively 12.0 (SD 0.8) years in girls, and 13.7 (SD 1.0) years in boys. Conclusions: Present data suggest that the course of the shoe size of children visiting the outpatient clinic can be a useful first tool for predicting the timing of the pubertal growth spurt of sitting height, as a representative for spinal length. This claim needs verification by direct comparison of individual shoe size and sitting height data and than a step forward can be made in clinical decision making regarding adolescent idiopathic scoliosis.

Background

In adolescent idiopathic scoliosis in particular it is highly important to know when the peak growth velocity of spinal length takes place. Since a close relationship exists between the spinal growth of the patient and the angle progression of the idiopathic scoliosis, it is essential to know the timing of the pubertal growth spurt in order to determine the optimum treatment strategy for the individual child [1][2][3][4]. However, exact spinal length is hard to obtain and therefore sitting height can be a representative alternative.

It is still highly difficult to predict when the individual child will have his or her pubertal growth spurt. 95% of the girls experience their peak growth velocity between ages ten and fourteen, and 95% of the boys between age twelve and sixteen [5][6][7]. This range is too wide to be able to make an accurate prediction in the individual patient.

It is known that different parts of the body each have their own typical growth pattern. Cameron et al. [8], Dimeglio [9], and Welon and Bielicki [10] all confirm the distal-to-proximal growth gradient as described earlier by Tanner [11], meaning that more distal body parts have their pubertal growth spurt earlier in adolescence. Furthermore, it is known that the sequence of growth spurts of different body parts is similar in individual children, regardless of being an "early" or "late" maturer [10]. Therefore, the timing of the growth spurt of foot length could be an early indicator for the timing of the growth spurt of sitting height [12].

For an accurate determination of the timing of the peak growth velocity of foot length, longitudinal growth data are needed. However, during a first visit to the outpatient clinic patients usually don't have information concerning their foot lengths over the last years. Therefore the clinician can not make an accurate assessment at that moment, as would be preferable. To overcome this lack of information concerning the longitudinal growth of the foot, it is useful to have a representative alternative for foot length. This could be the shoe size. Pilot work for present study in the orthopaedic outpatient clinic confirmed that patients and their parents remember to a large extent when they bought new shoes and what size these shoes were. This could therefore be a very easy, first clinical tool that can help in determining the timing of the growth spurt of the foot, and therefore in predicting the timing of the growth spurt of sitting height.

Information concerning longitudinal increases in shoe size is lacking and therefore the aim of this study was to describe the increase in shoe size during adolescence. It was hypothesized that an earlier "peak increase" in shoe size would occur in comparison to the general timing of the peak growth velocity of sitting height, and that therefore the increase in shoe size could be an early indictor for the timing of the pubertal growth spurt.

Methods

Longitudinal data of shoe sizes were collected in two large shoe shops in the Netherlands from 1991 to 2008. Data were collected in a similar manner in the two shops. Data were collected each time a client visited the shoe shop. Each client's bare left and right foot were measured individually while standing full weight bearing. The client stood in the calliper with the back of the heel against the stationary arm, and the movable arm was brought into contact with the tip of the longest toe. The shoe size was measured to the nearest half-size, and an average was taken for both feet. Shoe size was expressed in European standards. For translation to English and American sizes see Table 1.

The shoe sizes used for data-analysis were the standard measured sizes, and not the size of the shoes which were sold to the clients.

The age at the time of measurement was determined by subtracting the date of birth from the date of the measurement.

The data were anonymized by an external organisation before transfer to the researchers.

The "period of peak increase" in shoe size was defined as the shortest period in which the shoe size increased by two whole sizes. The age of the peak increase was defined as the age in the middle between the start-age and the end-age of this period (peak increase in Figure 1). The average magnitude of the increase was calculated in shoe sizes per year.

