After a spinal cord injury, nerves above the level of injury keep working normally. At the level of injury, messages may be blocked from being transmitted from above that level to below the level of injury. Messages from the body (such as sensory messages from touch and temperature) may also be impeded. In general, the higher the level at which the spinal cord damage occurs, the greater the degree of impairment. For example, injuries to the upper cervical region (neck) can result in loss of respiratory, arm, leg, bowel, bladder, and sexual function, whereas individuals with thoracic injuries and lower may have full use of their arms and hands.
The neurological level of injury refers to the lowest level of the body where there is both normal muscle movement and intact sensation. Medical professionals use the International Standards for Neurological Classification of SCI exam (ISNCSCI-sometimes referred to as the ASIA exam) to determine the neurological level and severity of injury. Spinal cord injuries may be referred to as complete or incomplete. The difference between complete and incomplete is whether or not feeling in the anal area is present, or the ability to tighten the anus remains. With a complete injury (AIS A) there is no ability to tighten the anus voluntarily, and no sensation is present in the anal area. Individuals with incomplete injuries demonstrate sensation in the anal area and/or voluntary ability to contract the anus. Incomplete injuries may be referred to as AIS B, C, or D and these grades are determined by the amount of feeling or movement present below the level of injury.
Some Common Secondary Health Complications
Depression is common in the spinal cord injury population, affecting an estimated 11% to 37% of people with SCI.
Chronic pain is also a serious problem that can negatively impact the quality life of many people with SCI. Pain can occur in parts of the body where there is normal sensation as well as areas that have little or no feeling. It is often related to nerve damage or musculoskeletal problems that arise after SCI.
Individuals with SCI are at high risk for developing pressure injuries (pressure sores), which are areas of the skin or underlying tissue (muscle, bone) damaged due to loss of blood flow to the area. After injury, messages from the sensory nerves may not normally reach the brain. With little or no feeling, typical warning signs that let the individual know they’ve been in one position too long are impaired and circulation is affected. Pressure injury is a serious medical condition that can lead to life-threatening infections. Up to 80% of individuals with SCI will have a pressure sore during their lifetime, and 30% will have more than one pressure sore.
About 65%–78% of the SCI population have some amount of spasticity, or the uncontrolled tightening or contracting of the muscles. After SCI, the normal flow of signals from the spinal cord are disrupted, and the messages do not reach the brain. Instead, the signals are sent back to the motor cells in the spinal cord and cause a reflex muscle spasm. This can result in a twitch, jerk or stiffening of the muscle. Spasticity can be irritating, inconvenient, and at their most severe, pose a risk to safety and affect an individual’s ability to go about their activities of daily living.
Spinal cord injury can also lead to changes in bowel and bladder function and may impact an individual’s ability to voluntarily empty their bowels and bladder. Some complications associated with neurogenic bowel include constipation and impaction, incontinence, nausea, bloating, and autonomic dysreflexia (a potentially dangerous spike in blood pressure). During rehabilitation, bowel programs are initiated to help promote routine and timely bowel emptying. SCI injury may also impair voluntary control over bladder emptying and the bladder may become overactive or retain urine. Uncontrolled bladder contractions or urinary retention can lead to urinary tract infection (UTI), a frequent complication of SCI. There are a number of bladder management options following SCI, each with its own advantages and disadvantages.
Depending on the level of injury, respiratory issues may also occur. For those with high cervical injuries, there may be loss or weakness of diaphragm function. This may require a tracheostomy (an opening through the neck into the trachea, the main airway to help a person breathe) or a ventilator (a machine that helps a person breathe by pushing air into the lungs). Depending on the level and completeness of injury, some individuals may be able to wean from the ventilator. Individuals with injuries about the lumbar region may also have some impairment of respiratory function. Abdominal muscles and intercostal muscles (between the ribs) are involved with respiratory function. For those with cervical or thoracic injuries, there may be some impairment of respiratory function due to some degree of abdominal muscles and intercostal muscles (between the ribs) paralysis. The amount of impact on respiratory function depends on the location and extent of spinal cord damage.
Sexuality after SCI can be impacted by changes in muscle function, altered sense of touch, and changes in sexual reflexes. How these changes affect arousal, orgasm, and fertility depend on the level and completeness of injury. The information above and more detailed data and facts on spinal cord injury can be found at these websites:
–Model Systems Knowledge Translation Center: https://msktc.org/sci
–National Spinal Cord Industry Statistical Center: https://www.nscisc.uab.edu/
–Spinal Cord Resource Center: https://askus-resource-center.unitedspinal.org/