Back and leg pain

Back and leg pain are divided into the following types:

According to time characteristics - acute (with a sudden onset and duration of up to 3 months), subacute (with a slow onset and the same duration), chronic (duration more than 3 months regardless of the nature of the onset) and recurrent.

By the features of localization and distribution - local pain in the lower lumbar and lumbosacral region (most often lumbago and lumbodynia), reflected (pain is felt in the area that has a common embryonic origin with the affected tissues and is most often localized in the inguinal, gluteal or anterior, lateral and posterior surface of the thigh, but can sometimes extend to the knee), radicular (pain is distributed along the dermatomal distribution of spinal roots; on the leg most often along the sciatic nerve) and neural; finally, there are pains associated mainly with pathology of internal organs.

According to the mechanisms of occurrence, all pain syndromes in the domestic literature are also divided into two groups: reflex, which do not have signs of damage to the peripheral nervous system, and compression (mainly radiculopathy)

Pain not associated with the involvement of the roots and peripheral nerves, as well as internal organs, is classified as musculoskeletal pain (non-specific age-related or associated with microdamage, or musculoskeletal dysfunction, musculoskeletal changes). This is the most common type of pain (almost 98% of all cases of back pain). In ICD 10, non-specific pain syndromes in the back (with possible irradiation to the extremities) are classified in class XIII "Diseases of the musculoskeletal system and connective tissue".

In addition to taking into account the type of pain, it is important to analyze the pattern of pain (its nature and distribution).

It is important to note that the terminology used in Russian literature to describe back pain syndromes does not always meet academic requirements, is replete with neologisms, and is not accepted in most developed countries. In Russian literature, the term "osteochondrosis" and "neurological manifestations of spinal osteochondrosis" are used in an excessively broad sense.

The following characteristics of pain are especially important for diagnosis: localization and distribution (irradiation zone); nature (quality) of pain; time characteristics (how it started, intermittent or progressive course; periods of relief, remission, exacerbation); severity of pain syndrome and dynamics of pain severity; provoking and relieving factors; concomitant (sensory, motor, vegetative and other) manifestations (neurological deficit); presence of other somatic diseases (diabetes mellitus, vascular disease, tuberculosis, arthritis, carcinoma, etc.); it is always important to pay attention to the personality traits of the patient and possible symptoms of drug addiction.

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V. Other Causes of Back and Leg Pain

Other causes of back and leg pain include phantom pain, referred pain from visceral diseases (inflammatory infiltrates and tumors in the retroperitoneal space, diseases of the gastrointestinal tract, genitourinary system, aortic aneurysm) and orthopedic disorders. Leg pain may be caused by muscle bed syndrome (for example, "anterior tibial syndrome"), Barre-Masson tumor.

Phantom pain, due to its specific clinical manifestations, rarely gives rise to serious diagnostic doubts.

There are some warning signs (in history and status) that should be noted that may indicate possible more serious causes of back pain:

I. In the anamnesis:

1. Increased pain at rest or at night.
2. Increasing intensity of pain over a week or more.
3. History of malignancy.
4. History of chronic infectious disease.
5. History of trauma.
6. Duration of pain over 1 month.
7. History of treatment with corticosteroids.

II. During objective examination:

1. Unexplained fever.
2. Unexplained weight loss.
3. Pain upon light percussion of the spinous processes.
4. Unusual nature of pain: sensation of passing electric current, paroxysmal, vegetative coloration.
5. Unusual irradiation of pain (girdle, perineum, abdomen, etc.).
6. Relationship of pain with food intake, defecation, sexual intercourse, urination.
7. Associated somatic disorders (gastrointestinal, genitourinary, gynecological, hematological, etc.).
8. Rapidly progressive neurological deficit.

Lumbago in childhood can be caused by processes associated with non-closure of the vertebral arches (in the cystic form), rigid terminal thread syndrome, coarse lumbarization or sacralization, and other orthopedic pathology.

Among the possible somatic causes of back and leg pain in adults, the most important are: myeloma, diseases of the urinary tract and kidneys, tuberculosis, syphilis, brucellosis, sarcoidosis, polymyositis, dissecting aortic aneurysm, pancreatic diseases, duodenal ulcer, gynecological diseases, ectopic pregnancy, hormonal spondylopathy, iatrogenic syndromes (post-injection complications), coxarthrosis, occlusion of the femoral artery.