A customized program in Matlab ® (Mathworks, Natick MA, USA) was used to plot the data of each individual client, and the results were checked visually for outliers. The period of peak increase was calculated by the program, as well as the age of the peak increase and the peak velocity of shoe size increase.  Secondary outcome measures were related to the cessation of foot growth. The age at the end of foot growth was determined in the individual graphs as the age from where the shoe size did not increase any further. This plateau period should at least continue for 1 year for the client to be included in the data-analysis of the plateau phase (plateau 2 in Figure 1). Furthermore, the start-age of the plateau phase should be higher than the age of the peak growth velocity. In this way temporary and short plateau phases, or phases which occurred before the peak growth, were excluded (plateau 1 in Figure 1).

Clients who had more than 4 measurements above the age of 8 years, as well as a follow up time of more than two years were selected. Furthermore the last measurement of shoe size should be above 12 years in girls and 13 years in boys. Only data above 8 years were used for analysis of the peak increase in shoe size since it was not expected that the growth spurt would occur earlier in healthy children, and to exclude boys and girls with precocious puberty. The selection of the clients was performed to make sure the pubertal growth spurt in shoe size was not missed. For example, if a client had data until age 10 or 11 years, the Matlab program could still calculate a shortest period in which the shoe size increased two sizes. However, this would result in a "false growth spurt" which would not represent the actual pubertal growth spurt.

Results

A database was collected with longitudinal data of standardized shoe sizes of 636 girls and 513 boys. The individual series of ages of the clients ranged from 10 months to 17.1 years in girls, and 10 months to 17.2 years in boys.

After selection, the database provided 242 girls and 104 boys. Mean follow up time after 8 years of age was 5.4 (SD 1.2) years in girls, and 6.2 (SD 1.2) years in boys. The average number of measurements after 8 years of age was 8.9 (SD 1.9) in girls and 9.0 (SD 2.3) in boys (Table 2). Therefore, the average time between two visits after the age of 8 years was 0.61 years in girls (SD 0.29) and 0.69 years in boys (SD 0.34).

The average age of the peak increase in shoe size for girls was 10.4 years (SD 1.1), and for boys 11.5 years (SD 1.5). The average peak velocity of shoe size increase was 2.4 shoe sizes per year for girls (SD 1.3), and 2.6 shoe sizes per year for boys (SD 1.6). See Figure 2 and Table 3 The average age for girls (n = 138) to reach a plateau phase in their shoe size was 12.0 years (SD 0.8). At that time the shoe size was on average 38.9 (SD 1.5). Boys (n = 36) reached a plateau at the age of 13.7 years (SD 1.0), with a shoe size of 41.1 (SD 1.8) ( Table 3).

The average longitudinal curves for peak increase of the shoe size of girls and boys are shown in Figure 2.

Discussion

Many researchers have tried to predict the timing of the pubertal growth spurt, or peak growth velocity of total body height in the individual patient. Less researchers have investigated the prediction of the growth spurt in spinal length or sitting height, but this knowledge is of great value for optimizing treatment strategies in patients with adolescent idiopathic scoliosis.

This study showed that the timing of the peak increase in shoe size was 10.4 years in girls, and 11.5 years in boys. Furthermore, the shoe size did not increase any further for at least 1 year after the age of 12.0 (SD 0.8) in girls, and 13.7 years (SD 1.0) in boys. Stavlas et al. also showed a different growth potential of the feet in boys and girls in the sense that the physiological process of foot development occurred earlier in girls in comparison to boys [13].

