Research: more on cortical pathology and its link to epilepsy

Epub ahead of printCalabrese et al. Cortical pathology in multiple sclerosis patients with epilepsy: a 3 year longitudinal study. J Neurol Neurosurg Psychiatry. 2011 Sep 2. 

Background: The cause of epilepsy in MS'ers has not yet been elucidated. The relevance of cortical pathology (cortical lesions and thickness) in MS'ers with and without epilepsy was evaluated in a longitudinal study.

Methods: 32 RRMS'ers with epilepsy and 60 matched RRMS'ers without epilepsy were included in a 3 year longitudinal study. 

Results

1. At baseline, cortical lesions were observed in 27/32 (84.4%) RRMS'ers with epilepsy and in 26/60 (43.3%) RRMS'ers without epilepsy (p<0.001). 

2. The RRMS'ers with epilepsy had a higher number (10.2±8.9 vs 4.5±2.4; p<0.001) and total volume (2.0±1.3 vs 0.7±0.8cm(3); p<0.001) of cortical lesions compared with the RRMS group without epilepsy. 

2. There was no significant difference in the white matter lesion volume between the two groups. 

3. Global cortical thickness was lower in RRMS'ers with epilepsy (2.12±0.19 vs 2.35±0.14mm; p<0.001), and this group also showed a decline in cognition (cognitive score 10.9±6.3 vs 6.2±3.5; p<0.001). 

4. After 3years the RRMS'ers with epilepsy had a higher accumulation of new cortical lesions (3.4±3.2 vs 1.2±1.1; p<0.001) and faster reduction  in the grey matter fraction of their brains (p=0.022), while the two groups did not differ in the number of new white matter lesions.

Discussion: RRMS'ers with epilepsy had a more severe and rapidly evolving cortical pathology (cortical lesions and gray matter atrophy) compared with RRMS'ers without epilepsy. The RRMS'ers with epilepsy were also characterised by more pronounced cognitive decline, higher EDSS and a higher prevalence of men.

"Another study highlighting the problem of gray matter pathology in MS and its progression over 3 years. The interesting aspect of this study is the correlation of gray matter pathology with epilepsy. This is to be expected as epilepsy arises in the gray matter on the surface of the brain. A confounder in this study may be the drugs we use to treat epilepsy; the are referred to as anti-convulsants  and are all associated with significant side effects that include poor cognition."

"This study suggests that gray matter pathology and white matter pathology are not necessarily associated with each other. This will need to be confirmed in other studies."

"This study would suggest that if you have a seizure as a result of your MS it is associated with a worse outcome."