Multifocal Acquired Demyelinating Sensory and Motor Neuropathy: An Atypical Chronic Inflammatory Demyelinating Polyradiculoneuropathy Variant Responsive to Intravenous Immunoglobulin

Abstract

We report the case of a male patient in his mid-30s with a progressive, fluctuating sensorimotor neuropathy beginning in 2022. His symptoms were marked by asymmetric weakness, predominantly affecting the lower limbs, along with distal sensory disturbances, including numbness and paraesthesia. Functional impairment progressed over time, significantly affecting daily activities. Electrophysiological studies revealed a generalized, asymmetric, multifocal demyelinating neuropathy with conduction blocks at atypical, non-compressive sites. These findings were consistent with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). The patient showed no clinical response to corticosteroid therapy but achieved significant improvement following intravenous immunoglobulin (IVIG) treatment.