Asymmetric brachial plexus MRI and electrophysiological abnormalities in Lewis-Sumner syndrome

Authors

Salma Tabati, Leila Tamaoui, Nazha Birouk, Nada Adjou, Hamza Retal, Meriem Fikri, Firdaous Touarsa

Journal Information

Journal: Medpeer Publisher

ISSN: 3066-2737

Volume: 3

Issue: 8

Date of Publication: 2026/08/06

DOI: 10.70780/medpeer.000QGUR

Abstract

Lewis-Sumner syndrome is an uncommon asymmetric inflammatory demyelinating neuropathy. A 20-year-old patient presented with multifocal upper-limb paraesthesias, finger-extensor weakness and generalised areflexia. Electrophysiology showed proximal motor conduction blocks despite normal distal sensory studies. MRI demonstrated bilateral asymmetric C5-T1 root and brachial plexus enlargement, STIR hyperintensity and enhancement, with intercostal nerve involvement. Intravenous immunoglobulin was initiated. Contribution: MRI supported the diagnosis and revealed clinically occult disease extension.

Keywords

Lewis-Sumner syndrome; multifocal CIDP; brachial plexus; magnetic resonance neurography; nerve root hypertrophy; conduction block; STIR-SPACE; multifocal motor neuropathy