Peripheral nerve transection (laceration)


General or Other | - Others | Peripheral nerve transection (laceration) (Disease)


Description

Peripheral nerve injury or disease can cause symptoms of pain, dysesthesias, and either partial or complete loss of sensory and motor function.

Causes and Risk factors

Peripheral neuropathy may be either acquired or inherited.

Causes of acquired peripheral neuropathy include:

(1) physical injury (trauma) to a nerve

(2) tumors

(3) toxins

(4) autoimmune responses

(5) nutritional deficiencies

(7) alcoholism

(8) vascular and metabolic disorders

Acquired peripheral neuropathies are grouped into three broad categories:

(1) those caused by systemic disease

(2) those caused by trauma from external agents

(3) those caused by infections or autoimmune disorders affecting nerve tissue

Diagnosis and Treatment

A thorough clinical history, physical examination, electrodiagnostic evaluation, and relevant radiographic studies should be performed to distinguish a peripheral nerve problem from one involving the spinal cord or brain, bone, or soft tissues. In addition, early neurosurgical consultation should be obtained.

The strength of individual muscles or muscle groups is graded. A sensory exam is performed which includes testing for light touch, pinprick, two-point discrimination, vibration, and proprioception accordingly.

It is helpful to test sensation in the autonomous zones of a nerve where there is minimal overlap from adjacent nerves. The presence of Tinels sign is useful to localize a nerve injury. The Tinels sign refers to paresthesias elicited by tapping along the course of a nerve. Progressive distal advancement of a Tinels sign over time can be useful clinically to follow the course of regenerating sensory axons. However, the presence of a Tinel’s sign does not guarantee motor recovery.

Return of sweating in an autonomous zone signifies sympathetic nerve fiber regeneration. Reflex changes are also sensitive and early indicators of nerve damage.

Both electromyography (EMG) and nerve conduction studies (NCS) are useful to distinguish an upper from lower motor neuron disorder as well as diagnose a primary muscle disease. For EMG studies, a needle electrode is placed through the skin into a specific muscle and the activity at rest and electrical response to graded muscle contractions are determined. The nerve conduction study involves stimulation and recording along the course of peripheral nerves. This allows one to measure the velocity and amplitude of the propagating nerve action potential.

If the nerve is injured but not cut in two, the team will assess whether the nerve is healing.

If the nerve is healing properly, which can take up to two years, there is a good chance that the patient doesnt need surgical repair.

The patient will need regular checkups to make sure you...