Back and leg pain depending on the source of pain:

I. Pain of vertebrogenic nature:

1. Disc prolapse and protrusion.
2. Spinal segment instability and spondylolisthesis.
3. Lumbar stenosis.
4. Ankylosing spondylitis.
5. Spondylitis of other etiology.
6. Vertebral fracture.
7. Vertebral tumor (primary or metastatic), myeloma.
8. Paget's disease.
9. Recklinghausen's disease.
10. Osteomyelitis of the vertebra.
11. Osteophytes.
12. Lumbar spondylosis.
13. Other sondilopathies and congenital deformities.
14. Facet syndrome.
15. Osteoporosis.
16. Sacralization and lumbalization.

Pathological processes in the spine that can sometimes cause compression lesions of the roots, membranes, vessels and substance of the spinal cord.

II. Pain of non-vertebrogenic origin:

1. Tunnel syndromes:
   • neuropathy of the lateral femoral cutaneous nerve;
   • obturator neuropathy;
   • sciatic nerve neuropathy;
   • femoral nerve neuropathy;
   • neuropathy of the common peroneal nerve and its branches;
   • tibial nerve neuropathy;
   • Morton's metatarsalgia.
2. Traumatic neuropathies; herpetic ganglionitis (herpes zoster); postherpetic neuralgia.
3. Metabolic mononeuropathies and polyneuropathies.
4. Tumors of the spinal cord (extra- and intraspinal) and cauda equina.
5. Epidural abscess or hematoma.
6. Meningeal carcinomatosis or chronic meningitis.
7. Spinal root neurinoma.
8. Complex regional pain syndrome (reflex sympathetic dystrophy).
9. Spinal syphilis.
10. Central (thalamic) pain.
11. Plexopathies.
12. Pain-fasciculation syndrome.
13. Syringomyelia.
14. "Intermittent claudication" of the cauda equina.
15. Acute spinal circulatory disorder.

III. Myofascial pain syndromes.

IV. Psychogenic pain.

V. Other reasons.

I. Back and leg pain of vertebrogenic origin

Damage to a particular lumbar disc may be an accidental radiological finding or cause a variety of pain syndromes. Local pain in the lumbar region, local and reflected pain, radicular pain, and a full-blown radicular syndrome with symptoms of prolapse may be observed in isolation or in combination.

Some pathological processes in the spine (in its discs, joints, ligaments, muscles and tendons) manifest themselves as musculoskeletal pain, muscle tension and changes in mobility (block or instability) of the spinal motion segment (disc protrusion, osteophytes, lumbar spondylosis, sacralization and lumbarization, facet arthropathy, osteoporosis, some spondylopathies), while other diseases lead to compression lesions of the nerve root, cauda equina, dural sac, spinal cord: disc herniation; age-related changes in the spine leading to stenosis of the spinal canal; sometimes - facet syndrome, spondylitis; tumors; compression fractures of the vertebrae; spondylolisthesis; spondylopathies accompanied by deformation of the spine.

The first group of disorders (musculoskeletal pain) is much more common than the second. In musculoskeletal pain, no correlation is found between the clinical manifestations of pain syndrome and morphological changes in the structures of the spine.

In the absence of compression symptoms, the affected disc is detected by palpation (local muscle tension) or percussion of the spinous processes, as well as neuroimaging methods. Often the patient assumes a pathological posture with the trunk tilted to the opposite side and has limited movements in the spinal segment. Isolated back pain is more typical for a rupture of the fibrous ring, facet syndrome, while pain along the sciatic nerve more often indicates a disc protrusion or lumbar stenosis of the spinal canal. Severe disc damage is usually preceded by multiple episodes of lumbar pain in the anamnesis.

There are five most common causes of back pain and pain along the sciatic nerve:

1. Herniated disc.
2. Rupture of the fibrous ring.
3. Myogenic pain.
4. Spinal stenosis.
5. Facet arthropathy.

Disc herniation is characterized by: a history of specific trauma; leg pain is more severe than back pain; symptoms of prolapse and Lasegue's sign are present; pain increases with sitting, bending forward, coughing, sneezing and straightening the leg, plantar flexion of the ipsilateral (and sometimes contralateral) foot; there is radiological evidence of root involvement (CT). The manifestations of disc herniation depend on its degree (protrusion, prolapse), mobility and direction (medial, posterolateral, foraminal, extraforaminal).

