Verification of the Accuracy of Cervical Spinal Cord Injury Prognosis Prediction Using Clinical Data-Based Artificial Neural Networks

Abstract

Background: In patients with cervical spinal cord injury (SCI), we need to make accurate prognostic predictions in the acute phase for more effective rehabilitation. We hypothesized that a multivariate prognosis would be useful for patients with cervical SCI.

Methods: We made two predictive models using Multiple Linear Regression (MLR) and Artificial Neural Networks (ANNs). We adopted MLR as a conventional predictive model. Both models were created using the same 20 clinical parameters of the acute phase data at the time of admission. The prediction results were classified by the ASIA Impairment Scale. The training data consisted of 60 cases, and prognosis prediction was performed for 20 future cases (test cohort). All patients were treated in the Spinal Injuries Center (SIC) in Fukuoka, Japan.

Results: A total of 16 out of 20 cases were predictable. The correct answer rate of MLR was 31.3%, while the rate of ANNs was 75.0% (number of correct answers: 12).

Conclusion: We were able to predict the prognosis of patients with cervical SCI from acute clinical data using ANNs. Performing effective rehabilitation based on this prediction will improve the patient's quality of life after discharge. Although there is room for improvement, ANNs are useful as a prognostic tool for patients with cervical SCI.

Keywords: artificial intelligence; artificial neural networks (ANNs); cervical spinal cord injury; prognosis prediction; rehabilitation.

Figure 1

ANNs are inspired by the sophisticated functionality of human brains.

Figure 2

They are comprised of a large number of connected nodes, each of which performs a simple mathematical operation.

Figure 3

We adopted neural networks in JMP^® Pro version 14.2.0 (SAS Institute Inc., Cary, NC, USA). Weight Decay is used as a penalty method. It consists of input, 1st, 2nd, and output layers. The number of nodes in the 1st and 2nd layers are 5 and 10, respectively. The outputs are the ASIA Impairment Scale (AIS) at hospital discharge.

Figure 4

The prediction accuracy of MLR was 31.3% (5 correct answers). On the other hand, the correct answer rate of prediction using ANNs was 75.0% (12 correct answers). The correct answer rate of ANNs for each final AIS was 66% for AIS A, 50% for B, 60% for C, and 100% for D. The size of the circle represents the number of applicable cases. Green indicates that the prediction is correct, yellow indicates an error of one level, and red indicates an error of two or more levels.