Peripheral Nervous System

The peripheral nervous system is a part of the nervous system that includes the cranial and spinal peripheral nerves, providing the connection of the central nerves with the organs and systems of the body.

Among the most frequently diagnosed diseases of the peripheral nervous system of a person, several forms of neuritis, plaxitis, neuralgia are distinguished, as well as all kinds of these pathologies, which have different topography and are manifested most often by sharp and sometimes mild pains of a permanent nature. By the way, such widespread radiculitis is also a peripheral lesion.

Diseases of the peripheral nervous system are the most common in the neurological clinic and account for up to 50% of outpatients. Not representing, as a rule, a threat to the life of patients, which are the primary cause of disability.

The causes of damage to the peripheral nervous system can be acute and chronic infections, trauma, intoxication, hypovitaminosis, ischemia, hypothermia, compression, degenerative changes in the spine.

Pathology of the peripheral nervous system at the site of localization:

Depending on the localization and pathogenesis, the following diseases of the peripheral nervous system are distinguished.

Neuritis (neuropathy) is a disease in which pathomorphological changes in the peripheral nerve are accompanied by impaired motor, sensory, and autonomic functions. Neuralgia is characterized by attacks of pain along the nerve without signs of organic damage.

This pathology of the peripheral nervous system is mainly due to metabolic, degenerative processes in the nerve fiber, with minor inflammatory changes in it.

• Polyneuritis (polyneuropathy) is damage to many peripheral nerves.
• Plexitis is a lesion of the nerve plexus.
• Ganglionitis is a lesion of the intervertebral nodes.
• Radiculitis is a lesion of the roots of the spinal cord.
• Radiculoneuritis is a simultaneous lesion of the roots of the spinal cord and nerve trunks.
• Myeloradiculoneuritis is a lesion of the spinal cord, roots, and nerve trunks.

The most common forms of disorders of the peripheral nervous system are vertebrogenic pathology (osteochondrosis), neuritis (neuropathy), and neuralgia. Moreover, those nerves most often suffer, whose trunks pass through narrow bony canals – facial, trigeminal, sciatic.

Lesions of the peripheral nervous system: plexitis

Cervical plexitis is caused by infections, tumors, tuberculosis, and injuries to the cervical spine; it is manifested by pain and sensory disturbances in the occiput, ear, neck, upper scapula, and shoulder. This plexitis is characterized by dysfunctions of the phrenic nerve (respiratory failure, hiccups, complete or partial immobility of the diaphragm).

Shoulder plexitis occurs after shoulder injuries, collarbone fracture, infections, pathology of the spine and lungs. Depending on the localization of the lesion, upper, lower, and total brachial plexitis is distinguished. 

Upper (Duchenne-Erb paralysis) is manifested by pain in the upper third of the shoulder, decreased reflex with t. Biceps, difficulty in shoulder abduction, supination, flexion of the arm at the elbow, and impaired sensitivity on the outer surface of the shoulder and forearm.

 Lower (Dejerine-Klumpke paralysis) is characterized by pain and sensory disturbances along the inner surface of the shoulder and forearm, paresis and atrophy of the muscles of the hand and forearm, and a decrease in the carporadial reflex. Possible Horner-Bernard syndrome.

Lumbosacral plexitis occurs as a result of infections, intoxications, diseases of the pelvic organs and abdominal cavity, during pregnancy, with pathological childbirth and injuries of the spine and pelvic bones. Clinically, plexitis is manifested by pain and impaired sensitivity in the buttocks, thighs, and lower legs, loss of the knee and Achilles reflexes, paresis of the foot, and atrophy of the muscles in the buttocks and thighs.

Peripheral nervous system disorders: facial neuritis

Neuritis of the oculomotor peripheral nerve. The disease is predominantly of vascular, inflammatory, diabetic genesis. It is observed with tumors.

Such peripheral neuritis is manifested by the drooping of the upper eyelid, dilated pupil, diverging strabismus, and double vision.

Treatment according to the etiology of the disease, vitamin therapy, biostimulants.

Facial nerve neuropathy. It is more common than lesions of other cranial nerves.

The cause of the disease can be hypothermia, infection, trauma, inflammation of the ear or meninges, tumors of the base of the skull.

 Since the trunk of the facial nerve passes through a narrow bony canal and its terminal branches are located superficially, the nerve is easily injured, and tissue edema develops during inflammatory processes, which leads to compression of the nerve and the vessels feeding it.

This peripheral nerve neuritis develops acutely or subacutely. How can we distinguish between peripheral and central paralysis of the facial nerve?

Peripheral paralysis is characterized by facial asymmetry – the face is skewed to the healthy side. On the side of the lesion, the skin folds are smoothed, the eye does not close, when you try to close the eye, the eyeball rolls up (Bell’s symptom), food gets stuck behind the cheek, teeth grin more in a healthy direction. Dry eyes or watery eyes, hearing, taste, and salivation disorders are possible.

With central paralysis, only flattening of the nasolabial fold and drooping of the corner of the mouth are observed.

A complication of this disease of peripheral nerves can be persistent contracture of the affected muscles and tonic muscle spasm – facial hemispasm.

Diagnosis is based on clinical data, and sometimes LOP examination, skull X-ray, computed tomography are performed to clarify the diagnosis.

Treatment for this disease of the peripheral nervous system should be started early and appropriate to the cause of the lesion. For infectious and inflammatory genesis, salicylates, urotropine, indomethacin, acyclovir, prednisolone are prescribed.