Total lesion volume and index lesion-related severity correlated with EDSS scores and cognitive performance, while volumetric cortical and subcortical gray matter correlated less strongly.
Long-term clinical-radiographic-cognitive outcomes in patients with pathologically confirmed central nervous system (CNS) demyelinating disease are comparable to those with typical multiple sclerosis (MS), according to results from a cohort study.
Senior author Claudia F. Lucchinetti, MD, staff neurologist, Mayo Clinic, and colleagues collected data on 75 patients with pathologically confirmed CNS demyelinating disease, consistent with MS who underwent clinical assessment, standardized 3T-MRI brain, and cognitive battery. At follow-up, median duration since biopsy was 11 years.
Clinical diagnosis at follow-up was MS in 76% (n = 57) of patients, clinically isolated syndrome in 23% (n = 17), and 1 patient who had radiologically isolated syndrome (RIS). Additionally, the median Expanded Disability Status Scale (EDSS) score at follow-up was 3 (interquartile range [IQR], 2-3.5; range, 0-8).
"Our study would suggest a relatively milder clinical outcome with regard to ambulation, EDSS and progression conversion in a cohort of predominantly tumefactive demyelinating disease compared to a community based cohort of patients with MS,” Lucchinetti et al wrote.
Two cohorts were used for comparison where applicable: a population-based Olmsted County MS prevalence cohort (n = 218), and an existing early relapsing-remitting MS (RRMS) cohort with detailed similar imaging protocol (n = 76). In the Olmsted County cohort, given the shorter disease duration at follow-up, EDSS was compared stratified by disease duration, with similar severity. Disability scores using this analysis were comparable from the biopsied cohort to the Olmsted County prevalence cohort (P <.001).
Biopsied lesion size was at least 2 cm in 62 of 75 patients at initial scan. The extent of the lesion at follow-up had a lesion severity-score distribution of mild in 31% (22 of 72), moderate in 26% (19 of 72), and severe in 43% (31 of 72). At follow-up, EDSS correlated with biopsy lesion severity score (r = 0.24; P <.001) and white matter (WM) lesion volume (r = 0.38; P <.001), but not lesion count.
Thalamus and caudate volumes correlated with EDSS (r = –0.40, P <.001; and r = –0.31, P <.01, respectively), but not with age. Additionally, precentral and postcentral cortical thickness correlated significantly with EDSS (r = –0.31 and r = –0.27, respectively; both P <.05), as did corpus callosum volume (r = –0.37; P <.01), and Patient Health Questionnaire (PHQ) score (r = –0.35; P <.01), but not with disease duration/age.
Psychometric scores including attention (r = –0.32; P <.01), working memory (r = –0.24; P <.05), executive function (r = –0.24; P <.05), episodic memory (r = –0.37; P <.01), delayed episodic memory (r = –0.40; P <.001), and composite cognitive impairment score (r = 0.35; P <.01) all correlated with EDSS after adjustment for sex, age, and disease duration.
Volumetric cortical and subcortical GM correlated less than lesion metrics to cognitive outcomes. These included working memory correlations to cortical, thalamus and putamen volumes, and episodic memory scores with pallidum volume.
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