Lumbosciatica is the association of low back pain and neuralgia of the sciatic nerve. It results in pain manifesting in the lower back and radiating into the lower limb. Acute lumbosciatica is most often caused by a herniated disc, but other causes exist. Some lumbosciatica are medical emergencies.

Definition of lumbosciatica

Lumbosciatica is the association of two painful conditions:

• a low back pain which corresponds to lumbar pain, that is to say pain in the lower back in the lumbar region;
• neuralgia of the sciatic nerve, more commonly known as sciatica, which is characterized by pain along the lower limb (along the sciatic nerve providing part of the sensitivity and movement of the lower limb).

By definition, low back pain is lower back pain that does not radiate further than the gluteal fold. Sciatica is characterized by pain mainly manifesting in the buttock and thigh. In other words, we speak of lumbosciatica in case of pain radiating from the lower back to the lower limb.

Causes de la lombosciatique

Several causes have been identified.

The so-called common lumbosciatica are due to a disco-radicular conflict, and more generally to a herniated disc. It is the protrusion of a portion of an intervertebral disc. This hernia causes compression of the sciatic nerve at one of the roots of the nerve, causing sudden pain to appear. In medical parlance, it is referred to as acute lumbosciatica. In some cases, compression of the sciatic nerve can be caused by osteoarthritis in the lumbar region.

Rarer, symptomatic lumbosciatica is a clinical manifestation of a specific pathology such as:

• an infection ;
• an inflammatory condition;
• trauma (eg a fracture);
• tumor development.

Some lumbosciatics are more specific and constitute medical emergencies. They are the consequence of particular forms of sciatica:

• hyperalgesic sciatica which is characterized by unbearable pain and resistant to major analgesics;
• paralyzing sciatica which causes sudden or progressive motor deficit;
• sciatica with cauda equina syndrome which results in the appearance of sphincter disorders (urinary incontinence, etc.).

Diagnosis of lumbosciatica

The clinical examination makes it possible to orient the diagnosis towards lumbosciatica. The doctor is interested in the perceived pain and the existence of associated symptoms. A physical exam can assess pain and identify the type of lumbosciatica. Some cases constitute medical emergencies, especially during unbearable pain and / or motor deficit.

Additional examinations may be required to confirm and deepen the diagnosis. These are usually medical imaging exams like a CT scan or MRI (magnetic resonance imaging).

Pain characteristic of lumbosciatica

Lumbosciatica is characterized by pain occurring in the lower back and extending into the lower limb. The characteristics of this pain can vary depending on the cause. Pain can:

• settle abruptly or gradually;
• manifest during the day with activity or appear during the night at rest;
• be unilateral or bilateral.

Muscle weakness and tingling

In some cases, the pain may be accompanied by numbness and tingling in the lower extremity.

Signs requiring prompt medical attention

It is strongly recommended to consult a healthcare professional if the pain is accompanied by the following signs:

• fever;
• motor deficit in one or both lower limbs;
• loss of sensitivity in the perineum;
• difficulty in passing urine or an urgent need to pass urine, which may suggest disturbances in urinary sphincter control;
• constipation, which may suggest disturbances in the control of the anorectal sphincters;
• urinary tract infection;
• etc.

Several treatments can be considered depending on the cause of lumbosciatica, its evolution and the condition of the person concerned. Support may in particular be based on:

• drug treatment based on analgesics, anti-inflammatory drugs and / or muscle relaxants;
• physiotherapy sessions;
• a surgical intervention.

Several measures have been identified to prevent lumbosciatica. Prevention consists in particular of:

• maintain a healthy and balanced diet;
• fight against a sedentary lifestyle by avoiding prolonged sitting;
• fight against overweight;
• have regular physical activity;
• keep your back straight, including when sitting;
• bend the knees to pick up an object or lift a heavy load.