Sciatica
Sciatica is a radiating pain along the distribution area of the sciatic nerve, mainly in the buttock, posterior thigh, posterior lateral calf, and dorsal lateral foot.
1.Etiology
(1) Primary sciatica (sciatica neuritis) is of unknown cause and is relatively rare in clinical practice.
(2) Secondary sciatica is caused by the compression or stimulation of adjacent lesions, and is divided into radicular and dry sciatica, referring to whether the site of compression is in the nerve root or in the nerve stem, respectively, radicular is common, and the cause is most common with intervertebral disc herniation, other causes include intravertebral canal tumors, vertebral metastases, lumbar tuberculosis, lumbar spinal stenosis, etc.; dry can be caused by sacroiliac arthritis, intrapelvic tumors, pregnancy uterine compression, hip osteoarthritis, external gluteal pain. hip arthritis, hip trauma, diabetes, etc.
2.Check
Blood sedimentation may be increased, anti-“O”, rheumatoid factor may be abnormal, spinal X-ray, lumbar spine CT, MRI, etc. may have corresponding changes, such as intra-vertebral canal occupying lesions, lumbar puncture CSF examination protein more elevated, if necessary, spinal canal imaging to clarify the diagnosis.
3.Clinical manifestations
Sciatic neuropathy is mostly seen in middle-aged and elderly men, and is more common unilaterally. The onset of the disease is rapid, with the first feeling of lower back pain and lumbar stiffness, or a few weeks before the onset of the disease, when walking and exercising, there is transient pain in the lower limbs, which gradually worsens and develops into severe pain, starting from the waist, buttocks or hip, and spreading down the back of the thigh, N fossa, lateral calf and dorsal foot. The pain starts from the lower back, buttock or hip, and spreads downward along the thigh, N fossa, lateral calf and dorsal foot.
4.Sciatica classification
(1) Radicular sciatica
The most common lumbar intervertebral disc herniation, often under the force, bending or strenuous activities and other triggers, acute or subacute onset, a few chronic onset, pain often from the lumbar to one side of the hip, thigh, N fossa, lateral calf and foot radiation, burning-like or cutting-like pain, coughing and force when the pain can be increased, more severe at night, the patient to avoid nerve stretching, pressure, often take a special In order to avoid nerve strain and pressure, patients often adopt special pain-reducing postures, such as sleeping on the healthy side, flexing the hip and knee, standing on the healthy side, causing scoliosis over time, bending to the healthy side, and sitting with the hip tilted to the healthy side to reduce the pressure on the nerve root, which can trigger pain or increase pain, such as Kernig’s sign positive (the patient lies supine, first flexing the hip and knee at right angles, then lifting the lower leg up, due to flexor muscle spasm, thus limiting knee extension and There may be pressure pain in the sciatic nerve pathway, such as the paraspinal point, gluteal point, national point, ankle point and metatarsal point, etc. There is often numbness and hypesthesia in the lateral calf and dorsal foot of the affected limb, hip muscle tone is relaxed, thumb extension and flexion muscle strength is reduced, and Achilles tendon The reflexes are weakened or disappeared.
(2) Dry sciatica
The pain often radiates from the buttock to the posterior femur, posterior lateral calf and lateral foot, and increases when walking, moving and tugging on the sciatic nerve, with pressure points below the gluteal point.
Physical examination reveals
(1) There are pressure points along the sciatic nerve distribution area such as paraspinal, iliac, gluteal, fibular, and ankle points.
(2) Positive sciatic nerve involvement signs, such as Kernig’s sign, Laseque’s sign, Bonnet’s sign, etc.
(3) There are varying degrees of motor, sensory, reflex and vegetative dysfunction within the sciatic nerve innervation, resulting in weak dorsiflexion of the affected toes, hyperalgesia of the lateral calf skin, loss of Achilles tendon reflex, and decreased hip tone.
5.Clinical diagnosis
It is not difficult to diagnose according to the location and direction of pain radiation, factors that aggravate pain, pain-reducing posture, traction pain and pressure pain points, but it is important to determine the cause.
(1) Lumbar disc herniation: the patient often has a long history of recurrent low back pain, or a history of heavy physical labor, often acute onset after a lumbar injury or bending labor, in addition to the typical symptoms and signs of radicular sciatica, there is lumbar muscle spasm, lumbar spine activity restriction and loss of raw amount of forward flexion, the intervertebral space at the site of disc herniation may have obvious pressure pain and radiological pain, X-ray radiographs may have narrowing of the affected intervertebral space, CT CT examination can confirm the diagnosis.
(2) Cauda equina tumor: the onset is slow, gradually worsening, often unilateral radicular sciatica at the beginning of the disease, gradually developing into bilateral, the pain is significantly increased at night, the course of the disease is progressively aggravated, and there is sphincter dysfunction and hyperalgesia in the saddle area, lumbar puncture with subarachnoid obstruction and cerebrospinal fluid protein quantification is significantly increased, and even Froin’s sign (cerebrospinal fluid is yellow and coagulates on its own after placement), spinal iodine hydrography or MRI can confirm the diagnosis. The diagnosis can be confirmed by spinal iodine hydrography or MRI.
(3) Lumbar spinal stenosis: Mostly seen in middle-aged men, early on there is often “intermittent claudication”, the pain in the lower extremities is aggravated after walking, but the symptoms are reduced or disappear after bending and walking or resting, when the nerve root or cauda equina is severely compressed, symptoms and signs of sciatica may also appear on one or both sides, the course of the disease is progressively aggravated, bed rest or traction, etc. If treatment is ineffective, lumbosacral spine X-ray or CT can confirm the diagnosis.
(4) Lumbosacral radiculitis: it develops due to infection, poisoning, nutritional and metabolic disorders or strain, cold and other factors, and generally has an acute onset, and the damage often extends beyond the sciatic nerve innervation area, manifesting as weakness, pain and mild muscle atrophy of the entire lower limb, and the knee tendon reflex is often weakened or disappeared in addition to the Achilles tendon reflex.
(5) It is also necessary to consider lumbar spine tuberculosis, metastatic cancer of the vertebral body, etc. In case of dry sciatica, attention should be paid to the history of cold or infection, as well as lesions of the sacroiliac joint, hip joint, pelvis and hip.