Clinical and Radiological Variability in Episodic Ataxia Type 2: A Case Report and Review of the Literature.

Episodic ataxia type 2 (EA2) is an autosomal dominant channelopathy caused by CACNA1A mutations, typically presenting with recurrent episodes of ataxia, vertigo, and hemiplegic migraine, often with a normal brain MRI or cerebellar atrophy. This report describes a 47-year-old man with a 22-year history of recurrent severe headaches, limb weakness, truncal ataxia, sensory disturbances, and profound fatigue, triggered by stress or minor trauma. Interictal recovery was complete, but serial MRI revealed extensive T2/FLAIR white matter hyperintensities, initially raising concern for multiple sclerosis or cerebral vasculitis. Lumbar puncture was unremarkable. Genetic testing identified a pathogenic heterozygous CACNA1A variant (c.7411 C > T, p.R2471*), confirming EA2. Symptomatic management with acetazolamide and trigger avoidance improved episode frequency and severity. This case highlights the diagnostic challenges of EA2 when MRI shows atypical white matter lesions and emphasizes the value of genetic testing in atypical presentations. Recognizing these findings can prevent misdiagnosis, guide targeted therapy, and inform family counseling. Pearls: · The variability of CACNA1A- related disorders is broad and continues to expand. The gene-phenotype spectrum includes episodic ataxia type 2 (EA2), familial hemiplegic migraine type 1 (FMH1), sporadic hemiplegic migraine (SHM), spinocerebellar ataxia type 6, epilepsy and developmental epileptic encephalopathy. · Patients with episodic ataxia type 2 have either a normal MRI or cerebellar atrophy, mainly at the vermis. · Episodic ataxia type 2, may be treated with acetazolamide and 4-aminopyridine. Oysters: · EA2 may present in the absence of family history. · It is very common for patients with EA2, to be erroneously diagnosed with another disorder, and the disease is very infrequent. · CACNA1A associated diseases may present with clinical overlap.