Lower back pain is one of the most common causes of neurological consultation. Loss of work hours and loss of productivity due to back pain is huge and this creates a significant burden on society.

Etiology

In many patients this is related to bad sitting posture and occupation. Trauma is also an important cause of low back pain. Back pain can be neurogenic (related to nerve, nerve roots, spinal cord injury) or mechanical (related to musculoskeletal injury). Intra-abdominal causes like urinary stones, abdominal aneurysm, pelvic inflammatory disease, tumors may also cause back pain.

Diagnosis

Low back pain is a symptom and the underlying cause has to be detected for an effective treatment. The neurological dictum of anatomical localization (where is the lesion/abnormality) and determining the etiology (what is the lesion) applies here.

A through history in many cases will point to the etiology. For example, acute onset severe back radiating to the leg after lifting heavy weight is usually due to a prolapsed intervertebral disc (PID) pressing on the spinal nerve root. A long history of relapsing back pain without leg pain suggests a mechanical back pain. This includes facet joint arthritis, disc pain and pain from ligaments. Recent onset back pain with weight loss may suggest tuberculosis of spine or a malignancy.

Investigations

All patients with back pain and abnormal neurological examination need MRI imaging. MRI is also sensitive for disc, ligaments, vertebral, paravertebral imaging. MRI may over diagnose abnormalities and these may be seen even in asymptomatic individuals. MRI can miss vascular abnormalities and sometimes paravertebral lesions Back pain with normal neuro-exam may need x-rays as deemed necessary.

In some case CT myelography, angiography may be needed. EMG and NCS can correctly localize nerve root, plexus and nerve lesions.

Treatment

This depends on the cause of the back pain. For mechanical back pain without neurological deficit a short course of analgesics, with rest followed by physical therapy is usually sufficient. Recurrent back pain may become a chronic pain condition and require multidisciplinary management.

In the presence of a neuro deficit urgent intervention may be required to restore function (e.g., PID with cauda equina syndrome).

Prevention

Maintaining a correct posture while sitting, control of abdominal obesity, regular back strengthening exercises go a long way in preventing mechanical back pain.