Peripheral Nervous System and Neuromuscular Junction Disorders
- Radiculopathies are disorders of the roots of spinal cord nerves. The roots may be compressed, inflamed, or torn. Clinical manifestations include local pain or paresthesias in the sensory root distribution. Treatment may involve surgery, antibiotics, steroids, radiation therapy, and chemotherapy.
- Plexus injuries involve the plexus distal to the spinal roots. Paralysis can occur with complete plexus involvement.
- Neuropathies are the resulting syndrome when the peripheral nerves are affected. Axon and myelin degeneration may be present. Neuropathies are classified as sensorimotor, sensory, or motor. The neuropathies are characterized by varying degrees of sensory disturbance, paresis, and paralysis. Secondary atrophy may be present.
- Guillain-Barré syndrome is a demyelinating disorder caused by a humoral and cell-mediated immunologic reaction directed at the peripheral nerves. The clinical manifestations may vary from paresis of the legs to complete quadriplegia, respiratory insufficiency, and autonomic nervous system instability. Plasmapheresis is used during the acute phase and followed by aggressive rehabilitation.
- Myasthenia gravis is a disorder of voluntary muscles characterized by muscle weakness and fatigability. It is considered an autoimmune disease and is associated with an increased incidence of other autoimmune diseases.
- Myasthenia gravis results from a defect in nerve impulse transmission at the neuromuscular junction. IgG antibody is secreted against the “self” acetylcholine receptors and blocks the binding of acetylcholine.
- Primary disorders of muscles with weakness and atrophy are known as myopathies.