Alternating flexed-extended posturing in progressive supranuclear palsy

A 69-year-old man who had been bedridden in nursing home because of a 5-year history of progressive supranuclear palsy (PSP) was admitted due to aspiration pneumonia. Besides neck dystonia in extension, he showed “alternating flexed–extended posturing”, in which the arm was flexed on one side and extended on the other. Magnetic resonance imaging of the brain revealed global cerebral atrophy that predominantly affected the cortex and midbrain. The mechanisms of complex posturing in late-stage PSP may sometimes be related to decortication and decerebration as well as dystonia, and “alternating flexed–extended posturing” might be one of the phenotypes of pathological progression in PSP.