The Hot Cross Bun (HCB) sign is a characteristic MRI finding of pontocerebellar degeneration, classically seen in multiple system atrophy of the cerebellar type (MSA-C). It has not been previously reported in association with gluten ataxia, an immune-mediated and potentially reversible cause of progressive cerebellar ataxia.
We report a 29-year-old woman with a one-year history of progressive gait imbalance, lower limb numbness, upper limb incoordination, dysarthria, and 11 kg weight loss. Examination revealed scanning speech, gaze-evoked nystagmus, intention tremor, dysdiadochokinesia, impaired heel–shin test, and wide-based gait. MRI brain showed the classical Hot Cross Bun sign in the pons. Laboratory evaluation demonstrated iron deficiency anemia and elevated anti-TTG IgA antibodies, and duodenal biopsy confirmed celiac disease. Neurophysiological studies were normal and paraneoplastic screening was negative. Remarkably, the patient demonstrated significant clinical improvement in gait and speech after only one month of strict gluten-free diet.