Lumbosacral plexopathy is a lesion of the nerve plexus of the same name. It may have an infectious, traumatic, toxic, autoimmune, iatrogenic etiology. Manifests plexalgia with the addition of muscle weakness and hypotension, tendon hyporeflexia and sensitivity disorders, and then trophic disorders in the lower limb on the affected side. Disease is diagnosed by a neurologist together with other specialists based on the results of examination, ENG, ultrasound and tomography of the abdominal cavity and pelvic organs. Treatment is aimed at relieving causal pathology, reducing pain, improving metabolism and blood supply to plexus tissues, restoring lost nerve functions.
General information
The term “lumbosacral plexopathy” combines the pathology of the lumbar and sacral plexuses formed by the anterior (ventral) branches of the spinal nerves L1-S4. The lumbar plexus includes some branches of the root Th12 and all ventral branches L1-L3, the sacral plexus is formed by ventral branches S1-S4. The root L4 gives part of its anterior branches to the lumbar plexus, and part to the sacral. This feature, as well as the close location of both plexuses, causes their frequent joint lesion, diagnosed in clinical neurology as lumbosacral plexopathy.
As a rule, the disease is unilateral, but it can also be bilateral. Total lesion of the plexus is observed quite rarely. Partial lumbosacral plexopathy can manifest as a combined lesion of individual nerves originating in the lumbar and sacral plexus.
Causes
Lumbosacral plexopathy develops as a result of injury to the plexuses with various injuries to the area of their location. For example, with a fracture of the pelvic bones, proximal hip fractures with displacement, pelvic contusion, complicated childbirth, etc. The occurrence of plexitis is possible in the third trimester of pregnancy, diabetes mellitus, aortic atherosclerosis, systemic vasculitis. Lumbosacral plexopathy of infectious genesis can be observed in tuberculosis, influenza, brucellosis, etc. Like brachial plexitis, the lesion of the lumbar and sacral plexuses may have an autoimmune etiology.
Volumetric formations of the pelvis and retroperitoneal space, such as tumors (large benign ovarian tumors, ovarian cancer, uterine body cancer, prostate cancer, bladder tumors, colon cancer), aortic aneurysm, soft tissue abscesses, hematomas formed as a result of hemorrhage during trauma, anticoagulant therapy, hemophilia, provoke lumbar-sacral plexitis of compression genesis. Iatrogenic plexitis is included in the list of complications of surgical operations on the hip joint and in the pelvic cavity, abdominal cavity interventions; in rare cases, it is a consequence of vaccination. Possible toxic damage to the plexuses in case of poisoning with arsenic, lead, etc.
Symptoms
At the beginning of its development, lumbosacral plexopathy manifests plexalgia – intense pain in the lower back, sacrum, buttock and thigh, radiating down to the foot or in the groin area. Increased pain during movements makes walking very difficult. Patients complain of a feeling of numbness and paresthesia in the lower limb, groin area. Objectively, there is a decrease in muscle strength in the legs, loss of knee and achilles tendon reflexes, hypesthesia mainly along the anterior (with a lesion of the lumbar plexus) or mainly along the posterior (with a lesion of the sacral plexus) surface of the leg.
The soreness of trigger points palpable along the sciatic, gluteal and femoral nerves is revealed. Sharply positive symptoms of tension of nerves emanating from the affected plexus are determined. The Lasega symptom is checked in the back position, when lifting an even leg up, there is a sharp soreness, while when lifting a leg bent at the knee, it is absent. Wasserman’s symptom is determined in a position on the stomach, a characteristic pain occurs when trying to lift the patient’s leg straightened at the knee joint.
Over time, these symptoms are joined by muscular hypotrophy, vasomotor and trophic disorders of the tissues of the lower extremities. There is swelling of the legs, sweating disorder (anhidrosis or hyperhidrosis of the feet), thinning, paleness and dry skin.
Total lumbosacral plexopathy is characterized by a disorder of the motor and sensory sphere throughout the lower limb. With a partial lesion, lumbosacral plexopathy may have a different clinical picture, depending on which plexus fibers were involved in the pathological process. There may be mainly a violation of the function of the lateral cutaneous nerve of the thigh, manifested by paresthesia of the lateral surface of the thigh. If the function of the femoral nerve mainly suffers, then the weakness of the extensor muscles of the lower leg, etc., comes to the fore. With a bilateral lesion of the sacral plexus, pelvic disorders may be noted.
Diagnostics
Neurologists are engaged in the diagnosis of plexopathy. However, depending on its genesis, the diagnostic algorithm includes a consultation with a traumatologist, an infectious disease specialist, a gynecologist, an oncologist. Neurological examination consists in assessing muscle strength and tone, checking reflexes, identifying areas of sensitive disorders, determining trigger points and tension symptoms. To confirm the topic of the lesion, electroneurography is used.
In order to exclude volumetric formations, ultrasound of the pelvis and retroperitoneal space, MSCT of the abdominal cavity is performed. According to the indications, gynecological examination, rectoromanoscopy, prostate MRI, etc. can be prescribed. When making a diagnosis, a neurologist differentiates this disease with various vertebral and spinal pathology — radiculitis, osteochondrosis, spondyloarthrosis, herniated intervertebral disc, compression myelopathy. In addition, partial lumbosacral plexopathy should be distinguished from mononeuropathies of the nerves of the lower extremities – femoral nerve neuropathy, sciatic nerve neuropathy, external cutaneous nerve neuropathy of the thigh.
Treatment
The primary task of therapy is to eliminate the pathology underlying plexitis — detoxification, normalization of blood sugar figures in diabetes, treatment of infectious disease, elimination of post-traumatic hematoma, adequate management of pregnancy. If we are talking about tumors, then the main therapy is carried out by oncologists. Neurological treatment is aimed at relieving pain, improving blood circulation and trophics of the affected plexus. Medical prescriptions include anti-inflammatory drugs (diclofenac, ketorolac), painkillers novocaine blockades, vasoactive pharmaceuticals (nicotinic acid, pentoxifylline, xanthinol nicotinate), vitamins g.B, ATP, neostigmine, etc.
Physiotherapy procedures, namely electrophoresis, reflexotherapy, SMT, UHF, magnetotherapy, ultraphonophoresis, thermal therapy, mud therapy, have proven themselves well in the therapy of plexitis. After the acute pain syndrome is relieved, massage and physical therapy are included in the treatment.
Prognosis and prevention
Timely treatment and elimination of the etiofactor that caused the pathology of the lumbar and sacral plexuses, in most cases, guarantees the recovery of the patient. If it is impossible to eliminate the root cause of plexitis, the forecast is less optimistic. The existence of the disease for longer than 1 year leads to the development of irreversible changes in the muscles innervated by the plexus nerves, with the formation of persistent paresis and contractures of the joints. Prevention of plexitis implies effective treatment of infections and metabolic disorders, prevention of injuries and intoxication, adequate immobilization, compliance with surgical procedures.