Rabbit syndrome in a neuroleptic naive patient with associated basal ganglia perfusion alterations treated with madopar fade‒out of perioral tremor after administration of L‒DOPA: role of thalamus in pathophysiology of post‒stroke rabbit syndrome

Abstract

Rabbit syndrome is an extrapyramidal side effect that has been linked with chronic antipsychotic therapy. We report herein a rare case of rabbit syndrome that occurred withoutin administration of a neuroleptics naive patient. A 90-year old female exhibited a perioral tremor movement disorder resembling rabbit syndrome, although she the patient revealed no previous psychiatric history and had never taken antipsychotic medication. Single photon emission computed tomography (SPECT) revealed increased perfusion of the right basal ganglia and left thalamus. Treatment with L-DOPA Madopar faded out resolved the movement disorder, and the second reevaluation by SPECT showed that basal ganglia/thalamus perfusion had returned to baseline. Rabbit syndrome is an extrapyramidal side effect that has been linked with chronic antipsychotic therapy. We present a rare case of rabbit syndrome in a patient naive to antipsychotics that was associated with increased perfusion of the basal ganglia. The underlying cause of the movement disorder and altered perfusion in this case is unknown. However, standard treatment antiparkinsonian treatment for antipsychotic induced rabbit syndrome was effective in this case indicating involvement of the dopaminergic or cholinergic system.