Spinal and nucleus caudalis dorsal root entry zone operations for chronic pain

Dorsal root entry zone (DREZ) operations came into medical practice after the demonstration of increased electrical activity in the dorsal horn of the spinal cord and brainstem in patients with deafferentation of the central nervous system after injury to these areas. The aim of the study was to describe the technique and the effectiveness of spinal DREZ and nucleus caudalis (NC) DREZ operations, which may be the treatments of choice in unique chronic pain conditions that do not respond to medical therapy or any other surgical methods.

Fifty-five patients (44 spinal, 11 NC DREZ) underwent 59 (48 spinal, 11 NC DREZ) operations. There were 44 men and 11 women with a mean age of 46.4 years (range, 24-74 yr). The mean follow-up period was 72 months (range, 6 mo-20 yr). Follow-up assessments were performed with clinical examination on the first day and in the sixth and twelfth months postoperatively. Patients' pain scores and Karnofsky Performance Scale scores were also evaluated pre- and postoperatively.

The initial success rates for spinal and NC DREZotomy procedures were 77 and 72.5%, respectively. In the spinal DREZotomy group, mortality occurred in one patient (2.2%). There were two cases of transient muscle weakness (4.4%) and two of cerebrospinal fluid fistulae (4.4%). In the NC DREZotomy group, mortality occurred in one patient (9%). There were two cases of transient ataxia (18%) and two of transient hemiparesis (18%).

Spinal and trigeminal NC DREZ operations are effective in the treatment of intractable pain syndromes, especially in traumatic brachial plexus avulsions, segmental pain after spinal cord injury, postherpetic neuralgia, topographically limited cancer pain, and atypical facial pain.