What causes leg pain and numbness? This disease is the most common!

If you experience leg pain and numbness, you should be alert in time as it is likely a lumbar disc herniation. Lumbar disc herniation can cause symptoms of lower back pain, leg pain, and leg numbness. Nowadays, people are prone to lumbar disc herniation, so you need to take timely precautions in your daily life.

(1) Low back pain: More than 95% of patients with lumbar disc herniation have this symptom, including those with vertebral disc herniation.

① Mechanism: It is mainly due to the degenerated nucleus pulposus entering the vertebral body or the posterior longitudinal ligament, causing mechanical stimulation and compression to the adjacent tissues (mainly nerve roots and sinus-vertebral nerves), or due to the overflow of glycoproteins and β-proteins in the nucleus pulposus and the release of histamine (H substance), which stimulates the adjacent spinal nerve roots or sinus-vertebral nerves and causes chemical and/or mechanical radiculitis.

②Manifestations: Clinically, persistent dull pain in the lower back and back is the most common, which is relieved in the supine position and aggravated when standing. It is generally tolerable and allows moderate waist movement and slow walking. It is mainly caused by mechanical compression. The duration can be as short as 2 weeks or as long as several months or even years. Another type of pain is severe spasmodic pain in the lower back, which not only occurs suddenly but is also often unbearable and requires bed rest. This is mainly due to ischemic radiculitis, that is, the nucleus pulposus suddenly protrudes and compresses the nerve roots, causing the blood vessels at the roots to be compressed at the same time, resulting in a series of changes such as ischemia, congestion, hypoxia and edema, which can last for several days to several weeks (this symptom may also occur in people with spinal stenosis, but the duration is very short, only a few minutes). Lying on a plank bed, blockade therapy and various dehydrating agents can help relieve the symptoms early.

(2) Radiating pain in the lower limbs: This symptom occurs in more than 80% of cases, of which the posterior type can reach more than 95%.

①Mechanism: The same mechanism as the previous one, mainly due to mechanical and (or) chemical stimulation of the spinal nerve roots. In addition, reflex sciatica (also known as "pseudo-sciatica") may also occur through the sinovertebral nerve of the affected segment.

②Symptoms: In mild cases, symptoms include radiating tingling or numbness from the waist to the thighs and back of the calves, reaching the soles of the feet; it is generally tolerable. In severe cases, the symptoms include electric shock-like severe pain from the waist to the feet, often accompanied by numbness. Although those with mild pain can still walk, their gait is unstable and they limp; they often lean forward or support their waist with their hands to relieve the tension on the sciatic nerve. For severe cases, the patient should rest in bed, and preferably lie on the side with the hips and knees flexed. Any factor that increases abdominal pressure will aggravate the radiating pain. Since neck flexion can aggravate the stimulation to the spinal nerves by pulling on the dura mater sac (ie, neck flexion test), the patient's head and neck are usually in the extended position.

The radiating pain in the limbs is mostly unilateral, and only a very small number of patients with central or paracentral nucleus pulposus herniation show symptoms in both lower limbs.

(3) Limb numbness: It is often associated with the above symptoms. Only about 5% of patients present with numbness without pain. This is mainly due to the stimulation of the proprioceptive and tactile fibers in the spinal nerve roots. Its range and location depend on the number of nerve root sequences affected.

(4) Cold limbs: A small number of cases (about 5% to 10%) experience cold limbs, which is mainly due to the stimulation of the sympathetic nerve fibers in the spinal canal. Clinically, it is common to find cases where patients complain of fever in their limbs on the day after surgery, which is the same mechanism.