Symptoms of lumbar plexus and its branches

The lumbar plexus (pl. Lumbalis) is formed from the anterior branches of the three upper lumbar spines, as well as parts of the fibers of TVII and LIV of the spinal nerves. It is located in front of the transverse processes of the lumbar vertebrae, on the front surface of the square muscle of the waist and in the thick of the large lumbar muscle. From this plexus consecutively following nerves follow: iliac-hypogastric, ilio-inguinal, femoral-genital, lateral cutaneous nerve of hip, locking and femoral. With the help of two or three connecting branches, the lumbar plexus will anastomose with the lumbar part of the sympathetic trunk. The motor fibers, which are part of the lumbar plexus, innervate the muscles of the abdominal wall and pelvic girdle. These muscles bend and tilt the spine, bend and unbend the lower limb in the hip joint, divert, lead and rotate the lower limb, unbend it at the knee joint. Sensitive fibers of this plexus innervate the skin of the lower abdomen, anterior, medial and external surface of the thigh, scrotum and upper-upper parts of the buttock.

Because of the large extent, the lumbar plexus is completely affected relatively rarely. Sometimes it is observed in muscle injuries with a sharp object, with bone fragments (with spine fractures and pelvic bones) or with hematoma, surrounding tissue tumors, a pregnant uterus, inflammatory processes in the retroperitoneum (myositis of the lumbar muscles, phlegmon, abscess) and infiltrate due to inflammatory processes in the ovaries, vermiform appendage, etc. More often one-sided lesion of the plexus, or part of it.

Symptoms of lumbar plexitis are characterized by pain in the zone of innervation of the lower abdomen, lumbar region, pelvic bones (neuralgic form of plexitis). All types of sensitivity are reduced (hypesthesia or anesthesia of the skin of the pelvic girdle and thighs.

Pain is revealed with deep palpation through the anterior abdominal wall of the lateral parts of the spine and behind in the quadrangular space between the lower rib and the iliac crest where the square muscle of the loin is located and attached. Pain intensification occurs when the straightened lower limb is lifted upwards (in the position of the patient lying on the back) and when the lumbar spine is tilted to the sides. In the paralytic form of the lumbar plexitis, weakness, hypotonia and hypotrophy of the muscles of the pelvic girdle and hips develop. The knee jerk is reduced or lost. Violations of movement in the lumbar spine, in the hip and knee joints.

The topical differential diagnosis must be performed with multiple lesions of the spinal nerves forming it (in the initial phase of infectious-allergic polyradiculoneuritis of the Guillain-Barre-Strohl type, with epiduritis) and in compression of the upper parts of the horse tail.

The ilio-hypogastric nerve (n. Iliohypogastricuras) is formed by fibers of TXII and LI of the spinal roots. From the lumbar plexus, it emerges from under the lateral margin m. Psoas major and directed along the front surface of the square lumbar muscle (behind the lower pole of the kidney) obliquely downward and laterally. Above the iliac crest, the nerve perforates the transverse abdominal muscle and is located between it and the inner oblique abdominal muscle along n above the cristae iliacae.

Reaching the inguinal (papartal) ligament, the ilio-hypogastric nerve passes through the thickness of the inner oblique abdominal muscle and is located under the aponeurosis of the external oblique muscle, along and above the inguinal ligament, then approaches the lateral edge of the rectus abdominis and branches into the skin of the hypogastric region. Along the way, this nerve is anastomosed with the ilio-inguinal nerve, and then three branches branch out from it: the motor branches (directed toward the lower abdominal wall muscles) and the two sensitive ones - the lateral and anterior cutaneous branches. The lateral and cutaneous branch extends above the middle of the iliac crest and, perforating the oblique muscles, is guided to the skin above the middle gluteus muscle and the muscle that strains the fascia of the thigh. The anterior cutaneous branch is terminal and penetrates through the front wall of the vagina of the rectus abdominis above the outer ring of the inguinal canal, where it terminates in the skin above and is medial to the external opening of the inguinal canal.