To determine the relationship between the timing of the peak increase in shoe size and the timing of the pubertal growth spurt in sitting height, a comparison was made to reliable growth data of a comparable Dutch population. Secular trends in the pubertal growth spurt should be taken into account when comparing present data with known data for sitting height. Therefore growth data from Gerver and de Bruin were taken which were collected from 1995 to 1999 [5], in comparison to the shoe sizes in present study which were collected from 1991 to 2008. Gerver and De Bruin [5] found a peak growth velocity of sitting height to occur at 11.7 years in girls (SD 0.8), and at 14.0 years in boys (SD 0.9). Thus, the average peak increase in shoe size generally occurred 1.3 years and 2.5 years before the average peak growth of sitting height, in girls and boys respectively. A second useful finding in the present study is that on average, the increase in shoe size diminishes when the peak growth velocity of sitting height occurs. The plateau phase of shoe size began at 12 years in girls, and a little under 14 years in boys, nearly similar to when the growth velocity of sitting height in both groups is largest (Figure 2).  These results suggest that the longitudinal course in shoe size and the timing of the peak increase in shoe size can be helpful as a first indication for the timing of the pubertal growth spurt of sitting height. A major advantage of using shoe size as an alternative for actual foot length is that patients and their parents can recall when they bought new shoes, and what the size was. Therefore the clinician already has access to some longitudinal data at the first visit of the patient, which are missing for actual foot length. Furthermore, this is a very easy and non time consuming way of getting a first impression on the stadium of growth of the patient. It is important to ask for the course in shoe size. Children and their parents remember to a large extent that they first had to buy a larger size after 1 year and than suddenly they had to buy a larger size after 0. Average growth curves of girls and boys from 8-18 years of age. The differences between the timing of peak foot growth velocity based on shoe size and total body height are shown. Growth velocity of total body height is expressed in cm/year and increase in shoe size in shoe sizes/year, both on the same axis. Data concerning growth velocity of total body height are derived from Gerver and de Bruin with permission [5,6]. When the increase in shoe size is approximately 2.5 sizes per year (in both girls and boys), the physician knows that on average the peak growth velocity of sitting height will occur 1.3 or 2.5 years later in girls and boys respectively. A pilot study in the orthopaedic outpatient clinic revealed that from 20 patients and their parents, 16 knew the course of their shoe size for at least 1.5 years back. However, repeated measurements should be performed in a coming longitudinal study to reveal a possible recall bias. Present results could not be compared with existing data since no studies were found who investigated the course of the shoe size in children. However, when comparing results of the present study with four different studies measuring actual foot length, striking agreements were seen [8,10,14,15] (Table 4). The range for the timing of peak growth velocity of foot length was 10.4 to 12.3 years in girls (with three studies between 10.4 and 10.6 years), and 12.1 to 13.8 years in boys. The agreements for girls were largest, whereas the boys in present study showed a somewhat earlier growth spurt in shoe size in comparison to the other studies. No conclusive explanation for the differences concerning the boys could be found.

Anderson et al [14] and Liu et al [15] found a cessation of the foot growth around 13.5 years in girls and 16 years in boys (Table 4). This age was higher compared to the present study for the reason that Anderson and Liu used a limit of less than 2 mm growth of the feet. One shoe size represents approximately 7 mm, so the feet can still grow more than 2 mm before a larger shoe size is needed. There might be additional factors to explain the difference of 2.3 years in boys. This will be discussed further in the next section.

A disadvantage of the initial available database was that less data were available for higher ages. Many clients only had measurements until age 10 or 11. As a result of the strict selection criteria, the initial group of clients was therefore decreased by respectively 62% and 80% for girls and boys. However, no indications were found in the non-selected group for differences in increases of shoe size. Furthermore, as will be outlined below, the results were unaffected by changing the selection criteria, thereby suggesting that the results were not biased by selection.

The minimum age for the last measurement was higher for boys and therefore fewer boys were included than girls. The minimum age was chosen to prevent the inclusion of "false" growth spurts, as described earlier in the methods section. It was shown during the analysis of the data that the ages of the peak increase did not change when only the clients were selected who had a last measurement above a higher age. For example, when only the male clients were selected who had the last measurement of shoe size above 14 years of age (instead of 13) the peak growth velocity still occurred at 11.5 years (n = 55). When the group was selected who had their last measurement above 15 years (n = 27), the age at peak growth velocity was 11.4 years. A similar test was done for the female clients and 12 years appeared to be an adequate cut-off point (n = 131 for the group with the last measurement above age 13 and age at peak growth velocity 10.4 years; n = 50 for the group with the last measurement above age 14 and age at peak growth velocity 10.6 years). Thus, for both boys and girls, the primary outcome measure, i.e. the age of peak foot growth velocity based on shoe size, seems reliable.

