The brain and skeletal muscle oxidative metabolism of a patient with prolonged aura was studied by phosphorus magnetic resonance spectroscopy. We found that the phosphocreatine to ATP ratio in brain was reduced, while the inorganic phosphate to phosphocreatine ratio and the calculated ADP concentration were increased. The phosphorylation potential and percentage of maximal rate of ATP synthesis were also altered. Intracellular pH and inorganic phosphate concentration were normal. In muscle we found a low post-exercise recovery of phosphocreatine. These data indicate an impairment of energy oxidative metabolism both in brain and muscle.