Ulnar Nerve Palsy

　　The ulnar nerve is the most superficial at the posterior aspect of the medial epicondyle of the humerus and the olecranon process, and is prone to injury from incisions or fractures. Conditions such as pressure on the elbow joint, trauma, leprosy, abnormal development of the medial epicondyle of the humerus, and varus deformity of the elbow can also cause symptoms. Ulnar tunnel syndrome is also common. There may be indentation, thinning, swelling near the proximal end, and congestion.

　　The following situations can all cause ulnar nerve palsy. There may be varying degrees of adhesions, abnormal position of the ulnar nerve groove, ulnar nerve gliding, and new growths within the ulnar nerve. After surgery, the ulnar nerve is transferred to the anterior or posterior of the elbow, and the symptoms are relieved, indicating that the main cause of ulnar nerve lesions behind the elbow is long-term compression, traction, and wear. The causes of the above lesions include elbow varus, increased carrying angle, relative shortening of the ulnar nerve, and when the elbow joint is flexed, the ulnar nerve is subjected to traction, compression, and wear. Ulnar nerve subluxation: approximately 2-16% of normal people have ulnar nerve subluxation, and among them, those with symptoms are very few. When the elbow is flexed, the ulnar nerve leaves the ulnar nerve groove or moves to the front of the elbow through the medial malleolus, and returns to its original place when the elbow is extended. Such long-term back and forth movement causes the ulnar nerve to be continuously abraded, pulled, and compressed.

　　The ulnar nerve is compressed within the cubital tunnel

　　The ulnar nerve is located in the cubital tunnel behind the elbow. The bottom of the tunnel is the medial collateral ligament of the elbow joint, the lateral side is the olecranon process, the medial side is the medial malleolus, and the top is a fascia. When the elbow joint is flexed, the medial collateral ligament protrudes, the fascia is tightened, causing the tunnel to narrow and the ulnar nerve is easily compressed. There is often a band under the fascia, so the ulnar nerve is more prone to compression. In addition, any changes in the anatomical relationship of the elbow or the hyperplasia of the cubital tunnel structure can cause the narrowing of the tunnel cavity, leading to compression of the ulnar nerve. Fracture malunion of the elbow is most common in children with fractures of the olecranon process, medial epicondyle, radial head, and elbow dislocation, which can cause malunion with varus or other deformities, leading to chronic injury of the ulnar nerve. New growths in the cubital tunnel are rare. For example, ganglion cysts, osteophytes, and others.

　　If ulnar nerve palsy is not treated in a timely manner, or if health care and prevention are not done well during or after treatment, complications such as limited separation and adduction of the fingers, loss of movement of the little finger, and others may occur. Limited separation and adduction of the fingers, and loss of movement of the little finger.

　　The earliest symptoms of ulnar nerve palsy often include numbness or reduced skin sensation in the ulnar nerve distribution area of the hand, followed by the disappearance of skin tingling, with more severe sensory impairment in the distal phalanges of the fingers. The sensory impairment becomes less severe as it moves towards the proximal part, and it is rare for the ulnar half of the hand to completely lose skin sensation. Sometimes, there may be radiating pain in the ulnar half of the hand. The interosseous muscles and the hypothenar muscle group may have varying degrees of atrophy and paralysis, usually mild, but severe cases may present with ulnar clawing, limited adduction and abduction, weakened paper holding strength, and reduced grip strength. The ulnar half of the forearm flexor muscles may also have varying degrees of atrophy. Due to excessive contraction of the extensors, the base joint of the fingers extends excessively, the distal phalanx bends, the hypothenar flattens, the interosseous muscles atrophy and indent, the fingers separate and cannot be brought together, the little finger loses movement and is abducted, fine motor skills of the fingers are lost, and the 4th and 5th fingers cannot be extended and remain in a flexed position, resembling a claw hand. If there are patients who feel significant skin impairment in the ulnar half of the hand, obvious atrophy of the interosseous muscles, and those with claw hand and weakened finger holding strength, they should undergo ulnar nerve anterior transfer surgery, and in some cases, ulnar nerve decompression surgery may be necessary.

　　Ulnar nerve palsy often occurs due to compression of the ulnar nerve within the cubital tunnel. The ulnar nerve is located within the cubital tunnel behind the elbow. The bottom of the tunnel is the medial collateral ligament of the elbow joint, the lateral side is the olecranon process, the medial side is the medial malleolus, and the top is an aponeurosis. When the elbow is flexed, the medial collateral ligament protrudes, and the aponeurosis is tightened, leading to a narrowing of the tunnel and easy compression of the ulnar nerve. There is often a band below the aponeurosis, making the ulnar nerve more susceptible to compression. Additionally, any changes in the anatomical relationship of the elbow or the hypertrophy of the cubital tunnel structure can cause narrowing of the tunnel, leading to compression of the ulnar nerve.

