[Lambert-Eaton myasthenic syndrome].

Area of Science:

• Neurology
• Oncology
• Immunology

Background:

• Lambert-Eaton myasthenic syndrome (LEMS) diagnosis relies on clinical signs, neurophysiology, and antibody titers for early treatment and cancer screening.
• Published reports on LEMS patients in Latin America are limited.

Purpose of the Study:

• To characterize LEMS patients from a private center in Buenos Aires, Argentina.
• To compare these characteristics with previously published LEMS case series.

Main Methods:

• Retrospective review of 13 LEMS patients' medical records.
• Diagnosis confirmed by clinical findings, electromyography, and/or positive antibodies.
• Follow-up to rule out or confirm associated neoplasia.

Main Results:

• Four patients had tumor-associated LEMS (T-LEMS), with two diagnosed with small-cell lung carcinoma.
• Nine patients had non-tumor-associated LEMS (NT-LEMS); five had a DELTA-P score of 3 or 4.
• Nine patients presented with the classic LEMS triad; all showed compatible electromyography findings.
• Symptomatic improvement with pyridostigmine was observed in 70% of patients.

Conclusions:

• Clinical presentation and neurophysiological studies are adequate for LEMS diagnosis.
• The study could not replicate the link between DELTA-P score and small-cell lung carcinoma risk.
• Pyridostigmine is an effective symptomatic treatment for LEMS.