BACKGROUND: Lambert-Eaton myasthenic syndrome (LEMS) is a presynaptic neuromuscular junction disorder that is most frequently associated with small-cell lung cancer (SCLC). The titers of antibodies against voltage-gated calcium channels are frequently increased in LEMS, but only rarely is titer of anti-acetylcholine-receptor-binding antibodies (AChR-abs) increased. CASE REPORT: A 57-year-old male was admitted to our hospital due to dry mouth and eyes and progressive proximal limb weakness of 2 months duration. The results of a repetitive nerve stimulation test disclosed all criteria for the electrophysiological LEMS pattern, and the patient's AChR-abs titer was 0.587 nmol/L. At a follow-up performed 5 years after successful treatment of SCLC and LEMS, his AChR-abs titer had decreased to 0.001 nmol/L. CONCLUSIONS: We suggest that this was a case of transient pseudopositivity of AChR-abs in SCLC with LEMS.
Antibodies ; Calcium Channels ; Extremities ; Eye ; Follow-Up Studies ; Humans ; Lambert-Eaton Myasthenic Syndrome ; Lung ; Lung Neoplasms ; Male ; Mouth ; Myasthenia Gravis ; Neuromuscular Junction Diseases

BACKGROUND: The coexistence of myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) is very rare and remains controversial. CASE REPORT: A 48-year-old woman initially presented with noticeable right ptosis and intermittent diplopia. She then developed fluctuating proximal limb weakness and difficulty in swallowing. The serum titer of anti-acetylcholine-receptor antibody was elevated and the edrophonium (Tensilon) test was positive. However, repetitive nerve stimulation revealed abnormalities typical of LEMS. The patient exhibited a good response to treatment with anticholinesterase inhibitors and steroids, and long-term evaluation disclosed that she presented with the clinical, electrophysiological, and immunological characteristics of both diseases. CONCLUSIONS: The reported clinical and electrophysiological features suggest that this patient was a very rare case of combined MG and LEMS.
Deglutition ; Diplopia ; Edrophonium ; Extremities ; Female ; Humans ; Lambert-Eaton Myasthenic Syndrome ; Middle Aged ; Myasthenia Gravis ; Steroids

BACKGROUND: Lambert-Eaton myasthenic syndrome is well known to be a classical paraneoplastic syndrome of small cell lung carcinoma (SCLC). Three cases of seronegative myasthenia gravis (MG) and SCLC were previously reported. CASE REPORT: A 65-year-old man developed a severe progressive respiratory failure with clinical features of MG. Tests showed a decremental response in the repetitive nerve stimulation test, abnormal single-fiber electromyography, and positive acetylcholine receptor antibody. SCLC was confirmed by the lung biopsy. CONCLUSIONS: This case represents the first case of seropositive MG and SCLC.
Acetylcholine ; Aged ; Electromyography ; Humans ; Lambert-Eaton Myasthenic Syndrome ; Lung ; Myasthenia Gravis ; Paraneoplastic Syndromes ; Respiratory Insufficiency ; Small Cell Lung Carcinoma

Lambert-Eaton myasthenic syndrome (LEMS) is characterized clinically by fluctuating muscular weakness; presentation with ocular symptoms is unusual. A 60-year-old man had developed diplopia and ptosis 2 years previously. The findings of a neurologic examination were normal except for bilateral ptosis and ophthalmoplegia. The amplitude of compound muscle action potentials recorded on the abductor digiti minimi increased (by more than 500%) during 50-Hz stimulation. This case demonstrates that LEMS should be included in the differential diagnosis of myasthenic symptom confined to the ocular muscles.
Action Potentials ; Diagnosis, Differential ; Diplopia ; Humans ; Lambert-Eaton Myasthenic Syndrome ; Middle Aged ; Muscles ; Neurologic Examination ; Ophthalmoplegia

There are many causes of prolonged postoperative muscle weakness, including drugs, residual anesthetics, cerebrovascular events, electrolyte imbalance, hypothermia, and neuromuscular disease. Neuromuscular diseases are relatively rare, with the most common being myasthenia gravis and Lambert-Eaton myasthenic syndrome (LEMS). We report an unusual case in which a patient who was given a muscle relaxant during mediastinoscopy developed postoperative muscle weakness that was ultimately diagnosed as secondary to LEMS.
Anesthetics ; Humans ; Hypothermia ; Lambert-Eaton Myasthenic Syndrome ; Mediastinoscopy ; Muscle Weakness ; Muscles ; Myasthenia Gravis ; Neuromuscular Diseases

