[Lambert-Eaton Myasthenic Syndrome associated with vocal cord carcinoma].
BACKGROUND
Lambert-Eaton Myasthenic Syndrome (LEMS) is an autoimmune channelopathy in which patients produce autoantibodies directed against voltage-gated calcium channels. LEMS is paraneoplastic in 50% of patients, most frequently associated with small cell lung carcinoma. We describe a case of paraneoplastic LEMS associated with a vocal cord carcinoma.


METHODS
A 64-year-old man developed in five months muscle weakness affecting gait. Clinical examination showed proximal muscular deficiency, areflexia and dysphonia. Electrophysiologic study showed potentiation greater than 500% after post exercise facilitation and 76 percent increment response at high-rate repetitive nerve stimulation (20Hz). Diagnosis of LEMS was confirmed by electrophysiologic study and anti-voltage gated calcium channel antibodies (90pM, positive value greater or equal to 70pM). Left vocal cord lesion histology showed epidermoid carcinoma. A combination of vocal cord tumor removal by endoscopy and treatment by pyridostigmine, 3-4 diaminopyridine and intravenous human immunoglobulin improved neurological symptoms.


CONCLUSIONS
Paraneoplastic syndromes in association with cancers of the larynx and hypopharynx are unusual. Only two cases are reported with LEMS associated with larynx carcinoma. We describe an unusual case of LEMS associated with a left vocal cord carcinoma.
Shipley
E
E
Service de neurologie, hôpital du Haut-Lévêque, CHU de Bordeaux, avenue de Magellan, 33604 Pessac, France.
Krim
E
E
Deminière
C
C
Lagueny
A
A
D015761:4-Aminopyridine / Q000031:analogs & derivatives / Q000627:therapeutic use; D000077770:Amifampridine; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D004594:Electrophysiology; D004724:Endoscopy; D015444:Exercise / Q000502:physiology; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000150:complications / Q000473:pathology*; D007822:Laryngeal Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000150:complications / Q000473:pathology; D009431:Neural Conduction; D026902:Potassium Channel Blockers / Q000627:therapeutic use; D011729:Pyridostigmine Bromide / Q000627:therapeutic use; D014459:Ulnar Nerve / Q000502:physiology; D014827:Vocal Cords / Q000473:pathology*; D014832:Voice Disorders / Q000150:complications / Q000473:pathology
D002800:Cholinesterase Inhibitors; D026902:Potassium Channel Blockers; D015761:4-Aminopyridine; D011729:Pyridostigmine Bromide; D000077770:Amifampridine