BACKGROUND Cortical disease has emerged as a critical aspect of the pathogenesis of multiple sclerosis, 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 multiple sclerosis, and the noninflammatory nature of these lesions has been emphasized. Magnetic resonance imaging studies indicate that cortical damage occurs early in the disease. METHODS We evaluated the prevalence and character of demyelinating cortical lesions in patients with multiple sclerosis. 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. Patients with sufficient cortex (138 of 563 patients screened) were evaluated for cortical demyelination. Using immunohistochemistry, we characterized cortical lesions with respect to demyelinating activity, inflammatory infiltrates, the presence of meningeal inflammation, and a topographic association between cortical demyelination and meningeal inflammation. Diagnoses were ascertained in a subgroup of 77 patients (56%) at the last follow-up visit (at a median of 3.5 years). 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 CD3+ 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. CONCLUSIONS In this cohort of patients with early-stage multiple sclerosis, cortical demyelinating lesions were frequent, inflammatory, and strongly associated with meningeal inflammation. (Funded by the National Multiple Sclerosis Society and the National Institutes of Health.)

Objective: To describe a patient presenting with a clinically silent, incidentally found, and pathologically confirmed active demyelinating solitary cortical lesion showing MRI gadolinium contrast enhancement, in whom biopsy was performed before the radiographic appearance of disseminated white matter lesions.Methods: Neurologic examination, MRI, CSF and serologic analyses, and brain biopsy were performed. Sections of formalin-fixed paraffin-embedded biopsied brain tissue were stained with histologic and immunohistochemical stains.Results: Biopsy revealed an inflammatory subpial lesion containing lymphocytes and myelin-laden macrophages. Recurrent relapses with dissemination of MRI-typical white matter lesions characterized the subsequent course. Conclusions:Our findings highlight that cortical demyelination occurs on a background of inflammation and suggest that the noninflammatory character of chronic cortical demyelination may relate to long intervals between lesion formation and autopsy. This case provides pathologic evidence of relapsing-remitting MS presenting with inflammatory cortical demyelination and emphasizes the importance of considering demyelinating disease in the differential diagnosis of patients presenting with a solitary cortical enhancing lesion. Neurology Traditionally, multiple sclerosis (MS) has been considered a disease primarily affecting the CNS white matter. Nevertheless, gray matter involvement has been recognized for a long time.1 Recent pathologic studies have revealed that cortical demyelination is more extensive than previously appreciated, 2,3 is characteristic of progressive MS, 4 and is devoid of lymphocytes and macrophages.3 However, these studies have relied on postmortem tissue analysis from patients with longstanding disease. Therefore, the pathology of early cortical demyelinating MS lesions is virtually unknown. Interestingly, pathologic findings in a focal cortical experimental autoimmune encephalomyelitis (EAE) animal model have challenged the concept that cortical lesions are noninflammatory. 5Recent histopathologic studies have shown that cortical demyelination may occur spatially removed from white matter pathology, without obvious anatomic relationships.6 Therefore, it is plausible that cortical demyelination could represent the earliest pathologic event in some patients with MS and, indeed, MRI evidence of MS cortical onset has been previously reported. 7 We describe a patient presenting with a clinically silent, incidentally found, and pathologically confirmed active demyelinating cortical lesion showing MRI gadolinium contrast enhancement, in whom biopsy was performed before the radiographic appearance of disseminated white matter lesions. The patient subsequently fulfilled diagnostic criteria for

Objective Axonal damage occurs early in multiple sclerosis (MS) and contributes to the degree of clinical disability. Children with MS more often show disabling and polyfocal neurological symptoms at disease onset than adults with MS. Thus, axonal damage may differ between pediatric and adult MS patients. Methods We analyzed axonal pathology in archival brain biopsy and autopsy samples from 19 children with early MS. Lesions were classified according to demyelinating activity and presence of remyelination. Axonal density and extent of acute axonal damage were assessed using Bielschowsky silver impregnation and immunohistochemistry for amyloid precursor protein (APP), respectively. Axonal injury was correlated with the inflammatory infiltrate as well as clinical characteristics. Results were compared with data from adult MS patients. Results Acute axonal damage was most extensive in early active demyelinating (EA) lesions of pediatric patients and correlated positively with the Expanded Disability Status Scale at attack leading to biopsy/autopsy. Comparison with 12 adult patients showed a 50% increase in the extent of acute axonal damage in EA lesions from children compared to adults, with the highest number of APP-positive spheroids found prior to puberty. The extent of acute axonal damage correlated positively with the number of lesional macrophages. Axonal density was reduced in pediatric lesions irrespective of the demyelinating activity or the presence of remyelination. Axonal reduction was similar between children and adults. Interpretation Our results provide evidence for more pronounced acute axonal damage in inflammatory demyelinating lesions from children compared to adults.

Background: In 2015, the first nationwide, multicenter Multiple Sclerosis (MS) registry was initiated in the Kingdom of Saudi Arabia (KSA) mainly with an objective to describe current epidemiology, disease patterns, and clinical characteristics of MS in Saudi Arabia. This article aimed to report initial findings of the registry and regional prevalence of MS. Method: In 2015, a national MS registry was launched in KSA to register all MS patient with confirmed diagnosis according to the 2010 McDonald Criteria. The registry aimed to identify and recruit all healthcare facilities treating MS patients in the Kingdom, and collect data such as demographics, clinical characteristics (disease onset, diagnosis, presentation of symptoms at onset, disease course, relapse rate, and disability measures), family history, and treatments. All the included sites have obtained IRB/EC approvals for participating in the registry. Currently, the registry includes 20 hospitals from different regions across the Kingdom. The Projected prevalence was calculated based on the assumption that the number of diagnosed MS cases in participating hospitals (in each region) is similar to the number of cases in remaining nonparticipant hospitals in the same region. Results: As of September 2018, the registry has included 20 hospitals from the different regions across the Kingdom and has collected comprehensive data on 2516 patients from those hospitals, with median age 32 (Range: 11-63) and 66.5% being females. The reported prevalence of MS for those hospitals was estimated to be 7.70/100,000 population and 11.80/100,000 Saudi nationals. Based on the assumption made earlier, we projected the prevalence for each region and for the country as a whole. The overall prevalence of MS at the country level was reported to be 40.40/100,000 total population and 61.95/100,000 Saudi nationals. Around 3 out of every 4 patients (77.5%) were 40 years of age or younger. Female to male ratio was 2:1. The prevalence was higher among females, young and educated individuals across all five regions of Saudi Arabia. Conclusion: The prevalence of MS has significantly increased in Saudi Arabia but is still much lower than that in the western and other neighboring countries like Kuwait, Qatar, and the UAE. However, compared to the past rates, Saudi Arabia's projected prevalence of MS through this national study is 40.40/100,000 population, putting the Kingdom above the low risk zone as per Kurtzke classification. The projected prevalence was estimated to be much higher among Saudi nationals (61.95/100,000 Saudi-nationals). The prevalence was higher among female, younger and educated individuals. Further studies are needed to assess the risk factors associated with increased prevalence in Saudi Arabia.

In this consensus statement, we provide updated recommendations on multiple sclerosis (MS) management during the COVID-19 crisis and the post-pandemic period applicable to neurology services around the world. Statements/recommendations were generated based on available literature and the experience of 13 MS expert panelists using a modified Delphi approach online. The statements/recommendations give advice regarding implementation of telemedicine; use of disease-modifying therapies and management of MS relapses during the pandemic; management of people with MS at highest risk from COVID-19; management of radiological monitoring; use of remote pharmacovigilance; impact on MS research; implications for lowest income settings, and other key issues.