PROTON MR SPECTROSCOPY OF THE BRAIN IN 14 PATIENTS WITH PARKINSONS-DISEASE

PURPOSE: To determine whether the proton spectra from patients with cl inically diagnosed Parkinson disease differ from the spectra of age-ma tched healthy subjects with respect to the major cerebral metabolite r esonances as well as lactate. METHODS: Fourteen patients with Parkinso n disease (38 to 81 years of age) and 13 healthy control subjects (37 to 81 years of age) were studied using image-guided, single-voxel (27- cm(3) volume) proton MR spectroscopy of the occipital lobe. RESULTS: T he peak area ratios of N-acetyl aspartate to creatine and N-acetyl asp artate to choline for Parkinson patients did not show a statistically significant difference from the corresponding ratios for control subje cts. There was a very significant increase in the ratio of lactate to N-acetyl aspartate for patients with Parkinson disease, with the great est increase (threefold) manifested by the subgroup (n = 4) with demen tia. The difference in N-acetyl aspartate to choline between women (n = 7) with Parkinson disease and healthy women (n = 9) approached signi ficance. No dependence of the peak ratios on age, duration of Parkinso n disease, or medication (L-dopa) regimen was found. CONCLUSION: Preli minary results indicating an increase in cerebral lactate in patients with Parkinson disease support the hypothesis that Parkinson disease i s a systemic disorder characterized by an impairment of oxidative ener gy metabolism. The larger increases for Parkinson patients with dement ia may be diagnostically useful in assessing clinical course and in di fferentiating Parkinson disease from other causes of dementia. Additio nal studies are needed, though, to quantitate lactate changes and iden tify potential contributions from lipid resonances better.