Question

Explain the difference between Complete and Incomplete SCI, and also the ASIA Scale used for SCI patients

Answer 1

In a spinal chord, all the fiber are running through it some of which are tracks for motors while some other tracks are for sensory. The function of the spinal chord is to relay the messages from the brain to the body and from the body back ot the brain. All sensation of the body are relayed through the spinal chord. So,when a person has an incomplete injury, some of the fibers gets damaged while rest are working fine causing some messages to be transmitted. These messages can either be movement and/or sensation.A complete injury means that there is no transmission of messages beyond the level of injury. This results in no sensation and no voluntary moment below this area.

ASIA stands American Spinal Injury Association and is used to classify spinal chord injury. It was developed as a universal classification for a spinal chord injuries based on the standardised sensory and motor assessment. In the motor examination there are 10 muscle groups that are being tested. These muscle groups are innervated by the cervical and lumbar sacral nerve roots. Thoraic levels are much easier to determine from sensory levels. Anal sphincter is innervated by S4 and S5 nerve roots and represents the end of the spinal chord and is critical part in SPI examination. Sensory level of this examination is performed by light touch and pimprick. The most caudal level with intact sensation defines a level of involvement.

In simple words, on the basis of severity of SPI, ASIA Impairment Scale categorizes the level from A to E class where A represents the most severe condition while E represents the least severe -

If there is no no motor or sensory function preserved in the sacral segment, it falls in ASEA A category.

If there is sensation but no motor function preserved in the sacral segment, it falls in ASEA B category.

If more than half of the key muscles have a muscle grade less than level 3 below the neurological level, it falls in ASEA C category.

If more than half of the key muscles have a muscle grade more than or equal to level 3 below the neurological level, it falls in ASEA D category.

If the patient has normal motor and sensory function, it comes under ASEA E category.