Neurocognitive Impairment Following Recovery From Adamts13-Deficient Thrombotic Thrombocytopenia Purpura (Ttp)

Patients who survive an acute episode of TTP often describe persistent problems with concentration, memory and fatigue in spite of continued remission. To assess these symptoms, we performed neuropsychological tests assessing 11 cognitive domains. We hypothesized that domains assessing complex attention/concentration skills and high level memory functions would be affected because these are characteristically abnormal in disorders with diffuse microvascular subcortical lesions. The Oklahoma TTP-HUS Registry enrolled 247 consecutive patients with their first episode of clinically diagnosed TTP from 11-13-1995 (the date of our initial ADAMTS13 measurement) to 6-30-2006; ADAMTS13 activity was measured in 228 (92%) patients immediately before their first plasma exchange treatment; 42 (18%) patients had ADAMTS13 activity <10%; 31 were currently alive; 25 (81%) were included in this study (3 patients were excluded because of dementia, 1 was too young to be evaluated, 1 was incarcerated, 1 was lost to follow-up). 21 (84%) patients were women; 9 (36%) were black; median age was 44 years (range 20–64); median time since their last episode was 46 months (range 2–127). At the time of the evaluation physical examinations and the Mini-Mental State Exams were normal. Median hematocrit was 39% (range 31–51%, 1 women had iron deficiency). Median platelet count was 303 (range 81–518; 1 woman has had persistent mild thrombocytopenia). ADAMTS13 levels remained <10% in 4 patients and were 10–20% in 4 additional patients. Results from the neuropsychological tests were compared to normal population values matched for age and education level and converted to a score with a mean value of 0 and a standard deviation of 1.