Nucleus caudalis dorsal root entry zone lesioning for the treatment of anesthesia dolorosa.

Deafferentation facial pain (anesthesia dolorosa) can occur after injury of the first-order trigeminal nerve. It is often debilitating and difficult to treat. The authors report the treatment of anesthesia dolorosa in a 69-year-old man with a 7-year history of pain. The pain occurred after an open resection of a right trigeminal neuroma. After treatment with medications failed, the patient was treated with nucleus caudalis (dorsal root entry zone) lesioning. His facial pain was immediately and completely eliminated. The authors describe the technique of this central neuroablative procedure, and they review the available literature regarding this procedure as well as the current evidence base for neuromodulatory surgeries. After the 1-year follow-up, the authors conclude that the patient attained lasting relief.

Nucleus caudalis lesioning: Case report of chronic traumatic headache relief.

BACKGROUND: The nucleus caudalis dorsal root entry zone (DREZ) surgery is used to treat intractable central craniofacial pain. This is the first journal publication of DREZ lesioning used for the long-term relief of an intractable chronic traumatic headache. CASE DESCRIPTION: A 40-year-old female experienced new-onset bi-temporal headaches following a traumatic head injury. Despite medical treatment, her pain was severe on over 20 days per month, 3 years after the injury. The patient underwent trigeminal nucleus caudalis DREZ lesioning. Bilateral single-row lesions were made at 1-mm interval between the level of the obex and the C2 dorsal nerve roots, using angled radiofrequency electrodes, brought to 80°C for 15 seconds each, along a path 1 to 1.2 mm posterior to the accessory nerve rootlets. The headache improved, but gradually returned. Five years later, her headaches were severe on over 24 days per month. The DREZ surgery was then repeated. Her headaches improved and the relief has continued for 5 additional years. She has remained functional, with no limitation in instrumental activities of daily living. CONCLUSIONS: The nucleus caudalis DREZ surgery brought long-term relief to a patient suffering from chronic traumatic headache.

Trigeminal nucleus caudalis anatomy: guidance for radiofrequency dorsal root entry zone lesioning.

OBJECT: This study seeks to improve the accuracy of trigeminal nucleus caudalis dorsal root entry zone (DREZ) radiofrequency lesioning by quantifying the size and orientation of the nucleus caudalis. METHODS: Using serial axial photographs of 6 formalin-fixed cadaver brainstems, digital nucleus caudalis measurements were taken at 1-mm intervals from the level of the obex to the C(2) dorsal nerve roots. RESULTS: From the obex to the C(2) dorsal nerve roots, the nucleus caudalis decreases in width (from 2.6 ± 0.2 to 1.0 ± 0.3 mm) and, excluding superficial tract thickness, decreases in axial nucleus depth (from 2.4 ± 0.3 to 1.7 ± 0.2 mm). At levels between the obex and 10 mm caudal to the obex, the accessory nerve rootlets exit the brainstem at the junction of the spinal trigeminal tract and the dorsal spinocerebellar tract. CONCLUSION: This study details the anatomic dimensions and orientation of the nucleus caudalis for surgeons who perform DREZ lesioning.