This study showed a plateau phase in shoe size of at least 1 year in boys starting on average at 13.7 years. The shoe size at that time was on average 41.4, which was smaller than expected.

A possible explanation could be that more remaining growth of the feet occurred in boys at a higher age. Not all boys with data at higher ages showed a plateau phase. Boys without a plateau were not included in the selection of the boys for the data analysis of the plateau phase. However, these boys possibly showed a plateau phase at a later age with a larger shoe size, but these data were not available in the present database. The database provided only few boys who had longitudinal data after the age of 15 or 16. One example showed a plateau phase from 13.5 to 15.3 years, and again some growth of the shoe size after that (Figure 3). It is possible that some boys have a "second" short growth spurt of shoe size in a later stage of puberty. Therefore, we may have underestimated the secondary outcome measures, i.e. final shoe size and the age of cessation of foot growth, in boys. There are some limitations to the use of the shoe size. Different brands do not always use similar size-length ratios. E.g. size 39 in one brand is not necessarily the same length as size 39 in a different brand. Pilot work for the present study showed that clients recognize this difference and know their "general" shoe size. However, further research should be performed to evaluate the reliability of the use of shoe size in a clinical setting and to evaluate a possible recall bias of patients and their parents.

For further validation of the use of shoe size for prediction of the peak growth velocity of sitting height it is essential to combine both measurements in a single study. Present work of our study group will concern these measurements, but the results will be available only after collection of longitudinal data for several years [16].

Conclusions

The present data suggest that the course of the shoe size of children visiting the outpatient clinic can be useful as a first indicator for the timing of the pubertal growth spurt of sitting height. This claim needs verification by direct comparison of individual shoe size and sitting height data. If such work supports our claim, a step forward can be made in clinical decision making regarding adolescent idiopathic scoliosis. Submit your manuscript at www.biomedcentral.com/submit

Figure 1
1Example of a growth curve of the shoe size of a girl. The start and end of the peak increase of the shoe size are shown as dotted lines. The age at peak increase is shown as the fat dotted line. Age is expressed in years, shoe size in European standards.

SD = standard deviation.

Figure 2
2Figure 2 Average growth curves of girls and boys from 8-18 years of age. The differences between the timing of peak foot growth velocity based on shoe size and total body height are shown. Growth velocity of total body height is expressed in cm/year and increase in shoe size in shoe sizes/year, both on the same axis. Data concerning growth velocity of total body height are derived from Gerver and de Bruin with permission [5,6].

Figure 3
3Example of a growth curve of shoe size of a boy. The curve shows a plateau phase between 13.5 and 15.3 years and again an increase of the shoe size after 15 years. Shoe size is expressed in European standards. 16. Busscher I, Wapstra FH, Veldhuizen AG: Predicting growth and curve progression in the individual patient with adolescent idiopathic scoliosis: design of a prospective longitudinal cohort study. BMC Musculoskeletal Disorders 2010, 11:93. doi:10.1186/1748-7161-6-1 Cite this article as: Busscher et al.: The value of shoe size for prediction of the timing of the pubertal growth spurt. Scoliosis 2011 6:1. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution

Table 1
1Translation of shoe sizes for different regions. UK = United Kingdom, USA = United States of America.Europe
UK
USA

Male
Female

36
3
4.5

36.5
3.5
5

37
4
5.5

37.5
4.5
6

38
5
5.5
6.5

38.5 -39
5.5
6
7

39 -39.5
6
6.5
7.5

40
6.5
7
8

40.5
7
7.5
8.5

41 -41.5
7.5
8
9

42
8
8.5
9.5

42.5
8.5
9
10

43
9
9.5

43.5 -44
9.5
10

44 -44.5
10
10.5

45
10.5
11

46
11
11.5

46.5
11.5
12

Table 2
2General demographics of the used database.

