Physician's Resources: Neuropathy Testing

WHO IS A CANDIDATE FOR THIS TYPE OF SURGERY?
The ideal candidate for surgery to restore sensation and strength is the diabetic who is beginning to experience numbness and tingling in the hands or feet and who may have noticed weakness, loss of balance or loss if control of some of the muscles in the hands or feet. This patient should be examined in order to measure to measure to the degree of sensory and motor loss. Neurosensory testing can accomplish this purpose for you. Ask your doctor where you can have this painless testing done.

If the patient is seed sufficiently early in the course of nerve compression, it may be possible to relieve some of the pressure upon the nerve by wearing splints for the hands or shoes inserts (orthotics) for the feet. Special instruction is given to the patient in terms of using the hands at works, in activities of daily living and in inspection of the foot for early signs of skin breakdown or infection. When the neurosensory testing demonstrates sufficient sensory loss, special shoes may be required to protect the feet. There are some medications that can be given to relieve the discomfort of the neuropathy. And, of course, you must be sure that you blood sugar level is the best that it can be. Advice help from your primary care doctor, your endocrinologist and your foot and ankle specialist are essential to prevent worsening of the symptoms.

If the sensory loss progresses to the point where you have numbness and tingling throughout the day and weakness or clumsiness interfere with your daily activities, then you may be a candidate for surgical decompression of your nerve. The ideal candidate does not wait until there is no feeling left or until there is already an ulceration present. The ideal candidate seeks surgical consultation while there is still time to reverse the damage to the nerve.

HOW DOES THE SURGEON SEE THE NERVE?
Surgery is done in a bloodless field This is achieved by placing a tourniquet about your upper arm or thigh once you are asleep. Once inflated, this prevents any bleeding during the surgery. The surgeon wears loupes, small microsurgical operating glasses that magnify about 3 times in order to see the nerves and delicate tissues. The nerve is located in specific places in relation to the muscle and ligaments which helps in their identification.

HOW LONG DOES THE SURGERY TAKE?
From the time you enter the operating room until the tie you enter the recovery room is about two. You will stay in the recovery room for another hour. These times vary for the individual patients.

DO I HAVE TO BE PUT TO SLEEP?
Most often, it is easier for you to have a general anesthetic is which you are truly put to sleep. I the surgery is on your legs, it is possible to have spinal anesthesia which just puts your legs to sleep. With a spinal anesthesia, you are usually made sleepy but do all your own breathing. This is also know as twilight medicine Sometimes, if there are medical reasons why it may be too risky for you to have a general anesthetic, the surgery can be done with a local anesthetic. With this, you are made sleepy with medication given to you through your vein by an I.V. The best method for you will be determined in consultation with your own doctor, the anesthesiologist and, of course, we will try to accommodate any wishes you may have.

IS THE SURGERY PAINFUL?
No surgery is pain free but this surgery is not usually very painful. Partly this is because you already have lost some of our sensation and partly it is because the surgery does not go into the joints. The surgery usually involves just cutting the s kin and ligaments and this usually is not too painful. The surgery to correct compression of the ulnar nerve at the elbow does require division and reattachment of some muscles and this surgery causes more pain than the other surgeries.

A long-acting local anesthetic will put into your incisions so that when you awake not only will there be very little pain but, in fact, you will feel your hand or foot at all.

When the local anesthetic wears off, in about four hours, you will begin to feel your hand or foot. If this becomes painful for you, you will have been given pain medication. You may need to take this medication for a few weeks after surgery.

If the surgery has been to your tarsal tunnel, on the inside of your ankle, you may have some increased pain as you begin to walk again.

When the nerves that have been asleep awaken, you may experience hot or cold shooting pains in your fingers or toes. This is a good sign as it shows recovery, but itmay still be uncomfortable for you. There is medication that can help these feelings, too.

DO I HAVE TO BE HOSPITALIZED?
No. Most patients can have the surgery safely as an outpatient. There may be medical reasons why it will be best and safer for you to stay one night in the hospital, such as to receive intravenous antibiotics, or to receive proper care for your heart or kidneys.

WHAT SHOULD I BRING FOR MY CONSULTATION WITH YOU?
You should have a letter of referral sent by your doctor. That letter should state how long you have had diabetes and what your current medications are, including your dose schedule for insulin.

You do not need to bring x-rays with you.

If you have had a nerve conduction test (EMG or NCV), you should bring a copy of the electro diagnostic test with you, test either you, however, it is not necessary to have this test before your consultation.

WHEN WILL I HAVE NEUROSENSORY AND MOTOR TESTING?
Neurosensory testing with the Pressure-Specified sensory Device (PSSD) is the best way we have to measure the degree of function in your fingers and toes. This testing is done with a computer and does not hurt because there are no needles and no electric shocks. This is different from the electrodiagnostic studies you may already have had. Diabetics should have neurosensory testing every year. It must be done before surgery and, if you have not already had it, it can be done on the day of your office visit if ou ask the receptionist to schedule the testing at the time of your office visit. Otherwise, you can come back and have it don another day. The testing takes less than on house.

You will have the testing done after surgery, too. Usually, it is done at about six to twelve weeks after surgery to document that neutral regeneration is occurring. This will also document that the operated hand and foot is improving and help us determine if you should proceed to have surgery upon your opposite arm or leg.

WHAT ARE THE RISKS OF THIS SURGERY?
The biggest risk of the surgery is the risk of anesthesia, which can include death. Although very rare, severe complications are possible. This is why your past medical history is so important to us in selecting the safest anesthesia for your surgery and in selecting the safest anesthesia for your surgery and in selecting the appropriate type of medical facility in which you school have your surgery.