Rupture of the fibrous ring is characterized by: a history of trauma; back pain is usually more severe than leg pain. Leg pain may be bilateral or unilateral. Lasegue's sign is present (but there is no radiological confirmation of root compression). The pain increases with sitting, bending forward, coughing, sneezing, and straightening the leg.

Myogenic pain (pain of muscle origin) is characterized by a history of muscle strain; there is an association between recurrent pain and muscle strain. Strain of the paravertebral lumbar muscles ("myositis") causes pain. Strain of the gluteus maximus causes pain in this area and in the thigh. The pain is unilateral or bilateral rather than in the midline and does not extend beyond the knee. Muscle soreness and tightness increase in the morning and after rest, and with cold. The pain increases with prolonged muscle work; it is most intense after cessation of muscle work (immediately after its completion or the following day). The severity of symptoms depends on the degree of muscle load. Local tension in the involved muscles is palpated; the pain increases with active and passive contraction of the muscle. CT scan does not reveal pathology.

Lumbar stenosis is characterized by back and/or leg pain (bilateral or unilateral) occurring after walking a certain distance; symptoms worsen with continued walking. There is weakness and numbness in the legs. Bending relieves symptoms. There are no symptoms of prolapse. CT may show decreased disc height, facet joint hypertrophy, degenerative spondylolisthesis.

Facet arthropathy. It is characterized by a history of trauma; localized tension on one side over the joint. Pain occurs immediately upon extension of the spine; it increases with flexion toward the painful side. It stops with the injection of an anesthetic or corticosteroid into the joint.

A positive Lasegue sign suggests involvement of the lumbosacral roots or sciatic nerve. In the presence of radiculopathy, the nature of the neurological symptoms allows one to identify the affected root.

In most cases, the L4-L5 disc (L5 root) or the L5-S1 disc (S1 root) is affected. The other discs at the lumbar level are rarely involved: less than 5% of all cases. Protrusions or prolapses of the lumbar discs can cause radiculopathy, but cannot cause myelopathy, since the spinal cord ends above the L1-L2 disc.

When determining the level of the affected root, the localization of sensory disturbances, the localization of motor disorders (the muscles in which weakness is detected are identified, as well as the characteristics of pain distribution and the state of reflexes) are taken into account.

Symptoms of L3-L4 disc protrusion (L4 root compression) include weakness of the quadriceps muscle and decreased or absent knee reflex; hyperesthesia or hypoesthesia in the L4 dermatome is possible.

Signs of L1-L5 disc protrusion (L5 root compression) are weakness of m. tibialis anterior, extensor digitorum and hallucis longus. Characteristic weakness of the extensor muscles of the toes is revealed; weakness of these muscles is also revealed with compression of the S1 root. Sensitivity disorders are observed in the L5 dermatome.

Symptoms of L5-S1 disc protrusion (S1 root compression) are manifested by weakness of the posterior thigh muscles (biceps femoris, semimembranosus, semitendinosus), which extend the hip and flex the leg. Weakness of the m. dluteus maximus and gastrocnemius muscles is also revealed. The Achilles reflex is reduced or absent. Sensitivity disturbance is observed in the S1 dermatome.

Large central disc prolapse may cause bilateral radiculopathy and sometimes leads to acute cauda equina syndrome with severe pain, flaccid paralysis of the legs, areflexia, and pelvic disorders. The syndrome requires rapid neurosurgical intervention whenever possible.

II. Back and leg pain of non-vertebrogenic origin

Main tunnel syndromes:

Neuropathy of the lateral femoral cutaneous nerve (Roth-Bernhardt disease). Compression of the nerve at the level of the inguinal ligament is the most common cause of "meralgia paresthetica". Typical sensations of numbness, burning, tingling and other paresthesias in the anterolateral thigh are observed, which increase with compression of the lateral part of the inguinal ligament.

Differential diagnosis with damage to the roots of L2g - L3 (which is accompanied, however, by motor loss) and coxarthrosis, in which pain is localized in the upper parts of the outer surface of the thigh and there is no typical paresthesia and sensory disturbances.

