Epidemiology of Peripheral Neuropathies

The definition of peripheral neuropathy varies considerably among clinicians. Neuropathies may present in many different forms depending on location, level, or types of neurons or Schwann cells affected, rate of progression, severity, etiology, and other factors. Many nonneurologists use the term “neuropathy” to denote any type of dysfunction of peripheral nerves; for neurologists it denotes a peripheral polyneuropathy, not single nerve lesions. Broadly, peripheral neuropathies can be categorized into mononeuropathies and polyneuropathies. One definition of peripheral neuropathy is that of deranged function and structure of peripheral motor, sensory, and autonomic neurons, involving either the entire neuron or selected levels of it. Bell’s palsy is the most common disease affecting the facial nerve. Entrapment of the median nerve at the wrist is a common clinical problem, which, in early stages, causes paresthesias and numbness in the distribution of the median nerve, and, later, muscle atrophy and weakness in median innervated hand muscles.