Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer

Citation
P. Maddison et al., Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer, J NE NE PSY, 70(2), 2001, pp. 212-217
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurology,"Neurosciences & Behavoir
Journal title
JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY
ISSN journal
0022-3050 → ACNP
Volume
70
Issue
2
Year of publication
2001
Pages
212 - 217
Database
ISI
SICI code
0022-3050(200102)70:2<212:LTOILM>2.0.ZU;2-F
Abstract
Objectives-To determine the prognosis in patients with Lambert-Eaton myasth enic syndrome (LEMS) without small cell lung cancer (SCLC), and to analyse longitudinal clinical, electrophysiological, and immunological data on each patient to establish prognostic factors for long term outcome. Methods-The retrospective and part prospective study of 47 patients with LE MS was undertaken from data recorded during visits to a specialist neuromus cular clinic. Serial measurements of muscle strength score in shoulder abdu ction, elbow extension and hip flexion, compound muscle action potential (C MAP) amplitude, and postcontraction increment in abductor digiti minimi (AD M), and anti-P/Q-type voltage gated calcium channel (VGCC) antibody titre w ere made at each visit. Results-Muscle strength scores were improved in 88% of patients after a med ian duration of immunosuppressive treatment of 6 years (range 1.3 to 17 yea rs); anti-VGCC antibody titres fell in 52% after treatment; and mean restin g CMAP amplitude improved from 2.7 mV initially to 8.8 mV after 2 years of treatment p<0.001). Initial pretreatment anti-VGCC antibody titre did not c orrelate significantly with either CMAP amplitude, CMAP increment, or clini cal score: from serial measurements made during follow up, significant corr elation between antibody titre and CMAP amplitude was seen in only two pati ents. Sustained clinical remission was achieved by 20 (43%) of whom only fo ur remained in remission without the need for immunosuppression. Using a Co x proportional hazards model, the only independent predictor of sustained c linical remission was initial pretreatment clinical score (p=0.03). Lymphom a presented in three patients during the study. Conclusions-The prognosis in patients with LEMS without SCLC is favourable, although patients often need significant doses of immunosuppressive treatm ent to remain clinically stable. Only initial clinical muscle strength meas urements and not anti-VGCC antibody titres or electrophysiological recordin gs are predictive of long term outcome.