Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 24-28: Peripheral Neuropathies + Key Features Download Section PDF Listen +++ ++ Can be categorized on the basis of the structure primarily affected Predominant pathologic feature may be axonal degeneration (axonal or neuronal neuropathies) or paranodal or segmental demyelination Distinction may be possible on the basis of neurophysiologic findings + Clinical Findings Download Section PDF Listen +++ ++ Common mononeuropathies Lead to a sensory, motor, or mixed deficit that is restricted to the territory of the affected nerve A similar clinical disturbance is produced by peripheral nerve tumors, but these are rare except in patients with neurofibromatosis type 1 Multiple mononeuropathies suggest a patchy multifocal disease process such as Vasculopathy (eg, diabetes, arteritis) Infiltrative process (eg, leprosy, sarcoidosis) Radiation damage Immunologic disorder (eg, brachial plexopathy) Diffuse polyneuropathies Lead to a symmetric sensory, motor, or mixed deficits, often most marked distally Examples include Hereditary, metabolic (eg, diabetic, hyperthyroidism and hypothyroidism, amyloidosis), infectious (eg, syphilis), and toxic (eg, alcohol, lead) disorders Idiopathic inflammatory polyneuropathy (Guillain-Barré syndrome) Nonmetastatic complication of malignant disease (paraneoplastic antineuronal antibodies) Tendon reflexes are depressed or absent Paresthesias, pain (dysesthesia, neuralgia), and muscle tenderness may also occur + Diagnosis Download Section PDF Listen +++ ++ Blood glucose, serum gamma glutamyl transferase (GGT), thyroid stimulating hormone (TSH), serologic test for syphilis, heavy metals screen, antibodies associated with neoplasia (eg, anti-Hu antibodies, also known as anti-neuronal nuclear antibody type 1 [ANNA-1]) Nerve conduction velocity and electromyography Motor and sensory conduction velocity are measured in accessible segments of peripheral nerves In axonal neuropathies Nerve conduction velocity is normal or only mildly reduced Needle electromyography provides evidence of denervation in affected muscles In demyelinating neuropathies Nerve conduction velocity may be slowed considerably in affected fibers In more severe cases, conduction is blocked completely, without accompanying electromyographic signs of denervation Sural nerve biopsy may be required to establish a pathologic diagnosis in some conditions (eg, amyloidosis, hereditary neuropathies) + Treatment Download Section PDF Listen +++ ++ Treatment is directed at underlying disease process (eg, control of blood glucose in diabetes; surgery, chemotherapy and/or radiation for malignancy) Agents useful in control of dysesthesia and neuralgia include Gabapentin, 300–3600 mg orally daily in divided doses Tricyclic antidepressants (eg, desipramine, 25–50 mg orally nightly) Pregabalin, 50–100 mg orally three times daily Duloxetine, 60–120 mg orally daily Opioid agent (submaximal dose particularly in combination with submaximal dose of gabapentin)