Clarifying Differences

Dear Editor,
    This is in response to a letter by Tim Jordan [“Postmarks,” July 29]. Mark Zupan is indeed a quadriplegic as stated in the article “Zupan on Impact” [Screens, July 22], although the author, Mr. Badgley, reduces the discussion of the difference between paraplegia and quadriplegia to a degree of penile rigidity.
    Paraplegia and quadriplegia are both caused by damage to the spinal cord. The distinction is determined by where the injury occurs along the spinal cord: The closer to the brain the injury is, the more extensive the paralysis. Quadriplegia results from damage to the portion of the spinal cord housed within the seven cervical (neck) vertebrae and technically means there is some degree of paralysis in all four limbs as a result. The range of function among people classified as quadriplegic is immense.
    For example, Christopher Reeve and Mark Zupan both broke their necks, but Reeve's injury was at the second cervical vertebra (C-2), while Zupan broke his neck about three inches lower at C-6. Nerves within that short section of the spinal cord connect the brain to the diaphragm and respiratory muscles, as well as the muscles of the shoulders, arms, and hands. Thus Zupan is able to propel a manual wheelchair and play rugby while Reeve required a mechanical ventilator to breathe, yet both individuals would be considered quadriplegic. While Zupan appears to have complete use of his upper extremities, he has significant impairment in his hand function.
    Spinal cord injuries are further classified as “complete” or “incomplete” according to the extent of damage to the nervous tissue within the cord. Someone with a complete injury would have no sensation or muscle function below the level of the injury. An incomplete injury is more common and may include any combination of sensation and/or muscle function below the injury site. There are even incomplete quadriplegics who can stand and walk.