In the Eaton Lambert syndrome, the amplitude of the muscle action potential evoked by stimulation of its nerve is markedly reduced, and with repetitive stimulation the action potential is augmented.
Parthenogenesis of Lambert Eaton
The first cases were all associated with oat-cell carcinoma of the lung, but cases have been found with other tumors, other diseases, and sometimes with no complicating disorder. Microelectrode studies indicate that the defect is due to impaired release of ace tylcholine at the nerve terminals. How the tumor effects this syndrome is not known.
Lambert Eaton,Clinical Manifestations.
The first evidence Of the Eaton-Lambert syndrome may be prolonged apnea after curarization for surgery. Formal testing with dtubocurarine also indicates that patients are unduly sensitive. Other patients may have symptoms of limb weakness, but cranial muscle weakness is never prominent. The response to cholinergic drugs is usually equiv- Ocal at best. Pain in the limbs may be prominent. Movements may be peculiarly slow. In tests of strength it may seem as though the patient gets stronger with continued effort, Myotatic reflexes are frequently depressed.
Diagnosis of Lambert Eaton
The signs listed above diverge sufficiently from myasthenia to avoid confusion; only limb weakness and curare sensitivity are similar. The remainder of the syndrome resembles polymyositis, and polyneuritis would also have to be considered. The diagnosis is made by electromyography.
Treatment of Lambert Eaton
Under a variety of experimental conditions, guanidine promotes the release of acvtyleholine. It was therefore a logical choice to treat this rare syndrome, and the drug is effective in daily doses of 35 mg per kilogram of body weight, given orally. This drug may suppress bone marrow, and appropriate precautions should be taken.