Spinal cord atrophy in spinocerebellar ataxia type 3 and 6: Impact on clinical disability

• Published in: Journal of neurology 2008-08, Vol.255 (8), p.1244-1249
• Main Authors: Lukas, C., Hahn, H. K., Bellenberg, B., Hellwig, K., Globas, C., Schimrigk, S. K., Köster, O., Schöls, L.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Ataxia; Atrophy - etiology; Biological and medical sciences; Case-Control Studies; Disability Evaluation; Female; Humans; Image Processing, Computer-Assisted; Injuries of the nervous system and the skull. Diseases due to physical agents; Machado-Joseph Disease - complications; Magnetic Resonance Imaging - methods; Male; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; Neurology; Neuroradiology; Neurosciences; Original Communication; Regression Analysis; Reproducibility of Results; Severity of Illness Index; Spinal cord; Spinal Cord - pathology; Spinocerebellar Ataxias - complications; Statistics, Nonparametric; Traumas. Diseases due to physical agents
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-008-0907-6

Objective To quantify spinal cord atrophy and its impact on clinical disability in spinocerebellar ataxia (SCA) type 3 and 6. Methods Atrophy of the upper spinal cord was assessed by high resolution T1-weighted MRI of patients with SCA3 (n = 14) and SCA6 (n = 10). Furthermore, two groups of age- and sex-matched healthy control subjects (n = 24,) corresponding to the two SCA groups, were studied. Images were post-processed by a semi-automated volumetry method combining a marker based segmentation and an automatic histogram method facilitating highly reliable quantification and morphometry of the upper cervical cord in vivo. Results We found a significant reduction of normalized mean crosssectional area of the spinal cord in SCA3 (p < 0.0005), whereas in SCA6 patients normalized mean crosssectional area was in the normal range (p = 0.379). No correlation was found between spinal cord atrophy and disease duration as well as CAG repeat length in both subtypes. In SCA6 a negative dependency between clinical disability, as expressed by the International Cooperative Ataxia Rating Scale as a well established ataxia score, and the mean cross-sectional area was found (p = 0.02). A similar correlation was observed in SCA3 but did not reach statistical significance. Conclusion Our results quantify for the first time in vivo spinal cord atrophy as a non-cerebellar neurodegenerative process in SCA3. Our results suggest MR volumetry of the upper cervical cord as a marker of functional importance in SCA3 and SCA6.