Definition of Pisa syndrome

Pisa syndrome: A condition in which there is sustained involuntary flexion of the body and head to one side and slight rotation of the trunk so the person appears to lean like the Leaning Tower of Pisa.

The Pisa syndrome is an adverse effect (a side-effect) of some medications. It occurs sometimes following the long-term use of narcoleptics (drugs used to treat schizophrenia) or cholinesterase inhibitors (a class of drugs used to treat Alzheimer disease).