New research was presented at AAN 2021, the American Academy of Neurology Annual Meeting, from April 17-22. The features below highlight some of the MS-focused studies that emerged from the conference.

Multidisciplinary Team Meeting Influences MS Management
Management of patients with MS in the era of disease-modifying therapies (DMT) relies heavily on MRI. While decisions are influenced by the reporting prowess of neuroradiologists, imaging can be reported by general radiologists. Researchers developed a monthly neuroinflammatory multi-disciplinary team (MDT) meeting with neuro-radiology to obtain second opinions on complex cases. For a 1-month retrospective study, they assessed data on demographics, original scan authors, the nature and frequency of reporting revisions made, and subsequent changes in management and investigation strategies, as well as the frequency of scan report revisions and their impact on clinical management. Of analyzed cases, 61% had a confirmed diagnosis of MS, and 39% were under ongoing investigation. Of total cases, 71% were originally reported by a general radiologist and 29% by a neuroradiologist. Following neuroradiology review at the MDT meeting, 42% had the original report amended; of these, 77% were originally authored by a non-neuroradiologist. Of scan reports authored by a general radiologist, 46% were amended following this specialist review. The most frequently occurring revision was identification of additional, originally unreported brain lesions. Of the report revisions, 46.2% resulted in a change in clinical management, such as DMT commencement or escalation.

Disability Accrual in Primary Vs Secondary Progressive MS
With previous cohort studies that compared primary progressive MS (PPMS) and secondary progressive MS (SPMS) providing unclear, and sometimes conflicting, results, investigators conducted a study to compare disability accrual in PPMS and SPMS in the international MSBase cohort, using multivariable survival models and applying objective diagnostic criteria for SPMS. Among approximately 2,600 patients each with PPMS or SPMS, disability accrual was defined by sustained Expanded Disability Status Scale (EDSS) score increase, adjusted for baseline disability, with hazard ratios (HRs) for disability accrual adjusted for sex, time-varying age, baseline disability, EDSS score frequency, and disease-modifying or immunosuppressant therapy. Estimates of age at progressive-phase onset and EDSS score of 7 or greater (wheelchair requirement) were obtained via Kaplan-Meier analysis. While median age at progressive-phase onset was older in patients with SPMS than in those with PPMS (46.7 vs 41.9), and hazard of disability accrual was decreased in SPMS versus PPMS (HR, 0.85) and increased in males (HR, 1.18), patients in both groups reached wheelchair requirement at similar ages.

Homogenous & Clinically Meaningful MS Phenotypes Identified
Although evidence shows that cognitive impairment is a common and disabling feature of MS, a precise characterization of cognitive phenotypes in patients with MS is lacking. Seeking to go beyond the traditional preserved/impaired classification dichotomy and set the stage for future research and tailored management approaches, investigators used a data-drive approach to define homogenous cognitive phenotypes among a large cohort of patients with MS and assess their distinctive clinical and MRI features. They identified five cognitive phenotypes among participants: “preserved-cognition” (19%), “mild verbal memory/semantic fluency” (30%), “mild-multi-domain” (19%), “severe-attention/ executive” (14%), and “severe-multi-domain” (18%) involvement. Patients with reserved cognition and mild-verbal memory/semantic fluency were younger and had shorter disease duration compared with patients with the other phenotypes. Physical disability was lowest in patients with preserved cognition and highest in those with severe-multi-domain involvement. Severe cognitive phenotypes prevailed in progressive patients. At MRI evaluation, when compared with patients with preserved-cognition, those with mild verbal memory/semantic fluency exhibited reduced hippocampal volume, mildmulti-domain reduced cortical gray matter volume, severe-attention/executive higher T2- hyperintense lesion volume, and severe-multidomain extensive brain damage.

Cognitive Tasks Negatively Affect Dual Task Performance
Prior research indicates that patients with MS may have difficulty performing dual tasks (DT) while walking, causing interference. With data lacking on the role of disability degree in the severity of the interference produced during DT, researchers compared DT performance between patients with MS and healthy controls (HCs), while also analyzing DT performance according to degree of disability. DT completed by participants, all of whom had similar ages and education, included cognitive–motor and motor–motor tasks. Patients with MS performed worse on cognitive– motor DT but not on motor–motor DT. Patients with MS and Expanded Disability Status Scale scores greater than 2 performed worse than HCs in both DT types. “Studying patient’s performance in DT allows an ecological approach to their symptoms in order to directly intervene in daily life alterations,” write the study authors.

Early MRI Helps Predict LongTerm Prognosis in Pediatric Patients With MS
Evidence suggests that the main clinical and MRI features that influence therapeutic choices among adults with MS are not as clear for pediatric patients with MS. To assess early predictors or longterm, clinically relevant outcomes among pediatric patients with MS, researchers performed clinical and MRI assessments among those in this population at disease onset and at 1, 2, and 3 years, with long-term outcomes evaluated at a 9-year clinical follow-up. Shorter time to first relapse was predicted by optic nerve lesions (hazard ratio, 1.9). Baseline predictors of annualized relapse were presence of cerebellar and cervical cord lesions. These variables, along with time to first relapse and number of relapses, predicted annualized relapse over the short term. Worsening disability at 9-year follow-up was predicted by optic nerve lesions at baseline, Expanded Disability Status Scale (EDSS) changes at 1 and 2 years, and detection of two or more new T2-lesions in 2 years at 2 and 3 years. Higher EDSS score at 9 years was predicted by baseline EDSS score, presence of brainstem lesions at baseline, number of cervical cord lesions at baseline, and EDSS changes at years 1-3, together with detection of two or more T2-lesions at years 1 and 2.