Selected highlights from the American Academy of Neurology annual meeting, Seattle WA, 2-7 April 2022.
CONGRESS HIGHLIGHTS – MONDAY EDITION
Over 500 articles have now reported on the effect of DMTs on COVID-19 vaccine response and a meta-analysis (N=1239 patients) is now available (Gombolay et al. AAN 2022;S5.007). Overall, antibody responses were detected in 100% of untreated MS patients and those receiving glatiramer acetate, dimethyl fumarate, teriflunomide, natalizumab or alemtuzumab; 99% in healthy controls or patients on beta-interferons; 93% on cladribine; 70% on S1PR agents; and 46% on anti-CD20 agents. Antibody response was higher with rituximab compared to ocrelizumab (62% vs. 39%).
While older age at MS onset has been associated with worse 10-year outcomes, a new study has found that younger age at onset is associated with worse outcomes at age 50 years (Bose et al. AAN 2022;P17.008). The study looked at outcomes at age 50 in 550 MS patients with >10 years’ disease duration. Mean age at MS onset was 30.8 years; 86.9% started treatment with a first-line injectable; and 38.5% switched to a high-efficacy DMT during the clinical course. The EDSS score was 0.42 points worse for every 5-year increment that symptoms developed earlier. Earlier onset was associated with a higher risk of SPMS (OR 1.56), greater T2 lesion volume (1.16 cm3) and greater brain atrophy (brain parenchymal fraction 0.55% lower). It is unclear if outcomes would have been more favourable in this cohort if higher-efficacy therapies had been available earlier in the clinical course.
Serum neurofilament-light chain (sNfL) has been proposed as a biomarker of inflammatory disease activity. An Italian study reported that sNfL levels were elevated in 72% of patients with clinical activity and 75% of patients with new MRI lesions (Malucchi et al. AAN 2022;S19.001). In addition, 10% of NEDA patients had elevated sNfL, which may indicate an impending loss of NEDA.
A separate study found that elevated baseline sNfL was predictive of loss of NEDA or new MRI lesions but not of relapses (Lin et al. AAN 2022;S19.005). Adding OCT measures (ganglion cell and inner plexiform layer [GCIPL] thinning) improved the prognostic value: abnormal NfL + GCIPL thinning was predictive of loss of NEDA (HR 3.61), new MRI lesion (HR 3.19) and new relapse (HR 5.38).
A pilot study at St. Michael’s Hospital, Toronto, reported that plasma NfL levels were significantly higher in subjects with radiologically isolated syndrome (RIS) with a high lesion load (>20 lesions with the central vein sign or >50 white-matter lesions) compared to healthy controls (Schneider et al. AAN 2022). The authors suggested that NfL may be useful in identifying RIS subjects at higher risk of developing MS.
A Canadian study (CanProCo) obtained 3T brain MRIs in 14 RIS subjects (mean age 50 years) and compared them to 14 healthy controls (Glaister et al. AAN 2022;P15.010). RIS was associated with lower cerebellar hemispheric gray-matter volume; this was most apparent along the lateral edges of the cerebellar hemispheres. RIS was also associated with increased whole-brain atrophy and atrophy of the right frontal medial cortex. The authors noted that the cerebellum may be the site of early tissue loss in RIS.
A NARCOMS survey reported that 20% of MS patients are current cannabis users (N=3240 respondents) (Fox et al. AAN 2022;P10.003). The most common sources of medical guidance on cannabis use were “nobody/self” (47%) and people working at the dispensary (20%). Dispensaries (45%) or dealers/friends (31%) were the preferred sources for what was in the cannabis product. Patients generally did not ask for guidance on cannabis use from their MS physician (12%) or another physician (11%).