2025 American Academy of Neurology Abstract Website

Objective:

Although most patients with multifocal motor neuropathy (MMN) respond to intravenous immunoglobulin, many experience residual disability and are dependent on chronic immunotherapy. The frequency of patients achieving minimal manifestations (MM) and predictors of MM status are unknown. This study aims to determine (1) frequency of patients achieving MM, (2) frequency of drug-free remission, and (3) predictors of MM or drug-free remission.

Background:

Design/Methods:

We retrospectively analyzed 20 patients with MMN diagnosed per EFNS/PNS guidelines. Data on demographics, disease course, diagnostics, and treatment were collected. Outcomes (grip strength, MMN-RODS score, MRC 80 sum score, patient-reported disability) were recorded at peak disease and last follow-up. MM was defined as an MRC sum score ≥78/80 with no individual muscle <4, MMN-RODS score ≥46/50, and no patient-perceived activity limitations. Data was analyzed after stratifying patients into those with and without MM status.

Results:

Mean age at onset was 41.9 years, and 70% were male. Three patients (15%) achieved drug-free remission for at least 6 months. Five (25%) met our definition of MM. Patients with MM tended to have earlier onset (35.0 vs. 44.2 years), higher MMN-RODS scores (less disability) at peak severity (46 vs.35.4), and higher MRC scores in weakest muscle group at peak (3.75 vs. 1.31). Average disease duration (onset to last follow-up) in MM group was 198 months vs 214 months without MM. GM1 antibodies were positive in 40.0% of MM patients, vs 46.7% in those without MM. Drug-free remission was associated with absence of lower-extremity involvement at peak severity (p=0.013).

Conclusions:

Minimal manifestations are rare in MMN, but may be more common in patients with less disease-associated manifestations at peak severity, which can have important treatment implications. This ongoing study aims to include an additional 10 patients for the MM predictive analysis.