Usually, this nerve is affected during surgery on the abdominal and pelvic organs or in hernia. In the postoperative period, there is a constant pain, increasing with walking and torso of the trunk forward. The pain is localized in the lower part of the abdomen above the inguinal ligament, sometimes in the zone of the large trochanter of the thigh. Strengthening pain and paresthesia is noted when palpation of the upper edge of the outer ring of the inguinal canal and at the level of the large trochanter of the thigh. Hypesesia is localized over the middle gluteus muscle and in the groin.

The ilio-inguinal nerve (n. Ilioinguinalis) is formed from the anterior branch of LI (sometimes LII) of the spinal root and lies below, parallel to the ilio-hypogastric nerve. In the intra-abdominal region, the nerve passes under the large lumbar muscle, then perforates or traces its outer part and then proceeds along the front surface of the square muscle to the waist under the fascia. Inside the anterior superiority of the iliac spine is the place of possible compression of the nerve, because at this level it permeates first the transverse abdominal muscle or its aponeurosis, then at an angle of about 90 ° it perforates the inner oblique mosshu of the abdomen and again almost at right angles changes its course, inner and outer oblique abdominal muscles. From the ilio-inguinal nerve, the motor branches branch out to the very lowest sections of the transverse and internal oblique muscles of the abdomen. The terminal sensory branch permeates the outer oblique mosshu of the abdomen or its aponeurosis immediately ventro-caudal from the superior anterior iliac spine and extends further inside the inguinal canal. Its ramifications supply the skin above the pubis, as well as in men - above the root of the penis and the proximal part of the scrotum, in women - the upper part of the large labia. Sensitive branches also supply a small area in the upper part of the anterior inner thigh surface, but this area can be overlapped by the femoral-genital nerve. There is also a sensitive recurrent branch that supplies a narrow strip of skin above the inguinal ligament up to the iliac crest.

Non-traumatic ileal-inguinal nerve injury usually occurs near the superior anterior iliac awn where the nerve passes through the transverse and internal oblique muscles of the abdomen and changes in a zigzag direction at the level of the contiguous edges of these muscles. Here, the nerve can be mechanically irritated with muscle or fibrous cords, when their edges, compressed, press on the nerve with a constant or periodic muscle tension, for example, when walking. Compression-ischemic neuropathy develops as a tunnel syndrome. In addition, often the ilio-inguinal nerve is affected during surgical interventions, more often after hernia, appendectomy, nephrectomy. Neuralgia of the ilio-inguinal nerve after hernia repair is possible when tightening the nerve with a silk suture in the region of the internal oblique abdominal muscle. The aponeurosis may also be exerted on the nerve after an operation performed by the Bassini method, or the nerve can be compressed after many months and even years after surgery by a scar tissue that forms between the inner and outer oblique muscles of the abdomen.

The clinical manifestation of ilio-inguinal neuropathy is divided into two groups - symptoms of damage to sensory and motor fibers. The greatest diagnostic value is the damage of sensitive fibers. Patients experience pain and paresthesia in the inguinal region, sometimes painful sensations spread to the upper sections of the anterior and inner thigh and into the lumbar region.

Palpable tenderness is typical in a typical place of nerve compression - at a point slightly higher and 1-1.5 cm inward from the superior anterior iliac spine. Finger compression at this point in the defeat of the ilio-inguinal nerve, as a rule, causes or intensifies painful sensations. Painful palpation in the area of the external opening of the inguinal canal. However, this symptom is not pathognomonic. Palpatory tenderness at this point is also noted in the defeat of the femoral-genital nerve. In addition, with compression syndromes, the entire distal segment of the nerve trunk, starting from the level of compression, has an increased excitability for mechanical irritation.

