The usage of proton magnetic resonance spectroscopy in Parkinson's disease

Parkinson's disease is a degenerative disorder of the central nervous system resulting from neuronal loss in the substantia nigra (a region of the mid brain) and BSG. Proton magnetic resonance spectroscopy (1H-MRS) has been previously performed in Parkinson's disease (PD) to evaluate in vivo concentration of basal ganglia (BSG) and cerebral cortex metabolites. However this technique has never been used to evaluate the substantia nigra (SN) in PD patients. In this preliminary report, single voxel MRS of BSG and SN was performed in PD and normal control (non-PD) to evaluate the usage of MRS in PD patients.

Seventeen PD patients including 12 men and five women with a mean age 60.5 years (SD 9.4) and a mean duration of the disease 5.9 years (SD 4.2) based on Hoehn & Yahr stage I to III, and 14 healthy age-matched controls including eight men and six women with a mean age 55.5 years (SD 5.8) were enrolled. Patients with evidence of brain atrophy and cognitive impairment were excluded.

A significant reduction in the NAA/Cr ratio was observed in the SN ofPD compared with controls (p < 0.05). BSG spectra did not allow any evaluation due to the presence of artifacts related to inorganic paramagnetic substances.

1H-MRS could be used as a sensitive tool for studying neuronal dysfunction in SN of PD patients and may be a useful technique to monitor the disease. The SN reduction of NAA/Cr ratio in PD patients may be the marker of neuronal loss in SN of patients with PD.