C1-C3 unilateral dorsal root entry zone rhizotomy for the treatment of persistent postherpetic occipital neuralgia

Background: Postherpetic occipital neuralgia (PHON) is a neuropathic pain condition that usually presents as paroxysmal pain that is stabbing in nature.[5,7] It involves the occiput and posterior scalp in the distribution of the greater and/or lesser occipital nerves. It usually develops after an episode of shingles.[5,7] Treatment usually first consists of medical therapy and then progresses to invasive treatment (e.g., peripheral nerve stimulation, spinal cord epidural stimulation, C2-C3 ganglionectomy, or dorsal root entry zone [DREZ] rhizotomy).[1-4,6] Here, we present a case of persistent PHON that was treated with C1-C3 DREZ. Case Description: A 37-year-old female had a history of several episodes of shingles involving the left neck and occiput; they resolved after treatment with valacyclovir. Subsequently, however, she developed severe lancinating pain of the neck and the occiput and was diagnosed with PHON. Initially, she was treated with oxcarbazepine but was stopped due to cognitive side effects. She then had a cervical spinal cord stimulator implanted which produced relief for several years; it was later removed due to breakage of the electrodes. She then underwent a left- sided C1-C2 hemilaminectomy with a C1-C3 DREZ procedure.[1] Postoperatively, she had immediate resolution of her pain, but developed a new left hemiparesis (4+/5), accompanied by imbalance, decreased sensation to light touch, and loss of proprioception. On 6 weeks follow up, the pain was still relieved, and she exhibited significant improvement in her left-sided hemiparesis and hemisensory deficit to which returned to baseline. Similar outcome was maintained at four months follow up. Conclusion: Although high cervical DREZ lesions may effectively treat post herpetic/occipital neuralgia that fails other measures, there may be associated major neurological morbidity that makes this procedure acceptable as a salvage option, and after clearly explaining the risks to the patient.