Therefore, with finger compression or pokapachivakii in the area of the projection of the nerve, only the upper level of provocation of painful sensations corresponds to the place of compression. The area of sensitive disorders includes a site along the inguinal ligament, half of the pubic region, the upper two-thirds of the scrotum or large labia, the upper part of the anterior-inner thigh surface. Sometimes there is a characteristic antalgic posture when walking - with the torso bending forward, a slight flexion and internal rotation of the thigh on the side of the lesion. Such antalgic fixation of the femur is also noted in the position of the patient lying on his back. Some patients take a forced pose on their side with the lower extremities lowered to the abdomen. In patients with this mononeuropathy there is a restriction of extension, internal rotation and hip abduction. There is an increase in pain along the nerve when trying to sit down from a supine position with a simultaneous rotation of the trunk. It is possible to lower or increase the tone of the lower abdominal muscles on the side of the lesion. Since the ilio-inguinal nerve innervates only a part of the internal oblique and transverse abdominal muscles, their weakness with this neuropathy is difficult to determine in clinical methods of investigation; this can be detected by electromyography. At rest, on the side of the lesion, there are potentials of fibrillation and even fasciculations. At the maximum stress (retraction of the abdomen), the amplitude of the oscillations on the interference electromyogram is significantly reduced in comparison with the norm. In addition, the potential amplitude on the affected side is 1.5-2 times lower than in the healthy one. Sometimes the cremaster reflex is reduced.

The defeat of the ilio-inguinal nerve is not easily distinguished from the pathology of the femoral-genital nerve, since they both innervate the scrotum or large labia. In the first case, the upper level of provocation of painful sensations in digital compression is near the superior anterior iliac spine, in the second - near the inner opening of the inguinal canal. There are also zones of sensitive fallout. When the genitofemoral nerve is damaged, there is no site of skin hypoesthesia along the inguinal ligament.

The femoral-genital nerve (n. Genitofemoralis) is formed from fibers of LI and LIII of spinal nerves. It passes obliquely through the thickness of the large lumbar muscle, perforates its inner edge and then follows the anterior surface of this muscle. At this level, the nerve is located posterior to the ureter and is directed to the inguinal region. The femoral-genital nerve can consist of one, two or three trunks, but most often it is divided on the surface of the large lumbar muscle (occasionally in its thickness) at the level of the projection of the body LIII into two branches - femoral and sexual.

The femoral branch of the nerve is located outward and posteriorly from the external iliac vessels. It is in its turn located first behind the iliac fascia, then in front of it and then passes through the vascular space under the inguinal ligament, which is located outside and anterior to the femoral artery. Then it pierces the wide fascia of the thigh in the area of the subcutaneous opening of the trellis plate and supplies the skin of this area. Other her branches innervate the skin of the upper part of the femoral triangle. These branches can connect with the anterior cutaneous branches of the femoral nerve and with the branches of the ilio-inguinal nerve.

The sexual branch of the nerve is located on the anterior surface of the large lumbar muscle to the inside of the femoral branch. First it is located outside of the iliac vessels, then crosses the lower end of the external iliac artery and penetrates into the inguinal canal through the deep inguinal ring. In the canal, along with the genital branch, men have a spermatic cord, and in women there is a round ligament of the uterus. Leaving the channel through the surface ring, the genital branch of the men goes further to the muscle that raises the scrotum, and to the skin of the upper part of the scrotum, the testicle shell and to the skin of the inner surface of the thigh. In women, this branch supplies a round ligament of the uterus, the skin of the area of the superficial ring of the inguinal canal and large labia. This nerve can be affected at various levels. In addition to squeezing the main nerve trunk or both of its branches at the level of the large lumbar muscle, sometimes the femoral and genital branches can be damaged selectively. The compression of the femoral branch happens when it passes through the vascular space under the inguinal ligament, and the genital branch when passing through the inguinal canal.

