Episodic ataxia type 2: case report

*Correspondence: [e-mail].

Abstract

Case Presentation: BHN, 4 years old, experienced episodes of vomiting, ataxia, and subsequent progressive drowsiness starting at 2 years of age. Additionally, there was a delay in language development. Initially, it was investigated as benign paroxysmal vertigo, and treatment with flunarizine was initiated with no improvement. As the episodes became more frequent, genetic investigation was chosen, revealing a mutation in the CACNA1A gene, leading to a diagnosis of episodic ataxia type 2 (EA2). Pharmacological treatment with acetazolamide was initiated, resulting in improvement. The patient continues to receive follow-up care in our service and undergoes language stimulation therapies.

Discussion: EA2 is a rare neurological disorder that affects the cerebellum, caused by an autosomal dominant genetic mutation in the CACNA1A gene, which is responsible for producing a P/Q-type calcium channel protein. Dysfunction in this protein leads to abnormal excitability of cerebellar neurons. The estimated prevalence is 1-2 in 100,000, with geographic and ethnic variations. The typical age range of onset described in the literature is the second decade of life. Two families were reported by von Brederlow et al. in 1995, involving children between 2 and 5 years old, similar to our patient. Clinical manifestations include episodes of incoordination, imbalance, progressive ataxia, speech problems, and unstable vision. These episodes can last from minutes to hours and occur from several times a day to a few times a year. In the case of our patient, the occurrences were weekly. Precipitating factors described in the literature include nicotine, caffeine, and alcohol. There is no cure for EA2, but medications such as acetazolamide at a dose of 8-30 mg/kg/day can help reduce the frequency and severity of ataxic episodes. Rehabilitation therapies such as physiotherapy and occupational therapy can also be beneficial. The literature reports a more rapid progression in individuals with an onset younger than 20 years old.

Final Comments: Genetic etiology is a common cause of episodic ataxia, as described in the literature. The current focus on the causes of episodic ataxias is based on identifying mutations in genes responsible for ion channel formation, correlating them with clinical signs and responsiveness to pharmacological treatment

 

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Publication History

Article published online:
12 May 2025