Herpes Zoster Radiculopathy Treated with Fluoroscopically-Guided Selective Nerve Root Injection

Abstract

Background: Varicella-zoster virus, a member of the herpes virus family, is a neurotrophic virus that primarily affects afferent sensory neurons. Reactivation of latent virus within the dorsal root ganglion and axoplasmic transport to epithelial nerve terminals causes the segmental cutaneous rash and neuralgic pain characteristic of herpes zoster. Setting: Outpatient orthopedic practice. Case Description: A 75-year-old male developed a herpetic rash followed by burning pain in the right L5 distribution. The pain was exacerbated by standing or walking. Six weeks later, the rash had improved, but the patient developed a right foot drop requiring use of a molded ankle-foot orthosis. MRI of the lumbar spine revealed mild degenerative changes without evidence of significant spinal stenosis or disc disease. Electrodiagnostic studies confirmed the diagnosis of right L5 radiculopathy. Results: The patient had dramatic improvement of pain and weakness after undergoing a fluoroscopically guided right L5 selective nerve root block with Depo-Medrol and Lidocaine. He then began a course of physical therapy and, 6 weeks later, had only trace weakness of the ankle dorsiflexor group on the right side. The patient has continued without significant weakness or pain since the procedure and has returned to normal functioning. Discussion: This case demonstrates apparent treatment of a relatively uncommon phenomenon, herpes zoster radiculopathy, using selective nerve root block. Limitations: There is a limited amount of data regarding this disorder presently available regarding Herpes Zoster Radiculopathy. A second limitation would be an inability to exclude spinal pathology as an alternative etiology of this patient’s condition. Conclusion: Cases of herpes zoster-induced radiculopathy may become more frequent, as evidenced by the increasing number of cases of herpes zoster in the United States noted epidemiologically. Key words: Herpes zoster, shingles, lumbar radiculopathy, lumbar stenosis, dermatome, electrodiagnosis, selective nerve, root injection