Purpose of the study was to investigate clinical predictors of functional independence in patients with cervical tetraplegia at different periods after a spinal cord injury (SCI).

MATERIAL AND METHODS

190 patients (151 men and 39 women) with an SCI from 3 months to 6 years old were included in a retrospective study. The average age was 27 years. The examination was carried out using the international standard for neurological classification of spinal cord injury (ASIA) with the definition of motor score ASIA for the upper extremity (ASIA _{upper extremity}), neurological (NL) and motor levels (ML), and the completeness of spinal cord injury (AIS). Functional assessment was performed using the FIM motor subscale. The study of neuromuscular conduction of the median nerves — according to stimulation electroneuromyography (SENMG). The degree of functional independence was assessed as a severe disability with FIM less than 42 points, mild and moderate — FIM 42 points or more.

RESULTS

Using logistic regression analysis, it was found that in the first 6 months after SCI, the main predictors are ASIA_{upper extremity} (AUC=0.84; X²=3.32; p=0.06) and NL (AUC=0.80; X²=2.96; p=0.09). When observed in the first 12 months, ASIA_{upper extremity} (AUC=0.86) remains the leading predictor. Moreover, pronounced functional limitations can be predicted using predictors of ASIA_{upper extremity} in 84.4% and completeness of injury (AIS) in 81.2% of cases, moderate and mild limitations — ASIA_{upper extremity} in 81.4%, NL in 86.0% and functional tenodesis (FT) in 100% of cases. In the long-term period (more than 12 months), the exceptional predictive power of the predictor ASIA_{upper extremity} (AUC=0.92) is noted both in the prediction of severe (82.5%) cases and moderate and mild functional disorders (91.8% of cases). In addition, in the SCI long-term period, the predictor AIS plays a significant role in severe disorders (in 82.5% of cases), and NL (88.2%) and FT (100%) — in moderate and mild disorders. The boundaries between functional groups according to functional independence in groups of 12 months and more than 12 months after SMT are presented: ASIA_{upper extremity} 22.4 and 22.6 points, ML more than 6.5 and the presence of FT with a ML of more than 5.6, respectively. At the same time, the results of SENMG showed low predictive significance.

CONCLUSION

Motor score ASIA_{upper extremity} is a leading predictor in all periods after SCI, while completeness of spinal cord injury (AIS) more accurately predicts pronounced functional limitations, and ML and FT predict moderate functional limitations. The FT, a neurological level of C6 and higher, a motor score ASIA _{upper extremity} of more than 22 points are criteria for achieving moderate functional independence.