Proton magnetic resonance spectroscopy in an italian family with spinocerebellar ataxia type 1

Linkage and DNA analysis, magnetic resonance (MR) imaging, and single‐voxel proton MR spectroscopy were obtained in 10 members of an Italian kindred with spinocerebellar ataxia type 1 (SCA1). The size of the basis pontis, cerebellar hemispheres, middle cerebellar peduncles, and medulla oblongata were decreased in 4 members carrying the SCA1 gene, compared with 6 unaffected subjects. Diffuse signal changes in the pons and cerebellum were observed only in the carrier with the longest disease duration and greatest disability. The N‐acetylaspartate/creatine ratio and the choline/creatine ratio in the basis points were markedly decreased in 2 symptomatic SCA1 carriers and moderately decreased in 2 asymptomatic SCA1 carriers, compared with the unaffected family members and a control group of 10 healthy volunteers. Minor decreases in the N‐acetylaspartate/creatine ratio and the normal choline/creatine ratio, demonstrated by MR spectroscopy in the pons, is likely to reflect a loss of neuronal viability and might represent a biochemical marker of SCA1 more sensitive than brainstem and cerebellum atrophy and signal changes shown by MR imaging.