Paraplegia and Paraplegic
- Causes of Paraplegia
- Symptoms of Paraplegia
- Function of Spinal Nerves Affected by Paraplegia
- Secondary Medical Complications in Paraplegics
- ASIA Impairment Scale
Causes of Paraplegia
Paraplegia due to a spinal cord injury results in an impairment in motor or sensory function of the lower half of the body. The condition occurs due to damage to the cellular structure of the spinal cord within the spinal canal. The area of the spinal cord which is affected in paraplegia is either the thoracic, lumbar, or sacral regions of the spinal column. If the arms are also affected by paralysis, quadriplegia/tetraplegia is the correct terminology.
Symptoms of Paraplegia
Injury to the spinal cord at the thoracic level and below result in paraplegia, with the arms and hands unaffected. People with injuries to the spinal cord segments T-1 to T-8 usually retain control of the arms and hands but have poor trunk control and balance due to the lack of abdominal muscle control. Lower thoracic injuries (T-9 to T-12) retain good truck control and good abdominal muscle control. The sitting balance of people with lower spinal cord injuries is usually very good. Lumbar and sacral injuries result in decreased control of the hip flexors and legs. Although paraplegia occures below L2, the correct terminology for injury to these lower spinal nerves is called "cauda equina syndrome".
Spinal Nerves and Levels
Each part of the body is supplied by a particular level or segment of the spinal cord and its corresponding spinal nerve. Function below the level of spinal cord injury will be either lost or impaired
Function of the spinal nerves in the cervical section of the spinal cord are usually unaffected by paraplegia and remain fully functional in someone with paraplegia.
Function of the spinal nerves below the cervical sections of the spinal cord are usually impaired due to damage in either the thoracic, lumbar or sacral areas, resulting in paraplegia.
- The following spinal cord segments are responsible for the following functions:
- T1 Spreads the fingers and supplies small muscles of the hand.
- T1 –T12 supplies the chest wall (intercostal muscles) and abdominal muscles.
- T10 - L2 Psychogenic erections (thought controlled).
- L2 Bends the hip.
- L1, L2, L3, L4 Thigh flexion.
- L2, L3, L4 Extension of leg at the knee (quadriceps femoris)
- L2, L3, L4 Thigh adduction.
- L4, L5, S1 Thigh abduction.
- L4, L5, S1 Dorsiflexion of foot (tibialis anterior).
- L4, L5, S1 Extension of toes.
- L4, L5, S1, S2 Flexion of leg at the knee (hamstrings).
- L5, S1, S2 Extension of leg at the hip (gluteus maximus).
- L5, S1, S2 Plantar flexion of foot.
- L5, S1, S2 Flexion of toes.
- S2, S3, S4 Control a man's ability to have a reflex erection.
- S2, S3, S4 Ejaculation is generated by the bulbospongiosus muscle under the control of a spinal reflex via the pudendal nerve.
- S3,4 and 5 supply the bladder, bowel and sex organs and the anal and other pelvic muscles.
- Coc1 Responsible for sensation only over the coccyx area.
Secondary Medical Complications
Secondary medical complications of paraplegia include pressure sores (decubitus), thrombosis (blood clots), low blood pressure, autonomic dysreflexia and pneumonia. Dysfunction of the bowel and bladder will usually also occur. Sexual functioning is frequently impaired or lost with SCI. Men may have their fertility affected, while a women's fertility is generally not affected. Physiotherapy and various rehabilitation exercise equipment such as functional electrical stimulation, as well as vigilant self observation and care may aid in helping to prevent future and mitigate existing complications.
As paraplegia is most often the result of a traumatic injury to spinal cord tissue, other nerve related complications can and do occur. Cases of chronic neuropathic nerve pain in the areas surrounding the point of injury are not uncommon. Neuropathic pain occures when neurones within the damaged spinal cord send false pain messages to the brain. This type of pain can be treated by medication and to a lesser degree non-medicinal therapies.
ASIA impairment scale
Spinal cord injuries are classified by the American Spinal Injury Association (ASIA) classification. The ASIA scale grades patients based on their functional impairment as a result of the injury, grading a patient from A to D
- A = Complete: No motor or sensory function is preserved in the sacral segments S4–S5.
- B = Incomplete: Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4–S5.
- C = Incomplete: Motor function is preserved below the neurological level, and more than half of key muscles below the neurological level have a muscle grade less than 3.
- D = Incomplete: Motor function is preserved below the neurological level, and at least half of key muscles below the neurological level have a muscle grade of 3 or more.
- E = Normal