Deficit of brain and skeletal muscle bioenergetics in progressive supranuclear palsy shown in vivo by phosphorus magnetic resonance spectroscopy.

Brain and muscle energy metabolism was assessed in vivo in five patients with progressive supranuclear palsy (PSP) using phosphorous magnetic resonance spectroscopy (31P MRS). 31P MRS disclosed a reduced phosphocreatine (PCr) and an increased calculated free adenosine diphosphate (ADP) in the occipital lobes of all patients. In our patients with PSP, inorganic phosphate (Pi) was significantly increased and Mg2+ was reduced. In the gastrocnemius muscle, Pi at rest was increased in four patients, and the three patients who were able to perform an incremental exercise showed a rate of PCr postexercise recovery slower than control subjects. Our findings show that multisystemic deficit of energy metabolism occurs in PSP and suggest that it may play a role in the pathogenesis of this disorder.