Failure of long term high-dose lecithin to retard progression of early-onset Alzheimer's disease. A double-blind, placebo controlled trial of high-dose lecithin in Alzheimer's disease. Lecithin treatment of cognitively impaired Parkinson's patients. A dose-ranging study of lecithin in the treatment of primary degenerative dementia (Alzheimer disease). Alzheimer disease: lack of effect of lecithin treatment for 3 months. Lecithin administration in Alzheimer dementia. Chronic oral physostigmine without lecithin improves memory in Alzheimer's disease. A crossover study of lecithin treatment of tardive dyskinesia. Short-term administration of selegiline for mild-to-moderate dementia of the Alzheimer's type.
We conducted a six-month, randomized, double-blind trial of lecithin therapy in early-onset Alzheimer's disease. We hypothesized that such therapy would retard the progression of the clinical and neuropsychological manifestations of this illness. Of the 73 referred patients, 37 met strict requirements for diagnosis and compliance. The 21 placebo and 16 lecithin-treated patients (mean age 63 years) had a comparable degree of severity of dementia (mean Clinical Dementia Rating 1.6). Lecithin therapy produced an increase in mean plasma choline levels from a baseline of 15.9 to 28.8 nmol/ml. Patients were evaluated by the physician using clinical assessments (CDR, Lawton ADL and other rating scales) and by the neuropsychologist who determined the outcome of therapy on a battery of tests (Mini Mental State Examination, Wepman Aphasia Screen, Verbal Fluency Test, Verbal Selective Reminding Test and Spatial Memory Test). Only 6 (37.5%) of the 16 lecithin-treated patients were considered by the neurologist to be clinically stable or improved as compared to 12 (57.1%) of the 21 patients given placebo (difference -19.6%, 95% confidence limits of -51% to 12%). The neuropsychologic scores showed no differences in the stability of the dementing process over time between the lecithin-treated (50.0%) and placebo (47.6%) groups. On the basis of these clinical and neuropsychological findings, it appears that lecithin alone has no important therapeutic effect in early-onset Alzheimer's disease. The first long-term double-blind placebo controlled trial of high dose lecithin in senile dementia of the Alzheimer type is reported. Fifty one subjects were given 20-25 g/day of purified soya lecithin (containing 90% phosphatidyl plus lysophosphatidyl choline) for six months and followed up for at least a further six months. Plasma choline levels were monitored throughout the treatment period. There were no differences between the placebo group and the lecithin group but there was an improvement in a subgroup of relatively poor compliers. These were older and had intermediate levels of plasma choline. It is suggested that the effects of lecithin are complex but that there may be a "therapeutic window" for the effects of lecithin in the condition and that this may be more evident in older patients. To test the effects of lecithin on cognitive deficits associated with Parkinson's disease, sixteen elderly and mentally-impaired outpatients with Parkinson's disease participated in a 9-week double-blind placebo-controlled study. Each patient took a daily dose of approximately 32 g of a commercial lecithin preparation containing 25% phosphatidylcholine, or an equivalent amount of powdered skim milk placebo. Marked clinical improvement was not observed, but some indications of a positive treatment effect were obtained on memory, cognition, and motility tests. nan Eleven outpatients with Alzheimer disease of moderate severity completed a double-blind placebo-controlled crossover trial of lecithin. Each patient received 10 gm three times daily of a placebo for 3 months. Plasma choline levels rose threefold and remained at that level throughout the lecithin administration period. A significant difference between mean baseline scores and treatment scores was found on tests of new learning ability, indicating a practice effect in these tests. However, there were no differences between mean placebo and lecithin scores on any of the psychological test measures. nan Sixteen patients with early Alzheimer's disease (AD) completed a 3-month outpatient double-blind parallel trial of oral physostigmine versus placebo. Ten subjects received drug; six received placebo. After a dose-titration phase, each patient was placed on his or her best dose of drug or placebo. Subjects were evaluated with both memory and nonmemory tasks. Seven of the ten drug-treated patients, but none of the six placebo-treated patients, demonstrated improvement on a selective reminding task, a test of verbal memory. Family members reported improvement in six of ten drug-treated patients and none of six placebo-treated individuals. There was a trend toward greater improvement with increasing drug dose. There was no improvement on the nonmemory tests administered. The data indicate that oral physostigmine improves memory but not other areas of cognition. The authors enrolled 21 patients in a random-order, crossover, double-blind trial of phosphatidylcholine (lecithin) 20 g/day and placebo. Fourteen patients completed at least 6 weeks of the second 8-week trial and were used for efficacy analyses. Side effects were minimal. The lecithin treatment effect--about one half of an Abnormal Involuntary Movement Scale point--was seen as a statistical effect of treatment order, based on differences between patients who took the active compound before or after they took the placebo. Clinically, however, the lecithin effect was negligible. As a follow-up to an earlier study showing short-term benefit in inpatients with more severe dementia, the authors studied the short-term cognitive, functional, and behavioral effects of selegiline in outpatients with mild-to-moderate dementia of the Alzheimer type (DAT) by means of a double-blind, randomized, crossover study of placebo vs. selegiline. Fifty outpatients with mild-to-moderate DAT and no behavioral disturbances were given selegiline in two 8-week treatment periods separated by a 4-week washout. Outcome was assessed with standardized measures of dementia severity, daily functioning, behavior, and cognition. There was no drug-placebo difference in any outcome measure. Selegiline did not show short-term benefit in this study, contrary to the earlier study, perhaps because the patients were studied less intensively and/or lacked behavioral problems that could show response, although the medication was well tolerated.
Evidence from randomized trials does not support the use of lecithin in the treatment of patients with dementia. A moderate effect cannot be ruled out, but results from the small trials to date do not indicate priority for a large randomized trial.