Ischemic neuropathy of nerves: species

When it comes to  ischemic neuropathy,  everyone immediately remembers the pathology of the optic nerve caused by impaired circulation in one part of the eye. More precisely, even the parts of the nerve itself, which adjoins the eyeball. Intra- and retrobulbar departments are most susceptible to ischemic lesions.

Ischemic optic neuropathy

Ischemic optic neuropathy  implies 2 types of pathologies that differ localization of the site of lesion of the optic nerve. Anterior ischemic neuropathy of the  optic nerve is a lesion of nerve fibers in the intrabulbar department, which is bounded by the sclera and located within the eyeball. This is the shortest section of the optic nerve (only 0.5 mm), in which its disk is located.

Ischemic disturbances in the visual disk (with the anterior shape of the pathology affected retinal, choroidal or scleral layer) can be seen already at an early stage, even with the usual ophthalmoscopy.

The posterior ischemic neuropathy of the optic nerve  is a change in the retrobulbar (same intraorbital) department. The length of this department is from 2.5 to 3.5 cm, it is located between the sclera and the orbit opening of the visual canal. Alas, the violation of blood supply to the nerves in this department at the beginning of the pathology is invisible in the conduct of ophthalmoscopy or retinography. Only electrophysiological methods of investigation and dopplerography of the vessels (carotid, ocular and supra-block artery) will be informative.

As in the first case, the disease affects mainly people of age. The frequency of detection of this pathology in men is much higher than that of women.

The main specific symptom of both pathologies is a sharp decrease in the quality of vision due to vasospasm, clot obstruction or sclerotic changes. The influence of systemic diseases and acute blood loss is not ruled out.

But ischemic processes can occur not only in the optic nerve, but also in other structures of the nervous system. The cause of neuropathies in any case will be a violation of blood flow in the vessels that nourish a particular nerve.

Ischemic neuropathy of the facial nerve 

This is the defeat of one of the youngest nerves in the skull. This legkoranimoe education carries an important function of regulating facial expressions. In other words, it is responsible for the innervation of facial muscles. It is clear that reducing its function leads to the appearance on the face of a strange grimace, which a person can not control. A worsening of the work of nerve fibers can occur due to a violation of blood circulation in one of the vessels passing near a certain branch of the facial nerve.

The facial nerve is a rather complicated branching structure, the fibers of which intertwine with the fibers of other structures responsible for the sensitivity of the tongue, salivation and tearing. In the immediate vicinity of the nucleus of the facial nerve, in the depths of the brainstem, there are also nuclei of other nerves (auditory, abduction, trigeminal). The defeat of these nervous structures is also possible, then symptoms such as changes in taste perception, strabismus, hearing impairment, drooling, abundant symptoms can be superimposed on the symptoms of facial nerve lesions (half-closed eyes and mouth, distorted facial features, sagging cheeks, etc.) allocation of tears, etc.

According to statistics, the incidence of this type of pathology is of the order of 0.025%. Treatment of the disease is quite long - 21-30 days, and the recovery period can last from 3 weeks in mild cases to six months in neglected. The prognosis depends on the degree of nerve damage. Full paralysis of the muscles gives a half-prediction. Complete recovery of muscle mobility is observed in half of patients. With partial paralysis, this figure increases to 85%. In 1 out of 10 patients, the disease can relapse.

Depending on the degree of lesion of the facial nerve, mimicry is replaced by a strange mask. With a complete atony of the muscles, a strange picture is observed. Usually the process is one-sided, so one half of the face has the same usual expression, and the other turns into a grimace: there are no wrinkles on the forehead, around the eye, in the nasolabial triangle, the eyelid and the corner of the lips drop, the eye gap becomes unusually wide, with this person can not completely close his eyes. Because of the slightly open mouth, there are difficulties with eating, especially liquid, which pours out.

Well, we go further, from the head sinking to the trunk. In the area of the shoulder, we observe a nerve plexus consisting of the thoracic spinal cord and cervical nerves. Knee from him (along the arm) diverge as far as short and long branches, and any of them can undergo ischemic damage if the blood flow of the vessel nourishing the nerve is disturbed.

One of the long branches of the brachial plexus is the median nerve that passes along the shoulder artery along the arm artery and then extends along the medial edge of the humerus. In the lower part of the shoulder dives under the Struser bunch, then leaves in the thickness of the round muscle, called the pronator, and leaves on the forearm. On this segment, the nerve has practically no branches. They appear in the area of the forearm and hand.

On the forearm, the nerve passes under the muscles responsible for the flexion of the fingers. Here, under his control, is the entire anterior muscle group.

