Nucleus caudalis dorsal root entry zone lesions: a clinical-radiographic case report

The purpose of this paper is to report on a case of a successful dorsal root entry zone procedure done for the treatment of postherpetic neuralgia and to provide unique MRI documentation outlining the precise location of the surgical lesion.

A 79-year-old female presented with postherpetic neuralgia in the left V1 distribution following a herpes zoster infection in that area 7 weeks earlier. She described the pain as constant, burning, aching, and throbbing, rating it as a 10 on a scale from 1 to 10. Prior to surgery, the patient was on large doses of narcotics, which were causing her to be severely somnolent. INTERVENTION OR TECHNIQUE: A dorsal root entry zone electrode with 2 mm of exposed tip was sequentially inserted into the dorsal root entry zone where 30-second, 80-degree lesions were made. The lesions were superficially continuous over the entire dorsal root entry zone from the upper cervical region to the obex. The postherpetic pain completely resolved immediately after surgery and the patient continued to have total pain relief 1 year later. An MRI performed 2 weeks after surgery clearly showed the location of the lesions.

This unique clinical radiographic correlation shows that a nucleus caudalis dorsal root entry zone lesion, performed according to the described procedure, will be largely confined to the nucleus caudalis.