Magnetic resonance imaging in the diagnosis of cerebellar-type multiple system atrophy

Cerebellar-type multiple system atrophy (MSA-C) presents significant challenges for early diagnosis due to the absence of specific biomarkers and its clinical similarity to other forms of ataxia. The presented clinical case highlights the importance of dynamic monitoring of magnetic resonance imaging (MRI) changes for confirming the diagnosis of MSA-C and demonstrates the characteristic temporal evolution of key neuroimaging markers.A clinical observation of a 47‑year-old patient with progressive cerebellar ataxia and autonomic failure (orthostatic hypotension, urinary incontinence) consistent with established diagnostic criteria for MSA-C is presented. Brain MRI findings obtained in follow-up with a 7‑month interval are of particular value. First detection of the highly specific “hot cross bun” sign for MSA-C – a cross-shaped area of hyperintense signal in the central pons. Progressive thinning of the middle cerebellar peduncles (by 3 mm), cerebellar vermis atrophy (by 2 mm), and enlargement of the fourth ventricle and pontine cisterns were also documented. These changes objectively correlated with the progression of cerebellar clinical symptoms in the patient.The findings of this clinical case indicate that dynamic MRI evaluation is an indispensable method in the diagnosis of MSA-C. The appearance of the pathognomonic “hot cross bun” sign and quantitatively measurable progression of atrophy in specific posterior fossa structures (the cerebellum, middle cerebellar peduncles, and pons) over a short time interval represent highly specific radiological criteria that allow reliable differentiation of MSA-C from hereditary ataxias even in the absence of definitive biomarkers. Early and sequential MRI with assessment of imaging changes over time significantly improves the accuracy of antemortem diagnosis of this severe neurodegenerative disease.