MR spectroscopy of the cerebellum in gluten ataxia and gluten encephalopathy

OBJECTIVE: To identify any MR spectroscopy differences amongst patients with gluten ataxia and patients with gluten encephalopathy and interpret what this tells us about cerebellar functionality. METHODS: Retrospective review of MR spectroscopy baseline data from 40 patients with gluten ataxia (GA), 40 patients with gluten encephalopathy (GE) and a group of 55 healthy controls. RESULTS: The mean age at development of ataxia in the GA group was 50 years. In the GE group, the mean age at development of neurological symptoms was 37 years. The mean age of the healthy control group at the time of scanning was 41 years. Patients with GA showed highly significant reduction in the NAA/Cr (N-acetyl-aspartate/creatine) ratio from the vermis NAA/Cr 0.85 vs 0.99 in healthy controls (p = 0.0000105, Welch's t-test). Within this same group, the right hemisphere NAA/Cr area ratio was 0.969 vs 1.01 in healthy controls (p = 0.058). By contrast, patients with GE showed significant reduction of NAA/Cr area ratio in the right hemisphere 0.926 vs 1.01 in healthy controls (p = 0.00053, Welch's t-test) but no difference from control subjects when comparing vermis NAA/Cr. CONCLUSIONS: MR spectroscopy of the cerebellum demonstrates dysfunction in the vermis in patients with GA, whereas patients with GE have abnormal spectroscopy in the right cerebellar hemisphere in the absence of ataxia. The right cerebellar hemisphere may be implicated in cerebellar cognitive affective syndrome.