Spinal Cord Injury Glossary
The spinal cord is the major collection of nerves which transmits motor and sensory information from the brain to and from the rest of the body. It is surrounded by a column of bony rings called vertebrae. The column of nerves that travel from the brain to the tail bone make up the spinal cord and the column of protective bones is the spine. An injury to the spine may cause the bones around the spinal cord to break and press against the spinal cord, which can damage the nerves, affecting movement and sensation. Damage to the spinal cord and nerves can also occur without damage to the bones.
Nerves operate along a pathway (the spinal cord). When the path is broken, the messages cannot get through. This occurs when there is an injury or disease of the spinal cord. The amount of the loss of body function following injury or disease to the spinal cord depends on the level and "completeness" of the injury. The completeness of the injury refers to the amount of messages that are getting through the spinal cord. If someone is without any feeling or movement below their level of injury, then it is considered a complete injury. If someone has some feeling or movement well below their injury level, then it is an incomplete injury.
In addition to movement and sensation, the spinal cord carries nerves signals that affect many other body systems such as skin, bowel, bladder, and breathing. So, following damage to the spinal cord, depending on the level and "completeness" of the injury, these body functions may not work the same as before.
Other terms related to spinal cord and spinal cord injury:
Anterior Cord Syndrome: Condition affecting anterior part of spinal cord which involves variable loss of motor function and sensitivity to pain and temperature, while proprioception is preserved.
Autonomic Dysreflexia (going hyper): Uninhibited, sympathetic response below the level of injury, affecting persons with neurologic levels of T6 and above, resulting in abnormally high blood pressure with resulting headache, sweating above the level of injury, goosebumps and chills/fever. Considered a medical emergency if untreated.
ASIA Impairment Scale: The American Spinal Injury Association’s (ASIA) system of neurological classification is the most commonly accepted evaluation of impairment for spinal cord injury.
- A - Complete: No sensory or motor function is preserved in sacral segments S4-S5.
- B - Incomplete: Sensory, but not motor, function is preserved below the neurologic level and extends through sacral segments S4-S5.
- C - Incomplete: Motor function is preserved below the neurologic level and most key muscles below the neurologic level have muscle grade less than 3.
- D - Incomplete: Motor function is preserved below the neurologic level and most key muscles below the neurologic level have muscle grade greater than or equal to 3.
- E - Normal: Sensory and motor functions are normal.
Brown-Séquard Syndrome: Involves a hemisection lesion of the cord, causing greater ipsilateral proprioceptive and motor loss with contralateral loss of sensitivity to pain and temperature.
Cauda Equina Syndrome: Involves injury to the lumbosacral nerve roots in the spinal canal leading to areflexic bladder, bowel and lower limbs.
Central Cord Syndrome: An injury involving the central part of the cervical region of the spinal cord resulting in greater weakness in the upper limbs than in the lower limbs with sacral sensory sparing.
Complete Spinal Cord Injury: No sensory or motor function in sacral segments of spinal cord S4-S5.
Incomplete Spinal Cord Injury: Sensory and/or motor function in sacral segments of spinal cord S4-S5.
Paraplegia: Injury to the thoracic, lumbar or sacral level of the spinal cord, resulting in paralysis of the lower extremities
Quadriplegia: Injuries at the cervical level of the spinal cord resulting in paralysis of the upper and lower extremities (more commonly referred to as tetraplegia).
Sacral Sparing: Sensory or motor function at the anal mucocutaneous junction. The presence of either is considered sacral sparing.
Spinal Shock: Often occurring soon after spinal cord injury, this is a loss of reflexes below the level of injury with associated loss of sensorimotor functions. This condition can last for several hours to days after initial injury.
Tetraplegia: (The more commonly used term for quadriplegia) Injury to the spinal cord in the cervical region with resulting loss of muscle strength in all 4 extremities.
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