title: Lewis-sumner syndrome of pure upper-limb onset: diagnostic, prognostic, and therapeutic features.
abstract: Lewis-Sumner syndrome (L-SS) represents the asymmetric variant of chronic inflammatory demyelinating polyneuropathy (CIDP). The characteristics and specificities of L-SS of pure upper-limb onset, as initially described by Lewis et al. [Multifocal demyelinating neuropathy with persistent conduction block. Neurology 32:958-964, 1982], have not been studied. We describe 8 such patients and review 82 previously reported cases. Distal involvement predominates and is mixed, sensory and motor from onset in only 50% of patients. Pain is a feature in about 20%. Subsequent lower-limb involvement occurs in <40% of cases. Electrophysiologically, upper-limb-onset L-SS is characterized by the presence of motor conduction blocks in arm nerves in about 90% of cases, and other demyelinating motor abnormalities are significantly less frequent. Cerebrospinal fluid (CSF) protein levels are raised in about 40% of cases and are moderate in most. Mildly raised anti-GM1 antibody titers are rare (<5%), but very high titers (> or =1:6400) have not been reported. Over 80% of treated patients respond, and intravenous immunoglobulins may be more effective than steroids. The prognosis is favorable in 40% of patients who eventually stabilize without treatment. We also reviewed 36 cases of other forms of L-SS, and present a further 2 cases. The upper-limb-onset variant is significantly less likely to spread to other limbs and may be less likely to have raised CSF protein levels. This could reflect a more localized disease process in upper-limb-onset L-SS. This variant may represent a separate entity, to be distinguished from other asymmetric forms of CIDP.
authors.affiliation: Neuromuscular Clinic, Department of Neurology, University Hospitals of Leicester, Leicester LE5 4PW, UK. yusuf.rajabally@uhl-tr.nhs.uk
authors.forename: Yusuf A
authors.initials: YA
authors.lastname: Rajabally
authors.forename: Govindsinh
authors.initials: G
authors.lastname: Chavada
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood; D005260:Female; D005696:Galactosidases / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D010146:Pain / Q000209:etiology; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D034941:Upper Extremity / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D000906:Antibodies; D005696:Galactosidases