a cerebral venous thrombosis ( cvt ) is an uncommon type of stroke accounting for 0.5% of all strokes4 ) . the pathogenesis is multifactorial , and the disease could occur at any age , including in neonates . however , a prothrombotic condition plays a key role in its occurrence . because of the thrombogenic effect of estrogen , an increased incidence in women who take oral contraceptives as well as in pregnant women has been highlighted in previous reports , particularly in europe and america where a high use of oral contraceptives has been reported3,18 ) . this study was conducted on the premise that there have been no clinical reviews of cvt in korea , and , thus the clinical characteristics of 36 cvt patients in a single center were reviewed and compared with those in previous studies . from august 2005 to may 2013 , 40 patients diagnosed with cvt were treated in a single center . three patients who were not evaluated for prothrombotic conditions because of personal reasons were excluded from the study group . one patient , who was transferred to another hospital with an incomplete work - up , was excluded , and 36 patients were included in the study . we retrospectively collected these patients ' data regarding age , sex , the disease stage , pathogenesis , location , laboratory findings , radiological findings , and treatment modalities such as anticoagulant and/or antiplatelet therapy . the patients were categorized by age and sex into groups , and the incidence in each group was evaluated . thorough history taking , physical and neurological examinations , and evaluation of the laboratory and radiological findings were performed in an attempt to identify each patient 's pathogenesis . for the evaluation of prothrombotic conditions , blood samples were taken and checked for serum levels of anti - ds - dna antibody , epithelial neutrophil - activating protein , anti - cardiolipin igm & igg , anti - phospholipid igm & igg , protein c antigen and activity , protein s antigen and activity , a lupus anticoagulant , thrombin - antithrombin complex , antithrombin iii , and the platelet count . patients with abnormal laboratory values were repeatedly tested after 1 to 2 weeks , and those with consistent abnormal values were regarded to have a prothrombotic condition . unless otherwise indicated , a prothrombotic condition was presumed to be the primary cause of cvt in these patients . cancer , iron - deficiency anemia , and other systemic diseases were assumed to be causative factors in patients with normal laboratory values and without other causes of cvt . the group of patients with normal laboratory values and in whom all known possible causes of cvt were excluded was categorized as the " idiopathic " group . the patients who developed a cvt after intracranial surgery were included in the " post - operative change " group . all the patients were asymptomatic except for a patient who experienced a partial seizure resulting from a left transverse sinus thrombosis after undergoing a suboccipital craniotomy for a left vestibular schwannoma . infection was considered the causative factor for the patients who displayed a definite , localized infection with an adjacent venous sinus thrombosis . the disease stages were grouped as " acute " , " subacute " , and " chronic " , depending on the time interval between the onset of the clinical symptoms and the time of diagnosis , as proposed by the international study on cerebral venous and dural sinuses thrombosis ( iscvt ) , which is the largest cohort study conducted on cvt . the period from the onset of symptoms until the time of diagnosis was investigated , and less than 48 hours was designated as " acute " , between 48 hours and 30 days as " subacute " and more than 30 days as " chronic"18 ) . the location of the disease , the presence of hemorrhagic infarctions , and the presence of dural arteriovenous fistulas ( avf ) were determined by imaging studies including ct and mri . the location was divided into the following five groups depending on the primary cvt site : the sigmoid and/or transverse sinus , superior sagittal sinus , cavernous sinus , cortical vein , and deep vein . first , we attempted to verify the relationship between a hemorrhagic infarction and factors such as the location of the cvt and presence of a dural avf . fisher 's exact test was used to determine any significant relationship between a hemorrhagic infarction and each pathogenesis , the location of the cvt and the presence of a dural avf . all the analyses were tested at the p<0.05 level of significance , and sas , version 9.4 ( sas institute , inc . fisher 's exact test was used to determine any significant relationship between a hemorrhagic infarction and each pathogenesis , the location of the cvt and the presence of a dural avf . all the analyses were tested at the p<0.05 level of significance , and sas , version 9.4 ( sas institute , inc . the patient group included 21 men and 15 women with a mean age of 46.9 years at diagnosis ( ranging from 3 months to 77 years ) . in the age groups by decades , the highest prevalence was seen in the sixth decade ( n=9 ) . within the patient group , 14 ( 38.9% ) patients were in the acute stage at the time of diagnosis , 11 ( 30.1% ) were in the sub - acute stage , and 11 ( 30.1% ) were in the chronic stage . concerning the pathogenesis , 8 ( 22.2% ) cases resulted from a prothrombotic condition , 7 ( 19.4% ) were because of a post - operative change , 5 ( 13.9% ) were from an infection , 2 ( 5.6% ) followed a trauma , 2 ( 5.6% ) resulted from local invasion of a preexisting brain tumor , 1 ( 2.8% ) was cancer - related , 1 ( 2.8% ) was related to systemic diseases ( chronic renal disease and gout ) , 1 ( 2.8% ) occurred after hormonal replacement ( estradiol hemihydrate ) therapy , 1 ( 2.8% ) resulted from a congenital anomaly , and 1 ( 2.8% ) was caused by iron - deficiency anemia . the specific laboratory findings of the 8 patients with a prothrombotic condition are presented in table 1 . among the 7 patients in the post - operative change group , 2 patients had undergone a craniotomy for a parasagittal meningioma , 1 for a right occipital skull plasmacytoma , 1 for a left vestibular schwannoma , 1 for a right vagus schwannoma , 1 for a right cerebellar hematoma following an arteriovenous malformation rupture , and 1 for a left cerebellopontine angle meningioma . in the infection group , the patients had infections in the following locations : a right superior ophthalmic vein thrombophlebitis , a right periorbital abscess and diffuse pachymeningitis , central nervous system aspergillosis , a right otomastoiditis , and a fungal sinusitis with brain abscess . the radiological findings showed that 13 patients ( 36.1% ) had a hemorrhagic infarction at diagnosis , whereas 23 ( 63.9% ) were without a hemorrhage . none of the hematomas resulted in a severe mass effect that warranted emergency surgical decompression . a dural avf was initially present in 8 patients ( 22.2% ) and was newly diagnosed during the follow - up in 1 patient ( 2.8% ) . , 22 patients had a thrombosis predominantly in the transverse and/or sigmoid sinus , 6 patients mainly in the superior sagittal sinus , 3 patients in the cavernous sinus , 4 patients within the cortical vein , and 1 patient in the deep venous system . a brief summary of the clinical characteristics of the patients is provided in table 2 . of the 8 patients in the prothrombotic group , 6 had a hemorrhagic infarction , and 2 had a venous infarction without a hemorrhage . of the 28 patients in the non - prothrombotic group , 7 patients had a hemorrhagic infarction , whereas 21 had a venous infarction without a hemorrhage . the prothrombotic group had more frequent hemorrhagic infarctions , whereas the non - prothrombotic group had more venous infarctions , which was statistically significant ( p=0.016 ) ( table 3 ) . the identical analysis was conducted for each pathogenesis entity ; the remaining differences were insignificant . four of the 9 patients ( 44.4% ) with a dural avf and 9 of the 27 patients ( 33.3% ) without a dural avf had a hemorrhagic infarction . the presence of a dural avf did not have a significant relationship with hemorrhagic infarction ( p=0.4097 ) . nine of the 22 patients ( 40.9% ) with mainly transverse and/or sigmoid sinus involvement , none of the 6 patients ( 0% ) with mainly superior sagittal sinus involvement , none of the 3 patients ( 0% ) with a cavernous sinus thrombosis , 3 of the 4 patients ( 75% ) with a cortical vein thrombosis and 1 of the 1 patient ( 100% ) with a deep vein thrombosis had a hemorrhagic infarction ; however , the relationship between the location and hemorrhagic infarction was not significant ( p=0.501 , 0.068 , 0.288 , 0.124 , 0.361 , respectively ) . the incidence of hemorrhagic infarction was higher in the group with a transverse and/or sigmoid sinus thrombosis , and the proportion of hemorrhagic infarction was higher in the cortical venous thrombosis and the deep venous thrombosis groups ; no noteworthy relationship was observed . anticoagulants and/or antiplatelets were prescribed for all the possible candidates , regardless of their disease stage . their therapeutic plans were individualized based on the difference in their presentation , general condition , and accompanying risk of bleeding . thirteen patients ( 36.1% ) were administered anticoagulant therapy with or without antiplatelets , and 3 patients ( 8.3% ) received antiplatelet therapy only . twenty patients ( 55.6% ) were not prescribed anticoagulants or antiplatelets ; 9 patients had recently undergone a craniotomy , 2 initially had a trauma - related hemorrhagic lesion , 2 had a sizable hemorrhagic infarction at diagnosis , and all