The ASIA scale and the cervical spine

C-4 ASIA B (incomplete) was the diagnosis arrived at in May 2008, during my initial evaluation at the Kennedy-Krieger Institute, and it was my first spark of hope.
The American Spinal Injury Association (ASIA) Impairment Scale is the method by which doctors can classify an injury in uniform and unambiguous terms. Its parameters provide guidelines by which to determine whether an injury is complete (no motor/sensory function below the level of injury) or incomplete (some degree of motor/sensory function present below the level of injury). The scale ranges from A to E, with A indicating the most impairment and E indicating no impairment.

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: Motor and sensory function are normal.

The C-4 designation indicates an injury at the fourth vertebra of the cervical spine. Nerve roots, which insert at each level of the spine, correspond to different parts of the body, thus where the injury is located on the spine determines what level of functionality the injured person will have. The nerve roots of the cervical spine and corresponding levels are:

C3 - an injury at this level or above will result in respirator dependence
C4 - shoulders, diaphragm, weak biceps
C5 - biceps, deltoids, some wrist
C6 - wrist, thumb
C7 - triceps, fingers

My initial injury was C-5/6, but that's another story for another day. Suffice it to say, when I left primary care, five weeks after the accident, and went to rehab, my injury level was at C4, and that's where it is today.

In the first few months post-injury, there was some debate as to whether my injury was complete or incomplete, but after I came home from rehab doctors told me it was in fact complete (or, ASIA A), and I'd come to accept that. So, ASIA B was news to me.

It was my first spark of hope, but also the first indication of what I'd had wrong all these years. Everything I knew about SCI has been turned upside down. All the definites have become maybes, all the impossibles, possible.