Testing Spinal Cord Injuries: The ASIA Exam
An American Spinal Injury Association (ASIA) exam is a standard physical to help:
- Determine which parts of the body are working normally and which parts are affected by the spinal cord injury.
- Classify the level of your spinal cord injury.
- Predict your recovery from the injury.
The exam is extensive because it covers the whole body. A physician trained in performing the exam will test strength and sensation.
- The motor exam tests five key muscles in each arm and leg.
- There are 20 key muscles that are tested overall.
- Each key muscle corresponds to a level in the spinal cord:
- A C5 level corresponds to bending the elbow
- An L3 level corresponds to straightening the knee
- There are two parts of the sensory exam: light touch and pinprick. Light touch and pinprick are tested separately because they travel in different nerve pathways in the spinal cord.
- Each spot on your skin corresponds to a level in the spinal cord:
- Sensation on the tip of your middle finger corresponds to C7
- Sensation behind the knee corresponds to S2
- The pinprick pathway travels closer to the motor pathway than the light touch pathway.
- Recovering sensation in the pinprick pathway can better predict recovery than light touch in the motor pathway:
- If you have normal light touch sensation at the tip of the finger, the chance of getting strength back in the muscles that straighten the elbow would be about one in 10.
- If there were normal pinprick sensation at the tip of the finger, however, the odds of getting strength back to the elbow muscle group would be at least six in 10.
- This is an important last step in the ASIA exam.
- The very end of the spinal cord sends motor signals to the external anal sphincter, which is the muscle that contracts when the patient is trying to hold a bowel movement. The same nerves that control that muscle send light touch and pinprick signals back to the spinal cord.
- The physician will ask you whether you can feel pinprick and light touch in the anal area. You also will squeeze the physician’s gloved finger when it is inserted in the rectum.
- If the motor and sensory functions are intact on the rectal exam, the injury is incomplete.
- If you cannot contract the anal muscle and cannot feel light touch and pinprick, the injury is considered complete.