these factors added to an increased risk of intracranial hemorrhage . four patients with a dural avf without notable intraparenchymal lesions had undergone endovascular sinus occlusion with dural arteriovenous fistula embolization and were not administered additional anticoagulants . the patient group included 21 men and 15 women with a mean age of 46.9 years at diagnosis ( ranging from 3 months to 77 years ) . in the age groups by decades , the highest prevalence was seen in the sixth decade ( n=9 ) . within the patient group , 14 ( 38.9% ) patients were in the acute stage at the time of diagnosis , 11 ( 30.1% ) were in the sub - acute stage , and 11 ( 30.1% ) were in the chronic stage . concerning the pathogenesis , 8 ( 22.2% ) cases resulted from a prothrombotic condition , 7 ( 19.4% ) were because of a post - operative change , 5 ( 13.9% ) were from an infection , 2 ( 5.6% ) followed a trauma , 2 ( 5.6% ) resulted from local invasion of a preexisting brain tumor , 1 ( 2.8% ) was cancer - related , 1 ( 2.8% ) was related to systemic diseases ( chronic renal disease and gout ) , 1 ( 2.8% ) occurred after hormonal replacement ( estradiol hemihydrate ) therapy , 1 ( 2.8% ) resulted from a congenital anomaly , and 1 ( 2.8% ) was caused by iron - deficiency anemia . the specific laboratory findings of the 8 patients with a prothrombotic condition are presented in table 1 . among the 7 patients in the post - operative change group , 2 patients had undergone a craniotomy for a parasagittal meningioma , 1 for a right occipital skull plasmacytoma , 1 for a left vestibular schwannoma , 1 for a right vagus schwannoma , 1 for a right cerebellar hematoma following an arteriovenous malformation rupture , and 1 for a left cerebellopontine angle meningioma . in the infection group , the patients had infections in the following locations : a right superior ophthalmic vein thrombophlebitis , a right periorbital abscess and diffuse pachymeningitis , central nervous system aspergillosis , a right otomastoiditis , and a fungal sinusitis with brain abscess . the radiological findings showed that 13 patients ( 36.1% ) had a hemorrhagic infarction at diagnosis , whereas 23 ( 63.9% ) were without a hemorrhage . none of the hematomas resulted in a severe mass effect that warranted emergency surgical decompression . a dural avf was initially present in 8 patients ( 22.2% ) and was newly diagnosed during the follow - up in 1 patient ( 2.8% ) . , 22 patients had a thrombosis predominantly in the transverse and/or sigmoid sinus , 6 patients mainly in the superior sagittal sinus , 3 patients in the cavernous sinus , 4 patients within the cortical vein , and 1 patient in the deep venous system . a brief summary of the clinical characteristics of the patients is provided in table 2 . each pathogenesis group was analyzed for an association with hemorrhagic infarction . of the 8 patients in the prothrombotic group , 6 had a hemorrhagic infarction , and 2 had a venous infarction without a hemorrhage . of the 28 patients in the non - prothrombotic group , 7 patients had a hemorrhagic infarction , whereas 21 had a venous infarction without a hemorrhage . the prothrombotic group had more frequent hemorrhagic infarctions , whereas the non - prothrombotic group had more venous infarctions , which was statistically significant ( p=0.016 ) ( table 3 ) . the identical analysis was conducted for each pathogenesis entity ; the remaining differences were insignificant . four of the 9 patients ( 44.4% ) with a dural avf and 9 of the 27 patients ( 33.3% ) without a dural avf had a hemorrhagic infarction . the presence of a dural avf did not have a significant relationship with hemorrhagic infarction ( p=0.4097 ) . nine of the 22 patients ( 40.9% ) with mainly transverse and/or sigmoid sinus involvement , none of the 6 patients ( 0% ) with mainly superior sagittal sinus involvement , none of the 3 patients ( 0% ) with a cavernous sinus thrombosis , 3 of the 4 patients ( 75% ) with a cortical vein thrombosis and 1 of the 1 patient ( 100% ) with a deep vein thrombosis had a hemorrhagic infarction ; however , the relationship between the location and hemorrhagic infarction was not significant ( p=0.501 , 0.068 , 0.288 , 0.124 , 0.361 , respectively ) . the incidence of hemorrhagic infarction was higher in the group with a transverse and/or sigmoid sinus thrombosis , and the proportion of hemorrhagic infarction was higher in the cortical venous thrombosis and the deep venous thrombosis groups ; no noteworthy relationship was observed . anticoagulants and/or antiplatelets were prescribed for all the possible candidates , regardless of their disease stage . their therapeutic plans were individualized based on the difference in their presentation , general condition , and accompanying risk of bleeding . thirteen patients ( 36.1% ) were administered anticoagulant therapy with