[Predictors of upper limbs' function in patients with cervical tetraplegia]

Patients with traumatic cervical injury of the spinal cord show clinical symptoms of tetraplegia. Furthermore, the motor function of the upper limbs is a key function for such patients, because it has a significant impact on the quality of life. One of the components of the definition of rehabilitation potential is the identification of the possible functions' ceiling and compliance of the patient's current condition with known model characteristics.

The aim of the study is to determine the predictors of upper limb functional motor activity in patients in the late period after spinal cord injury (SCI).

The study included 190 patients with SCI: 151 men and 49 women. The mean age of patients was 30.0±12.9 years, the age of SCI - 1.9 [0.60; 5.40] years, in 93% of cases SCI was traumatic. Patients were classified using the ASIA International Neurological Standard. Upper limb function was evaluated using a short version of the Van Lushot Test (VLT). Stimulation electroneuromyography (SENMG) from the median and ulnar nerves was performed. The distribution at the motor level (ML) was as follows: C4-C6 - 117 patients; C7-D1 - 73 patients; depending on the severity of injury (SI): type A and B - 132 patients; upper limb motor score (ASIAarm) was 25.0±12.2, on VLT - 38.3±20.9. The factor loading of 10 factors was evaluated simultaneously in a linear discriminant analysis, the cut-off point was 20 and 40 scores on VLT (25 and 50% on the International Classification of Functioning, Disability and Health without the domain «balance»).

According to SENMG, denervation changes were detected in 15% of median and in 23% of ulnar nerves. The rank significance for the VLT threshold of 20 scores was: ASIA_arm - 100, functional tenodesis (FT) - 91, ML - 73, SI - 18; the classification tree had one branching at the ASIA_arm point of 17.3 score. The rank significance for the threshold of 40 scores was: ASIA_arm - 100, ML - 59, SI - 50, FT - 28, M response from the median nerve - 5; the classification tree had one branching at the ASIA_arm point of 26.9 score. The results of multivariate linear regression analysis confirmed the highest factor loading of ML predictor, motor score for upper limb (ASIA_arm) in both cases (R=0.67, R₂=0.45, F=38.0, p=0.00 and R=0.69, R₂=0.47; F=42.0, p=0.00, respectively).

In the late period after a spinal injury the leading predicative value for functional motor activity has the motor score of ASIA for the upper limb. The ASIA score more than 27 scores is the prediction of moderate and mild impairments, and less than 17 - severe impairments.