Back pain (radiculopathy/ myelopathy)
Back pain is one of the most common conditions for which patients seek a neurologist’s opinion. There can be protean causes of back pain and before we discuss them here, a brief discussion about the anatomy of the spine shall serve us well.
Anatomy of the spine:
The human spinal column is made up of bones called the vertebra stacked one on top of the other (like a column), As the vertebral column is made up of multiple bones articulating with each other, it allows for mobility. We can bend forward (flexion of the spine), arch our back ( extension of the spine) and can also flex our spines laterally in both directions (lateral flexion of the spine). The soft cartilagenous tissue found between two vertebral bodies is called an intervertebral disc. The spinal cord is enclosed in this skeleton of vertebral bones and thus is protected from injury. From the sides of the vertebral bodies the nerve roots come out. These are the roots which later on join to form the big nerves which innervate the muscles of the arms and legs.
What is meant by disc herniation?
Other terms used to describe this common condition include “slipped disc” . A herniated or slipped disc refers to the condition where-in the intervertebral disc gets dislodged (herniates out of its right place or slips out of its right place). When the disc herniates out it puts pressure on the nerve roots exiting the spinal cord at that level. Inflammation of the nerve roots results. This can lead to an intense painful condition where-in the patient complains of pain radiating down in the distribution of that nerve root. We in neurology refer to this condition as Radiculopathy.
Depending upon which nerve root is compressed and at which level patients have pain. For example a disc in your neck slips out, you have pain radiating usually into your arms or even into your finger tips, while if a disc in the lower back slips out, patients usually have pain radiating down their leg ( a condition commonly referred to as sciatica).
Causes of back pain:
As I stated earlier there can be protean causes of back pain. Here I shall list some of the common causes.
1) Slipped or herniated disk.
2) Mechanical trauma to the back resulting in soft tissue injury (injury to the para-vertebral muscles or the soft tissues eg fat).
3) Fracture/ dislocation of the vertebral bodies: sometimes the vertebral bodies may get dislocated or malaligned. One vertebral body may get displaced in relation to the vertebrae below. This condition is referred to as Spondylolisthesis. The vertebral body itself or any of its parts (arch, pedicle) may get fractured resulting in pain. Fractures of the vertebral column can either be traumatic (occuring in the setting of significant trauma) or they can be secondary fractures. Secondary fractures occur when the vertebral body is weakened by an infectious or malignant (cancerous) process.
4) Spondylosis: is one of the most common causes of back and neck pain especially in the middle aged and elderly population. In its most simplistic defination, spondylosis refers to degeneration of the vertebral column. This degeneration of the bones of the spine becomes more apparent as we age, spur formation may occur (osteophytes). These osteophyted may compress the exiting nerve root leading to pain (radicular symptoms). Further on the spinal canal may get narrowed. When this occurs the spinal cord does not have enough space, a condition referred to as spinal canal stenosis. Spinal canal stenosis classically presents with pain which radiates into the buttocks. Patient complains of pain when he walks, with relief of pain on sitting or when he bends forward (flexion). This condition is referred to as neurogenic claudication.
It is important that spinal canal stenosis be diagnosed correctly as it responds to surgical intervention with good relief of pain and discomfort.
“For one who has conquered the mind, the Supersoul is already reached, for he has attained tranquillity. To such a man happiness and distress, heat and cold, honor and dishonor are all the same”
Lord Krishna in the Bhagavad Gita