Unique to the surgery you will have is the possibility of having a painful scar, of your having apparent worsening of your symptoms as the diabetic nerve regenerates and delayed wound healing.

WHAT ARE THE CHANCES OF SUCCESS?
Over the past fifteen years, the results of this type of surgery have been carefully evaluated. Four separate studies have been done, and reported between 1992 and 2000. These studies reached the same conclusion: Overall about 80% of those diabetic patients who have had a nerve decompressed have had decreased pain and improved sensory and motor function. Balance is improved.

Patients usually seek attention sooner when it is their hands that bother them. Therefore, we have better success in restoring sensation and motor function to the hand. In one such recent study, 88% of upper extremity nerves sensory functions were improved by surgery. For the lower extremity, the degree of sensory loss in the feet was more advanced (worse) than it was for the hands. Still, 69%of nerves decompressed I the lower extremity resulted in improved sensation. None of these patients had ulcerations or amputated toes at the time of their surgery.

The presence of ulceration or previous toe amputation does not mean you are passed the point where you can be helped. Only a consultation can determine this.

A postoperative patient survey has shown that over the period of time that this surgery has been done, none of the patients had been admitted to the hospital for treatment of foot infection or ulceration. No patient has had an amputation. No one has fallen or broken a hip.

While these results I no way guarantee that you will achieve an excellent outcome they are suggestive of what can be achieved by this approach.

Nerve Injury, Nerve Reconstruction, and Recovery of Nerve Function

PAIN

Pain is related to nerve injury and to and to nerve reconstruction. When a divided sensory nerve attempts to regenerate and does so into an area of scar, then the nerve endings that normally tell the brain about pain, temperature, and touch get caught in the scar tissue. Any movement of that scar can set off a message to the brain that is interpreted as pain. Nerve endings stuck in scar tissue that send a pain message are called a painful neuroma. Regardless of how much pain this one neuroma creates, the pain is always related to the region that the sensory nerve fibers originally innervated. When pain occurs after a nerve injury and the pain expands into many areas that are outside the distribution of a sing le nerve injury, then this pain can be given a different name. This pain may be called reflex sympathetic dystrophy (RSD) or complex regional pain syndrome (GRPS) or sympathetically maintained pain (SMP). This condition is not just one of pain, but is associated with over activity of sympathetic nervous system, so that the area of pain is a different color, like pink or purple, and is usually a different temperature, like cooler, than the surrounding non-painful skin. The painful area is often sweaty, swollen and stiff. It is possible for several sensory nerves to be either involved in neuroma formation or be compressed in the injured area, and for the combined areas of these several nerves to give the diffuse pain usually associated with RSD, even when the other features of RSD are not present. It may be difficult for doctors to distinguish these situations.

Treatment of pain of neural origin requires correct diagnosis as to which nerve is involved in the pain mechanism and as to whether there is a neuroma present or compressed nerve or both. This decision often requires that the supposed painful nerves are briefly put to sleep by injecting tem with a local anesthetic, like xylocaine or marcaine. Your response to these nerve blocks will determine subsequent treatment for the pain. When these nerve blocks are done to the sympathetic nerve fibers in your neck to evaluate the presence of sympathetically maintained pain, then they area called a stellate ganglion block. If they are done to evaluate the sympathetic system in the leg, then they are called a lumbar sympathetic block. This local anesthetic can be infused for prolonged period of time to treat lower extremity pain through a catheter placed near the spinal canal, called an indwelling epidural catheter.

Prior to surgery, attempts to treat the pain should be tried that include desensitization, scar massage, steroid creams, and steroid injections, transcutaneous electrical stimulation, and certain medication. These meicatin include non-steroidal anti-inflammatory agents, like advil, ultram, celebrex or viox , and the newer group of drugs for neuropathic pain like dilantin, tegretol, elavil, and neurontin. None of these are narcotics. Some pain specialists may prescribe long acting narcotics for severe pain that seems to have no other treatment available for pain relief, but this approach can produce drug addiction.

If putting a non-critical sensory nerve to sleep eliminates your pain, than the neuroma on that nerve can be removed, trading a numb or anesthetic region for the painful region. Sometimes several nerves must be removed. This is the approach taken for a painful knee or a painful area of the hand or the top of the foot. Since the cell body for the resected neuroma is still alive, in the dorsal rot ganglion, next to the spinal cord, this nerve will attempt to regenerate, just as if the nerve had been repaired. In order to minimize the chance for the regeneration to results in another painful neuroma, the end of the nerve is placed loosely into an area away from joint movement, away from tension, and into an environment that has no degenerating sensory nerve fibers, such as normal muscle. If this new hiding place in the muscle is directly hit, the pain may come back, but the se nerve ending s cannot regrow into the original injured area. Within the injured area, some sensation may be recovered by ingrowth of normal nerve fibers from the adjacent normal skin. This protective mechanism is called collateral sprouting, and may, on its own, produce some disturbing sensations for a few months.

The usual the usual events associated with normal nerve regeneration can be painful. As the regenerating ends of the nerve, called sprouts, travel, they make contact with each other and with structural proteins. The neural impulses generate d by this activity may be interpreted by your brain as pain. It should be expected that for the time period associated with nerve regeneration there may be pain sufficient to need therapy and/or pain medication. Just understanding that this is expected to occur, and is good pain, or pain for a good reason, is enough to help many people adjust to ita presence. Some patients may need much more than this reassurance, and Neurosensory Testing with the Pressure-Specified sensory Device, can document this nerve regeneration. Therapy to enable the brain to reorganize to these new neural inputs is called sensory re-education. A program of sensory re-education can be provided for you by your doctor or a therapist.