Antipsychotic-Induced Pisa Syndrome: A 2-Year Follow-up Study

Pisa syndrome is characterized by lateral trunk flexion. It is an uncommon adverse drug reaction in patients on antipsychotic medication. Although Pisa syndrome has been reported in patients on antipsychotic treatment, previous studies have not discussed the prognosis of patients with Pisa syndrome. We studied psychiatric patients with Pisa syndrome following antipsychotic treatment for a 2-year period.

From January 2012 to December 2014, 13 inpatients with Pisa syndrome following antipsychotic treatment were identified at our institution, from a prospectively collected database. These patients were studied for a 2-year period.

The prevalence rate of Pisa syndrome during neuroleptic treatment was 0.45% in men and 0.37% in women, with a collective prevalence rate of 0.42%. The mean age of patients with Pisa syndrome was 47 years. Eight (61.5%) of the cases had a position with a tilt toward the right side. In 5 (38.5%) of the cases, a tilt toward the left side was observed. The average Cobb angle of the trunk was 17.3 (SD, 4.0) degrees. On presentation with Pisa syndrome within 3 months of medication modification, the pattern of trunk dystonia had a significantly shorter duration (P = .024) compared with that seen in the tardive-onset group.

Pisa syndrome is an uncommon adverse event that can also be chronic or recurrent, especially in those with tardive onset. We should be aware of the risks in patients with the following predisposing factors: old age, chronic psychosis, long-term antipsychotic use, advanced drug-induced parkinsonism, and combined pharmacologic treatment.