Early cortical disease in MS

Lucchinetti et al. Inflammatory cortical demyelination in early multiple sclerosis. N Engl J Med 2011;365:2188-97.

BACKGROUND: Cortical (the outside bit of the brain containing the nerve cell bodies) disease has emerged as a critical aspect of the pathogenesis of MS, being associated with disease progression and cognitive impairment. Most studies of cortical lesions have focused on autopsy findings in patients with long-standing, chronic, progressive MS, and the noninflammatory nature of these lesions has been emphasized. MRI studies indicate that cortical damage occurs early in the disease.

METHODS: The investigators evaluated the prevalence and character of demyelinating cortical lesions in MS'ers. Cortical tissues were obtained in passing during biopsy sampling of white-matter lesions. In most cases, biopsy was done with the use of stereotactic procedures to diagnose suspected tumors. MS'ers with sufficient cortex (138 of 563 patients screened) were evaluated for cortical demyelination.

RESULTS: Cortical demyelination was present in 53 patients (38%) (104 lesions and 222 tissue blocks) and was absent in 85 patients (121 tissue blocks). Twenty-five patients with cortical demyelination had definite multiple sclerosis (81% of 31 patients who underwent long-term follow-up), as did 33 patients without cortical demyelination (72% of 46 patients who underwent long-term follow-up). In representative tissues, 58 of 71 lesions (82%) showed T-cell infiltrates, and 32 of 78 lesions (41%) showed macrophage-associated demyelination. Meningeal inflammation was topographically associated with cortical demyelination in patients who had sufficient meningeal tissue for study.



Cortical lesions on MRI in MS

CONCLUSIONS: In this cohort of patients with early-stage MS, cortical demyelinating lesions were frequent, inflammatory, and strongly associated with meningeal inflammation.#

"This study supports MRI findings and what we know about cognitive impairment in early MS. 30-50% of subjects with CIS (first demyelinating event) have significant cognitive impairment. I am not sure that this study provides any new insights, except cortical lesions are not associated with Dawson's fingers; their morphology is very different to white matter lesions. Understanding gray matter cortical lesions is clearly very important and area of active research. "

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However, this is not really a paradign shift as claimed on the radio, but is providing evidence that is supportive of things that we thought we knew already.

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