Deep Brain Stimulation of the Internal Globus Pallidus for Generalized Dystonia Associated with Spinocerebellar Ataxia Type 1: A Case Report

Abstract

Ataxia is a common movement disorder affecting primarily balance and coordination. The cerebellar circuitry is most commonly involved, but there can also be involvement of connected structures, including the thalamus, globus pallidus, and striatum ( 1. Schöls L Bauer P Schmidt T Schulte T Riess O. Autosomal dominant cerebellar ataxias: clinical features, genetics, and pathogenesis. Lancet Neurol. 2004; 3: 291-304 Abstract Full Text Full Text PDF PubMed Scopus (793) Google Scholar , 2. Rüb U Del Turco D Del Tredici K et al. Thalamic involvement in a spinocerebellar ataxia type 2 (SCA2) and a spinocerebellar ataxia type 3 (SCA3) patient, and its clinical relevance. Brain. 2003; 126: 2257-2272 Crossref PubMed Scopus (65) Google Scholar ). There is a subset of ataxic syndromes that are inherited in an autosomal dominant fashion. Spinocerebellar ataxia type 1 (SCA1) is an inherited form of ataxia associated with abnormal CAG repeats on the ataxin 1 gene on chromosome 6 ( 3. Zoghbi HY Orr HT. Spinocerebellar ataxias. in: Scriver CR Beaudt AL Valle D The Metabolic and Molecular Bases of Inherited Disease. 8th ed. McGraw-Hill, New York2001: 5741-5758 Google Scholar ). The highly variable clinical features of this disorder are well documented and may include dystonia, parkinsonism, cognitive dysfunction, and other movement disorders in addition to ataxia ( 1. Schöls L Bauer P Schmidt T Schulte T Riess O. Autosomal dominant cerebellar ataxias: clinical features, genetics, and pathogenesis. Lancet Neurol. 2004; 3: 291-304 Abstract Full Text Full Text PDF PubMed Scopus (793) Google Scholar , 4. Bu?rk K Globas C Bösch S et al. Cognitive deficits in spinocerebellar ataxia types 1, 2, and 3. J Neurol. 2003; 250: 207-211 Crossref PubMed Scopus (163) Google Scholar ). Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been established as a treatment for generalized dystonia. Recent imaging techniques, such as diffusion tensor imaging (DTI), provide an in vivo estimation of the anatomical tracts affected by DBS ( 5. Butson CR Cooper SE Henderson JM McIntyre CC. Patient-specific analysis of the volume of tissue activated during deep brain stimulation. Neuroimage. 2007; 34: 661-670 Crossref PubMed Scopus (350) Google Scholar ). We present a case of generalized dystonia in a patient with genetically confirmed SCA1 who responded well to bilateral deep brain stimulation of the GPi.