This case report describes a patient (who previously received a diagnosis of immune thrombocytopenic purpura) admitted to the hospital with disturbed activity, ataxic gait, and subacute onset of apathy.
A woman in her mid to late 70s who had previously received a diagnosis of immune thrombocytopenic purpura was admitted to the hospital with disturbed activity, ataxic gait, and subacute onset of apathy. She had severe disturbance of consciousness with quadriplegia and global dysphagia, and her National Institutes of Health Stroke Scale score was 28 (range, 0-42, with 0 indicating no stroke symptom and 21-42 indicating severe stroke). She had severe thrombocytopenia (platelet count, <5 × 103/µL [to convert to ×109 per liter, multiply by 1.0]) right before hospitalization. Computed tomography of her brain revealed bleeding throughout the brain (Figure, A-C). Susceptibility weighted imaging with 3-T magnetic resonance imaging revealed abundant microbleeds and macrobleeds in the lobar area in particular. These bleeds included lesions that were visible and lesions that were invisible to computed tomography (Figure, D-F). Cerebral spinal fluid analysis revealed a remarkable decrease in the Aβ40 level (929 pg/mL; mean [SD] level, 4003  pg/mL) and in the Aβ40/Aβ42 ratio (1.56; mean [SD] ratio, 4.91 [1.13]).1 Thus, the radiological and biochemical findings suggested underlying arteriopathy related to cerebral amyloid angiopathy (CAA), albeit combined with some hypertensive arteriopathy. The administration of high doses of corticosteroids and γ-globulin rapidly brought her platelet count back to normal levels. Notably, she also quickly regained her consciousness, and she was discharged from the hospital a month later, with no neurological deficits; her National Institutes of Health Stroke Scale score was 0. For 2 years after being discharged, her platelet count was maintained at the level of 10 to 20 × 103/µL, and the numbers of microbleeds and macrobleeds detected by use of susceptibility weighted imaging with 3-T magnetic resonance imaging have not increased.