Peripheral Nervous System Damage and Tunnel Syndromes
Damage to peripheral nerves is one of the most common and complex injuries occurring more frequently at a young age, while tunnel canal syndromes are more common at a relative older age. Damage to peripheral nerves is not a life-threatening injury, although it may result in partial or total disability. Timely diagnosis and proper treatment are important to reduce the risk of developing the condition.
What is a peripheral nervous system damage?
Lesion of peripheral nerve stem can occur for a variety of reasons, such as an injury inflicted with a blunt, sharp or stabbing object, a firearm, or a traction injury. Damage to the nerve stem entails damage to its integrity or partial damage, resulting in limb dysfunction (limitation of movement, impaired sensory function, pain and muscle wasting). Radiological and high-tech examinations are used to diagnose the peripheral nervous system disorders: electroneuromyography, ultrasound or magnetic resonance imaging (MRI) of the nerve.
A variety of treatment is used for peripheral nerve lesions at New Hospitals.
- Restoration of nerve integrity
- Nerve neurolysis
- Endoneurolysis
What is Tunnel Syndrome?
Tunnel syndrome is a disease of the peripheral nervous system caused by compression (squeezing, pressure) of a nerve in anatomically narrow tunnels. The walls of the anatomical tunnel are represented by structures such as bones, tendons and muscles. Normally, peripheral nerves and blood vessels run through the tunnels, but due to certain pathological changes the canal narrows and puts pressure on the nerve. Tunnel syndromes can be caused by different conditions or injuries. For example, bone fractures in the extremities, elbow injuries, prolonged sitting in one posture for a long time (for example, when working with a computer), pregnancy, diabetes mellitus, etc. Radiological examinations such as electroneuromyography, ultrasound or X-ray of the nerve are used to diagnose tunnel syndrome.
There are different types of tunnel syndrome:
Median nerve neuropathy (carpal tunnel syndrome) is characterized by a numbness in the middle of the first, second, third and fourth fingers, an electric shock sensation, unbearable pain in the fingers that cannot be relieved by taking painkillers. The complaints of carpal tunnel syndrome are similar to those of cervical osteochondrosis.
Ulnar nerve neuropathy (cubital tunnel syndrome) is characterized by numbness in the hand, partly in the fourth and fifth fingers, weakness of the wrist and fourth and fifth fingers, difficulty extending the fourth and fifth fingers, muscle wasting between the thumb and forefinger, claw-like deformity of the hand.
Radial nerve neuropathy - one and main of the clinical symptoms of the radial nerve neuropathy is a wrist drop. The wrist drop is caused by paresis of the extensor muscles of the wrist and fingers. The patient is unable to extend his or her fingers and wrist.
Peroneal nerve neuropathy - at this time it is impossible to extend the foot and toes (the foot drop), sensory disturbances occur on the outer surface of the shin and on the posterior surface of the ankle.
Brachial plexus neuropathy – damage to the brachial plexus is one of the most complex and difficult to treat pathologies of the peripheral nervous system. The lesion can be with a complete or incomplete impairment of nerve conduction. During this injury the loss of both motor and sensory function occurs throughout the limb due to the blockade of nerve impulse conduction.
Tibial nerve neuropathy – the damage to the tibial nerve (neuropathy) causes paralysis of the flexor muscles of the foot and toes and the abductor muscles of the foot. In tibial nerve neuropathy sensory disturbances develop on the posterior surface of the ankle, foot and dorsal surface of the toes.
Various methods are used to treat tunnel syndromes at New Hospitals.
- Nerve neurolysis or endoneurolysis
- Decompression of the nerve in the tunnel canals
- Transposition of the nerve
- Removal of the irritating factor (bone fragment, metal construction after bone fixation)
What are benign and malignant tumors of the peripheral nerves?
Benign and malignant peripheral nerve tumors, such as schwannoma, neurofibroma, malignant peripheral nerve sheath tumors (MPNST), Barre-Masson tumor develop from the peripheral nerves without any impact. As for Morton’s neuroma, it develops as a result of nerve damage in the foot. All tumors, whether malignant or benign, can only be treated by removing the tumor. Tumors can be diagnosed by electroneuromyography, ultrasound and magnetic resonance imaging (MRI) of the nerve.
Peripheral nerve lesions can be either open or closed. Lesions can be caused by various injuries, such as wounds caused by a knife, shards of glass or other sharp objects, bone fractures, soft tissue compression, etc. In both open and closed nerve lesions, motor and sensory functions are impaired immediately after injury. The symptoms and complaints during these injuries correspond to the anatomical area of innervation of the damaged nerve.
Peripheral nerve damage is accompanied by clinical signs - symptoms that may indicate an injury:
Sensory impairment- the sensory impairment accompanies damage to the nerve and corresponds anatomically to the area of nerve innervation. This symptom appears immediately after the injury and recovery is impossible without nerve reconstruction. Due to the lack of sensibility, frostbite, burns etc. are the main risks for these patients.
Impaired motor function – in case of impaired motor function, there is dysfunction in the muscles innervated by the damaged nerve. As a result, the patient has difficulty or is unable to perform normal movements.
Trophic disorders – peripheral nerve damage can lead to trophic disorders which impair skin elasticity and turgor, resulting in thinning of the skin. The incidence of injury and development of ulcers is increased due to thinning of the skin. During this disorder, nail growth is also retarded. The extremities become atrophic. Over time, the trophic changes spread to the tendons, joint sacs and ligaments, resulting in limitation of limb motion and development of contractures.
Radial nerve damage - one of the main clinical symptoms of radial nerve damage is a wrist drop. The wrist drop is caused by paresis of the extensor muscles of the wrist and fingers. The patient is unable to extend his or her fingers and wrist.
Median nerve damage - with damage to the median nerve, a sensory disturbance develops on the palmar surface of the wrist, the first, second, third fingers and half of the fourth finger. Sensibility is also impaired on the dorsal surface of the ungual phalanges of the first, second and third fingers. It becomes hard or impossible to perceive the shape, size, consistency and temperature of an object in touching. Vasomotor, secretory, trophic lesions are revealed in the early stages of the damage. The skin is dry, cyanotic, easily damaged. The fingers are atrophied, the nails are deformed and brittle and their growth is retarded compared to undamaged nails. The manifestation of clinical severity depends on the grade of the lesion.
Ulnar nerve damage - one of the main symptoms of ulnar nerve damage is impaired motor function in the wrist and fingers accompanied by reduced sensibility. It becomes impossible to extend the fourth and fifth fingers, to stretch the fifth finger. Strength in the wrists and fingers is impaired; the muscle atrophy in the hand is noticeable in about 1-2 months after the damage, with particularly rapid muscle atrophy between the first and second fingers. The bones are sharply visualized on the dorsal surface of the hand due to the wasting of the interosseous and lumbrical muscles. Later the hand becomes deformed with the fourth and fifth fingers missing the surface of the palm when the hand is clenched into a fist.
