Dorsal root entry zone lesion: nuances of the technique and long-term results.

Stefano Ferraresi,Lorenzo Maistrello,Alba Scerrati,Elisabetta Basso,Piero Di Pasquale

doi:10.3171/2020.7.focvid2031

Abstract

The treatment of deafferentation pain is a primary goal of a referral center for peripheral nerve surgery. DREZ is an important asset in the neurosurgeon’s armamentarium. The surgical technique and long-term results are analyzed in two series, with or without intraoperative monitoring (IOM). DREZotomy is highly effective in lumbar root avulsive injuries but is ineffective in resolving pain due to spinal cord injuries. Cervical DREZotomy for cancer pain is not superior to intrathecal morphine. In brachial plexus avulsive injuries, the largest series shows a 74% success rate, but the efficacy of the procedure is lost over time. No relevant difference has been observed since the introduction of IOM.The video can be found here: https://youtu.be/uG_kkQj5m1U

Highlights

The treatment of deafferentation pain is a primary goal of a referral center for peripheral nerve surgery
This video illustrates our experience with microDREZotomy, by far the most effective procedure in the treatment of deafferentation pain due to avulsive injuries of the lumbar and brachial plexuses
The cervical DREZotomy plays a big role in the treatment of neuropathic pain due to avulsive injuries of the brachial plexus

Summary

FOCUS VIDEO

Stefano Ferraresi, MD, Elisabetta Basso, MD, Lorenzo Maistrello, MD, Alba Scerrati, MD, and Piero Di Pasquale, MD. We usually perform a 3D CISS MR myelography of the brachial plexus[6] (in the older cases, a myelogram) and, if the patients have been operated elsewhere for nerve reconstruction, we always require the surgical report This allows us to review the results obtained by the first surgery: sometimes an anatomically normal root which has proved not to be functioning may contribute to the generation of pain and is better included in the DREZ lesion. In pure upper C5–6 avulsive injuries (so-called Erb-Duchenne from the onset), which very rarely require a DREZotomy to treat the neuropathic pain radiating to the dorsal thumb and index finger, the lower limit can be halted in T1 In this latter group of injuries, we prefer to include the lamina of C7 in the bone removal, to be able to reach the root C8, which is, not rarely, the first normal root (avulsive injuries of C5–6 and C5–C6–C7 can share the same clinical presentation). Do not stick with the idea of the positive or negative spikes because it is an arbitrary setting; what we need to know is that the DREZ area should be neutral (flat signal), while as soon as we move to the motor and sensory “noble” areas, spikes of opposite signs are elicited

DREZ Stimulation Parameters

Tips and Tricks

Findings

Author Contributions