Everyone is familiar with the feeling of sharp pain as a result of an elbow strike. It’s as if an electric current shoots through the arm from the elbow joint to the little finger, sometimes radiating up the shoulder. This occurs due to contusion of the ulnar nerve. Compression of the nerve at the elbow joint is called cubital tunnel syndrome or cubital tunnel syndrome.
The disease is the second most common among carpal tunnel syndromes, second only to carpal tunnel syndrome.
Anatomy of the ulnar nerve and cubital tunnel
The ulnar nerve originates in the cervical plexus, being one of the three main nerves of the upper limb. It runs along the inner surface of the shoulder, then lies in the canal formed by the olecranon process, the internal epicondyle and the ligament that connects these two bone formations, forming a rather narrow cubital canal.
Next, the nerve passes through the intermuscular space of the forearm, flowing into another channel, this time on the wrist. This canal is called the Guyon Canal. It is at the level of this canal that the ulnar nerve begins to divide into 3, sometimes 4 branches, ending with the sensory branches of the 5th and inner half of the 4th fingers, as well as the motor branches of the 3-4-5 lumbrical muscles of the hand.
Consequences and complications
In the absence/inadequate treatment of carpal tunnel syndrome, damage to the median nerve may develop with dysfunction of the hand/wrist joint due to the inability to adduct/oppose the thumb, flex 1-3 fingers, which limits the patient’s ability to work. Persistent pain in the wrist area provokes emotional lability, increased fatigue, and disrupted night sleep. paresis and atrophy may form .
Causes of cubital tunnel syndrome
The cause of this particular disease is compression of the nerve in the cubital canal. In this article we do not discuss nerve injury.
There are several causes of cubital tunnel syndrome:
- repeated trauma to the ligaments and bone structures of the elbow joint that form the canal,
- intense sports,
- arthritis, arthrosis of the elbow joint
- synovitis of the elbow joint or hemarthrosis
- repeated monotonous activities,
- consequences of fractures can also be the causes of the syndrome.
For drivers, the disease can be caused by the habit of placing their elbow on the window opening of the car door. When symptoms appear, this habit will have to be eradicated.
At the computer, you should pay attention to the position of your hand when working on the keyboard and mouse. When doing this type of work, the forearm should rest completely on the tabletop. You can put something soft under the sore elbow.
Compression of the ulnar nerve in the canal can be caused by inflammatory processes not only in the nerve tissue, but also in the soft tissue component of the cubital canal wall. For example, with medial epicondylitis, inflammation in the projection of the internal epicondyle can cause swelling and compression of the nerve. Failure to consult a doctor in a timely manner and delays in starting treatment can lead to organic damage to the wall and the process becoming chronic. As a result of the thickening of the nerve sheath, the transmission of nerve impulses may become difficult, leading to loss of sensation and motor function in some muscles of the hand and forearm.
General information
Tunnel neuropathy in a broad sense refers to compression mononeuropathies, which are a clinical symptom complex that develops as a result of compression of the neurovascular bundle or individual nerve fibers/vessels in anatomically formed tunnels/channels formed by tendons, muscles, fascia or bones.
The term “tunnel” neuropathies is more often applied to compression of the nerve fiber/trunk in the connective tissue openings/canals when their diameter decreases, caused by hypertrophy or edema in conditions of increasing the diameter of the nerve trunk. Tunnel neuropathies are among the most common polyetiological diseases of the peripheral nervous system. According to the literature, they account for up to 40% of all PNS diseases. When compressing nerve trunks of any origin, one should take into account not only the purely mechanical effect on them, but also the disruption of blood circulation, since the vessels are also subject to compression along with the nerve trunks.
The development of tunnel syndrome can be facilitated by both general diseases of various origins and the state of local structures (strain of muscles/ligamentous apparatus surrounding nerve fibers). In this case, both compression of the nerve and its stretching can occur. The median and ulnar nerves are most often affected.
In this case, the ulnar nerve can be compressed both in the area of the elbow joint and at the wrist (Guyon's canal). The names of tunnel syndromes are based on the involvement of anatomical structures in the pathological process. Currently, about 30 variants of tunnel neuropathies are known. The main tunnel syndromes of the upper limbs are listed in the table below.
