New-Onset Psychosis: Consider Epilepsy

Article excerpt

Interictal psychosis of epilepsy (IPE) is schizophrenia-like psychosis associated with epilepsy that cannot be directly linked to an ictus. IPE often is indistinguishable from primary schizophrenia. This phenomenon commonly occurs in patients with a history of temporal lobe epilepsy (TLE); in those with frequent seizures; and in patients with a long history of epilepsy (Greater than 10 years). (1) Interictal psychosis rarely precedes seizure activity (2) and few cases have been reported. The epidemiology and clinical characteristics of IPE are poorly defined. (3) We recently treated a patient with suspected IPE.

Mr. R, age 18, presented to our emergency department with his mother, who stated that her son was behaving strangely and had slow speech for 4 days. He had decreased social interaction, reduced appetite, poor hygiene, decreased sleep, and auditory hallucinations. Mr. R demonstrated hypervigilance and paranoia. He repeatedly checked rooms in his house for intruders. Mr. R also expressed suicidal ideation and exhibited cognitive decline of memory, attention, and fund of knowledge. His physical exam, routine laboratory investigations, CT, and MRI were within normal limits. Urine drug screen was positive for marijuana. We made a clinical diagnosis of acute psychosis.

Mr. R was admitted and started on ziprasidone, titrated to 160 mg/d; however, he could not tolerate this medication because of orthostatic hypotension. We discontinued ziprasidone and started risperidone, titrated to 4 mg/d. By day 4 Mr. R remained psychotic and marijuana intoxication was ruled out. EEG demonstrated rare intermittent left temporal sharp slow wave discharges and sharply contoured slow waves. This suggested an underlying seizure disorder, although Mr. R had no history of seizure.

The psychosis resolved 3 weeks later with risperidone, 2 mg/d, risperidone long-acting injection, 25 mg every 2 weeks, and carbamazepine, 400 mg/d. …