Most causes of sciatica are due to lesions of structures near the sciatic nerve pathway that encroach on the sciatic nerve. Common ones are trauma-induced lumbar disc herniation, compression by an enlarged uterus in late pregnancy, uterine and adnexal inflammation, and chemical injury to the nerve caused by inappropriate injection sites of irritating drugs into the sciatic nerve stem at the buttock.
In a few patients, it can be caused by tumors in the spinal canal, trauma to the spine, skeletal and medullary joints, tuberculosis, inflammation, and tumors. The above are called secondary sciatica. There are a few patients who cannot find a clear cause, but often develop sciatica after getting cold or living in a humid environment for a long time, which is called primary sciatica, or sciatica.
Diagnosis and differential diagnosis
Main symptoms
Sciatica is most common in middle-aged and elderly men, and is more common unilaterally. The onset of sciatica is rapid, with the first sensation of lower back pain and lumbar stiffness. The pain in the lower extremities may be transient during walking and exercise a few weeks before the onset of the disease. Later, the pain gradually worsens and develops into severe pain. The pain starts in the lower back, buttocks or hips and spreads down the back of the thigh, N-fossa, lateral calf and dorsum of the foot, with a burning or pins-and-needles pain that increases in intensity on top of the persistent pain. It is worse at night.
Medical history
The nature of the occupation, the time of onset and the duration of the disease should be identified during history taking. In particular, detailed questions should be asked about the occurrence of sciatica: whether the pain is acute, chronic, or acute on top of long-term chronic pain, whether the pain is intermittent or persistent, whether there are triggers such as trauma, physical labor, cold stimulation, and a history of systemic or local infection.
More than half of patients with lumbar disc herniation have a history of chronic lumbar injury of varying degrees, while sciatica occurring after infection should often be considered as nerve root inflammatory damage, and patients with intravertebral tumors tend to have an insidious onset and a long course. If the disease progresses rapidly and the pain increases at night and is not relieved after rest, the possibility of metastatic tumor should be considered. In addition, it is necessary to understand the location, nature, influencing factors and concomitant symptoms of pain, and the patient’s past medical history is also helpful for diagnosis.
Imaging examination
CT, MRI, and spinal canal imaging can help to detect lesions in the spine and sciatic nerve joints, and can help to diagnose intravertebral tumors, arachnoiditis, and disc prolapse.
Western medical treatment
The main treatment is symptomatic treatment and removal of the cause of the disease.
Symptomatic treatment: Regardless of the cause of sciatica, effective clinical measures must be taken to eliminate or relieve the pain.
(l) Bed rest: In the acute stage of severe pain, rest in a hard bed, minimize the activity of the affected limb, avoid weight-bearing, and use a lumbar girth in heavy cases to reduce the tension and reactive edema of the diseased tissue, which can help accelerate the relief of symptoms.
(2) Drug therapy.
(1) Non-steroidal anti-inflammatory and analgesic drugs: such as anti-inflammatory pain, ibuprofen, fenpropathrin, celebrex, diclofenac (fotarine), etc. The most widely used, suitable for most patients, often for the treatment of this disease preferred drugs;
②Corticosteroid drugs: prednisone, dexamethasone, etc;
③Vitamins: vitamin B1 and B12, etc;
④Dehydration drugs: such as 20% mannitol, etc.
(3) Local physiotherapy: Acute pain can be treated with ultrashort wave, procaine iontophoresis, ultraviolet light, etc. After the pain is reduced, switch to induction electricity, ultra-short wave, iodine ion infusion and various kinds of heat therapy.
(4) Corticosteroid epidural injection: It can reduce the inflammation and adhesions around the nerve root. Prednisolone acetate plus lidocaine is commonly used in China. It has a high efficiency (76%) for the protruding and free type and a low efficiency (26%) for the bulging type. Another data [8] showed that the efficacy of corticosteroid epidural injection is the same as placebo.
(5) Nerve block: Those who still have severe pain after treatment by various methods can undergo nerve block, and depending on the site and nature of the lesion, epidural of the skeletal canal, spinal nerve of the spinal canal, spinal ganglion, and sciatic nerve stem of the hip can be used. Generally, 0.5%~1% procaine 10~30ml or lidocaine 50~100mg is used, sometimes flumethasone 0.5-1mg or prednisolone 1ml can be added, 3~5 times a day, 3~5 times a course of treatment. It is also possible to use 2% procaine or prednisolone 0.5-1ml each for local closure of painful spots.
Traction therapy
When the herniated disc causes radicular compression, traction can effectively extend the spine, widen the narrowed intervertebral space, reduce the pressure on the disc, release the surrounding tissue adhesions, promote local blood circulation and inflammation, expand the capacity of the spinal canal, and provide favorable conditions for the herniated material to automatically return, thus reducing the irritation or compression of the nerve root. Traction weight varies between 7-15 kg for 2 weeks, depending on the individual. It is contraindicated for pregnant women, hypertensive and cardiac patients. There are various computer-controlled traction beds available, which can control the weight of traction, change the line of force, and are easy to operate and adapt to different conditions of patients.
Etiological treatment
Different methods should be chosen according to the cause of the disease. If the local compression is severe and multiple methods are ineffective, elective surgery can be performed depending on the situation. For inflammatory lesions, the corresponding anti-inflammatory drugs should be used according to the etiology of the infection as much as possible. For osteoarthritis or pelvic disorders, targeted treatment should also be performed.
Surgical treatment
The most common and serious cause of sciatic nerve entrapment is lumbar disc herniation or intraspinal stenosis. For those whose disc herniation cannot be relieved by non-surgical treatment, surgical treatment must be considered, but the indications for surgery should be strictly controlled.