Intervertebral Neural Foraminal Stenosis Is a Risk Factor for Occurrence and Poor Prognosis of Segmental Zoster Paresis of the Upper Limb: A Retrospective Case–Control Study

INTRODUCTION/AIMS: Segmental zoster paresis (SZP) of the upper limb is a complication of herpes zoster (HZ), but the risk factors for onset and prognosis of SZP are still unknown. The aims of this study were to analyze the correlations between neural foraminal stenosis (NFS) and the incidence and prognosis of upper-limb SZP. METHODS: In this retrospective case-control study, 87 HZ inpatients with C5-T1 spinal nerves affected were reviewed and divided into a case group (n = 21) and a control group (n = 66) based on whether they had SZP. Logistic regression analysis was used to assess correlation between NFS and the incidence of upper-limb SZP. Within the case group, Cox regression analyses were used to evaluate the correlation between NFS and complete muscle strength recovery at 24 months. RESULTS: Univariate and multifactor logistic analysis revealed that the grade of NFS was an independent risk factor for the incidence of upper extremity SZP [mild NFS (aOR = 18, p < 0.05); moderate NFS (aOR = 30, p < 0.05); severe NFS (aOR = 90, p < 0.05)]. Univariate and multifactorial Cox regression analyses confirmed the grade of NFS (HR = 0.186, p < 0.05) and baseline muscle strength (HR = 23.015, p < 0.05) as independent prognostic factors affecting complete muscle strength recovery of upper-limb SZP. DISCUSSION: The grade of NFS is an independent risk factor for the occurrence and poor prognosis of SZP in patients with upper extremity HZ. The evaluation of NFS should be incorporated into the prognosis assessment and individualized treatment strategy development for patients with upper limb SZP. Prospective cohort studies with larger sample sizes are needed.