Recurrent episodes of perceptual alteration in patients treated with antipsychotic agents

Antipsychotics have been sporadically reported to induce the brief recurrent episodes characterized by hypersensitivity of the visual perception, which is known as paroxysmal perceptual alteration (PPA) mainly in Japan. PPA is characterized by hypersensitivity of perception mainly in visual modalities, which could occur in patients treated with antipsychotics. PPA is occasionally known to be accompanied by an oculogyric crisis (OGC). In this study, we examine the prevalence and the characteristics of patients with PPA. Three hundred thirty-eight patients who were treated with antipsychotics and diagnosed with schizophrenia, mood disorders, or neurotic disorders (International Classification of Disease, or ICD-10) were interviewed. We compared the characteristics between subjects with and without PPA. The mean overall prevalence of PPA was 3.25%, which was higher among patients treated with high-potency antipsychotics (3.91%) than in subjects treated with mid-potency or low-potency drugs (1.16%). PPA occurred simultaneously with OGC at the rate of 36.4%. We also found much similarity between PPA and OGC in terms of phenomenology. We suggest that PPA could manifest itself as an undesirable effect of antipsychotics, especially those of high potency. PPA and OGC may a share common underlying mechanism.