Evaluation of Effectiveness of Riluzole in the Treatment of Early Cervical Spondylotic Myelopathy using Diffusion Tensor Imaging: A Double Blinded, Placebo-Controlled Randomised Controlled trial
Authors: Rajasekaran S. , Aiyer Siddharth , Kanna Rishi , Shetty Ajoy Prasad 
Published: April 2016

Introduction

Treatment strategies in early cervical myelopathy have not been adequately outlined and considerable controvery exsists regarding best treatment options in such scenarios. There is inadequate evidence to suggest superiority of surgical Vs Conservative management in such cases with minimal dysfunction. Even with conservative treatment no gold standard has been identified. We assessed the efficacy of neuroprotective drug Riluzole in the treatment of early cervical myelopathy. Benefits were assessed using change in objective clinical scores, functional outcome and analysis of diffusion tensor imaging which reflect the qualitative and quantitative effects resulting from altered diffusion characteristics in the myelopathic cord.

Material and Methods

Patients presenting with early cervical myelopathy defined as Modified Japanese Orthopaedic Association (MJOA) scores of 13 or more were recruited for the double blinded, placebo controlled randomized control trial. Total of 30 patients were studied with 15 patients each in the test and placebo group. The subjects were analyzed with diffusion tensor imaging(DTI) and clinical evaluation, pre and post institution of Na+ channel blocker Riluzole for a period of 1 month (50 mg twice daily) for the test group and the placebo group received multivitamin tablets. Clinical assessment included comparison of Nurick grade, MJOA scores, Neck disability index (NDI) and SF-12 scores pre and post drug institution. Diffusion co-efficients fractional anisotrophy(FA), apparent diffusion co-efficient(ADC), volume ratio(VR), relative anisotrophy (RA) and eigenvectors were calculated pre and post drug therapy. The DTI datametric for diffusion co-efficient generated were analyzed against placebo group.

Results

The mean MJOA score was 15.6 (13–17) with no significant difference in the MJOA scores in either group. None of the participants showed a change of Nurick grade during the course of the study duration of 1 month. The mean SF-12 score was 35.54/40.14(PCS/MCS) and changed to 37.47/41.09(PCS/MCS) in the Riluzole group. The mean scores for SF-12 and NDI for the Riluzole group did not show a significant change following institution of drug. The mean ADC, FA values were 1533.36(1238–1779) and 494.36(364–628) and changed to 1531.57(1312–2091) and 484.86(294–597) in the Riluzole group. However, the changes in the values of ADC, FA in the two groups were not statistically significant. Datametric evaluation of the other diffusion co-efficient did not show significant change following drug therapy.

Conclusions

This study could not identify a significant change in the clinical outcomes and DTI indices with the use of Riluzole as a standalone pharmacotherapeutic agent for early cervical myelopathy. Further investigation may be required to confirm the effectiveness of neuroprotective drug Riluzole for the treatment of cervical myelopathy.