The peripheral nervous system serves as the link between your brain and spinal cord and the rest of our bodies. It is responsible for sensation and motor function.
Sounds important, right?
Well, as important as our peripheral nerves are, they’re also quite fragile. Even a minor injury to these nerves can affect your brain’s ability to communicate with your muscles and organs.
Let’s compare it to the U.S.’s outdated communications infrastructure: Much of the country is reliant on aboveground cables for communications and electricity. A significant storm can damage these vital connections, incapacitating or even paralyzing a city.
That is the role of your peripheral nerves.
What is the Peripheral Nervous System?
The peripheral nervous system is made up of 43 pairs of nerves that branch off from the central nervous system; that is, the central nerves of the brain and spinal cord.
While the central nerves are protected by the skull and vertebral canal of the spine, the peripheral nerves are relatively unprotected, easily damaged, and often slow to heal.
The peripheral nervous system has two parts.
The somatic nervous system handles our voluntary actions: picking up a cup, sitting down, and so forth. It transmits messages from the brain to the muscles that carry out the desired action. It also conducts sensations, such as taste and touch.
The autonomic nervous system handles our bodies’ involuntary physiological actions, such as digestion, heart rate, pupil dilation, and breathing,
Types of Peripheral Nerve Injury
Peripheral neuropathy, or damage to the peripheral nerves, can occur from severe pressure on or stretching of a nerve. Certain health conditions, such as diabetes or rheumatoid arthritis, can also damage the nerves.
Here are three common categories of peripheral nerve injury:
Sustained or direct pressure on a nerve can lead to pain, numbness, and muscle weakness. One well-known example is carpal tunnel syndrome, which is the compression of the median nerve in our arms. This median nerve injury leads to pain, tingling, or numbness in the hand.
Another example is neurapraxia, where blunt force causes trauma to a nerve and creates lesions that reduce the nerve’s function. Neurapraxia is common among football players and other athletes.
The peripheral nerves are relatively elastic, but – just like a rubber band – they can be stretched too far. A stretch injury typically results from an arm or leg stretching beyond its normal limits.
A nerve can stretch to about 6% of its normal length without a problem. But a longer stretch of, say, more than 15%? The nerve may tear or even snap, possibly causing irreversible damage.
Though not as common as compression or stretch injuries, transvection nerve damage is often the most serious, as it represents a laceration or severing of the nerve. Typical causes of transvection injuries include knife wounds, gunshots, and broken glass.
Although the nerve tissue will regenerate, the process can take months, during which time the connecting muscle may atrophy.
Treatment of Peripheral Nerve Injuries
Nerve cells aren’t skin cells – they take a long time to regenerate from even a minor injury. For this reason, peripheral nerve injuries often require expert diagnosis and attention in order for them to recover.
Our nerves are made of fibers called axons, and they’re coated by the myelin sheath – a fatty substance that insulates the nerve fibers and helps speed the transmission of signals. In many instances of compression or stretch injuries, either the axons or the myelin sheath is damaged. While any nerve injury can be serious, these types of injuries are more likely to heal.
Sometimes, all it takes to treat a compression injury is patient education.
For instance, if a case of carpal tunnel syndrome isn’t too far advanced, tips on developing a more ergonomically sound workspace could eventually remedy the problem. For other injuries, putting the affected limb in a sling or splint can take the pressure off the damaged nerve and allow it to heal. Physical therapy is often recommended in these cases, too.
With laceration injuries, the nerve may be completely cut. These types of injuries are more difficult to treat. Likely, an operation is required as soon as possible after the injury in order to explore the damaged area. If the cut is a “clean” one, then a direct surgical repair can be performed. If the laceration is more severe, the surgeon may attempt to approximate the location of the nerve endings in order to conduct a sensory topography of the area. Several weeks later, this information is used to guide the surgeon in a subsequent surgery to reconstruct the injured nerve.
Keep the Nerve Lines of Communication Open
Responsible for so many of our basic functions, the peripheral nervous system is the quiet hero of our body. Be sure to stretch often, exercise, and keep those nerves and muscles feeling good.