In the brush region, the median nerve enters through the carpal tunnel, which is otherwise called carpal tunnel. Here the nerve is responsible for the innervation of the muscles responsible for the movement of the thumb and the sensitivity of the skin from the palm of the hand to 3.5 fingers, including the large, vermiform muscles and wrist joint.

In connection with the special anatomical structure of the median nerve, in places its maximum vulnerability is considered to be tunnels, where the nerve passes between the muscles, ligaments, joints, where it can be clamped together with the nearby artery supplying the nerve. In tunnel syndromes are carpal tunnel syndrome, syndrome of the round pronator, Struzer tape syndrome, etc.

Ischemic neuropathy of the median nerve

It becomes clear that in this case it is not just about ischemic neuropathy, but about  compression-ischemic neuropathy of the median nerves, where ischemia occurs due to compression of the nerve and vessels. The cause of such compression may be injuries, tumors, inflammatory and degenerative processes in the muscles and joints. Sometimes tunnel syndrome is associated with professional activity and regular performance of tasks, in which there is a clamping of nerves and vessels.

The most revealing symptoms of the pathology are: severe pain, from which the areas of the medial surface of the forearm, the brush and the first 3 fingers may suffer, edematous region of the lesion, heat in this area (with ischemia often reverse reaction with cyanosis and hypothermia), sometimes numbness and tingling in the hand and palm. A person can not collect his fingers into a fist, bend or bend the thumb, the second finger does not usually bend, and with bending the third one certain difficulties are canceled.

Ischemic neuropathy of the ulnar nerve

The ulnar nerve is another long branch of the brachial plexus, which can be squeezed together with the vessels feeding it, as a result of which the compression-ischemic neuropathy of the ulnar nerve develops  . This nerve also branches from the forearm, but it is responsible for the innervation of the elbow flexor, the hand, some of the deep flexor of the fingers, the muscle responsible for bringing the thumb, interosseous and vermicular muscles, the muscles of the last finger, the skin of the palms and fingers.

Together with the ulnar artery, the nerve passes through the cubital canal (the ulnar canal) and the Guyon canal in the wrist area, where they are most often squeezed, accompanied by a weakness of the brush, which makes a person unable to perform the usual movements (take something in the hand, print on the text, play keyboards, etc.). Numbness is also a characteristic syndrome of pathology, it is felt in the area of the little finger and part of the ring finger, and also from the outside of the palm.

A person can feel discomfort and pain in the elbow, which often rests in the wrist and brush. The middle and extreme phalanges of the fingers are constantly bent, which gives the impression of a predator's paw with claws.

The causes of pathology are identical to the previous form of neuropathy. These are injuries, inflammations, rheumatic changes, as well as doing certain work and bad habits that lead to nerve compression at the elbow or wrist area.

Another long branch, emerging from the brachial plexus, is called the radial nerve. It goes along the back of the armpit and rests against the intersection of the widest dorsal muscle and tendon of the shoulder triceps. It is in this place that the compression of the radial nerve is possible.

Next, the nerve passes through the groove of the humerus, spiraling around the bone itself, where it can also be squeezed. The clamping of this nerve is also possible in the region of the elbow, where it passes along the inner part of the elbow fold, then descending to the brush in the form of two branches: superficial and deep.

Ischemic neuropathy of the radial nerve

The radial nerve is responsible for the innervation of the muscles extending the forearm and the wrist, removing the thumb, expanding the proximal phalanges of the fingers and turning the palm upward, providing sensitivity to the elbow, the back of the shoulder, the back of the forearm, some part of the hand and the first 3 fingers, except for the extreme (distal) phalanx.

Ischemic neuropathy of the radial nerve can be caused both by its compression due to trauma, tumor formations, untimely removal of the tourniquet, frequent regular hand flexions in the elbow or wrist, and gagging during sleep. Arms in the underarm area are due to the use of crutches or when resting on the knee bent in the knee during sitting. Contraction of the radial nerve in the hand area is possible when wearing handcuffs.

The cause of ischemic neuropathy can be inflammatory and degenerative changes in tissues in the region of the passage of the radial nerve and vessels feeding it. Ischemia can also result from infectious systemic diseases and severe intoxication.

If we are talking about the defeat of the nerve in the armpit, the symptoms will be difficulty in extending the arm in the area of the forearm, the hand and the phalanges of the fingers nearest to the palm. There is a strong weakening of the brush. Even if you raise your hands, the brush will still remain hanging. A person can not take his thumb aside, feels numbness and tingling from the back of the first 3 fingers, although the sensitivity of the distal phalanges persists.