The most frequent symptom of the neuropathy of the femoral-genital nerve is the pain in the groin. It usually radiates into the upper part of the inner surface of the thigh, occasionally - and into the lower abdomen. The pains are constant, they are felt by the patients in the prone position, but they become worse when standing and walking. In the initial stage of lesion of the femoral-genital nerve, only paresthesia can be noted, the pains are attached later.

When diagnosing the neuropathy of the femoral-genital nerve, the localization of pain and paresthesia, painfulness upon palpation of the inner inguinal ring are taken into account; the pain is irradiated to the upper part of the inner surface of the thigh. Characteristic is the intensification or occurrence of pain in the re-dissection of the limb in the hip joint. Hypesesia corresponds to the zone of innervation of this nerve.

The lateral cutaneous nerve of the thigh (n. Cutaneus femoris lateralis) is most often formed from the spinal roots LII and LIII, but variants are possible in which it is formed from the roots LI and LII. It begins from the lumbar plexus, which is located under the large lumbar muscle, then perforates its outer edge and continues obliquely downward and outward, passes through the iliac fossa to the superior anterior iliac ridge. At this level, it is located behind the inguinal ligament or in the canal formed by two leaves of the outer part of this ligament. In the iliac fossa, the nerve is retroperitoneal. Here it crosses the iliac muscle under the fascia covering it and the iliac branch of the ilio-lumbar artery. Retroperitoneally in front of the nerve are the cecum, the appendix and the ascending colon, to the left - the sigmoid colon. After passing the inguinal ligament, the nerve is most often located on the surface of the sartorius muscle, where it is divided into two branches (approximately 5 cm below the superior anterior iliac spine). The anterior branch extends downward and extends into the channel of the wide fascia of the thigh. Approximately 10 cm below the superior anterior iliac spine, it perforates the fascia and divides again into the outer and inner branches for the anterior and outer thigh surfaces, respectively. The posterior branch of the lateral cutaneous nerve of the femur turns posteriorly, is located subcutaneously and divides into branches that reach and innervate the skin above the large trochanter along the outer surface of the upper half of the thigh.

The lesions of this nerve are relatively common. As early as 1895, two basic theories were proposed, explaining its defeat: infectious-toxic (Bernhardt) and compression (VK Roth). Some anatomical features at the site of the passage of the nerve, which can increase the risk of its damage due to compression and tension, are elucidated.

1. The nerve when exiting from the pelvis cavity under the inguinal ligament makes a sharp bend at an angle and perforates the iliac fascia. At this point, it can squeeze and friction against the sharp edge of the fascia of the lower limb in the hip joint when the trunk is tilted forward.
2. The compression and friction of the nerve can occur at the point of its passage and bending at an angle between the superior anterior iliac spine and the place of attachment of the inguinal ligament.
3. The outer part of the inguinal ligament often bifurcates, forming a channel for the nerve, which can be squeezed at this level.
4. The nerve can pass alongside the uneven bone surface of the region of the superior iliac spine near the tendon of the tailor's muscle.
5. The nerve can pass and squeeze between the fibers of the sartorius muscle where it still consists primarily of tendon tissue.
6. The nerve sometimes crosses the iliac crest immediately behind the superior anterior iliac spine. Here, it can be squeezed by the edge of the bone and subjected to friction when moving in the hip joint or tilting the trunk forward.
7. The nerve can be squeezed in a tunnel formed by a wide fascia of the thigh and subject to friction against the edge of the fascia at the exit from this tunnel.

Nerve compression at the level of the inguinal ligament is the most common cause of its defeat. Less often the nerve can be squeezed at the level of the lumbar or ileum muscles with retroperitoneal hematoma, tumor, pregnancy, inflammatory diseases and operations in the abdominal cavity, etc.

In pregnant women, nerve compression does not occur on the abdominal segment, but at the level of the inguinal ligament. When pregnancy increases lumbar lordosis, the angle of the pelvis and extension in the hip joint. This leads to tension in the inguinal ligament and compression of the nerve if it passes through the duplication in this ligament.

