[Disappearance of paroxysmal perceptual alteration by switching to aripiprazole in a schizophrenic patient].

We report a schizophrenic patient with paroxysmal perceptual alteration (PPA) which disappeared completely on switching from the previous antipsychotic to aripiprazole (APZ). PPA is an attack characterized by hypersensitivity of perception mainly involving in the modality of visual sensation. The prevalence of PPA is about 4% in schizophrenia. It is regarded as a psychopharmacological symptom associated with antipsychotics, and a hypothesis regarding the cause has been proposed: PPA is caused by noradrenergic activation which compensates for the sudden incompetence of dopaminergic neural transmission in the context of chronic hypofunction of the dopamine system caused by antipsychotics. Since APZ maintains the dopaminergic nervous system in a steady state by its partial agonism of the D2 receptor, it is suggested that APZ could correct the chronic dysfunction of the dopamine system associated with PPA, explaining its resolution in this patient. Because APZ is positioned as a drug which relatively preserves tonic neurotransmission from the perspective of the tonic/phasic model of dopaminergic neurotransmission, an alternative hypothesis whereby a decrease in the tonic component might cause PPA can be proposed. Additionally, this patient experienced 'general restlessness' like akathisia shortly after we added a low dose of APZ to his formula, and we think that the symptom demands closer consideration on switching to APZ. Especially in chronic schizophrenic patients, PPA can be the main cause of a reduced quality of life, and treatment is essential. Switching to APZ should be a significant treatment option for PPA.