If the nerve is affected in the spiral canal, the elbow reflex and extension of the arm at the elbow are not violated, however, as is the sensitivity of the posterior surface of the shoulder.

When a nerve is injured near the elbow joint, a person experiences pain and a sensitivity disorder on the back of the hand each time they have to flex their arm in the elbow joint. The sensitivity of the forearm in this case may remain normal or slightly reduced.

Nerve damage in the wrist area is characterized by two syndromes: Turner (in fractures) and radial tunnel (with compression of the superficial branch). In both cases, the back of the hand and the fingers grow numb, on the back of the thumb there is a burning sensation and pain that can spread up the entire arm.

In the region of the upper limbs, there are several short nerves (long thoracic, subclavian, axillary, supra- and subscapular nerves, etc.), as well as long branches: the musculocutaneous and medial nerve of the forearm. All of them can also be subjected to ischemia, but this happens much less often than with the above nerves.

Ischemic neuropathies of the upper extremities are no longer senile pathologies. They are more characteristic of youth and middle-aged people, i.e. Able-bodied population.

And what will the nerves of the lower limbs tell us, for which ischemic neuropathy is also not something unimaginable, especially if we take into account the frequent cases of varicose veins and leg injuries?

The control of the muscles of our legs is carried out by two kinds of nerve plexuses. One of them is called lumbar, the second - sacral. From the lumbar coil, several branches appear in the ilio-crochet and inguinal region, in the region of the genital organs, in the thighs. The lumbar plexus also includes the lateral and the blocking nerve.

All these branches are engaged in innervation of the muscles and skin of the small pelvis and hip, and may undergo ischemia to a greater or lesser extent, but not as often as the nerves of the sacral plexus.

The sacral plexus has 3 departments: coccygeal, genital and sciatic. But of all the nerve fibers of the sacral plexus, the largest of the nerves is most often damaged, which is called sciatic because of its passage in the buttock region, and its branch is small and tibial nerves. The sciatic nerve branches into two unequal branches in the second half of the thigh length near the popliteal fossa.

The sciatic nerve passes inside the pelvis and through a special opening goes to the posterior surface of it, dives under the pear-shaped muscle, runs along the hip along the posterior part, and divides not far from the popliteal fossa. Thanks to this nerve, we can bend the leg in the knee.

Sciatic nerve damage is possible along the entire path of its passage as a result of injuries, tumor processes, hematomas, aneurysms, and prolonged compression. But most often it is squeezed by a pear-shaped muscle, altered as a result of various pathologies of the spine or improperly administered by intramuscular injection.

The defeat of the sciatic nerve, as well as of other nervous structures, is also possible with systemic infectious and inflammatory pathologies and toxic effects on the body.

Symptoms of sciatic nerve damage are piercing pain along the nerve, limiting limb movement, numbness and tingling in the back of the shin and foot, difficulties with bending the leg in the knee.

Neuropathy of the sciatic nerve according to the frequency of occurrence is second only to the pathology of one of its branches - the peroneal nerve. This nerve, passing under the knee, splits at the beginning of the fibular bones. Thus, deep and superficial branches become a continuation of the nerve. The first goes along the outer surface of the shin and the upper side of the foot, the second - along the anterior-lateral part of the shin with the transition to the medial part, where the nerve penetrates under the skin and branches into two parts. These parts are called intermediate and medial skin nerves.

The deep part of the peroneal nerve is responsible for the innervation of the muscles, which unbend the foot and toes, and also raise the outer edge of the foot. The superficial branch controls the muscles that provide the turn and plantar flexion of the foot, its sensitivity, innervates the skin between the fingers and in the lower part of the shin.

Most often the lesion of the peroneal nerve occurs around the head of the fibula and the place where the nerve exits to the foot. The compression of the nerve and passing vessels in these areas is called the upper and lower tunnel syndrome. In addition to compression, including wearing tight shoes and prolonged immobilization of limbs, injuries, systemic infections and intoxications, the cause of the disease may be changes in muscle tissue and joints caused by diseases of the spine. Less often, the disease causes tumors, connective tissue pathologies, metabolic disorders.

Neuropathy of the peroneal nerve

But vascular disorders (for example, varicose veins or vascular thrombosis) and compression are considered the most common causes of ischemic or compression-ischemic  neuropathy of the peroneal nerve.

