Generalized mitochondrial dysfunction in Parkinson's disease detected by magnetic resonance spectroscopy of muscle

OBJECTIVE: To explore mitochondrial dysfunction in Parkinson's disease (PD) using 31P magnetic resonance spectroscopy of resting muscle. DESIGN: Case-control study (28 PD patients and 28 normal controls) determining resting forearm inorganic phosphate/phosphocreatine (Pi/PCr) ratio. RESULTS: Significant difference (p = 0.004, one-tailed test) in Pi/PCr ratio between PD patients (0.122) and controls (0.104). No correlation of Pi/PCr ratio with duration, severity, or speed of onset of disease. Positive correlation of Pi/PCr ratio with age in control group; reversed in PD group. CONCLUSIONS: Suggests small generalized mitochondrial defect in PD. The possibility that earlier onset of disease is associated with more severe mitochondrial dysfunction needs further study.