Obturator nerve neuropathy. A rare syndrome that develops when the nerve is compressed by a retroperitoneal hematoma, fetal head, cervical or ovarian tumor, and other processes, including those that narrow the obturator canal. The syndrome manifests itself as pain in the groin area and inner thigh with paresthesia and hypoesthesia in the middle and lower third of the inner thigh. There may be hypotrophy of the muscles of the inner thigh and decreased strength of the muscles that adduct the thigh. Sometimes the reflex from the adductors of the thigh is lost or reduced.

Sciatic nerve neuropathy (piriformis syndrome). Characterized by soreness of the piriformis muscle at the point of exit of the sciatic nerve and dull pain along the back of the leg. In this case, the zone of decreased sensitivity does not rise above the level of the knee joint. When the piriformis syndrome and compression radiculopathy of the sciatic nerve roots are combined, lampas-like hypoesthesia is revealed with the spread of sensory and motor disorders (atrophy) to the gluteal region. In case of severe compression of the sciatic nerve, the characteristic pain syndrome (sciatica) is accompanied by a decrease or loss of the Achilles reflex. Paresis of the foot muscles develops less frequently.

Neuropathy of the femoral nerve. Compression damage to the femoral nerve most often develops in the place where the nerve passes between the pelvic bones and the iliac fascia (hematoma, enlarged lymph nodes, tumor, ligature during herniotomy), which is manifested by pain in the groin with irradiation to the thigh and lumbar region, hypotrophy and weakness of the quadriceps muscle of the thigh, loss of the knee reflex, instability when walking. Sometimes the patient takes a characteristic pose in a position on the sore side with flexion of the lumbar spine, as well as the hip and knee joints. Sensory disturbances are detected mainly in the lower half of the thigh on its anterior and inner surface, as well as on the inner surface of the shin and foot.

Neuropathy of the common peroneal nerve and its branches. The common peroneal nerve and its main branches (superficial, deep and recurrent peroneal nerves) are most often affected near the neck of the fibula under the fibrous band of the long peroneus muscle. Paresthesias are observed along the outer surface of the leg and foot and hypoesthesia in this area. Compression or tapping in the area of the upper head of the fibula causes characteristic pain. Paralysis of the extensors of the foot (drop foot) and the corresponding gait are observed.

Differential diagnosis with damage to the L5 root (radiculopathy with paralyzing sciatica syndrome), the clinical manifestations of which include paresis of not only the extensors of the foot, but also the corresponding gluteal muscles. The latter is manifested by a decrease in the force of pressing the extended leg to the bed in a lying position.

Neuropathy of the tibial nerve of compression origin (tarsal tunnel syndrome) usually develops behind and below the medial malleolus and manifests itself as pain in the plantar surface of the foot and toes when walking, often with irradiation upward along the sciatic nerve, as well as paresthesia and hypoesthesia mainly in the sole. Compression and tapping behind the ankle, as well as pronation of the foot, increase paresthesia and pain and cause their irradiation to the shin and foot. Less often, motor functions are affected (flexion and spreading of the toes).

Morton's metatarsalgia develops when the plantar digital I, II or III nerves are pressed against the transverse metatarsal ligament (it is stretched between the heads of the metatarsal bones) and is manifested by pain in the area of the distal parts of the metatarsal bones during walking or prolonged standing. The nerves of the II and III interosseous spaces are most often affected. Hypesthesia in this area is characteristic.

Traumatic neuropathies in the lower extremities are easily recognized by the presence of a history of trauma, and herpetic ganglionitis and postherpetic neuralgia are recognized by the corresponding skin manifestations of herpes zoster.

Metabolic mono- and polyneuropathies. Some variants of diabetic polyneuropathy, such as multiple mononeuropathy with predominant involvement of proximal muscles (diabetic amyotrophy) are accompanied by severe pain syndrome.

Pain syndrome in spinal cord tumors (extra- and intraspinal) is recognized by a characteristic progressive course with increasing neurological defect. A tumor of the equine tail is manifested by a pronounced and persistent pain syndrome in the area of the corresponding roots, hypoesthesia of the feet and shins, loss of Achilles and plantar reflexes, predominantly distal paraparesis, and dysfunction of the pelvic organs.