Table 3
3Results of database-study consisting longitudinal series of shoe sizes of 242 girls and 104 boysGirls (SD)
Boys (SD)
Total (SD)

Table 4
4Comparison of the present results with previous studiesCessation Standard Deviations (SD) were not shown in all studies. PGV SS = age in years at peak foot growth velocity based on shoe size. PGV FL = age in years at peak growth velocity of foot length. Cessation = the age at which the increase in shoe size or the growth of foot length is finished. Not all studies showed the age of cessation of the growth.Study
Girls (SD)
Boys (SD)

Present study 2009
Participants
242
104

PGV SS
10.4 (1.1)
11.5 (1.5)

Cessation
12.1 (0.8)
13.7 (1.0)

Anderson et al 1956
Participants
20
20

PGV FL
10.5
12.5

Cessation
13.5
16.0

Cameron et al 1982
Participants
20
29

PGV FL
12.3 (0.3)
13.8 (0.3)

Cessation

Liu et al 1998
Participants
198
146

PGV FL
10.4 (0.8)
12.1 (0.9)

Cessation
13.6 (1.2)
15.6 (1.3)

Welon et al 1979
Participants
215
121

PGV FL
10.6
13.0

AcknowledgementsThe authors would like to thank the shoe shops for providing the data used in the present study. This study was supported by the Dutch Technology Foundation STW, applied science division of NWO and the Technology Program of the Ministry of Economic Affairs. This sponsor had no involvement in the study design, the collection and analysis of the data, the writing of the paper, or the decision to submit this manuscript. No author has received any form of payment for producing of the manuscript. There are no other financial or other relationships which might have led to a conflict of interest.Authors' contributionsAll authors have read and approved the manuscript and believe the manuscript represents honest work. All authors (IB, IK, GJV, FHW, SKB, and AGV) have made substantial contributions to the design of the presented study. IB and IK have performed the data-analysis. IB has written the first manuscript. IK, FHW, SKB, GJV, and AGV have performed the reviewing of the manuscript.Competing interestsThe authors declare that they have no competing interests.
Growth and curve stabilization in girls with adolescent idiopathic scoliosis. F Escalada, E Marco, E Duarte, Spine. 30Escalada F, Marco E, Duarte E, et al: Growth and curve stabilization in girls with adolescent idiopathic scoliosis. Spine 2005, 30:411-417.

Assessment of angle velocity in girls with adolescent idiopathic scoliosis. F Escalada, E Marco, E Duarte, Scoliosis. 420Escalada F, Marco E, Duarte E, et al: Assessment of angle velocity in girls with adolescent idiopathic scoliosis. Scoliosis 2009, 4:20.

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Effect of growth velocity on the progression of adolescent idiopathic scoliosis in boys. T Yrjonen, M Ylikoski, J Pediatr Orthop B. 15Yrjonen T, Ylikoski M: Effect of growth velocity on the progression of adolescent idiopathic scoliosis in boys. J Pediatr Orthop B 2006, 15:311-315.

Paediatric morphometrics: a reference manual. W J Gerver, R De Bruin, UPM Maastricht. Gerver WJ, de Bruin R: Paediatric morphometrics: a reference manual. UPM Maastricht; 2001.

Growth velocity: a presentation of reference values in Dutch children. W J Gerver, R De Bruin, Horm Res. 60Gerver WJ, de Bruin R: Growth velocity: a presentation of reference values in Dutch children. Horm Res 2003, 60:181-184.

Clinical longitudinal standards for height and height velocity for North American children. J M Tanner, P S Davies, J Pediatr. 107Tanner JM, Davies PS: Clinical longitudinal standards for height and height velocity for North American children. J Pediatr 1985, 107:317-329.

A longitudinal analysis of the growth of limb segments in adolescence. N Cameron, J M Tanner, R H Whitehouse, Ann Hum Biol. 9Cameron N, Tanner JM, Whitehouse RH: A longitudinal analysis of the growth of limb segments in adolescence. Ann Hum Biol 1982, 9:211-220.

