When Antipsychotics Imitate Epilepsy: Diagnostic Dilemma in a Case of Treatment-Resistant Schizophrenia

Abstract

Oculogyric crisis (OGC), a form of acute dystonia, is a recognized adverse effect of antipsychotics. However, certain seizure disorders can mimic OGC, complicating diagnosis and treatment. This report describes a rare case of seizure disorder presenting as OGC in a patient with treatment-resistant schizophrenia, highlighting a critical diagnostic challenge in clinical psychiatry. This is a case of a 21-year-old female with a 3-year history of schizophrenia developed recurrent upward eye deviation episodes after switching antipsychotics from Olanzapine to Aripiprazole. These were initially diagnosed as antipsychotic-induced OGC but failed to respond to standard anticholinergic therapy. The introduction of Clozapine improved her psychosis but exacerbated the eye movements and led to new symptoms including jerky limb movements, stammering, and two episodes of loss of consciousness with postictal confusion and tongue biting. Electroencephalogram (EEG) revealed generalized rhythmic slowing, suggestive of an underlying seizure disorder. Her symptoms resolved following cross-tapering of Clozapine to Haloperidol and initiation of  Lamotrigine. This case underscores the importance of considering epilepsy in patients presenting with movement abnormalities unresponsive to anticholinergics, especially in the presence of a seizure history. Clozapine is known to lower the seizure threshold, potentially unmasking latent epilepsy. EEG findings, although non-specific, supported cortical dysfunction. The favorable response to antiepileptic therapy reinforced the revised diagnosis. Clinicians should maintain a high index of suspicion for seizure disorders in schizophrenia patients presenting with atypical or treatment resistant movement symptoms. Comprehensive neurological assessment and individualized pharmacologic strategies, including EEG and antiepileptic therapy, are essential for accurate diagnosis and effective management.