Spinal Cord

Introduction

The spinal cord is a long, thin mass of nerve tissue that runs down the back. It starts at the base of the brain and extends down to the lower back. The spinal cord is secured by the spinal column, a continuous arrangement of bones that surround and protect it.

Spinal cord function

1. Spinal Cord function is essential for movement and sensation. Paralysis or loss of sensation can be caused due to damage to the spinal cord. Rehabilitation therapies can help people regain some function after severe injury.
2. The spinal cord carries messages between the brain and the whole body. The spinal cord contains two nerve fibres: sensory fibres and motor fibres.

Segments of Spinal Cord

The spinal cord is divided into five segments: cervical, thoracic, lumbar sacral and coccyx. Each segment contains nerves whose function is somewhat related to the general region of the spine from where they emerge. Each segment also has paired nerve roots which consist of sensory and motor fibres exiting or entering the spinal cord, respectively.

• Cervical Segment

The upper section of the spinal cord, the cervical vertebrae, consists of 8 segments that continue to form higher spinal cord regions. The spinal cord in the cervical region is responsible for controlling muscles in the neck and upper body. It also contains nerve fibres that relay sensory information from the head and face.

• Thoracic Segment

The thoracic vertebrae make up the middle section of the spine and contain 12 segments. This spinal cord region is responsible for controlling muscles in the chest and arms. It also prevents nerve fibres that relay sensory information from the chest, abdomen and arm parts.

• Lumbar Segment

The lumbar vertebrae make up the lower section of the spine consisting of 5 segments. This spinal cord region is responsible for controlling muscles in the legs and hips. It also contains nerve fibres that relay sensory information from the lower back and legs.

• Sacral Segment

The sacral vertebrae make up the lowermost section of the spine and consist of only four segments. This spinal cord region is responsible for controlling muscles in the pelvic area and legs. It also contains nerve fibres that relay sensory information from the genitals, anus and perineum.

• Coccyx segment

The coccyx make up of four fused vertebrae and the button end of spinal column.Function is to provide attachment of ligaments and muscles of the pelvic floor. 

Diseases and Injuries:

Subacute Combined Degeneration of the Spinal Cord:

The spinal cord can be subject to various diseases and injuries. One such condition is subacute combined degeneration of the spinal cord, a rare neurological disorder that affects the myelin sheath, surrounding and protecting nerve fibres. The myelin sheath helps electrical signals travel along nerve fibres, so communication between the brain and other parts of the body can be impaired when it is damaged.

Symptoms of Subacute Combined Degeneration 

1. Trouble walking (gait disturbance)
2. Flaccid paralysis in one or more limbs
3. Loss of deep sensation; inability to feel pain, temperature, touch or vibration below the level of the lesion
4. Loss of proprioception or sense of where your body is in space
5. Ataxia, difficulty coordinating movements of the eyes and limbs
6. Muscle twitching
7. Muscle wasting
8. Lateral curvature (scoliosis) of the spine
9. Slurred speech
10. Bowel and bladder incontinence
11. Dementia

Causes of Subacute Combined Degeneration:

Subacute combined degeneration of the spinal cord is most commonly caused by a vitamin B12 deficiency, although it can also be due to other factors such as:

1. Poor diet
2. Smoking
3. Alcoholism
4. Kidney failure
5. Autoimmune diseases
6. Infections
7. Traumatic injuries
8. Tumours
9. Strokes

Treatment of Subacute Combined Degeneration of the Spinal Cord:

Treatment for subacute combined degeneration of the spinal cord usually involves managing the condition’s underlying cause, if possible. For example, if a vitamin B12 deficiency is responsible, treatment may include taking vitamin B12 supplements. In more severe cases, where there is significant damage to the spinal cord, surgery or other treatments may be necessary to improve function.

Anterior Cord Syndrome

Another condition that can affect the spinal cord is anterior cord syndrome. This occurs when there is damage to the front of the spinal cord, often resulting from a traumatic injury. 

Symptoms of anterior cord syndrome can include:

1. Loss of sensation and movement in the arms and legs
2. Difficulty breathing
3. Paralysis of the bladder and bowel
4. Sexual dysfunction
5. Changes in heart rate and blood pressure

Causes of anterior cord syndrome:

Anterior cord syndrome can be caused by spinal injuries such as:

1. A broken neck
2. A spinal cord injury that presses on the front of the spine
3. An infection in or around the spine, such as meningitis or shingles (herpes zoster)

Treatment for anterior cord syndrome:

Treatment involves managing the underlying cause of the condition, if possible. For example:

1. If a traumatic injury is responsible, treatment may involve surgery to repair the damage. In more severe cases, where there is significant damage to the spinal cord, surgery or other treatments may be necessary to improve function.
2. If a broken neck is a cause, the treatment will focus on stabilising the spine and preventing further damage. In more severe cases, surgery may be necessary to relieve pressure from the spinal cord or remove any damaged tissue.
3. In rare cases, anterior cord syndrome can be caused by a spinal tumour or cyst pressing on the front of the spinal cord. In such cases, surgery to remove the cause of the pressure is typically necessary.

Conclusion

The spinal cord is a vital part of the nervous system, responsible for transmitting signals between the brain and the rest of the body. Several conditions can affect the spinal cord, including subacute combined degeneration and anterior cord syndrome. Treatment for these conditions depends on the underlying cause but may involve surgery or other methods to improve function.