　　To prevent ulnar nerve palsy, one should often rest, protect the hands and elbows from pressure. Due to the reduced sensory function of the affected hand, it is important to protect the affected area during daily activities to prevent secondary injury, such as burns and abrasions. It is also necessary to keep away from water and fire sources.

　　If there is a loss of movement in the little finger, weak flexion strength of the wrist and fingers, inability to adduct and oppose the thumb, the hand deviates towards the radial side when flexing the wrist, and atrophy of the hypothenar muscle and interosseous muscles often occur, along with sensory impairment on the ulnar side of the little finger and ring finger, and a history of direct injury to the ulnar nerve due to fractures of the humerus, dislocation of the elbow joint, or trauma to the wrist or elbow, it indicates that the patient is very likely to have ulnar nerve palsy. The following are the examination descriptions for two types of ulnar nerve palsy syndromes.

　　Carpal tunnel syndrome of the ulnar nerve, since the dorsal branch of the ulnar nerve is not involved, the sensation on the back of the hand is normal. In some cases, the sensory branch of the ulnar nerve on the palm is also not involved, and there is no sensory impairment. The clinical manifestation is mainly the atrophy of the hypothenar muscle, the atrophy of the interosseous muscles and the lumbricals, the little finger in the abductory position, the ring finger and little finger in a claw-like shape, and the limitation of finger flexion and extension. Such cases should be differentiated from motor neuron disease.

　　Carpal tunnel syndrome (Guyon's syndrome): There is a canal on the radial side of the bean-shaped bone, known as the carpal tunnel of the ulnar nerve. The bottom and radial side of this canal are the carpal transverse ligament, the ulnar side is the bean-shaped bone, and the top is the aponeurosis. This aponeurosis originates from the ulnar flexor muscle tendon. The superficial branch of the ulnar nerve (sensory branch) passes through this canal into the palm, controlling the sensory skin of the little finger and the ulnar side of the ring finger. After passing through the canal, the deep branch (motor branch) of the ulnar nerve crosses the hook canal and the adductor muscle tube to enter the palm, where it支配the掌短肌, little finger abductor muscle (within the gugan canal), little finger short flexor muscle, little finger adductor muscle (within the hook canal), flexor digitorum profundus, interosseous muscles, adductor pollicis, abductor pollicis brevis, and the ulnar side of the flexor pollicis brevis. Any symptoms caused by compression of the ulnar nerve in any of these canals are called carpal tunnel syndrome.

　　After diagnosis is confirmed, the symptoms can be relieved by surgically cutting the carpal tunnel and hook tunnel of the ulnar nerve, and the longitudinal incision of the little finger adductor muscle tube. At the same time, perform a nerve decompression operation, which will result in a better therapeutic effect.

　　Patients with ulnar nerve palsy should pay special attention to their diet and living habits. They should rest more often, avoid overexertion, stay in warm places, and prevent catching a cold. It is also important to engage in appropriate activities and exercise daily to enhance nutrition and resistance, and not to stay up late.

　　In addition, try not to press the inner elbow on the desktop when working, try not to press the elbow when taking a nap on the stomach, and gentlemen who drive should try not to support the left elbow on the window frame. If there are any suspected symptoms of ulnar nerve compression, you can go to a rehabilitation department or neurology department that conducts nerve conduction examination for detailed examination. After confirming the diagnosis and evaluating the severity, the doctor will suggest subsequent conservative therapy or refer for surgical treatment.

　　Patients should eat more foods rich in B vitamins, such as yeast, rice bran, whole wheat, oatmeal, peanuts, pork, most types of vegetables, wheat bran, milk. It is taboo to drink strong tea, coffee, alcohol, and smoking for eczema patients. It is forbidden to eat spicy and刺激性食物.

　　The treatment of cubital tunnel syndrome can be fixed with a splint, taken non-steroidal anti-inflammatory drugs orally, and if there is still no effect after 3-4 months, surgical decompression should be considered. Generally, it is possible to use nerve nourishing drugs, physical therapy, and other treatments.

　　The disease onset is slow, and the initial symptoms are discomfort in the elbow, numbness and pain in the area of distribution. In severe cases, there may be a decrease in sensation in the area of distribution, atrophy of the hypothenar muscle and interosseous muscles. At this time, the thickened ulnar nerve can be felt in the ulnar groove, and it is sensitive when locally percussed. In terms of treatment, if there is numbness in the fingers and the hand is not flexible, vitamin B1, 20mg (injection 100mg) three times a day, vitamin B12 200mg intramuscular injection, and at the same time, reduce activity. It is possible to move the ulnar nerve forward by surgical method, but the ulnar nerve must not be tense, and it must be fixed effectively to prevent the ulnar nerve from moving back and forth after surgery, in order to prevent the aggravation of trauma. The key is to treat the cause of ulnar nerve palsy. If it is caused by trauma or surgery, only neurotrophic drugs are available, of course, in addition to vitamin B1 and mecobalamin tablets, if the economy permits, nerve gangliosides or nerve growth factors can also be used.