Altered mental status in thrombotic thrombocytopenic purpura is secondary to nonconvulsive status epilepticus.

Thrombotic thrombocytopenic purpura (TTP) is a syndrome with numerous neurological manifestations including altered mental status and seizures. At least 10% of the patients with TTP seen at our institution had nonconvulsive status epilepticus as a cause of or associated with their altered mental status. We propose that altered mental status secondary to nonconvulsive status epilepticus requiring electroencephalographic diagnosis and antiepileptic medication occurs in a substantial proportion of patients with TTP.