Episodic Ataxias: Faux or Real?

Abstract

The term Episodic Ataxias (EA) was originally used for a few autosomal dominant diseases, characterized by attacks of cerebellar dysfunction of variable duration and frequency, often accompanied by other ictal and interictal signs. The original group subsequently grew to include other very rare EAs, frequently reported in single families, for some of which no responsible gene was found. The clinical spectrum of these diseases has been enormously amplified over time. In addition, episodes of ataxia have been described as phenotypic variants in the context of several different disorders. The whole group is somewhat confused, since a strong evidence linking the mutation to a given phenotype has not always been established. In this review we will collect and examine all instances of ataxia episodes reported so far, emphasizing those for which the pathophysiology and the clinical spectrum is best defined.

Neuroimaging in cerebellar ataxia in childhood: A review

“…Episodic ataxias (EA) are a genetically and clinically heterogeneous group with autosomal dominant inheritance 170,171 . They are characterized by transient recurrent CA of variable duration and frequency and mostly associated with additional ictal and interictal symptoms 170,171 . Episodes are often triggered by physical exertion or emotional stress 170,171 .…”

“…170,171 They are characterized by transient recurrent CA of variable duration and frequency and mostly associated with additional ictal and interictal symptoms. 170,171 Episodes are often triggered by physical exertion or emotional stress. 170,171 Eight subtypes have been described, with EA1 (OMIM #160120) and EA2 (OMIM #108500) being most frequent and most relevant in the pediatric population.…”

“…170,171 Episodes are often triggered by physical exertion or emotional stress. 170,171 Eight subtypes have been described, with EA1 (OMIM #160120) and EA2 (OMIM #108500) being most frequent and most relevant in the pediatric population. 8,170,171 Mutated genes cause altered function in the voltage-gated potassium and calcium channel, respectively.…”

“…170,171 Eight subtypes have been described, with EA1 (OMIM #160120) and EA2 (OMIM #108500) being most frequent and most relevant in the pediatric population. 8,170,171 Mutated genes cause altered function in the voltage-gated potassium and calcium channel, respectively. 170,171 Both channelopathies have an early onset in infancy/childhood and feature attacks of vertigo, dizziness, and ataxia.…”

Genes of the Glutamatergic System and Tardive Dyskinesia in Patients with Schizophrenia

“…The SLC1A3 encodes for EAAT1 and is localized in chromosome 5p13.2. Mutations of this gene are thought to be responsible for the development of certain forms of episodic ataxias [ 41 , 42 ]. Three subtypes of the vesicular glutamate transporter exist of approximately 600 amino acid residues in size (VGLUTs 1, 2, and 3) [ 38 ].…”