Spinal Cord Injury Attorney
Spinal cord injuries cause myelopathy or damage to white matter or myelinated fiber tracts that carry signals to and from the brain. It also damages gray matter in the central part of the spine, causing segmental losses of interneurons and motorneurons. Spinal cord injury can occur from many causes, including trauma such as automobile, truck, motorcycle and bicycle crashes, falls, diving accidents, medical malpractice, construction accidents and various other trauma.
Stages
a) Stage of spinal shock - i.e., sensation and motor power localized below the vertical height of the lesion are lost. This stage lasts for 2 to 3 weeks in humans.
b) Stage of recovery - after a period typically ranging from 2 to 3 weeks of injury, the nerves partially recover, and the return of segmental reflexes produce paraplegia-in-flexion.
c) Stage of reflex failure - after a period of days the recovered reflexes again start to give way due to complete degeneration of nerve cells.
Classification
The American Spinal Injury Association or ASIA defines an international classification based on neurological levels, touch and pinprick sensations tested in each dermatome, and strength of ten key muscles on each side of the body, i.e. shoulder shrug (C4), elbow flexion (C5), wrist extension (C6), elbow extension (C7), hip flexion (L2). Traumatic spinal cord injury is classified into five types by the American Spinal Injury Association and the International Spinal Cord Injury Classification System.
- A indicates a "complete" spinal cord injury where no motor or sensory function is preserved in the sacral segments S4-S5. Since the S4-S5 segment is the lower segmental, absence of motor and sensory function indicates "complete" spinal cord injury.
- B indicates an "incomplete" spinal cord injury where sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-S5. This is typically a transient phase and if the person recovers any motor function below the neurological level, that person essentially becomes a motor incomplete, i.e. ASIA C or D.
- C indicates an "incomplete" spinal cord injury where motor function is preserved below the neurological level and more than half of key muscles below the neurological level have a muscle grade of less than 3.
- D indicates an "incomplete" spinal cord injury where motor function is preserved below the neurological level and at least half of the key muscles below the neurological level have a muscle grade of 3 or more.
One can have injury to the spine without spinal cord injury. For example, many people suffer transient loss of function ("stingers") in sports accidents or pain in "whiplash" of the neck without neurological loss and relatively few of these suffer spinal cord injury sufficient to warrant hospitalization. In the United States, the incidence of spinal cord injury has been estimated to be about 35 cases per million per year, or approximately 10,500 per year.
The Effects of Spinal Cord Injury
The exact effects of a spinal cord injury vary according to the type and level of injury, and can be organized into two types:
- In a complete injury, there is no function below the "neurological" level, defined as the lowest level that has intact neurological function. If a person has some level below which there is no motor and sensory function, the injury is said to be "complete". Recent evidence suggests that less than 5% of people with "complete" spinal cord injury recover movement.
- A person with an incomplete injury retains some sensation or movement below the level of the injury. The lowest spinal cord level is S4-5, representing the anal sphincter and peri-anal sensation. So, if a person is able to contract the anal sphincter voluntarily or is able to feel peri-anal pinprick or touch, the injury is said to be "incomplete". Recent evidence suggests that over 95% of people with "incomplete" spinal cord injury recover some movement ability.
In addition to a loss of sensation and motor function below the point of injury, individuals with spinal cord injuries will often experience other complications of spinal cord injury:
- Bowel and bladder function is regulated by the sacral region of the spine, so it is very common to experience dysfunction of the bowel and bladder, including infections of the bladder, and anal incontinence.
- Sexual function is also associated with the sacral region, and is often affected. Men normally have two types of erections. The brain is the source of psychogenic erections. The process begins with sexual thoughts or seeing or hearing something stimulating or arousing. Signals from the brain are then sent through the nerves of the spinal cord down to the T10-L2 levels. The signals are then relayed to the penis and trigger an erection. A reflex erection occurs with direct physical contact to the penis. A reflex erection is involuntary and can occur without sexually stimulating thoughts. The nerves that control a man’s ability to have a reflex erection are located in the sacral nerves (S2-S4) of the spinal cord.
- Injuries of the C-1, C-2 will often result in a loss of breathing, necessitating mechanical ventilators or phrenic nerve pacing.
- Inability or reduced ability to regulate heart rate, blood pressure, sweating and hence body temperature.
- Spasticity (increased reflexes and stiffness of the limbs).
- Neuropathic pain.
- Autonomic dysreflexia or abnormal increases in blood pressure, sweating, and other autonomic responses to pain or sensory disturbances.
- Atrophy of muscle.
- Superior Mesenteric Artery Syndrome
- Osteoporosis (loss of calcium) and bone degeneration.
- Gallbladder and renal stones.
Divisions of Spinal Segments |
|
Segmental Spinal Cord Level and Function |
|
Level |
Function |
Cl-C6 |
Neck flexors |
Cl-Tl |
Neck extensors |
C3, C4, C5 |
Supply diaphragm (mostly C4) |
C5, C6 |
Shoulder movement, raise arm (deltoid); flexion of elbow (biceps); C6 externally rotates the arm (supinates) |
C6, C7 |
Extends elbow and wrist (triceps and wrist extensors); pronates wrist |
C7, T1 |
Flexes wrist |
C7, T1 |
Supply small muscles of the hand |
T1 -T6 |
Intercostals and trunk above the waist |
T7-L1 |
Abdominal muscles |
L1, L2, L3, L4 |
Thigh flexion |
L2, L3, L4 |
Thigh adduction |
L4, L5, S1 |
Thigh abduction |
L5, S1, S2 |
Extension of leg at the hip (gluteus maximus) |
L2, L3, L4 |
Extension of leg at the knee (quadriceps femoris) |
L4, L5, S1, S2 |
Flexion of leg at the knee (hamstrings) |
L4, L5, S1 |
Dorsiflexion of foot (tibialis anterior) |
L4, L5, S1 |
Extension of toes |
L5, S1, S2 |
Plantar flexion of foot |
L5, S1, S2 |
Flexion of toes |
The Location of the Injury
Knowing the exact level of the injury on the spinal cord is important when predicting what parts of the body might be affected by paralysis and loss of function.
Cervical injuries
Cervical (neck) injuries usually result in full or partial tetraplegia (quadriplegia). Depending on the exact location of the injury, one with a spinal cord injury at the cervical level may retain some amount of function as detailed below, but otherwise be completely paralyzed.
- C3 vertebrae and above: Typically lose diaphragm function and require a ventilator to breathe.
- C4: May have some use of biceps and shoulders, but weaker.
- C5: May retain the use of shoulders and biceps, but not of the wrists or hands.
- C6: Generally retain some wrist control, but no hand function.
- C7 and T1: Can usually straighten their arms but still may have dexterity problems with the hand and fingers. C7 is generally the level for functional independence.
Thoracic injuries
Injuries at the thoracic level and below result in paraplegia. The hands, arms, head, and breathing are usually not affected.
- T1 to T8: Most often have control of the hands, but lack control of the abdominal muscles so control of the trunk is difficult or impossible. Effects are less severe the lower the injury.
- T9 to T12: Allows good trunk and abdominal muscle control, and sitting balance is very good.
Lumbar and Sacral injuries
The effect of injuries to the lumbar or sacral region of the spinal canal are decreased control of the legs and hips, urinary system, and anus, including sexual functioning.