The main types of lower extremity tunnel syndromes include:
obturator nerve syndrome , peroneal nerve damage , Roth disease , piriformis syndrome , tarsal tunnel syndrome , ilioinguinal neuropathy , saphenous nerve syndrome .
As an example, consider carpal tunnel syndrome. ICD-10 code: G56.0. Carpal tunnel syndrome (syn. carpal tunnel syndrome, carpal tunnel syndrome, hand tunnel syndrome). It occurs due to compression of the median nerve by the transverse carpal ligament at the point where the nerve passes through the carpal tunnel (Fig. below).
The carpal tunnel is formed by the bones and joints of the wrist, the flexor retinaculum, which are covered by ligaments. The median nerve is a mixed nerve that contains sensory/motor and autonomic fibers, primarily innervating the palmar skin of digits 1–3, the radial half of digit 4, and thenar muscles. The motor branch of the median nerve passes to the thenar muscle through the flexor retinaculum. When it is compressed, there is a selective loss of the functions of the thenar muscles innervated by this branch (at the same time (sensitivity is not impaired).
The prevalence of the syndrome in the human population varies depending on the social group and occupational risk factors, ranging from 1-5.8%. Carpal tunnel syndrome occurs mainly in people whose professional activities involve a high load on the hand (PC users, tailors, musicians, artists, office workers, jewelers), whose work is carried out in a state of excessive extension of the hand in the wrist joint in a static position. The risk of developing the disease increases for people who work at low temperatures (fishermen, butchers). At the same time, carpal syndrome occurs in women 5-6 times more often than in males.
In the vast majority of cases, carpal tunnel syndrome of the hand is idiopathic in nature (the cause has not been established); secondary carpal tunnel syndrome is less common, in which the cause of the development of the disease is identified.
Signs and symptoms of cubital tunnel syndrome
Symptoms of cubital tunnel syndrome include each of the following:
It is not necessary to have all the signs.
- Stiffness, loss of sensation, or significant dull or sharp pain in the ulnar part of the hand, 4th and 5th fingers.
- Pain and weakness when attempting to grasp an object with a brush.
- Discomfort in the elbow area.
Such symptoms indicate ischemia (lack of blood supply) of the nervous tissue. These symptoms are most pronounced in the morning, after the hand has been resting overnight. After some time, when the patient performs a certain amount of movements, the pain and numbness slightly recedes.
Symptoms
Symptoms of carpal tunnel syndrome, regardless of its location, include predominantly sensory disturbances ( pain , numbness , paresthesia ), motor disturbances (muscle fatigue/decreased muscle strength), and less commonly, trophic disturbances, which together form the individual picture of the disease. As a rule, tunnel syndromes debut with severe pain, including nociceptive/neuropathic components. The neuropathic component is caused by nerve damage, and nociceptive pain is caused by the inflammatory process and changes in the area of nerve channel conflict. Tunnel neuropathies are characterized by neuropathic manifestations in the form of allodynia (pain with non-painful stimulation), burning, sensation of electric shock (the so-called “electric shock”).
Symptoms of carpal tunnel syndrome include a combination of motor/sensory and autonomic disturbances at the level of the hand in the area of the median nerve. As a rule, sensory disturbances initially develop, manifested by numbness and paresthesia of the hand in the area of 1-3 fingers, which intensify with stress (drawing, working at the computer, driving a car, household chores), as well as at night and immediately after waking up. Motor disorders occur mainly at a later stage (after several years) and include atrophy of the thenar muscles, as well as paresis of 1-3 fingers: weakness of thumb abduction and flexion, palmar opposition. Carpal (carpal) tunnel syndrome can also manifest itself with vegetative manifestations ( swelling of the fingers / hands , neuropathic pain , Raynaud's syndrome , trophic changes in the skin ).
Patients often complain of changes in the shape of the hand, which is caused by wasting of the thenar muscles and is manifested by disturbances in fine motor skills: changes in handwriting, difficulty grasping small objects/fastening buttons. As weakness increases, the patient is unable to hold objects. In old age, the manifestations of carpal tunnel syndrome are more pronounced and are accompanied by severe wasting of the thenar muscles.