or without antiplatelets , and 3 patients ( 8.3% ) received antiplatelet therapy only . twenty patients ( 55.6% ) were not prescribed anticoagulants or antiplatelets ; 9 patients had recently undergone a craniotomy , 2 initially had a trauma - related hemorrhagic lesion , 2 had a sizable hemorrhagic infarction at diagnosis , and all these factors added to an increased risk of intracranial hemorrhage . four patients with a dural avf without notable intraparenchymal lesions had undergone endovascular sinus occlusion with dural arteriovenous fistula embolization and were not administered additional anticoagulants . the clinical characteristics of 36 korean patients diagnosed with cvt in a single center were reviewed in this study , which focused on the relationship of hemorrhagic infarction , disease stage , location of cvt , and pathogenesis . pregnancy and the puerperium are common causes of transient prothrombotic states because pregnancy induces several prothrombotic changes in coagulation . hypercoagulability is hypothesized to be aggravated after delivery as a result of volume depletion and trauma15 ) . a cvt associated with pregnancy and puerperium accounts for 21% of all the causes of cvt , according to the iscvt8 ) . the frequency of puerperium cvt is reported to be approximately 12 cases per 10000 deliveries16 ) . estrogen - containing oral contraceptives play an important role in the pathogenesis of cvt in young women2,6,14 ) . in most cvt studies , the use of oral contraceptives is the most frequent risk factor in women ; the rate of usage was 47% in the iscvt and as high as 96% in an italian study3 ) . in our study group , a potential explanation for this finding is that korea has considerably low crude birth and fertility rates as well as a markedly low usage of oral contraceptives by korean women compared to that in the united states and many european countries . the crude birth rate ( 9.6 births per 1000 population ) and fertility rate ( 1.3 births per woman ) in korea are among the lowest in the world22,23 ) . the use of oral pills as a means of contraception in korea is as low as 2.0% , whereas that rate is tenfold higher in the united states and up to twentyfold higher in many european countries21 ) . iatrogenic injury to the venous sinus during and after surgery near the sinuses might induce cvt , as observed in 7 of our patients . there have been case reports of cvt after applying topical hemostatic matrix and cauterization at the nearby sinus , as well as studies on the incidence at the remote site after lumbar csf drainage13,19 ) . in our study group , all of the seven cases displayed localized cvt near the surgical lesion , which implies iatrogenic injury to these sinuses . the assumed causative factors are mannitol and csf drainage during a craniotomy , which induces hyper - osmolality that aggravates cvt . overexposure of the sinus leads to desiccation of the dura surrounding the sinus , leading to shrinkage and thrombosis . retraction against the venous structures might limit blood flow and subsequent stasis and thrombosis . maintaining adequate hydration and minimizing sinus exposure and retraction against venous structures dominant sinuses should never be sacrificed , and careful decision - making is required when occluding non - dominant sinuses11 ) . because iatrogenic cvt might be asymptomatic or present with a headache , which is a non - specific symptom after craniotomy , complete pre - operative and post - operative imaging studies including angiography or venography are essential for the diagnosis of iatrogenic cvt . the incidence of the prothrombotic condition in cvt was reported to be 34.1% in the 624 cases in the iscvt8,20 ) and 21% in the 182 cases in a recent multicenter study by de freitas et al.5 ) . the roles of antiphospholipid antibodies , anticardiolipin antibodies , natural anticoagulant protein ( antithrombin iii , proteins c and s ) deficiencies , and factor v leiden gene mutation have been described in past studies1,18 ) . in our patient group , the incidence of a prothrombotic condition was 22% , which is similar to or slightly lesser than in previous studies . thrombosis of the cerebral venous sinus could later induce a dural avf , as seen in one of our patients , and a pre - existing fistula could be the underlying cause of cvt18 ) . a dural avf could spontaneously close after the sinus recanalizes . in cases in which a dural avf is found with the initial diagnosis of cvt , the order of the timing of the two disease entities could not be clearly decided . to clarify the actual incidence of dural avf and cvt and the relationship between them , larger cohort studies with long - term angiographic evaluation infection is hypothesized to cause cvt by altering the coagulation cascade and inducing a hypercoagulable state in patients with an active infection12 ) . cavernous and