What is neuropathy?
Neuropathy, also known as peripheral neuropathy and polyneuropathy, refers to damage of the nerves that run through the body — outside the brain and spinal cord.
How do nerves work?
The central nervous system (CNS) is made up of the brain and spinal. The brain is known as the command center, and receives and generates messages that are transmitted by the peripheral nervous system (PNS) — the nerves that run throughout the body. The nerves act like electrical cables that connect telephones and therefore, allow them to communicate over long distances.
When there is damage to certain nerves, the communication is interrupted and signals are either interpreted incorrectly, or not received at all.
Nerve fibers are classified based on their thickness into small fibers and large fibers.
Motor, Sensory, and Autonomic Neuropathies
Different cells in the peripheral nervous system (PNS) have different jobs.
Motor fibers connect to the skeletal and internal muscles to signal them to contract (muscle firing).
Sensory fibers are responsible for relaying information from other parts of the body to the brain.
Autonomic fibers supply blood vessels, sweat glands, the gastrointestinal organs, the urinary bladder and sexual organs.
Signals from small-fiber neurons also maintain the health and function of our body’s cells and tissues.
Symptoms of Neuropathies
When people hear the term “neuropathy” many people often think of numbness, tingling, pins and needles, or pain. They may also even associate neuropathy with diabetes. However, neuropathies are much more complex than just numbness and tingling, and there are far more causes than just diabetes.
Peripheral neuropathies cause different symptoms depending on which type of nerve fiber is damaged. Typically, the symptoms of polyneuropathy start first or are worse in the hands and feet.
Motor neuropathy symptoms come from the fact that our muscles don’t work well if the motor fibers are not sending the correct signals they need to function. Patients may notice fatigue or difficulty with movement (weakness), reduced size of muscles and muscle cramping.
Sensory neuropathy symptoms are usually divided into “negative” and “positive” symptoms. Negative symptoms reflect less ability to sense the world due to damage to sensory neurons. Examples can include reduced hearing (sensorineural hearing loss), reduced balance (sensory ataxia), or painless injuries. Positive symptoms mean that the sensory neurons are firing and sending false messages of sensation when there is no reason to. Examples include neuropathic pain and itch, where a person can feel as if they are being cut or burned even though nothing is touching them.
Autonomic neuropathy symptoms vary a lot depending on which organ is affected. If nerve cells going to the heart and blood vessels are damaged, patients may notice low or fluctuating blood pressure or a rapid heart rate. These cardiovascular symptoms can leave patients feeling weak, dizzy, or lightheaded when they stand or remain upright. Symptoms from the gastrointestinal tract can include bloating, nausea, or vomiting, often after eating, and constipation and/or diarrhea. Autonomic neuropathy can also affect the bladder and sexual function.
What is Autoimmune Small Fiber Polyneuropathy
Small fiber polyneuropathy (SFN) is a neurological disorder involving widespread damage to the small-diameter somatic and autonomic nerve fibers. While patients often experience pins and needles, burning pain sensations, itch, and numbness, the damage to the autonomic small fibers often result in dysfunction in the autonomic nervous system — which is responsible for controlling blood pressure, heart rate, temperature, and gastrointestinal motility.
It has become increasingly evident that autoimmune small fiber polyneuropathy may actually be the cause of POTS, gastroparesis, delayed intestinal motility, and CRPS in patients with Ehlers Danlos Syndrome. Why EDS patients are more susceptible or prone to autoimmune small fiber neuropathy in unclear, but may be linked to Mast Cell Activation Syndrome.
After many years of missing puzzle pieces, I was officially diagnosed with severe autoimmune small fiber polyneuropathy in 2021. Specifically, +TS-HDS antibodies.
The antibodies to TS-HDS are detected in up to 20% of patients with otherwise idiopathic small fiber neuropathy, but are rare in patients without small fiber neuropathy.
To learn more: Neuropathy Commons