Basic Neuroanatomy for People Suffering with Peripheral Neuropathy

 Peripheral Neuropathy is a condition of abnormal function of the nerves that live outside of the spinal cord. When nerves are still in the spinal cord we call them central, and as they leave the spinal column first as nerve roots, they later become peripheral nerves.

In addition, there are basically two types of nerve fibers that leave the spinal cord, we have small fiber nerves classified neurologically speaking as A delta and C fibers. These small unmyelinated, or lightly myelinated fibers carry information related to pain and temperature first  to your spinal cord, the up the spinal cord through something called the anterolateral system, then up to an area of your brain called the hypothalamus and thalamus; from there, nerves carry these massages up to your brains cortex for interpretation.

The other type of nerve fibers that we have are called large diameter nerves. These nerves carry some sensory information as well, but a different kind. Large fiber nerves are known as 1A and 1B nerves, and carry information related to vibration as well as joint position sense. Some of these fibers are carried in the back part of the spinal cord known as the posterior columns up to the brainstem and then on to our cerrebellum. From here more nerve fibers carry this information up through the midbrain and up to the cortex for evaluation and some complex calculations. Any Loss of function of these nerves anywhere along its pathway can lead to something called peripheral neuropathy, which means that regardless of where the pathology lies, you are experiencing the symptoms as though they lie outside the spinal cord, hence the term peripheral neuropathy, and also hence, the diffuclty for many doctors to give an accurate diagnosis and prognosis.

Types of Peripheral Neuropathy

As you can probably see from the above there are different classifications of neuropathies based upon the type of nerve fibers involved. You can have a small fiber neuropathy, you might have a large fiber neuropathy, or you may have a mixed fiber neuropathy. This is very important to know up front relative to the management of your condition. Unfortunately, Nerve conduction velocity tests, also known as NCV\'s can only test you for Large fiber neuropathy!

  Causes of Peripheral Neuropathy

There are many causes of peripheral neuropathy. The number one cause is a metabolic disorder called diabetes, but there are approximately 50 drugs that can cause PN, as well as autoimmune conditions,  spinal stenosis,  genetic causes, or  even idiopathic (this means the doctors are stumped), but the thing that most patients who suffer with neuropathy have in common is either numbness and tingling in the feet and lower legs or hands, or terrible burning sensations, or sometimes sharp stabbing pains, often so severe that they find it difficult to wear any kind of shoe. PN patients often complain of the feeling of insects crawling up their legs, or like they are walking on rocks, and other unusal symptoms typically felt in the feet and legs first.

Restless leg Syndrome is another presenting picture of peripheral neuropathy causing many restless nights and loss of sleep, where the only relief obtained is to get up and walk around! Some patients report that their neuropathies can be so bad that they can\'t stand even having sheets touch their feet at night.

Diagnosis

There are many different test that may need to be run to get to the bottom of a patients "peripheral neuropathy". Many patients who come to see me have already had an NCV( nerve conduction velocity) test, but as I stated earlier these test only confirm or deny the absence of a large fiber neuropathy. So we need to test the small fibers as well, and we can do that clinically in office. So the first step is a good clinical neurological examination. The next step after confirming the presence or absence of small or large or mixed fiber neuropathy, may be other specialized tests to get to the cause. These additional tests can include, but certainly aren\\\\\\\'t limited to Comprehensive metabolic work ups, autoimmune challenge tests,  T or B cell specialty tests, thyroid tests, food sensitivity tests , genetic disease testing, biopsy etc..

 Treatments

Most patients with neuropathy have until now, had few treatment options. In fact, most patients are given Neurontin and Gabapentin to centrally inhibit thier pain, and are told they will just have to live with it. PN or neuropathy can have a devastating effect on your life, often not allowing you to get a full nights rest, or limiting your mobility, or severly impacting your balance. The reason many PN sufferers have trouble with their balance, is because the loss of feeling in your feet, leads to loss of joint position sense and the brain has no idea where you are in time and space. This is quite dangerous, and can lead to the consequences of serious falls that may further incapacitate you. While some cases of neuropathy have an unknown cause what needs to be recognized is that there is a loss of function to the affected nerves and  any treatment modality to those nerves must take into account  the survivability and viability of those nerve pathways.

 Our treatments may include therapies not only for the peripheral nerves, but for the central nerves, or even brain based therapies. Some of these brain based therapies might serve to restore function to those pathways that have been functionally impaired, thus leading to an increased perception of pain, or to stimulate descending pain inhibiting pathways at the spinal cord level. We may treat immunological, or metabolic dysfunction as well. Simply stated  our treatments are based upon clinical testing, and then re-testing to make sure we are achieving the desired result.