Magnetic resonance spectroscopy of the cerebellum in patients with spinocerebellar ataxia type 3/Machado-Joseph disease.

OBJECTIVE: To evaluate the metabolite pattern and the severity in patients with spinocerebellar ataxia type 3/ Machado-Joseph disease (SCA3/MJD) by (1)H magnetic resonance spectroscopy ((1)H-MRS) on different cerebellar regions, including cerebellar vermis, cerebellar peduncles, cerebellar cortex, and dentatum.

METHODS: Thirty-six SCA3/MJD patients, and 27 sex, age-matched healthy controls were scanned with (1)H-MRS for N-acetylaspartate (NAA), choline (Cho) and creatine (Cr). We made cerebellar vermis, cerebellar peduncles, cerebellar cortex, and dentatum as the region of interests (ROI), and finally got access to NAA/Cr, Cho/Cr, and NAA/Cho ratios. We also examined the CAG repeat numbers of MJD1 gene, scored the 36 patients by the scale for the assessment and rating of ataxia (SARA), analyzed the differences in ratios between SCA3/MJD patients and the control group, and explored whether relevance existed between these ratios and duration of the disease, age of onset, CAG repeat times, and SARA scores respectively.

RESULTS: The ratio of NAA/Cr in SCA3/MJD patients showed a significant reduction in the cerebellar cortex, dentatum, cerebellar vermis and medipeduncle (P<0.01) compared with the controls. The ratio of NAA/Cho also showed significant reduction in the dentatum and cerebellar vermis (P<0.01). A number of correlations were found between the metabolite ratios of (1)H-MRS and duration of the disease, age of onset, expanded CAG and SARA score in SCA3/MJD patients.

CONCLUSION: (1)H-MRS, which shows the neural metabolic changes in the cerebella of SCA3/MJD patients, provides useful information about the severity of SCA3/MJD.