An epidural abscess is characterized by back pain at the level of the lesion (usually in the lower lumbar and mid-thoracic regions) followed by the addition of a developed radicular syndrome and, finally, paresis and paralysis against the background of general symptoms of the inflammatory process (fever, accelerated ESR). Lumbar puncture for an epidural abscess is a medical error due to the threat of purulent meningitis with subsequent disabling neurological defect.

Spinal arachnoiditis is often detected as a radiological finding of no clinical significance (usually after neurosurgery or myelography); rarely, it can progress. In most cases, the relationship of pain syndrome with the adhesive process in the membranes is uncertain and questionable.

Epidural hematoma is characterized by the acute development of pain syndrome and symptoms of spinal cord compression.

Carcinomatosis of the meninges at the level of the lumbar dural sac is manifested by pain syndrome, a picture of irritation of the meninges and is diagnosed by cytological examination of the cerebrospinal fluid.

Spinal root neurinoma is characterized by typical “shooting” pains of high intensity, motor and sensory manifestations of damage to the corresponding root, often a block of the subarachnoid space and a high protein content (in case of lumbar root neurinoma).

Complex regional pain syndrome (reflex sympathetic dystrophy) is a combination of burning, aching, aching pain with sensory disturbances (hypesthesia, hyperpathy, allodynia, i.e. perception of non-painful stimuli as painful) and vegetative-trophic disorders, including osteoporosis in the area of pain syndrome. The syndrome often undergoes regression after sympathetic blockade. It often develops after microtrauma of the limb or its immobilization and may be accompanied by symptoms of peripheral nerve involvement.

Spinal syphilis (syphilitic meningomyelitis, syphilitic spinal pachymeningitis, spinal vascular syphilis, tabes dorsalis) may include pain in the back and legs in its clinical manifestations, but pain is usually not one of the main manifestations of neurosyphilis and is accompanied by other typical symptoms.

Central (thalamic) pain usually develops in patients who have had a stroke after a long (several months) latent period; it progresses against the background of the restoration of motor functions and is characterized by a distribution predominantly by the hemitype with an unpleasant burning shade. Central pain has also been described in extrathalamic localization of stroke. It does not respond to the administration of analgesics. The presence of a stroke in the anamnesis and the nature of the pain syndrome, reminiscent of "burning of a hand immersed in ice water" determine the clinical diagnosis of this syndrome. Action allodynia (the appearance of pain when moving a limb) is often detected. Leg pain in this syndrome is usually part of a more widespread pain syndrome.

Plexus damage (lumbar and/or sacral) can cause pain in the lumbar region and leg. In lumbar plexopathy, pain is localized in the lumbar region with irradiation to the groin area and inner thigh. Sensory disturbances are observed in the anterior, lateral and inner thigh. Weakness of hip flexion and adduction, as well as extension of the lower leg, is noted. Knee and adductor reflexes are reduced on the affected side. Thus, motor and sensory "symptoms of loss" in plexopathy indicate damage to more than one peripheral nerve. Weakness is detected mainly in the proximal muscles: the ileopsoas, gluteal muscles and adductor muscles of the thigh are affected.

Sacral plexopathy is characterized by pain in the sacrum, buttocks, and perineum, with pain radiating to the back of the leg. Sensory disturbances affect the foot, shin (except for the inner surface), and back of the thigh. Weakness in the muscles of the foot and flexors of the shin is revealed. Rotation and abduction of the hip are difficult.

Causes of plexopathy: trauma (including birth and surgical), retroperitoneal tumor, abscesses, lymphoproliferative diseases, idiopathic lumbosacral plexopathy, vasculitis in systemic diseases, aneurysms of the abdominal aorta and pelvic arteries, radiation plexopathy, hematoma due to treatment with anticoagulants and other diseases of the pelvic organs. A rectal examination is necessary; for women - a consultation with a gynecologist.

Many pathological processes (trauma, malignant tumor, diabetes mellitus, etc.) can affect the peripheral nervous system at several levels at once (roots, plexus, peripheral nerve).

