[Paraneoplastic myasthenic syndrome].
We report a case of neuromuscular disease overlap between myasthenia gravis and Lambert-Eaton syndrome (LES). Clinical features were those of LES and occurred insidiously in this 68-year old man: proximal weakness predominant in the lower limbs, generalized areflexia, dryness of the mouth and partial right eye palsy. Investigations disclosed a small cell lung cancer. On the other hand, an electrophysiological study showed low amplitude of all motor evoked potentials, and significant decrement in the median nerve at repeated 3 Hz stimulation, but failed to disclose any increment of the motor evoked potential in abductor digiti minimi pedis muscle after both maximal voluntary contraction and repeated 20 Hz stimulation. In addition, the patient improved under anticholinesterase drugs, but failed to respond to guanidine. Titres for both anti-acetylcholine-receptor antibodies and calcium channel antibodies were negative. The relationship between our case and recently reported cases of co-existence of the Lambert-Eaton myasthenic syndrome and myasthenia gravis is discussed.
Léger
J M
JM
Service de Neurologie et Service d'Explorations Fonctionnelles Neurologie, Clinique Paul Castaigne, Hôpital de la Salpêtrière, Paris.
Bachoud-Lévi
A C
AC
Eymard
B
B
Théodore
C
C
Bouche
P
P
Pierrot-Deseilligny
C
C
D000368:Aged; D000549:Ambenonium Chloride / Q000627:therapeutic use; D001323:Autoantibodies / Q000032:analysis; D015220:Calcium Channels / Q000276:immunology; D002294:Carcinoma, Squamous Cell / Q000150:complications*; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000188:drug therapy / Q000209:etiology*; D008175:Lung Neoplasms / Q000150:complications*; D008297:Male; D009431:Neural Conduction; D010257:Paraneoplastic Syndromes; D011950:Receptors, Cholinergic / Q000276:immunology
D001323:Autoantibodies; D015220:Calcium Channels; D011950:Receptors, Cholinergic; D000549:Ambenonium Chloride
Syndrome myasthénique paranéoplasique.