Brain Advance Access originally published online on October 21, 2003
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brain, Vol. 127, No. 1, 175-181, 2004
© 2004 Guarantors of Brain
doi: 10.1093/brain/awh013
MRI-based volumetric differentiation of sporadic cerebellar ataxia
Departments of 1 Neurology, 2 Neuroradiology and 3 Medical Biometry, University of Tübingen and 4 Institute of Human Genetics, University of Lübeck, Germany
Correspondence to: K. Bürk, Department of Neurology, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076 Tübingen, Germany E-mail: buerk{at}uni-tuebingen.de
The term idiopathic cerebellar ataxia (IDCA) designates a variety of cerebellar syndromes that may present with a purely cerebellar syndrome (IDCA-C) or with additional extracerebellar features (IDCA-P). Multiple system atrophy is also a sporadic neurodegenerative disorder of unknown origin that may cause prominent cerebellar symptoms (MSA-C). The final neuropathological answer to the question whether IDCA-P and MSA-C represent different varieties of one disease or two distinct entities is still lacking. Three-dimensional MRI-based volumetry allows morphological investigations intra vitam. Volumetric analysis of cerebellum, brainstem and basal ganglia was therefore performed in 46 patients with sporadic cerebellar ataxia and 16 age-matched healthy controls. Patients with dementia were excluded from the study since cognitive impairment is an exclusion criterion for the diagnosis of MSA. Cerebellar patients were clinically divided into two groups: 33 patients with multiple system atrophy with prominent cerebellar symptoms (MSA-C) and 13 patients with extracerebellar features not corresponding to MSA-C (IDCA-P). There was evidence for substantial cerebellar atrophy in both cerebellar groups while additional brainstem atrophy was significantly more pronounced in MSA-C patients. Absolute caudate and putamen atrophy was found to be restricted to single MSA-C individuals while group comparisons of mean volumes did not yield significant differences from controls. Based on the volumetric data, diagnosis could be correctly predicted in 94% of control, 82% of MSA-C and 100% of IDCA-P individuals. The finding of specific imaging characteristics strengthens (i) the value of MRI volumetry in separating MSA-C from other types of sporadic cerebellar ataxia, and (ii) the hypothesis of two independent neurodegenerative disorders in MSA-C and IDCA-P.
Key Words: idiopathic cerebellar ataxia; multiple system atrophy; olivopontocerebellar atrophy; cerebellar atrophy
Abbreviations: ANOVA = analysis of variance; CCA = cortical cerebellar atrophy; IDCA = idiopathic cerebellar ataxia; IDCA-C = IDCA with a purely cerebellar syndrome; IDCA-P = IDCA with additional extracerebellar features; MRI = magnetic resonance imaging; MSA = multiple system atrophy; MSA-C = MSA of the cerebellar type; MSA-P = MSA of the striatonigral type; OPCA = olivopontocerebellar atrophy; SCA = spinocerebellar ataxia; TurboSE = turbo spin echo
Received January 22, 2003. Revised May 15, 2003. Second revision August 11, 2003. Accepted August 16, 2003 .