Predictive factors for favorable short-term response to interlaminar epidural block for cervical radiculopathy

We sought to identify clinical predictors of favorable short-term outcomes associated with cervical interlaminar epidural injection (CIEI). Previous studies investigating the predictive factors of CIEI efficacy have shown inconsistent results. Gaining information on the possible response determinants of CIEI is necessary for appropriate treatment selection and outcomes prediction in the treatment of cervical radiculopathy.

We analyzed the clinical data of 72 patients who received fluoroscopic-guided CIEI using the paramedian approach for cervical radiculopathy to identify the predictive factors for short-term outcomes of CIEI. Demographic characteristics, history of neck surgery, diagnosis, initial numeric rating score, duration of symptoms, Douleur Neuropathique 4 (DN4) questions, painDETECT questionnaire, neck disability index, and ventral epidural spread of contrast medium were assessed. Treatment success was defined as at least a 50% reduction in the numeric rating score after CIEI and was designated as a good response.

The short-term success rate of CIEI for cervical radiculopathy was 55.56%. Multivariate logistic regression analysis established that spinal stenosis (odds ratio 0.183; P = 0.012), a longer duration of > 24 weeks of symptoms (odds ratio 0.206; P = 0.026), and combined positive results for the DN4 and painDETECT (odds ratio, 0.019; P = 0.008) decreased the odds ratio of a good response, 2-3 weeks after CIEI.

CIEI provides a significant short-term outcome in patients with cervical radiculopathy. However, CIEI efficacy may be negatively affected in patients with spinal stenosis, the presence of a chronic state, and a possible neuropathic pain component.