What is Peripheral Neuropathy ?
Peripheral Neuropathy: Differential Diagnosis and Management
Peripheral neuropathy has a variety of systemic, metabolic and toxic causes. The most common treatable causes include diabetes mellitus, hypothyroidism and nutritional deficiencies. The diagnosis requires careful clinical assessment, judicious laboratory testing and electrodiagnostic studies or nerve biopsy if the diagnosis remains unclear. A systematic approach begins with localization of the lesion to the peripheral nerves, identification of the underlying etiology and exclusion of potentially treatable causes. Initial blood tests should include a complete blood count, comprehensive metabolic profile and measurement of erythrocyte sedimentation rate [ESR] and fasting blood glucose, vitamin B’12’ –and thyroid-stimulating hormone levels [TSH]. Lumbar puncture and cerebrospinal fluid analysis can be helpful in the diagnosis of Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy. Electrodiagnostic studies, including nerve conduction studies and electromyography, can help in the differentiation of axonal versus demyelinating or mixed neuropathy. Treatment should address the underlying disease process, correct any nutritional deficiencies and provide symptomatic treatment.
The peripheral nerves consist of bundles of long neuronal axons as they exit the central nervous system (CNS). Some peripheral nerves are wrapped in a myelin sheath generated by Schwann cells, whereas others are unmyelinated. Peripheral nerves serve different motor, sensory, and autonomic functions. The term peripheral neuropathy is usually used to describe symmetric and universal damage to adjacent nerves. The damage and clinical manifestations are usually located distally with a proximal progression. Several disorders can damage peripheral nerves and cause peripheral neuropathy; it is important to differentiate actual neuropathy from other disorders that can have a similar clinical presentation.
One study estimated that the prevalence of peripheral neuropathy in the family medicine setting is 8 percent in persons 55 years and older. The prevalence in the general population might be as high as 2.4 percent. A community-based study estimated the prevalence of peripheral neuropathy in patients with type 2 diabetes mellitus to be 26.4 percent.
Peripheral neuropathy can be caused by a variety of systemic diseases, toxic exposures, medications, infections, and hereditary disorders. The most common treatable causes are diabetes, hypothyroidism and nutritional deficiencies.