No abstract available.
Immunization, Passive ; Immunoglobulins ; Lambert-Eaton Myasthenic Syndrome

No abstract available.
Drug Therapy* ; Lambert-Eaton Myasthenic Syndrome* ; Small Cell Lung Carcinoma*

Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune neurological syndrome, is caused by defects in the secretion of acetylcholine from the presynaptic membrane, and is associated with the destruction of voltage gated calcium channels (VGCC) in the neuromuscular junction. LEMS can be confirmed by repetitive nerve stimulation and by the clinical symptoms, which are characterized by proximal muscle weakness in the lower extremities, decreased deep tendon reflexes and autonomic dysfunctions. In about 60% of patients with this disorder, underlying cancer-small cell lung cancer may be detected. Clinical symptoms may precede the diagnosis of malignancy, with the early diagnosis and treatment of the underlying malignancy being possible through the diagnosis of LEMS. A case of LEMS, with positive VGCC antibodies, in a 48-year-old man, which improved after chemotherapy of the underlying small cell lung cancer, is reported.
Acetylcholine ; Antibodies* ; Calcium Channels ; Diagnosis ; Drug Therapy ; Early Diagnosis ; Humans ; Lambert-Eaton Myasthenic Syndrome* ; Lower Extremity ; Lung Neoplasms ; Membranes ; Middle Aged ; Muscle Weakness ; Neuromuscular Junction ; Reflex, Stretch ; Small Cell Lung Carcinoma*

The Lambert-Eaton myasthenic syndrome (LEMS) is typically recognized as a paraneoplastic syndrome associated with a small cell lung carcinoma (SCLC), whereas LEMS with other neuroendocrine lung tumors, including carcinoids or large cell lung carcinoma, are highly unusual. Here, we report a rare case of LEMS with atypical bronchopulmonary carcinoid tumor: A 65-yr-old man presented with progressive leg weakness and a diagnosis of LEMS was made by serial repetitive nerve stimulation test. Chest CT revealed a lung nodule with enlargement of paratracheal lymph nodes, and surgically resected lesion showed pathological features of atypical carcinoid tumor. We concluded that LEMS could be associated with rare pulmonary neuroendocrine tumor other than SCLC, which necessitates pathologic confirmation followed by aggressive treatment for optimal management in these rare cases.
Aged ; Carcinoid Tumor/*complications/pathology/surgery ; Electromyography ; Humans ; Lambert-Eaton Myasthenic Syndrome/*complications/diagnosis ; Lung Neoplasms/*complications/pathology/surgery ; Male

Paraneoplastic syndrome is a rare neurologic disorder caused not by the direct invasion or metastasis of cancer, but by the remote effects of cancer. The central- and peripheral-nervous system or neuromuscular junction area were involved in this syndrome. The pathogenesis was thought as the autoimmune disease, the result of an immunologic response to cancer and to cross-react with self-cells of the nervous system or of the neuromuscular junction, causing neuronal dam-age. Specific forms of this syndrome are often associated with specific paraneoplastic autoantibodies and cancer. The onset of neurological symptoms and detection of these antibodies often precede the diagnosis of the cancer; therefore, detection of these antibodies greatly assists the diagnosis of this syndrome and prompts investigations for the underly-ing cancer. Some paraneoplastic central neurological syndromes, such as cerebellar degeneration, limbic encephalitis, and necrotizing myelitis, were not improved by putative pathogenic autoantibodies, or by immunosuppresant or tumor removal, inspite of improvement in other peripheral neurologic syndrome, Lambert-Eaton myasthenic syndrome, neu-romyotonia, and Stiff-man syndrome. A more detailed understanding of the relationship between the cancer and the neural involvement from the molecular biological standpoint may lead to rational tumor therapy and elucidation of the mechanism of neural death. Here, major clinical forms with well-known antineuronal antibodies and specific cancers are reviewed.
Antibodies ; Autoantibodies ; Autoimmune Diseases ; Diagnosis ; Lambert-Eaton Myasthenic Syndrome ; Limbic Encephalitis ; Myelitis, Transverse ; Neoplasm Metastasis ; Nervous System ; Nervous System Diseases ; Neuromuscular Junction ; Neurons ; Paraneoplastic Syndromes* ; Small Cell Lung Carcinoma ; Stiff-Person Syndrome