Growth in pediatric orthopaedics. A Dimeglio, J Pediatr Orthop. 21Dimeglio A: Growth in pediatric orthopaedics. J Pediatr Orthop 2001, 21:549-555.

The timing of adolescent growth spurts of 8 body dimensions in boys and girls of the Wroclaw growth study. Z Welon, T Bielicki, Stud Phys Anthrop. 5Welon Z, Bielicki T: The timing of adolescent growth spurts of 8 body dimensions in boys and girls of the Wroclaw growth study. Stud Phys Anthrop 1979, 5:75-79.

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Early markers of pubertal onset: height and foot size. K R Ford, J C Khoury, F M Biro, J Adolesc Health. 44Ford KR, Khoury JC, Biro FM: Early markers of pubertal onset: height and foot size. J Adolesc Health 2009, 44:500-501.

The evolution of foot morphology in children between 6 and 17 years of age: a crosssectional study based on footprints in a mediterranean population. P Stavlas, T B Grivas, C Michas, E Vasiliadis, V Polyzois, J Foot Ankle Surg. 44Stavlas P, Grivas TB, Michas C, Vasiliadis E, Polyzois V: The evolution of foot morphology in children between 6 and 17 years of age: a cross- sectional study based on footprints in a mediterranean population. J Foot Ankle Surg 2005, 44:424-428.

Growth of the normal foot during childhood and adolescence; length of the foot and interrelations of foot, stature, and lower extremity as seen in serial records of children between 1-18 years of age. Anderson, M Blais, W T Green, Am J Phys Anthropol. 14Anderson , Blais M, Green WT: Growth of the normal foot during childhood and adolescence; length of the foot and interrelations of foot, stature, and lower extremity as seen in serial records of children between 1-18 years of age. Am J Phys Anthropol 1956, 14:287-308.

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Reversible splenial lesion syndrome associated with dengue fever: a case report

Pavithra Sathananthasarma
PraveenNilendra Weeratunga
Thashi Chang
Reversible splenial lesion syndrome associated with dengue fever: a case report
10.1186/s13104-018-3491-6Sathananthasarma et al. BMC Res Notes (2018) 11:412 CASE REPORTDengueSpleniumCorpus callosum
Background: Dengue virus infection in humans can lead to a wide range of clinical manifestations, from mild fever to potentially fatal dengue shock syndrome. The incidence of dengue fever is on the rise in tropical countries. Due to the increasing incidence of dengue fever worldwide, atypical manifestations of the disease are increasingly reported. In this article we report a patient with dengue haemorrhagic fever who presented with reversible splenial lesion syndrome.Case presentation:A 24-year-old Sri Lankan man who presented with fever and confusion was eventually diagnosed to have reversible splenial lesion syndrome based on brain imaging. Clinical, serological and haematological parameters confirmed a diagnosis of dengue haemorrhagic fever. His presentation, assessment, and management are described in this case report.Conclusion:Reversible splenial lesion syndrome is a condition which is radiologically characterized by reversible lesion in the splenium of the corpus callosum. It is associated with infectious and non-infectious aetiologies. This case report highlights the occurrence of reversible splenial lesion syndrome as a presenting feature of the expanding list of unusual neurological manifestations of dengue infection.

Background

Dengue fever is a mosquito-borne viral infection caused by dengue virus, is endemic in Sri Lanka. The Epidemiology Unit of Sri Lanka reported 80,732 dengue fever cases, including 215 deaths during the first 6 months of 2017 [1]. Dengue virus infection in humans can lead to a wide range of clinical manifestations, from mild fever to potentially fatal dengue shock syndrome. Neurological manifestations of dengue fever are diverse and include encephalopathy, encephalitis, acute disseminated encephalomyelitis, Guillain-Barre syndrome, polyneuropathy, transverse myelitis and neuro-ophthalmic involvement [2,3]. Here, we report a patient with dengue fever who presented with reversible splenial lesion syndrome. Due to the increasing incidence of dengue fever worldwide atypical manifestations of the disease are increasingly reported.