This nerve can be affected in diabetes mellitus, typhoid fever, malaria, shingles, with avitaminosis. To promote the development of this neuropathy can be wearing a tight belt, corset or tight underwear.

In the clinical picture, with a lesion of the lateral cutaneous nerve of the femur, the most common feeling is numbness, paresthesia such as crawling and tingling, burning sensations, and coldness in the anterior anterior surface of the thigh. Less often there is a feeling of itching and unbearable pain, which sometimes have a causal character. The disease is called paresthetic melalgia (Roth-Bernhardt's disease). Skin hypoesthesia or anesthesia occurs in 68% of cases.

With paresthetic melalgia, the severity of the violation of tactile sensitivity is greater than pain and temperature. There is also a complete loss of all kinds of sensitivity: the pilomotor reflex disappears, trophic disorders can occur in the form of thinning of the skin, hyperhidrosis.

The disease can occur at any age, according to the most commonly ill people of middle age. Men get sick three times more often than women. There are family cases of this disease.

Typical attacks of paresthesia and pain along the anterior thoracic surface of the thigh, which occur when standing or long walking and when forced lying on the back with straight legs, suggest this disease. The diagnosis is confirmed by the occurrence of paresthesia and pain in the lower limb with finger compression of the outer part of the inguinal ligament near the superior anterior iliac spine. With the introduction of a local anesthetic (5-10 ml of a 0.5% solution of novocaine) at the level of compression of the nerve, the pain passes, which also confirms the diagnosis. Differential diagnosis is performed with lesions of the spinal roots LII-LIII, which is usually accompanied by motor impairment. With coxarthrosis, pains of indeterminate localization can occur in the upper parts of the external surface of the thigh, but there is no typical pain and no hypoesthesia.

The nerve block (n.obturatorius) is derived mainly from the anterior branches of LII-LIV (sometimes LI-LV) of the spinal nerves and is located behind or inside the large lumbar muscle. Further, it emerges from under the inner edge of this moss, pierces the iliac fascia and passes down at the level of the sacroiliac joint, then descends along the side wall of the pelvis and enters the occlusive channel together with the occlusion vessels. It is a bone-fibrous tunnel, the roof of which is the chamois of the pubic bone, the bottom is formed by the occlusal muscles separated from the nerve by a blocking membrane. Fibrous inelastic edge of the locking membrane is the most vulnerable place along the nerve. Through the obstructive canal from the pelvic cavity, the nerve passes to the thigh. The muscular branch separates above the canal from the nerve nerve. It also passes through the canal and then branches into the external locking muscle, which rotates the lower limb. At the level of the canal or below, the nerve is divided into the anterior and posterior branches.

The anterior branch supplies a long and short leading menshy, a thin and unstable - comb muscle. These long and short adductor muscles lead, bend and rotate the hip outward. To determine their strength, the following tests are used:

1. the subject, who lies on the spins with straightened lower limbs, suggests moving them; the examiner tries to dissolve them;
2. the subject, who lies on his side, is offered to lift the lower extremity located on top and bring her other lower limb to her. The examiner supports the raised lower limb, and the movement of the other lower limb, which is given, exerts resistance.

The fine muscle (m. Gracilis) leads the thigh and flexes the shin in the knee joint, rotating it inside.

The test for determining the action of a firebox: the subject who lies on his back is offered to bend the lower limb in the knee joint, turning it inside and leading the thigh; the examiner palpates the contracted muscle.

After the departure of the muscular branches, the anterior branch in the upper third of the thigh becomes only sensitive and supplies the skin to the inner surface of the thigh.

The posterior branch innervates the large adductor muscle of the hip, the joint hip pouch and the periosteum of the posterior surface of the femur.

The large adductor muscle leads the thigh.

