Overview of neuropathic pain syndromes.

Patients with peripheral nerve injury often express a variety of positive sensory symptoms. Description of these symptoms can range from "painful" to "painless" to "painless but very unpleasant." Although it is widely accepted that both peripheral and central processes may play a role in the pathophysiology of these symptoms, peripheral mechanisms in particular are often overlooked. Sensitization of nociceptor unit receptors, spontaneous or stimuli-induced ectopic impulse generation, "multiplication" of impulses, and ephaptic transmission are pathophysiologic mechanisms resolved at the peripheral level that may explain the patient's symptomatology. It is important to reach an accurate diagnosis and to investigate the pathophysiology of every individual symptom. Only when this has been achieved is it possible to plan adequate symptom-oriented therapeutic strategies. In the future, therapy will be more symptom-oriented than illness-oriented, and treatment options will most likely be tailored to fit the specific constellation of symptoms expressed by a particular patient.