Epub: Schoonheim et al. Subcortical atrophy and cognition: Sex effects in multiple sclerosis. Neurology. 2012 Sep 26.
OBJECTIVES: Gray matter (GM) atrophy is common in multiple sclerosis (MS), as is cognitive dysfunction. Understanding the exact relationship between atrophy and cognition requires further investigation. The aim of this study was to investigate the relationship between subcortical GM atrophy and cognition in early relapsing onset MS.
METHODS: Structural MRI and neuropsychological evaluations were performed in 120 patients (80 women) and 50 controls (30 women), part of an early inception cohort, 6 years postdiagnosis. Deep GM volumes were segmented automatically. Cognition was assessed in 7 domains. Stepwise linear regression was used to predict average cognition in the patient group.
RESULTS: Most deep GM volumes were reduced in patients, with larger effects on average in men (-11%) than in women (-6.3%). Only the bilateral hippocampus, amygdala, and right nucleus accumbens in men, and right hippocampus and nucleus accumbens, bilateral amygdala, and putamen in women, showed no atrophy compared to controls. All cognitive domains except visuospatial memory were affected in men; none were significantly affected in women. In the MS group, average cognition was best predicted by thalamic volume, sex, and education (adjusted R(2) = 0.31), while lesion volume was not a significant predictor in the model.
CONCLUSIONS: Six years postdiagnosis, almost all subcortical structures were affected by MS, especially in men. Cognition was most severely affected in male patients. Thalamic volume, sex, and education best predicted average cognition. These results underline the relevance of specific subcortical structures to cognition, as well as the relevance of (sex-specific) atrophy in MS.
The Grey Matter is dark blue
Cognitive impairment is a known consequence of multiple sclerosis (MS), affecting roughly 50% of all patients with MS. Information processing speed and memory are the most commonly affected domains, although deficits in executive function are also frequently reported. That cognitive impairment affects meaningful activities such as work is well known. The pathophysiologic basis for cognitive dysfunction in MS is an area of great interest because a better understanding could lead to more sensitive markers and improved therapies to slow or prevent cognitive decline. MRI offers some insight into the associations between various types of tissue damage and cognitive impairment. Early studies reported moderate correlations between cognitive performance and global measures of white matter lesion volume and atrophy,and more recent studies focusing on cortical lesions and regional gray matter atrophy have demonstrated stronger associations. This study looks at different brain areas and find that shrinkage some areas are more associated with cognitive decline especially in Men.