The test for determining the strength of the large adductor muscle: the subject lies on the back, the straightened lower limb is diverted to the side; He is offered to bring the withdrawn lower limb; The examiner is resisting this movement and palpating the contracted muscle. It should be noted the individual variability of the zone of sensitive innervation of the skin of the inner surface of the thigh from the upper third of the thigh to the middle of the inner surface of the shin. This is due to the fact that sensitive fibers from the composition of the nerve are combined with the same fibers of the femoral nerve, sometimes form a new independent trunk - an additional nerve block.

Lesions of the occlusal nerve are possible on several levels; at the beginning of the withdrawal - under the lumbar muscle or inside it (with retroperitoneal hematoma), at the level of the sacroiliac joint (with sacroiliitis), in the lateral wall of the pelvis (compression by the uterus during pregnancy, with a tumor of the cervix, ovaries, sigmoid colon, appendicular infiltrate in the case of pelvic appendices, etc.), at the level of the occlusal canal (with hernia of the occlusion aperture, lumbar ostitis with edema of the tissues forming the canal walls), at the level of the upper medial surface of the thigh (in the compression of scar tissue th, with a prolonged sharp bending of the thigh under anesthesia during surgery, etc.).

The clinical picture is characterized by sensory and motor disorders. Pain extends from the inguinal area to the inner thigh and is particularly intense when the nerve is compressed in the occlusion channel. There is also paresthesia and a feeling of numbness in the hip. In cases of compression of the nerve of the hernia of the occlusion aperture pain increases with increasing pressure in the abdominal cavity, for example, with coughing, as well as with extension, retraction and internal rotation of the thigh.

Sensitive fallouts are most often localized in the middle and lower thirds of the inner surface of the thigh, sometimes hypoesthesia can be detected on the inner surface of the shin, down to its middle. Due to overlapping of the cutaneous nerve innervation zone of the occlusive nerve by neighboring nerves, sensitivity disorders rarely reach the degree of anesthesia.

When lesion of the occlusal nerve develops the hypotrophy of the muscles of the inner surface of the thigh. It is quite pronounced, in spite of the fact that the large adductor muscle is partially innervated by the sciatic nerve. From the muscles provided by the nerve block, the external locking muscle rotates the hip outside, the resulting muscles participate in the rotation and flexion of the hip in the hip joint, and the thin muscle in the knee flexion of the knee. When the function of all these muscles falls out, only the hip reduction is markedly disturbed. Flexion and external rotation of the thigh, as well as movements in the knee joint, are sufficiently performed by the muscles innervated by other nerves. When the occlusal nerve is turned off, a pronounced weakness of the hip reduction develops, but this movement does not completely disappear. Irritation of the nerve can cause a noticeable secondary spasm of the adductor muscles, as well as reflex flexion contracture in the knee and hip joints. Since irritation of the occlusal nerve some movements of the thigh may increase pain, the patient gently gait, movements in the hip joint are limited. Due to the loss of the function of the adductor muscles of the hip, stability during standing and walking is impaired. The anteroposterior direction of movement of the lower extremities when walking is replaced by a directed limb to the outside. In this case, the foot in contact with the support and the entire lower limb are in an unstable position, and circumduction is noted when walking. On the affected side, there is also a loss or decrease in the reflex of the resulting hamstrings. There are difficulties when putting the sick leg on a healthy one (in the supine position, sitting).

Vegetative disorders in the lesion of the occlusal nerve are manifested in the form of anhidrosis in the zone of hypesthesia on the inner surface of the thigh.

Diagnosis of the lesion of the occlusal nerve is determined by the presence of characteristic pains, sensory and motor disorders. To reveal the paresis of the adductor muscles of the thigh, apply the above techniques.

The reflex from the leading hamstrings is caused by the sharp impact of the percussion hammer on the doctor's 1st finger, applied to the skin above the driving muscles at a right angle to their long axis, about 5 cm above the inner epicondyle of the thigh. At the same time, the reduction of the leading muscles is felt and the asymmetry of the reflex on the healthy and affected sides is revealed.

[1], [2], [3], [4], [5], [6]