In some cases, the diagnosis of peripheral nerve and muscle disease can be made from the clinical setting. As examples:
●The diagnosis of diabetic polyneuropathy in a patient with long-standing diabetes mellitus who presents with classic "stocking-glove" sensory loss is relatively straightforward. (See "Clinical manifestations and diagnosis of diabetic polyneuropathy".)
●A reasonable clinical hypothesis can be formed regarding the etiology of proximal weakness in patients taking drugs that can interfere with muscle function (eg, antimalarial, glucocorticoid, or cholesterol lowering medications). (See "Glucocorticoid-induced myopathy" and "Drug-induced myopathies".)
However, patients with disorders of nerves, muscle, or the neuromuscular junction can present with a similar constellation of symptoms. In addition, even when the process is localized to the nerve, it is not always clear if the origin of the problem is in the central or peripheral nervous system.
This topic will review the findings on history and physical examination that are characteristic of diseases of the nerve, muscle, and neuromuscular junction, and then present an approach to distinguishing central from peripheral neurologic disease. Specific neurologic syndromes are discussed in more detail separately.