transverse sinus thrombosis cases are most frequently associated with infections such as sinusitis , otitis , and mastoiditis , with staphylococcus aureus as the most frequently reported pathogen14 ) . in our study , the incidence of infection was 13.9% , and in the 3 patients with a cavernous sinus thrombosis , infection was the cause . the probability of a hemorrhage might increase with coagulopathy , and patients with hypercoagulability are less likely to experience a bleeding diathesis7 ) . in this study , the incidence of a hemorrhagic infarction was significantly higher in the patients with a prothrombotic condition . in arterial infarctions , a large - volume infarction , a delayed time of reperfusion and collateral flow failure are the factors associated with hemorrhagic transformation4,9 ) . similarly , the authors hypothesize that hypercoagulability leads to a more rapid thrombosis formation and venous sinus occlusion , which results in a more abrupt venous stasis and increased intracranial pressure , resulting in an increased probability of hemorrhagic transformation . first , the specificity and sensitivity of the hypercoagulability laboratory values might be altered because confounding factors were neglected . defining 1 or 2 positive findings of numerous hypercoagulability laboratory tests as a prothrombotic condition might be controversial . in addition , the sample size is limited , with 8 of the 36 patients having a prothrombotic condition . finally , this study was conducted retrospectively ; the patient data extracted from the medical charts were initially recorded for clinical use rather than for research purposes . in spite of these limitations , however , our study contains unique information on the characteristics of cvt patients in a korean sample and on the significance of the relationship between hemorrhagic infarction and prothrombotic condition . pregnancy and the puerperium are common causes of transient prothrombotic states because pregnancy induces several prothrombotic changes in coagulation . hypercoagulability is hypothesized to be aggravated after delivery as a result of volume depletion and trauma15 ) . a cvt associated with pregnancy and puerperium accounts for 21% of all the causes of cvt , according to the iscvt8 ) . the frequency of puerperium cvt is reported to be approximately 12 cases per 10000 deliveries16 ) . estrogen - containing oral contraceptives play an important role in the pathogenesis of cvt in young women2,6,14 ) . in most cvt studies , the use of oral contraceptives is the most frequent risk factor in women ; the rate of usage was 47% in the iscvt and as high as 96% in an italian study3 ) . in our study group , a potential explanation for this finding is that korea has considerably low crude birth and fertility rates as well as a markedly low usage of oral contraceptives by korean women compared to that in the united states and many european countries . the crude birth rate ( 9.6 births per 1000 population ) and fertility rate ( 1.3 births per woman ) in korea are among the lowest in the world22,23 ) . the use of oral pills as a means of contraception in korea is as low as 2.0% , whereas that rate is tenfold higher in the united states and up to twentyfold higher in many european countries21 ) . iatrogenic injury to the venous sinus during and after surgery near the sinuses might induce cvt , as observed in 7 of our patients . there have been case reports of cvt after applying topical hemostatic matrix and cauterization at the nearby sinus , as well as studies on the incidence at the remote site after lumbar csf drainage13,19 ) . in our study group , all of the seven cases displayed localized cvt near the surgical lesion , which implies iatrogenic injury to these sinuses . the assumed causative factors are mannitol and csf drainage during a craniotomy , which induces hyper - osmolality that aggravates cvt . overexposure of the sinus leads to desiccation of the dura surrounding the sinus , leading to shrinkage and thrombosis . retraction against the venous structures might limit blood flow and subsequent stasis and thrombosis . maintaining adequate hydration and minimizing sinus exposure and retraction against venous structures dominant sinuses should never be sacrificed , and careful decision - making is required when occluding non - dominant sinuses11 ) . because iatrogenic cvt might be asymptomatic or present with a headache , which is a non - specific symptom after craniotomy , complete pre - operative and post - operative imaging studies including angiography or venography are essential for the diagnosis of iatrogenic cvt . the incidence of the prothrombotic condition in cvt was reported to be 34.1% in the 624 cases in the iscvt8,20 ) and 21% in the 182 cases in a recent multicenter study by de freitas et al.5 ) . the roles of antiphospholipid antibodies , anticardiolipin