Understanding Nerves and Peripheral Neuropathy in Plain English
Understanding Nerves and Peripheral Neuropathy in Plain English:
Some of the terms associated with peripheral neuropathy are ridiculously long, confusing and can be just plain intimidating. I am referring to words like idiopathic neuropathy, sensory/ motor neuropathy, myelin and demyelinization. I am to attempt to clarify some of these terms so you don’t have to go running to a medical dictionary or the internet the next time you read about peripheral neuropathy.
What is peripheral neuropathy?
Peripheral neuropathy refers to a series of medical conditions affecting the nerves outside the brain and spinal cord. The brain and spinal cord comprise the central nervous system which is the “computer” of the nervous system-coordinating and processing information. The peripheral nervous system connects the brain and spinal cord to skin, muscles, tendons and internal organs. Damage to the nerves of the peripheral nervous system causes the condition of peripheral neuropathy.
You have some nerve!-what nerves look like and how they work:
The main component of the peripheral nervous system is called the neuron. A neuron is a nerve cell that sends and receives electrical signals. It carries information that allows different parts of the body to communicate with each other. Each neuron is made up of a cell body with a “tail, called the axon. The cell body receives and processes nerve signals and sends these signals through the axon to the end of the neuron, called the axon terminal. The axon terminal then releases chemicals called neurotransmitters, which allow the nerve signal to jump to the next neuron. The transmission of nerve impulses from one nerve to the next is called a synapse. Axons travel together in bundles called nerve trunks. Nerve bundles have a protective sheath, called mylelin. In some cases of neuropathy this protective sheath is stripped away and this process is called demyelinization.
Nerves that comprise the peripheral nervous system:
Damage to two types of nerves, sensory and motor nerves, causes most of peripheral neuropathy symptoms. Sensory nerves carry information from the brain and spinal cord to sense receptors located in the skin and other areas in the body. These nerves allow us to feel pain, hot and cold sensations, vibration and touch. They also communicate with the brain so we have the ability to sense the position, location and movement of our body parts. This ability is called proprioception.
Many people with peripheral neuropathy develop loss of sensation which often results in the more common symptoms of peripheral neuropathy including pain, tingling, and numbness and burning. With the loss of proprioception, we lose the ability to feel where our feet are positioned relative to the ground. This causes loss of balance which can result in severe walking difficulties.
Motor nerves carry information away from the brain and spinal cord to the muscles and responsible for voluntary movement. Damage to the motor nerves usually occurs in the later stages of the peripheral neuropathy process. Motor nerve disturbance can cause muscle weakness, walking difficulty, muscle cramps, a feeling of heaviness of the feet and legs and a condition called drop foot. People with drop foot cannot raise their foot at the ankle and tens to drag the affected foot or in some cases both feet. This makes walking extremely challenging.
Damage to the sensory and motor nerves primarily affects the lower extremities-legs, feet and toes. It is less common for people to develop neuropathy that simultaneously affect the feet and hands. Diabetics are more prone to developing neuropathies of the upper and lower extremities. One common neuropathy that affects the wrist and hand is carpal tunnel syndrome.