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Although not often performed, electrodiagnostic testing, which includes nerve conduction studies, needle electromyography, and repetitive nerve stimulation, remains the gold standard for diagnosing neuromuscular disorders. This activity describes the invaluable electrodiagnostic findings of nerve conduction studies, needle electromyography, and repetitive nerve stimulation and highlights the role of the interprofessional team. Objectives: Identify the indications for electrodiagnostic testing in a patient with a neuromuscular disorder. Assess the nerve conduction study findings in a patient with a neuromuscular disorder. Evaluate the electromyographic findings in a patient with neuromuscular disorders. Communicate the importance of collaboration of the interprofessional team to enhance the delivery of care for patients with neuromuscular disorders. Access free multiple choice questions on this topic.

Neuromuscular junction disorders are a group of conditions that cause muscle weakness. Their etiology can be autoimmune, congenital, metabolic, or toxic mediated. The 3 most common neuromuscular junction disorders are myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS), and botulism. The primary pathology is impaired neurotransmission at the interface (synapse) between the nerve ending and the skeletal muscle fiber. In myasthenia gravis, pathology occurs at the postsynaptic membrane.[1] In Lambert-Eaton myasthenic syndrome and botulism, the presynaptic membrane is affected.[1][2] Neuromuscular Junction disorder patients present with complaints of muscle fatigue and weakness that fluctuate with episodes of worsening after activity. The sensory system is unaffected, as sensory nerves do not have a neuromuscular junction. Patients present with proximal greater than distal muscle weakness. It is common to receive complaints about bulbar or extraocular muscle weakness. Myasthenia gravis patients frequently present with bulbar weakness and limb weakness. It is important to investigate if the patient has a history of thymoma.[3] LEMS patients less commonly present with bulbar weakness but have diffuse proximal limb weakness. LEMS has a strong correlation with small cell carcinoma.[4][5] Botulism is a rare condition caused by a toxin produced by Clostridium botulinum. In the United States, most cases are seen in infants.[6]

Neuromuscular junction disorders are a condition often seen in the outpatient setting. Patients frequently complain of muscular proximal weakness in the extremities with/without bulbar and extraocular findings. Electrodiagnostic studies should follow a comprehensive history and a physical exam. It is essential to take an interprofessional team, including physicians, physical therapists, occupational therapists, social workers, and case managers, who can work together to provide aggressive, multifaceted rehabilitation care to improve a patient's functional status.[18][19]