Eleonora Fiorenzato

Cognitive impairment in multiple system atrophy

The extent and the underlying anatomical signature of cognitive impairment (CI) in patients with multiple system atrophy (MSA) is still debated. We read with interest the study by Koga and colleagues, who reported CI in 32% of 102 autopsy-confirmed MSA patients. However, MSA-CI brains did not show significant cortical atrophy but, rather, neuronal cytoplasmic inclusions in the dentate gyrus although CI primarily affected processing speed and attention/executive functions, which are typically fronto-striatal. However, not all had structured cognitive evaluation cognitive testing (48%) that had been performed at variable intervals before death. The remaining subjects (52%) were assessed only by subjective indicators, which may have altered the proportion of patients with CI. We recently reported the results of MRI volumetric, clinical, and cognitive assessments in 72 probable MSA enrolled in 5 institutions as part of the Movement Disorder Society MSA study group. We used an MSA-specific MMSE screening cut-off score to define CI, which was associated with focal volume reduction in the left dorsolateral prefrontal cortex. Our interpretation was that CI in MSA is underlined by disruption of the striato-pallido-thalamo-cortical circuits and that cortical defects are secondary to subcortical alterations. Koga and colleagues reported CI predominantly in