With ischemic and compression nature of pathology, the symptoms of the disease appear gradually, their intensity increases with time. The defeat of the peroneal nerve to the point of branching under the knee is characterized by problems with extension of the foot and toes. The foot stays curved downwards, which presents certain difficulties during walking. A man has to raise his legs strongly, so as not to pinch the floor with his fingers (a cock or a horse's gait). The patient can also experience pains in the outer part of the shin or foot.

If ischemic lesion is subjected to a deep branch of the peroneal nerve, the hanging of the foot is not so pronounced, but the difficulties in its extension and movement with the fingers remain. There is a decrease in the sensitivity of the back of the foot and the gap between the two first fingers. If the disease persists for a long time, you can see the sinking of the interosseous gaps on the back of the foot.

With neuropathy of the superficial branch of the peroneal nerve, there is a decrease in the sensitivity of the lateral surfaces of the tibia in the lower part and the middle region of the rear of the foot. In these places, the patient may experience pain. Bending of the fingers is not broken, but the turn of the foot is somewhat weakened.

Ischemic neuropathy of the tibial nerve

The tibial nerve passes through the center of the popliteal fossa, between the medial and lateral head of the fleshy gastrocnemius muscle, then between the flexors of the fingers and dives into the ankle fork graft. From there, the nerve enters the tarsal canal, where it is securely fixed together with one of the tibial arteries by the flexor holder. It is in this channel that the nerve is most often squeezed.

The tibial nerve controls the movements and sensitivity of the skin and muscles responsible for flexing the foot and lower leg, the fold of the foot inside, various movements of the toes, extension of the distal phalanges.

In   addition to compression in the tarsal section, traumas can also result from ischemic neuropathy of the tibial nerve (often such injuries are received by athletes), deformities of the foot, prolonged stay in an uncomfortable position, diseases of the knee and ankle, tumor processes, metabolic disorders, vascular pathologies (eg, vasculitis, which causes inflammation and destruction of the vascular walls).

If the tibial nerve is affected in the area under the knee, the clinical picture of the pathology implies a violation of the flexion of the foot downwards (in the case of peroneal pathology the situation is reversed, although in either case it is noted that it is impossible to become "tiptoe"). During the movement, the person makes an emphasis on the heel, trying not to lean on the socks. The posterior group of the calf and foot muscles gradually atrophies and the foot begins to resemble the clawed paw of the animal (an identical situation is observed with the neuropathy of the ulnar nerve).

A sensitivity disorder is observed on the back of the shin and on the lower third of its anterior part, in the region of the sole. The sensitivity is reduced over the entire surface of the first 3 fingers and from the back of the 5th finger. The fourth finger is partially affected, because it is innervated by different nerves.

If neuropathy is traumatic, then on the contrary, the sensitivity can become excessively high, and the skin swollen.

Compression of the nerve and vessels feeding it in the tarsal canal will be manifested by burning and piercing pains in the region of the sole, which are delivered to the gastrocnemius muscle. Pain increases during running and walking, and also if the patient is long standing. At both ends of the foot, a pathological increase in sensitivity is observed. Stop after time becomes flatter, and fingers slightly bend inwards. If you knock with a hammer in the Achilles tendon area, the patient will complain of pain in this place.

The defeat of the medial nerve on the sole is manifested as pains on the inner edge of the foot and in the back of the first 3 fingers. If you perform a tapping (percussion) in the scaphoid bone area, then the sharp toe pains will be felt in the big toe.

Nerve compression in the tarsal canal and lesion of the medial branch of the tibial nerve are characteristic of people with high physical activity, athletes, tourists. Most often they are provoked by long walking or running.

The defeat of the branches of the tibial nerve in the region of the fingers is characteristic of people with excess weight who love heels. Thus, this pathology is more characteristic of women. She is characterized by pain syndrome, which begins at the arch of the foot. Pain is felt at the base of the foot, and also penetrates through the first 2-4 fingers, strengthening during standing or walking.

The defeat of the branch of the tibial nerve in the heel area, caused by prolonged walking without shoes or on a thin sole, and also by landing on the heel during a jump from height, is manifested by pains and a strong decrease in sensitivity in this area. But sometimes patients complain of unpleasant sensations in the heel (tingling, tickling, etc.) or increasing its sensitivity to touch (touching the tissues are painful). Because of fear of the appearance of such symptoms, a person tries to walk, not stepping on the heel.

It must be said that our body is wrapped around a huge network of intersecting nerves and vessels. Violation of blood flow in any part of the body can well lead to the defeat of nerves, i.e. To the development of ischemic neuropathy. And although the reasons for such violations can be completely different, the consequences of nerve damage always affect the quality of life of the patient, restrict movement, work capacity, and sometimes communication, affecting the psycho-emotional state of a person.