antibodies , natural anticoagulant protein ( antithrombin iii , proteins c and s ) deficiencies , and factor v leiden gene mutation have been described in past studies1,18 ) . in our patient group , the incidence of a prothrombotic condition was 22% , which is similar to or slightly lesser than in previous studies . thrombosis of the cerebral venous sinus could later induce a dural avf , as seen in one of our patients , and a pre - existing fistula could be the underlying cause of cvt18 ) . in which a dural avf is found with the initial diagnosis of cvt , the order of the timing of the two disease entities could not be clearly decided . to clarify the actual incidence of dural avf and cvt and the relationship between them , larger cohort studies with long - term angiographic evaluation are required . infection is hypothesized to cause cvt by altering the coagulation cascade and inducing a hypercoagulable state in patients with an active infection12 ) . cavernous and transverse sinus thrombosis cases are most frequently associated with infections such as sinusitis , otitis , and mastoiditis , with staphylococcus aureus as the most frequently reported pathogen14 ) . in our study , the incidence of infection was 13.9% , and in the 3 patients with a cavernous sinus thrombosis , infection was the cause . pregnancy and the puerperium are common causes of transient prothrombotic states because pregnancy induces several prothrombotic changes in coagulation . hypercoagulability is hypothesized to be aggravated after delivery as a result of volume depletion and trauma15 ) . a cvt associated with pregnancy and puerperium accounts for 21% of all the causes of cvt , according to the iscvt8 ) . the frequency of puerperium cvt is reported to be approximately 12 cases per 10000 deliveries16 ) . estrogen - containing oral contraceptives play an important role in the pathogenesis of cvt in young women2,6,14 ) . in most cvt studies , the use of oral contraceptives is the most frequent risk factor in women ; the rate of usage was 47% in the iscvt and as high as 96% in an italian study3 ) . in our study group , a potential explanation for this finding is that korea has considerably low crude birth and fertility rates as well as a markedly low usage of oral contraceptives by korean women compared to that in the united states and many european countries . the crude birth rate ( 9.6 births per 1000 population ) and fertility rate ( 1.3 births per woman ) in korea are among the lowest in the world22,23 ) . the use of oral pills as a means of contraception in korea is as low as 2.0% , whereas that rate is tenfold higher in the united states and up to twentyfold higher in many european countries21 ) . iatrogenic injury to the venous sinus during and after surgery near the sinuses might induce cvt , as observed in 7 of our patients . there have been case reports of cvt after applying topical hemostatic matrix and cauterization at the nearby sinus , as well as studies on the incidence at the remote site after lumbar csf drainage13,19 ) . in our study group , all of the seven cases displayed localized cvt near the surgical lesion , which implies iatrogenic injury to these sinuses . the assumed causative factors are mannitol and csf drainage during a craniotomy , which induces hyper - osmolality that aggravates cvt . overexposure of the sinus leads to desiccation of the dura surrounding the sinus , leading to shrinkage and thrombosis . retraction against the venous structures might limit blood flow and subsequent stasis and thrombosis . maintaining adequate hydration and minimizing sinus exposure and retraction against venous structures dominant sinuses should never be sacrificed , and careful decision - making is required when occluding non - dominant sinuses11 ) . because iatrogenic cvt might be asymptomatic or present with a headache , which is a non - specific symptom after craniotomy , complete pre - operative and post - operative imaging studies including angiography or venography are essential for the diagnosis of iatrogenic cvt . the incidence of the prothrombotic condition in cvt was reported to be 34.1% in the 624 cases in the iscvt8,20 ) and 21% in the 182 cases in a recent multicenter study by de freitas et al.5 ) . the roles of antiphospholipid antibodies , anticardiolipin antibodies , natural anticoagulant protein ( antithrombin iii , proteins c and s ) deficiencies , and factor v leiden gene mutation have been described in past studies1,18 ) . in our patient group , the incidence of a prothrombotic condition was 22% , which is similar to or slightly lesser than in previous studies . thrombosis of the cerebral venous sinus could later induce a dural avf , as seen in one of our patients , and a pre - existing fistula could be the underlying cause of cvt18 ) . a dural avf could spontaneously close after the sinus recanalizes . in cases in which