Cognitive deficits after recovery from thrombotic thrombocytopenic purpura.
BACKGROUND
Patients with apparent complete recovery from thrombotic thrombocytopenic purpura (TTP) often complain of problems with memory, concentration, and fatigue.


METHODS
Twenty-four patients who were enrolled in the Oklahoma TTP-HUS Registry for their initial episode of TTP, 1995-2006, and who had ADAMTS13 activity of less than 10 percent were evaluated for a broad range of cognitive functions 0.1 to 10.6 years (median, 4.0 years) after their most recent episode. At the time of their evaluation, they had normal physical and Mini-Mental State Examinations and no evidence of TTP.


RESULTS
The patients, as a group, performed significantly worse on 4 of the 11 cognitive domains tested than standardized US data from neurologically normal individuals adjusted for age, sex, and education (p < 0.05). These four domains measured complex attention and concentration skills, information processing speed, rapid language generation, and rote memorization. Twenty-one (88%) patients performed below expectations on at least 1 of the 11 domains. No clear patterns were observed between cognitive test results and patients' characteristics or features of the preceding TTP, including age, occurrence of severe neurologic abnormalities, multiple episodes, and interval from an acute episode.


CONCLUSIONS
Patients who have recovered from TTP may have persistent cognitive abnormalities. The abnormalities observed in these patients are characteristic of disorders associated with diffuse subcortical microvascular disease. Studies of larger patient groups will be required to confirm these preliminary observations and to determine patient characteristics that may contribute to persistent cognitive abnormalities.
Kennedy
April S
AS
Department of Medicine, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126-0901, USA.
Lewis
Qurana F
QF
Scott
James G
JG
Kremer Hovinga
Johanna A
JA
Lämmle
Bernhard
B
Terrell
Deirdra R
DR
Vesely
Sara K
SK
George
James N
JN
D051722:ADAM Proteins / Q000172:deficiency; D000071120:ADAMTS13 Protein; D000328:Adult; D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications*
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human