Diagnosis of cubital tunnel syndrome
When examining the elbow joint by a doctor, the patient may notice a significant increase in pain. A painful examination is necessary for a specialist to make an accurate diagnosis:
- If the nerve is compressed in the canal, there will be a positive Tinnel's sign, which is manifested by the sensation of a current shooting through the nerve into the little and ring fingers when the doctor taps with a neurological hammer - although this can happen when the nerve is without pathology, with a strong blow.
- The doctor will check to see if the nerve slips out of the canal when the patient bends the arm at the elbow.
- Tests sensitivity and strength in the hand and fingers.
If the doctor has doubts about the causes of cubital tunnel syndrome, the patient may be recommended to undergo additional examinations, such as MRI, ENMG, and radiography.
Radiography. Based on radiographs, it is possible to determine bone exostoses in the projection of the canal, which compress the nerve. But most of the causes of compression of the ulnar nerve cannot be seen on x-ray, since they are of soft tissue etiopathogenesis.
Electroneuromyography (ENMG). This study makes it possible to determine how well the impulses are transmitted along the nerve and to determine at what level and how much the nerve is compressed.
During nerve conduction testing, the nerve is stimulated proximally and the time required to conduct the impulse is measured and compared with normal values.
Tests and diagnostics
Clinical diagnosis of tunnel syndromes, as a rule, does not cause any particular difficulties and is based on identifying neurological symptoms caused by dysfunction of a particular nerve (sensitivity disorders, muscle weakness, muscle atrophy, trophic disorders).
If carpal tunnel syndrome is suspected, pain, vibration, temperature sensitivity in 1-3 fingers is studied and the motor activity of the hand is assessed, as well as possible autonomic ones. When making a diagnosis, tests are used to suggest compression of the median nerve: Tinel test/Phalen test, Gillette test.
Among the methods of instrumental analysis, electroneuromyography of the carpal canal is used (Fig. below).
To determine the location of nerve compression, ultrasound and MRI are prescribed, which allows effective visualization of the nerve, as well as surrounding tissue structures.
Treatment of cubital tunnel syndrome
The vast majority of such cases of the disease require non-surgical treatment. Non-surgical treatment options for cubital tunnel syndrome include:
- load reduction,
- temporary refusal of intense training,
- taking anti-inflammatory non-hormonal drugs.
Good remedies for treating cubital tunnel syndrome are anti-inflammatory non-steroidal ointments, taking vitamins and the patient undergoing a course of physiotherapy.
Surgical treatment of cubital tunnel syndrome is prescribed if therapeutic methods have not produced results after 12 weeks. During surgery, segments of the canal wall are removed from the patient and the tendon arches are cut. If it is impossible to expand the canal surgically, the nerve is completely removed from it, placing it between muscle tissue and fatty tissue.
Forecast
With comprehensive and timely treatment, carpal tunnel syndrome in most cases has a favorable prognosis. In 10-15% of cases, compression of the median nerve does not respond to conservative treatment and surgery is required. A good postoperative prognosis is observed in cases where the disease is not accompanied by atrophy of the hand muscles/complete loss of sensitivity. After surgery, in most cases, hand function is restored by approximately 70% within a month. However, muscle weakness can persist for several months. Recurrence of carpal tunnel syndrome rarely occurs.
List of sources
- Pain syndromes in neurological practice / Ed. O.V. Levina. - St. Petersburg: MedPRESS, 2010. - 308 p.
- Baitinger A.V., Cherdantsev D.V. Carpal tunnel syndrome: current state of the issue. Issues of reconstructive and plastic surgery 2018; 65(2): 12-18.
- Gilweg A.S., Parfenov V.A., Evzikov G.Yu. Immediate and long-term results of median nerve decompression in carpal tunnel syndrome. Neurology, neuropsychiatry, psychosomatics 2018; 10(3): 79-85.
- Gilweg A.S., Parfenov V.A., Evzikov G. Yu. Problems of diagnosis and treatment of compression neuropathy of the median nerve: analysis of typical medical practice. Journal of Neurology and Psychiatry. CC Korsakova 2018; 118(11): 30-34.
- Belova N.V., Yusupova D.G., Lagoda D.Yu., Vershinin A.V. et al. Modern ideas about the diagnosis and treatment of carpal tunnel syndrome // RMJ. 2015. No. 24. pp. 1429–1432.
