Intellectual Disability in Episodic Ataxia Type 2: Beyond Paroxysmal Vertigo and Ataxia

Area of Science:

• Neurogenetics
• Neurology
• Cognitive Science

Background:

• Episodic ataxia type 2 (EA2) is a neurological disorder caused by mutations in the CACNA1A gene.
• It is characterized by recurrent episodes of vertigo and ataxia.

Purpose of the Study:

• To evaluate the intellectual function in patients diagnosed with EA2.
• To identify potential cognitive impairments associated with EA2.

Main Methods:

• 13 patients with genetically confirmed EA2 were assessed using Korean versions of the Wechsler Intelligence Scales.
• Data were collected between 2019 and 2023 in South Korea.

Main Results:

• 11 out of 13 patients scored below average intelligence.
• Intellectual disability was present in 38.5% of patients, with impairments across verbal comprehension, perceptual reasoning, working memory, and processing speed.
• No correlation was found between full-scale IQ and age of onset for vertigo and ataxia.

Conclusions:

• EA2 patients may have undiagnosed intellectual disabilities, even without epilepsy or antiepileptic drug use.
• Genetic counseling and therapeutic interventions are recommended for EA2 patients.
• Early diagnosis and management are vital to prevent irreversible brain dysfunction.