Rapid Improvement of Persistent Catatonia Temporally Associated With Amantadine After Benzodiazepine Intolerance and Discontinuation of Electroconvulsive Therapy: A Case Report

Catatonia can be difficult to manage when benzodiazepines are poorly tolerated, and electroconvulsive therapy (ECT) cannot be continued.We report the case of a 23-year-old woman with a schizophreniaspectrum disorder and catatonia presenting with mutism, delayed responses, staring, posturing, waxy flexibility, withdrawal, and abnormal behavior.Treatment with lorazepam was limited by excessive sedation.She then received four bitemporal ECT sessions before she and her mother declined further ECT due to reported adverse effects.Soon after discharge, she was found wandering outside while confused and required readmission.Nine days after her last ECT session, her Bush-Francis Catatonia Rating Scale (BFCRS) severity score was 11.Amantadine 100 mg twice daily was started, and three days later her BFCRS severity score fell to 3, a 72.7% reduction.Because her altered mental status persisted, a neurologic evaluation was performed.Brain MRI, routine electroencephalography (EEG), cerebrospinal fluid (CSF) studies, infectious testing, and neuronal autoantibody testing, including N-methyl-D-aspartate (NMDA) receptor antibody testing, were unremarkable.Amantadine was then increased to 200 mg twice daily, and zolpidem 5 mg nightly was later added.Her final BFCRS severity score was 2. Although delayed ECT effects, concurrent treatment of the underlying psychotic disorder, spontaneous fluctuation, and subsequent interventions preclude causal attribution, this case shows rapid, objectively measured improvement temporally associated with the start of amantadine treatment.