The syndrome of "muscle pain and fasciculations" (syndrome of "muscle pain - fasciculations", "cramps and fasciculations syndrome", "benign disease of motor neuron") is manifested by cramps (in most cases - in the legs), constant fasciculations and (or) myokymia. Cramps increase with physical exertion, in more severe cases - already during walking. Tendon reflexes and the sensory sphere are intact. A good effect of carbamazepine or anthelopsin is noted. The pathogenesis of this syndrome is unclear. Its pathophysiology is associated with "hyperactivity of motor units".

Syringomyelia rarely causes lower back and leg pain, as the lumbosacral form of this disease is rare. It manifests itself in flaccid paresis, severe trophic disorders and dissociated sensory disturbances. Differential diagnosis with intramedullary tumor is solved using neuroimaging methods, cerebrospinal fluid examination and analysis of the course of the disease.

"Intermittent claudication" of the cauda equina may be of both vertebrogenic and non-vertebrogenic origin. It manifests itself as transient pain and paresthesia in the projection of certain roots of the equina's tail, developing in the lower limbs when standing or walking. The syndrome develops with mixed forms of lumbar stenosis (a combination of stenosis and disc herniation), in which both the roots and the accompanying vessels suffer. This "caudogenic intermittent claudication" should be distinguished from "myelogenous intermittent claudication", which manifests itself mainly as transient weakness in the legs. This weakness is provoked by walking and decreases at rest, it can be accompanied by a feeling of heaviness and numbness in the legs, but there is no pronounced pain syndrome, such as with caudogenic claudication or obliterating endarteritis.

Acute spinal circulatory disorder manifests itself as suddenly developed (although the degree of severity may vary) flaccid lower paraparesis, dysfunction of the pelvic organs, sensory disorders. Pain syndrome often precedes or accompanies the first stage of the course of spinal stroke.

IV. Psychogenic pain in the back and leg

Psychogenic pain in the lumbar region and lower extremities is usually part of a more generalized pain syndrome and is observed in the picture of behavioral disorders associated with emotional-personality (neurotic, psychopathic and psychotic) disorders. Pain syndrome is part of somatic complaints in depressive, hypochondriacal or conversion disorders, rent installations, anxiety states.

Back and leg pain can be a symptom of schizophrenia, personality disorders, and dementia.

Strictly localized pain in the absence of mental disorders requires persistent searches for somatic sources of pain syndrome.

Back and leg pain depending on topography

I. Back pain (dorsalgia)

Pain predominantly in the upper or middle back may be caused by Scheuermann's disease, thoracic spondylosis, or Bechterew's disease. It may be the result of excessive muscle activity, scapulocostal syndrome, or traumatic neuropathy of the intercostal nerves. Severe interscapular pain may be a sign of a spinal tumor, spondylitis, epidural hematoma, or incipient transverse myelitis.

Low back pain most often has orthopedic causes: osteochondrosis; spondylosis; spondylolisthesis and spondylolysis; Boostrup phenomenon - an increase in the vertical size of the spinous processes of the lumbar vertebrae, which sometimes leads to contact between the processes of adjacent vertebrae; sacroiliitis; coccygodynia. Young men may have Bechterew's disease involving the sacroiliac joint (night pain when lying down). Degeneration and damage to the disc is a common cause of low back pain. Other possible causes: arachnoid cyst in the sacral region, local muscle seals in the gluteal muscles, piriformis syndrome.

II. Pain in the leg

Pain radiating from the lumbar region to the upper thigh is most often associated with irritation of the sciatic nerve or its roots (usually due to protrusion or prolapse of a herniated disc in the lumbar spine). Lumbosacral radicular pain may be a manifestation of chronic adhesive leptomeningitis or a tumor. A similar picture is observed with tumors of the sacral plexus (for example, with retroperitoneal tumor). Unlike damage to the roots, compression of this plexus causes sweating disorders (sudomotor fibers exit the spinal cord through the anterior roots L2 - L3 and pass through the plexus). Sweating disorders are also characteristic of ischemic neuropathy of the sciatic nerve (vasculitis). In rare cases, pain in this localization is a manifestation of a spinal cord tumor. Other causes: piriformis syndrome, gluteal bursitis, cauditory intermittent claudication (epidural varicose veins are currently given less importance).