a dural avf is found with the initial diagnosis of cvt , the order of the timing of the two disease entities could not be clearly decided . to clarify the actual incidence of dural avf and cvt and the relationship between them , larger cohort studies with long - term angiographic evaluation are required . infection is hypothesized to cause cvt by altering the coagulation cascade and inducing a hypercoagulable state in patients with an active infection12 ) . cavernous and transverse sinus thrombosis cases are most frequently associated with infections such as sinusitis , otitis , and mastoiditis , with staphylococcus aureus as the most frequently reported pathogen14 ) . in our study , the incidence of infection was 13.9% , and in the 3 patients with a cavernous sinus thrombosis , infection was the cause . the probability of a hemorrhage might increase with coagulopathy , and patients with hypercoagulability are less likely to experience a bleeding diathesis7 ) . in this study , the incidence of a hemorrhagic infarction was significantly higher in the patients with a prothrombotic condition . in arterial infarctions , a large - volume infarction , a delayed time of reperfusion and collateral flow failure similarly , the authors hypothesize that hypercoagulability leads to a more rapid thrombosis formation and venous sinus occlusion , which results in a more abrupt venous stasis and increased intracranial pressure , resulting in an increased probability of hemorrhagic transformation . first , the specificity and sensitivity of the hypercoagulability laboratory values might be altered because confounding factors were neglected . defining 1 or 2 positive findings of numerous hypercoagulability laboratory tests as a prothrombotic condition might be controversial . in addition , the sample size is limited , with 8 of the 36 patients having a prothrombotic condition . more tests and larger randomized trials are needed to sufficiently verify this hypothesis . finally , this study was conducted retrospectively ; the patient data extracted from the medical charts were initially recorded for clinical use rather than for research purposes . in spite of these limitations , however , our study contains unique information on the characteristics of cvt patients in a korean sample and on the significance of the relationship between hemorrhagic infarction and prothrombotic condition . in this study , cvt was more prevalent in men , and the peak age at diagnosis was in the sixth decade of life . the most common cause was a prothrombotic condition , followed by infection and post - operative change . this finding was comparable with reports from europe or america , in which cvt was more common in younger women18 ) . the low proportion of korean women on oral contraceptives and the low birth rate in korea might have influenced those results . a hemorrhagic infarction was more common in the prothrombotic group than in the non - prothrombotic group ( p=0.016 ) . further studies with larger cohorts are required to evaluate the clinical characteristics of cvt patients in korea and to establish appropriate therapeutic strategies .
objectivethe purpose of this study is to investigate the clinical characteristics of cerebral venous thrombosis ( cvt ) in a single center in korea.methodsa total of 36 patients were diagnosed with cvt from august 2005 to may 2013 . 
 the patient data regarding age , sex , disease stage , pathogenesis , location , laboratory findings , radiological findings , and treatment modalities were retrospectively collected . 
 the results were compared with those of previous studies in other countries.resultsthe patient group comprised 21 men and 15 women with a mean age of 46.9 years ( ranging from three months to 77 years ) . 
 the most common cause was a prothrombotic condition ( 8 patients , 22.2% ) . 
 within the patient group , 13 patients ( 36.1% ) had a hemorrhagic infarction , whereas 23 ( 63.9% ) had a venous infarction without hemorrhage . by location , the incidence of hemorrhagic infarction was the highest in the group with a transverse and/or sigmoid sinus thrombosis ( n=9 ) ; however , the proportion of hemorrhagic infarction was higher in the cortical venous thrombosis group ( 75% ) and the deep venous thrombosis group ( 100% ) . 
 by pathogenesis , the incidence of hemorrhagic infarction was the highest in the prothrombotic group ( n=6 ) , which was statistically significant ( p=0.016).conclusionaccording to this study , cvt was more prevalent in men , and the peak age group comprised patients in the sixth decade . 
 the most common cause was a prothrombotic condition . 
 this finding was comparable with reports from europe or america , in which cvt was more common in younger women . 
 hemorrhagic infarction was more common in the prothrombotic group ( p=0.016 ) than in the non - prothrombotic group in this study .