ASIA Impairment Scale (AIS)

In the inpatient acute spinal cord injury rehabilitation unit, she learned transfers and electric wheelchair use, and learned how to direct her personal care including neurogenic bowel and bladder. Arrangements were made for home modifications and a safe discharge. On March 6th she was discharged home, and on that day she was examined and described by the resident dictating her discharge summary as having an “AIS B T4 spinal cord injury level at the time of discharge.”
Once home, Mrs. FL receives a copy of the discharge summary, and shares it with her community therapists and physicians in the Multiple Sclerosis Surveillance Clinic (MSSC). Mrs. FL is not sure what the ASIA Impairment scale is, and heard it is used for research purposes. She wonders how her AIS score relates to her long term prognosis and therapy prescription.
Describe the ASIA Impairment Scale including what it measures, how it is scored and advantages and disadvantages of the scale. What does an AIS B indicate?
1. The ASIA Impairment scale identifies sensory and motor levels indicative of the most rostral spinal levels demonstrating “unimpaired” function.
2. Twenty-eight dermatomes are assessed bilaterally using pinprick and light touch sensation and 10 key muscles are assessed bilaterally with manual muscle testing. The results are summed to produce overall sensory and motor scores and are used in combination with evaluation of anal sensory and motor function as a basis for the determination of the AIS.
3. A clinical examination is conducted to test whether sensation is 0=”absent”, 1=”impaired” or 2=”normal”. Muscle function is rated from 0=”total paralysis” to 5=” (normal), i.e. active movement, full ROM (range of motion) against significant resistance”. The presence of anal sensation and voluntary anal contraction are assessed as a yes/no.
4. Widely used for research and clinical purposes it has high content validity. In addition, AIS motor scores collected early following injury have some predictive validity in explaining functional outcomes mostly in traumatic injuries, not multiple sclerosis.
5. Inter-rater reliability for assignment of motor and sensory levels and AIS classifications is less than optimal.
6. AIS B indicates an incomplete injury where sensory but no motor function is preserved below the neurological level and includes the sacral segments S4 – S5.

For more information please see: ASIA Impairment Scale (AIS)