Numbness and tingling (paresthesia) are abnormal sensations that can be felt anywhere in the body. Most commonly, they can be perceived in the hands, arms, legs or feet. The feeling of numbness or tingling is a signal unrecognized by the brain and signals that something is wrong. The problem can come from a nerve impingement as it exits the spinal column or peripheral stimulus being muddled before or after the brain receives the information.
Most frequently, problems coming from the neck (cervical spine) result in a wide variety of symptoms. Pain, ache, numbness, and tingling are a few of the sensations interpreted by the brain. Actually, the sensations are warning signals to the brain that something is wrong. Numbness in one of the extremities is the most common problem that can be equated with a peripheral neuropathy, more commonly called a “pinched nerve.” Technically, a nerve does not really get “pinched,” but it is the word that makes sense to most people. However, the actual feeling of a peripheral neuropathy in the arms and hands can really feel like something is being pinched.
There are a billion nerve fibers in your body that are clumped together in bundles called nerves. These nerves travel inside the spinal column and exit through openings between the vertebrae. After leaving the spinal column, the nerves separate into smaller and smaller bundles and travel to every nook and cranny in the body. The nerves that exit the neck are distributed in the shoulder, arm and hand. They travel in a giant nerve group called the brachial plexus. The nerve can become entrapped in several places between the neck and hand.
Depending on which nerves are damaged, symptoms may appear in different areas of the extremity. Initial symptoms of a peripheral entrapment syndrome (pinched nerve) come primarily from the involved muscle. An adequate nerve supply must be present for all muscles to work efficiently. Therefore, when a nerve traveling to supply a muscle becomes pinched, the muscle will become weak and then begin to fasciculate (twitch). Deinnervation (limited nerve supply) of the muscle causes muscle wasting supplied by that particular nerve. A peripheral neuropathy will always follow a specific pattern of distribution.
Symptoms vary and need to be carefully described as to their exact nature. Therefore, a careful evaluation of the patient’s complaint is necessary for accurate assessment of the patient’s condition.
In reality, numbness or tingling in one or more extremity does not always mean that a pathological condition is present. Different tissues may be involved with the same type of symptoms. Mode of injury must always be carefully considered. For example, trauma to an area may result in vascular, or neurological, compromise. Other considerations for diagnosis may include a metabolic disorder, overuse syndrome, intervertebral disc syndrome, fracture, vascular compromise leading to ischemia, tumor, canal stenosis (nerve root lesion), peripheral entrapment neuropathy, or suprasegmental involvement of central structures (brain, brainstem, cerebellum, and spinal cord).