The most common of the many complications of diabetes is peripheral neuropathy. Peripheral neuropathy can occur despite good control of your blood sugar. As the disease progresses, peripheral neuropathy will develop in 60-90% of patients. Once diabetic peripheral neuropathy occurs, it gets progressively worse. A number of different neuropathies may occur in patients with diabetes, the most common of which affects the feet first and then the hands. Usually, the patient will notice changes in sensation. For example, numbness or tingling in the fingers or toes, which may occur intermittently at first and then persist and cause insomnia or awakening from sleep. Over time, these symptoms can worsen to the point of sensory loss. As a result, the patient cannot feel whether the shoes are too tight, the water in the bath is too hot or too cold, and the muscle strength changes. Weakness in the foot can lead to falls or arch collapse. Weakness in the hands may result in poor hand coordination and frequent dropping of objects such as bottles or keys to open doors. Neuropathy is a major cause of foot ulcers and infections. It is also a major cause of toe amputation and, in some severe cases, amputation.
I. Why peripheral nerves are compressed in patients with diabetic peripheral neuropathy
The peripheral nerve starts in the spinal cord and innervates the fingers and toes. In this pathway, there are multiple anatomical stenoses. These physical stenoses exist in everyone. For example, the ulnar canal and carpal tunnel and similar stenoses exist in the parapatellar and intra-ankle areas. Many people are born with these physiologic stenoses so the nerve is more likely to be compressed within them. For example, a small carpal tunnel or a canal with an extra muscle running through it. The following two factors may explain why peripheral nerves are susceptible to compression in people with diabetes.
1. The peripheral nerves in diabetic patients are swollen. Normally blood sugar enters the nerve to provide energy and convert it to fructose, and high blood sugar causes a buildup of fructose in the peripheral nerves of diabetics. The molecular formula of fructose determines that it binds water easily. Therefore, water is drawn into the nerve and causes swelling of the nerve. This phenomenon was confirmed in 1978. So it is conceivable that if a nerve swells at an anatomical stenosis, then the nerve will be compressed and produce symptoms.
2. The transmission system within the nerve is dysregulated in diabetic patients. Nerves are filled with a variety of substances that allow important chemical messages to pass within the nerve. It is the transmission of information that allows the central nerve to understand what is going on at the distal end. If a nerve is damaged such as by compression, its cell membrane needs to be rebuilt and these repair proteins need to be passed downstream along the microtubular proteins within the nerve. This dysfunction of cis-axis plasma transport in the nerves of diabetic patients was reported as early as 1979. This means that damaged nerves in diabetic patients have difficulty repairing themselves, so that nerve repair and consequent symptoms are difficult after peripheral nerve compression.
Second, what are the symptoms of nerve compression
If the median nerve in the carpal tunnel is compressed, it can cause symptoms in each of the fingers innervated by the median nerve, which is called carpal tunnel syndrome. Because there are few muscles innervated by the median nerve, patients with compression of the median nerve in the wrist may only experience decreased movement of the thumb. The nerve that governs the little finger is called the ulnar nerve. It can be compressed at the elbow or in a small canal next to the carpal tunnel. Therefore, if you experience numbness or tingling in the little finger, you can be sure that the ulnar nerve is compressed. Because the ulnar nerve innervates many important muscles, compression of the ulnar nerve at the wrist can lead to finger pinching or finger movement disorders. If the ulnar nerve is compressed at the elbow, which is known as elbow canal syndrome, it can lead to finger pinching and decreased grip function and loss of coordination. In the foot, a similar problem to carpal tunnel is called tarsal tunnel syndrome, which refers to compression of the posterior tibial nerve in the bony canal of the foot and ankle. The posterior tibial nerve innervates the entire plantar aspect of the foot including the heel. The compression causes numbness and tingling in the arch of the heel and the toes on the bottom of the foot. The loss of sensation in the foot can lead to a loss of balance, making the patient prone to falls.
