Lambert-Eaton Myasthenic Syndrome and Botulism

Abstract

PURPOSE OF REVIEW: This article reviews the pathophysiology, epidemiology, clinical features, diagnosis, and treatment of Lambert-Eaton myasthenic syndrome (LEMS) and botulism, presynaptic disorders of neuromuscular transmission in which rapid diagnosis improves long-term outcomes.RECENT FINDINGS: Therapy for LEMS has seen significant advances in recent years due to the approval of amifampridine-based compounds. LEMS is likely still underdiagnosed, particularly when no underlying malignancy is identified. Clinicians must have a strong suspicion for LEMS in any patient presenting with proximal weakness and autonomic dysfunction. Botulism is another rare disorder of presynaptic neuromuscular transmission that is most commonly associated with improper storage or preservation of food products. Over the past 2 decades, wound botulism has been increasingly reported among users of black tar heroin. A high degree of clinical suspicion and electrodiagnostic studies can be beneficial in distinguishing botulism from other acute neurologic disorders, and early involvement of state and federal health authorities may assist in confirming the diagnosis and obtaining treatment. When botulism is suspected, electrodiagnostic studies can provide clinical evidence of disordered neuromuscular transmission in advance of serologic confirmation, and providers should not wait for confirmation of the diagnosis to initiate treatment. SUMMARY: A targeted clinical history and a thorough neurologic examination with support from serologic and electrodiagnostic studies are key to early diagnosis of LEMS and botulism. Early diagnosis of both conditions creates opportunities for therapy and improves outcomes.

Electrophysiological evaluation of the neuromuscular junction: a brief review

“…Botulism is a disorder of NT characterized by afebrile, symmetric descending weakness, respiratory failure, and autonomic dysfunction. 64 Botulism is caused by a BoNT from Clostridium Botulinum , which prevents the presynaptic release of ACh from both somatic and autonomic synapses, blocking the molecular chain for it to happen. The BoNT-contaminated food intake is one of the causes.…”

Tata Laksana Lambert Eaton Myasthenic Syndrome

“…Pada LEMS, antibodi menghalangi VGCCs tipe P/Q di presinaps motor neuron mencegah masuknya ion kalsium dan pelepasan ACh. 2,3 Penyebab LEMS secara garis besar dibagi dua, yaitu berkaitan dengan kanker dan yang tidak berkaitan dengan kanker. 1 Penyebab LEMS yang tidak berkaitan dengan kanker masih ditelusuri, beberapa bukti menunjukkan komorbiditas penyakit autoimun dapat meningkatkan risiko kejadian LEMS.…”

“…1 Penyebab LEMS yang tidak berkaitan dengan kanker masih ditelusuri, beberapa bukti menunjukkan komorbiditas penyakit autoimun dapat meningkatkan risiko kejadian LEMS. 3 Kanker yang paling banyak menyebabkan LEMS adalah SCLC. Kanker lain, seperti kanker prostat dan timoma, juga dapat menyebabkan LEMS.…”

“…1 Kelemahan otot, hilangnya refleks tendon, dan disfungsi otonom antara lain merupakan akibat penurunan jumlah ACh di sinaps. [2][3][4] EPIDEMIOLOGI LEMS biasanya ditemukan pada usia 50-70 tahun. LEMS berkaitan dengan kanker lebih sering pada laki-laki, sedangkan prevalensi LEMS yang tidak berkaitan dengan kanker sama antara laki laki dan perempuan.…”

“…LEMS berkaitan dengan kanker lebih sering pada laki-laki, sedangkan prevalensi LEMS yang tidak berkaitan dengan kanker sama antara laki laki dan perempuan. 3 Diagnosis LEMS sering terlambat, terutama pada kasus LEMS yang tidak berkaitan dengan kanker, rata-rata durasi penyakit sebelum diagnosis adalah 17 bulan, sedangkan yang berkaitan dengan kanker durasinya 3,5 bulan. 3 Sebanyak 15 kasus LEMS pediatrik telah dilaporkan, 3 kasus di antaranya berkaitan dengan SCLC.…”