Pain in the lateral thigh area may be caused by pseudoradicular irradiation in diseases of the hip joint (lampas-like distribution of pain). Such pain may also be associated with damage to the upper lumbar roots (for example, with a herniated disc) and is manifested by acute lumbago, the corresponding vertebral syndrome, weakness of the quadriceps muscle of the thigh, decreased knee reflex, pain when rotating the straightened leg and sensory deficit in the L4 root area. Burning pain in the lateral thigh area is characteristic of meralgia paresthetica Roth-Bernard (tunnel syndrome of the lateral cutaneous nerve of the thigh).

Pain radiating along the anterior surface of the thigh is most often caused by predominant damage to the femoral nerve (for example, after hernia repair or other surgical interventions in the lower abdomen). Such damage is manifested by weakness of the quadriceps muscle of the thigh, decreased or lost knee reflex, sensory disturbances typical for femoral nerve disease.

Differential diagnosis between radicular lesion of L3-L4 and tumor compression of the lumbar plexus is often very difficult. Severe pain with atrophy of the thigh muscles is most often caused by asymmetric proximal neuropathy in diabetes mellitus. Extremely severe pain in this area, appearing together with paresis of m. quadriceps femoris, can be caused by retroperitoneal hematoma (usually during treatment with anticoagulants).

Pain in the knee joint is usually associated with orthopedic disorders (patella, meniscus, diseases of the knee and sometimes the hip joint). Paresthesia and pain in the zone of innervation of the obturator nerve can sometimes spread to the medial region of the knee joint (prostate cancer or other pelvic organs, pelvic bone fracture), which is also accompanied by weakness of the hip adductors.

Pain in the shin area can be bilateral: restless legs syndrome, muscle pain and fasciculations syndrome, chronic polyneuropathy. Unilateral pain syndrome is sometimes associated with muscle bed syndrome.

Caudogenic intermittent claudication (see above) can be unilateral or bilateral. Myalgic syndrome in the shins is typical for infections affecting the upper respiratory tract (acute myositis). Pain syndrome is typical for night cramps (can be either unilateral or bilateral). Other causes: obliterating endarteritis (characterized by the absence of a pulse on a.dorsalis pedis, typical intermittent claudication, trophic disorders), lumbar stenosis, tunnel syndromes in the legs (see above), occlusion of the anterior tibial artery (acute arterial obstruction).

Pain in the foot area is most often caused by orthopedic reasons (flat feet, "spurs", hallux valgus, etc.). Bilateral pain in the foot can take the form of burning paresthesia in polyneuropathy, or be a manifestation of erythromelalgia (idiopathic and symptomatic). Unilateral pain in the foot is characteristic of tarsal tunnel syndrome and Morton's metatarsalgia.

III. Myofascial pain syndromes in the back and leg

The source of this group of pain syndromes are the muscles of the lumbar and gluteal region, usually accompanied by pain in another localization (reflected pain). It is necessary to search for trigger points in the area of the thigh and shin muscles and analyze the pain pattern for an accurate diagnosis of myofascial syndrome.

Coccygodynia (pelvic floor syndrome) is most often a myofascial syndrome in the area of the perineal muscle, manifested by its local spasm with shortening of the pelvic ligaments.

Diagnostic tests for back and leg pain:

1. Neuroorthopedic examination.
2. X-ray of the lumbar and sacral spine with functional tests.
3. Computer tomography
4. Magnetic resonance imaging
5. Myelography (less commonly used now).
6. Ultrasound of abdominal organs
7. Positron emission tomography
8. Clinical and biochemical blood analysis
9. Calcium, phosphorus and alkaline and acid phosphatase
10. Urine analysis
11. Cerebrospinal fluid examination and culture
12. EMG

The following may be required: glucose tolerance test, serum protein electrophoresis, coagulation test, X-ray of the limb, ultrasound examination of blood flow (as well as abdominal and pelvic organs), arteriography, bone scan, lymph node (muscle, nerve) biopsy, blood pressure in the lower limbs (dissecting aneurysm), rectoscopy, consultation with a therapist and other (as indicated) studies.

Back pain during pregnancy can have other causes: disc herniation (increases when standing and sitting, decreases when lying down); lysis of bone tissue in the pubic symphysis (pain intensifies when standing up and while walking); transient osteoporosis of the hip; dysfunction of the sacroiliac joint.