Syndromes of the central nervous system46
Examples of central nervous system syndromes include encephalomyelitis, limbic encephalitis, and cancer-related retinopathy
—Lipka et al, 2020
The benefits of earlier diagnosis of Lambert-Eaton myasthenic syndrome (LEMS) include limiting disability along with the loss of muscle function, mobility, and quality of life for patients. But for more than half of patients afflicted with LEMS, the benefits of diagnosis are often even more significant.3,4
Approximately 60% of LEMS cases are caused by an underlying tumor, typically small cell lung cancer (SCLC).42 The reported median time between onset of LEMS and a subsequent cancer diagnosis is 6 months.9 Patients with SCLC-LEMS are more frequently found while still having limited disease.41 With regular screening, most SCLCs can be discovered within 1 year of a LEMS diagnosis.9,43
In this section, we’ll present clinical and practical information that will help you better understand the relationship between these two diseases and how you can use these insights to improve clinical outcomes for your patients.
Mazen Dimachkie, MD, is a leading consultant in the study of LEMS. As the Director of Neuromuscular Research at the University of Kansas Medical Center, he manages one of the busiest neuromuscular clinical trial units in North America.
NeuroseriesLive hosted a webinar featuring Dr. Dimachkie discussing LEMS: “Are My Muscles Aging? One Often-misdiagnosed Cause of Weakness and Fatigue.” Excerpts from this program appear throughout this website, and you can watch the full webinar here.*
*Sponsored by Catalyst Pharmaceuticals.
Paraneoplastic syndromes of the nervous system are a heterogeneous group of neurological disorders caused by the immune response to an underlying tumor—specifically, against the onconeural antigen expressed by both the tumor and the nervous system. These syndromes are not caused by cancer metastasis. LEMS is considered a classic example of this syndrome.44
In up to 80% of patients with paraneoplastic syndromes of the nervous system,
the neurological disorder develops before the tumor is detected44,45
Syndromes of the central nervous system46
Examples of central nervous system syndromes include encephalomyelitis, limbic encephalitis, and cancer-related retinopathy
Syndromes of the peripheral nervous system46
Examples of peripheral nervous system syndromes include Guillain-Barré syndrome and certain neuropathies
Syndromes of the neuromuscular junction and muscle46
LEMS and myasthenia gravis are the most common syndromes of the neuromuscular junction6,46
In a 155-publication review describing 227 cases of LEMS9:
*Carcinomas of the breast, maxillary glandule, laryngeal area, and gallbladder, along with rectal adenocarcinoma, malignant thymoma, ameloblastoma, other pulmonary malignancies, and lymph metastasis (unknown primary site).
In a Neurology 2020 observational study, “Long-term follow-up, qualify of life, and survival of patients with Lambert-Eaton myasthenic syndrome,” Lipka et al detail the findings of 150 patients with LEMS—54% related to small cell lung cancer (SCLC).41
Key insights from this study include41:
Patients with SCLC-LEMS had an improved tumor survival vs patients with SCLC alone41
Median survival is doubled in patients with SCLC-LEMS with extensive disease compared to patients with SCLC without LEMS, and overall 5-year survival is increased from 4.4% to 21%.41
—Lipka et al, 2020
LEMS Aware is designed to be a resource for physicians to find the latest clinical data, news, and information regarding the diagnosis and treatment of patients with LEMS. Sign up for email alerts so that we can let you know as new content—such as teaching aids, webinars, and other useful resources—becomes available.