Third, peripheral neuropathy and nerve compression between the two have those relationships
The most common neuropathy in diabetic patients is diabetic neuropathy, whose main symptom is the loss of sensation in the glove-like nerve distribution area, which means that the back of the palm of the hand is affected. These changes go up to the elbow and involve all the fingers. In the case of the foot, the dorsum of the foot is affected along with the palm of the foot. These symptoms can also rise to the knee and involve all the toes. The neuropathy is usually symmetrical in the extremities and the symptoms often begin in the feet. In contrast, nerve compression is often thought of as a single nerve compression in the lower or upper extremity and the symptoms are often numbness in the upper or part of the lower extremity. The difference between nerve compression-induced numbness and neuropathic numbness was a major factor in the past in why physicians believed that diabetic neuropathy was not caused by nerve compression.
We have learned that peripheral nerves are easily compressed in diabetic patients and we know that everyone has multiple physiologic stenoses, so diabetic patients may have multiple nerve compressions in the upper and lower extremities. If this is true, then multiple compressions in the peripheral nerve pathways can result in a glove-like distribution of numbness and tingling symptoms. From another perspective, the relationship between neuropathy and nerve compression is that certain metabolic abnormalities in diabetic patients lead to neuropathy, which in turn creates the conditions for nerve compression to occur. It is well known that nerve compression can lead to numbness, tingling and decreased muscle strength. Therefore, it is likely that nerve compression is based on neuropathy. This means that at some stages of the disease process, neuropathy and nerve compression are coexisting, but the symptoms may arise as a result of nerve compression.
IV. How diabetic peripheral neuropathy should be treated
The surgery often performed on patients with nerve compression (such as those with carpal tunnel syndrome) can also be used to treat diabetic patients and thereby restore their sensation and muscle strength. Peripheral nerve decompression can be performed on the arms, hands, legs and feet by cutting through ligaments or fibrous tissue to release the compressed areas on the nerve pathway. This reduces the compression on the nerve, improves the blood supply to the nerve, and allows the nerve to glide with the movement of the adjacent joint. Decompression of peripheral nerves in diabetic patients can alter the natural course of diabetic neuropathy, as it is the local compression of the nerve that causes the clinical symptoms. Peripheral nerve decompression does not resolve the metabolic abnormalities of neuropathy (which predispose the nerve to compression). However, if decompression is performed early in the course of nerve compression, blood flow to the nerve can be restored, symptoms of numbness and tingling can disappear, and muscle strength can be restored. If decompression is performed at a late stage of nerve compression, the nerve fibers have already begun to die, but decompression surgery can still help regenerate the nerve. Of course, if you wait until the lesion is very advanced to have the surgery, it will be difficult to recover. If you already have an ulcer on your foot or have had a toe amputation as a result, it is basically impossible to recover because the damage to the nerve is irreversible at that point.
V. Which patients are suitable for this surgery
The most suitable candidates for this procedure to restore sensation and muscle strength are diabetic patients who have just started to feel numbness and tingling in their hands and feet, who are unable to maintain balance or control certain muscles in their hands and feet. These patients must be examined to determine the extent of sensory and motor loss.
VI. Approximate time required for surgery
It is approximately 2 hours. You may need to stay in the recovery room for an additional hour. These times may vary slightly depending on the condition.
Do you have to undergo general anesthesia?
Usually general anesthesia may be better. For lower extremity surgery, spinal canal anesthesia may also be considered. You will often feel drowsy during spinal canal anesthesia, but your breathing is spontaneous. Local anesthesia is also possible. In this type of anesthesia, certain medications can be given intravenously to put you to sleep. Your doctor and anesthesiologist will decide on the best type of anesthesia.
VIII. Is this surgery painful?
This procedure is not very painful. On the one hand, because you are anesthetized during the procedure, and on the other hand, the procedure does not go into the joint cavity. The procedure is often just a cut of the skin and some ligaments, and this is not too painful.