Case presentation

A 24-year-old Sri Lankan man developed fever, profuse vomiting and diarrhoea followed by reduced level of consciousness over a 12-h duration. He had myalgia, arthralgia and frontal headache. He did not have photophobia, phonophobia, skin rash, fits, cough or urinary symptoms. He did not have any bleeding manifestations. He did not smoke tobacco or consume alcohol. There was no history of illicit drug abuse or high risk sexual behavior. He had been previously diagnosed with mild intermittent bronchial asthma.

On examination, he was febrile (101.3 °F), drowsy with a Glasgow coma scale of 11/15. There were no skin rashes or lymphadenopathy. No focal signs were noted in the neurological examination and fundoscopic examination was normal. His Pulse rate was 112 bpm; blood pressure was 100/60 mmHg with no postural hypotension; respiratory rate was 14/min. Rest of the general and systems examinations were normal.

His full blood count on admission showed white blood cells of 6 × 10 9 /L (Normal range [NR] 4.0-11.0 × 10 9 /L)

Open Access

BMC Research Notes

*Correspondence: firstname.lastname@example.com 1 Professorial Medical Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka Full list of author information is available at the end of the article with neutrophils of 59%; haemoglobin 14.3 g/dL (NR 13.5-16.5 g/dL) and platelet count of 74 × 10 9 /L (NR 150-450 × 10 9 /L). Erythrocyte sedimentation rate was 13 mm in first hour and C-reactive protein was 63 mg/l (NR < 5 mg/L). Serum electrolytes were normal with mild impaired renal function. Liver enzymes were elevated, alanine aminotransferase was 303 U/l (NR < 50 U/L) and aspartate aminotransferase was 482 U/l (NR < 50 U/L) with a total bilirubin of 10.6 µmol/L (NR 5-21 µmol/L). His urine analysis and coagulation profile were normal. Non-contrast CT brain demonstrated cerebral oedema. Lumbar puncture was precluded by a low platelet count.

Based on a working diagnosis of encephalitis, he was commenced on intravenous meropenem, vancomycin, aciclovir and dexamethasone, but were subsequently omitted once the diagnosis became evident.

On further investigation, dengue IgM antibody in serum was positive on day 6 of fever. Blood and urine cultures did not yield any microbial growth. Electroencephalography showed generalized slow wave activity. The cranial MRI showed an isolated ovoid hyperintensity in the splenium of the corpus callosum with homogeneous hyperintense signal on diffusion-weighted imaging (DWI) (Fig. 1). A diagnosis of reversible splenial lesion syndrome (RESLES) was suspected based on the MRI appearance.

Standard dengue monitoring of vitals, urine output, haematocrit and platelet count were done. His platelet count dropped to a nadir of 31 × 10 9 /L, but subsequently increased. The white cell count steadily increased to 14 × 10 9 /L and then stabilized around 7 × 10 9 /L. Fluid leakage was not detected on repeated ultrasound scanning during the acute phase of illness.

He was discharged from hospital on the tenth day of illness with complete clinical, heamatological and biochemical recovery. Follow-up cranial MRI done 1 month later showed complete resolution of the splenial lesion (Fig. 2).

Discussion and conclusion

We report a case of reversible splenial lesion syndrome (RESLES) manifesting as the presenting feature in a patient with dengue haemorrhagic fever complicated by encephalopathy. The patient made a complete recovery while follow-up brain imaging revealed a complete resolution of the splenial lesion.

The corpus callosum is the largest fibre bundle that connects the cerebral cortex of the left and right cerebral hemispheres, and promotes the functional integration of sensory and motor functions. It is anatomically divided into rostrum, genu, body and splenium which play an integral role in relaying sensory, motor and cognitive information from homologous regions in the two cerebral hemispheres. Infarctions of the corpus callosum are not common because of the rich blood supply from three main arterial systems: the anterior communicating artery, the pericallosal artery, and the posterior pericallosal artery.

