Cognitive impairment among patients with chronic immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an autoimmune disease typically associated with severely depleted platelet counts. However, additional symptoms (e.g. increased fatigue and memory/concentration difficulties) can profoundly impact patients' quality of life. The nature and severity of cognitive impairment in ITP, and potential association with patient/disease characteristics were evaluated in 49 adults with relapsed/refractory ITP. The Cogstate Brief Battery quantitatively assessed psychomotor function (DET), attention (IDN), visual learning (OCL) and working memory (ONB) individually, as well as DET/IDN and OCL/ONB composites. Clinically important cognitive impairment (defined as z-score ≤ -1) for ≥2 individual tests was observed in 29 patients (59%). Impairment was highest for IDN (67% of patients), followed by DET (53%), ONB (39%) and OCL (16%). A higher magnitude of impairment was observed for the DET/IDN composite (mean z-score -1.54; 95% CI, -1.94 to -1.13) than OCL/ONB (mean z-score -0.21; 95% CI, -0.49 to 0.07). The severity of cognitive impairment was comparable to mild traumatic brain injury and associated with increasing age and fatigue but unrelated to platelet count or corticosteroid use. Overall, these results warrant a clinical need to further consider the potential of cognitive dysfunction in assessing ITP patients.