Nerve Compression Health Article

Brachial plexus palsy

Palsy is a term meaning the inability to purposely move a body part. Brachial plexus palsy refers to paralysis that is associated with compression and tearing of a group of nerves called the brachial plexus. These nerves are a connection between the spinal cord and the nerves that run into the arms neck, and shoulders. The nerves can become compressed and even torn when the neck is stretched. This can occur in an infant born following a difficult delivery, which can occur if the baby is large, in a breech position, or if the period of labor is long. In these situations, the baby's neck can be abnormally flexed. The abnormal position damages the brachial plexus nerves.

The brachial plexus affects certain segments of the spinal cord. When viewed in a x ray, the spinal cord is reminiscent of Lego blocks stacked on each other. Each 'block' represents a segment. Typically, brachial nerves that originate from upper segments of the spinal column (segments C5 and C6) are affected. This condition is also called Erb's palsy. Less commonly, nerves associated with lower segments (C7 and T1) can be deranged. This condition is called Klumke's paralysis. In some cases, all the nerves of the brachial plexus can be affected.

The causes of nerve damage can also involve injuries to the shoulder, arm, and the collarbone (clavicle). The main symptom of brachial plexus palsy, paralysis in an arm, is evident immediately after birth. A newborn will lie with the affected arm by its side, with the elbow extended. While the other arm will be capable of a normal range of motion, the affected arm will be immobile.

Meralgia paresthetica

This painful condition is due to the pinching of the lateral femoral cutaneous nerve as the nerve exits the pelvis. The nerve can become pinched as the position of the pelvic region changes due to weight gain, injury, pregnancy, or extended periods of standing of walking (i.e., military marching). The affected nerve becomes compressed as it crosses a region of the pelvis called the iliac crest. As well, the nerve can be rubbed during the pelvic motions that occur with walking. This friction increases the nerve damage.

A person with meralgia paresthetica experiences an ache, numbness, tingling, or burning sensations in their thigh. The ache can be mild or severe, and generally eases during rest and returns with resumption of activity.

Cubital tunnel syndrome

This syndrome results from pressure that compresses the ulnar nerve. The ulnar nerve is one of the main nerves of the hand, which connects the muscles of the forearm and hand with the spinal cord. The nerve passes across the back of the elbow behind a bump called the medial epicondyle. The sensation that is described as the funny bone is actually the transient sensation that occurs when the ulnar nerve is compressed in a bump.

Cubital tunnel syndrome is a more protracted from of the nerve compression. It results from the stretching or pushing of the nerve against the medial epicondyle when the elbow is bent. The condition is aggravated over time by the bending of the elbow. Symptoms of cubital tunnel syndrome are typically a numb feeling in the ring finger and small finger, weakness in muscles of the hand and forearm, and elbow pain. Without intervention, more serious nerve damage can occur.

Diagnosis

Carpal tunnel syndrome is diagnosed based on the pattern of the symptoms, the location of the symptoms, and a history of repetitive activity that might predispose to the syndrome. Similarly, thoracic outlet syndrome is diagnosed by the location of the symptoms and a person's work history (i.e., a job involving a lot of lifting).

The diagnosis of brachial plexus palsy is prominently based on the visual observation of the motion difficulties experienced by the newborn. X rays may be taken to discount any other injuries such as fractures of the spine, clavicle (collarbone), humerus (the large bone in the upper arm), or a dislocation of the shoulder.

Meralgia paresthetica is diagnosed by the nature of the symptoms and the occupation of the person. For example, hip and thigh pain in a soldier can alert a clinician to the possibility of this malady. As well, people usually experience tenderness in a specific spot over a ligament in the hip, and symptoms can be made worse by extending the hip in the Nachlas test.

Diagnosis of meralgia paresthetica needs to rule out other maladies to the pelvis and spine, as well as diabetes mellitus. For example, damage to spinal discs will impair reflexes, while reflexes are normal in meralgia paresthetica.

Cubital tunnel syndrome is diagnosed by the type and location of the symptoms.