RESLES is a disorder radiologically characterized by reversible lesion in the splenium of the corpus callosum [3]. It is a non-specific radiological diagnosis associated with infectious and non-infectious aetiologies. In the case of infectious aetiologies, the syndrome is also called as mild encephalitis with reversible splenial lesion (MERS). Some authors name it as cytotoxic lesions of the corpus callosum (CLOCCs) based on its pathophysiology [4]. It is frequently observed in encephalitis caused by various pathogens such as influenza virus, rotavirus,  [3,[5][6][7][8]. Previously, only a single case of RESLES/MERS following dengue virus infection had been reported [9]. The patient described in the previous report was infected with dengue virus serotype 2, was younger than our patient and presented with delirium which progressed to ophthalmoplegia. However, the patient had demonstrated complete clinical and imaging resolution, consistent with the generally good prognosis associated with this rare clinico-radiological entity.

Among the non-infectious aetiologies, RESLES has been reported in association with anti-epileptic drug withdrawal, high-altitude cerebral edema (HACE), and metabolic disorders such as hypoglycaemia and hypernatremia [3,5,10,11]. Lesions of the corpus callosum can cause a diagnostic dilemma, both for the radiologist and the clinician. Clinical presentation of RESLES is non-specific, associated with neuropsychiatric symptoms, mainly inter-hemispheric disconnection syndromes. Patients may experience gait disorders, apraxia, agraphia, tactile anomia and alien hand syndrome [5]. The diagnosis is based on the neuroimaging appearance of a non-enhancing, round-shaped lesion centered in the splenium of the corpus callosum that resolves after a variable duration. Although CLOCCs are non-specific with regard to the underlying cause, additional imaging findings and the clinical findings can aid in making a specific diagnosis. It is associated with a generally good prognosis except in those patients with an underlying severe disorder [3].

RESLES is mostly attributed to cytotoxic oedema with the exception of HACE in which vasogenic oedema is thought to be the underlying mechanism. The reason for the predilection for the splenium of the corpus callosum remains obscure, but a relative lack of adrenergic tone and failure of autoregulation at this site is one hypothesized mechanism [12].

Dengue infection is endemic in the tropics and subtropics causing periodic epidemics in this region. The identification of RESLES occurring in association with dengue infection expand the aetiological spectrum associated with it. The recognition of this distinct radiological appearance should prompt appropriate differential diagnosis and reassurance of a generally good prognosis provided that the underlying aetiology is appropriately managed.

Fig. 1
1Initial MRI of brain (axial view) flair (a) and diffusion-weighted imaging (b) showing a lesion in the central splenium of corpus callosum measles, herpes virus, adenovirus, mumps, Epstein-Barr virus and Escherichia coli

Abbreviations RESLES: Reversible splenial lesion syndrome; ADEM: Acute disseminated encephalomyelitis; NR: Normal range; CRP: C-reactive protein; MRI: Magnetic resonance imaging; DWI: Diffusion weighted imaging; MERS: Mild encephalitis with reversible splenial lesion; HACE: High altitude cerebral oedema.
AcknowledgementsNot applicable.Authors' contributionsAll authors were involved in the management of this patient. PS wrote the initial manuscript. PNW and TC revised it. All authors read and approved the final manuscript.1Professorial Medical Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.2Department of Clinical Medicine, University of Colombo, Colombo, Sri Lanka.Author detailsCompeting interestsThe authors declare that they have no competing interests.Availability of data and materialsThe above patient's details, records and investigation reports including MRI brain films are with the author which can be shown on request.Learn more biomedcentral.com/submissionsReady to submit your research ? Choose BMC and benefit from:Consent for publicationInformed written consent was obtained from the patient for publication of this case report and any accompanying images. Copy of the written consent is available for review by the Editor-in-Chief of this journal.Ethics approval and consent to participate Not applicable.FundingNo funds were obtained.Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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