Neurophysiological Monitoring for the Nucleus Caudalis Dorsal Root Entry Zone Operation

Abstract

Despite patients in this series receiving fewer lesions, the efficacy of the DREZ operation was comparable to that reported in earlier studies. There were fewer complications when neurophysiological monitoring was used. Such monitoring should be considered for nucleus caudalis DREZ operations.

Cervicomedullary Junction Spinal Cord Stimulation for Head and Facial Pain

“…Akin to early failures with caudalis DREZ ablation secondary to inadequately ablating enough of the cephalad part of the nucleus caudalis, we suspect that disappointing outcomes for facial and head pain relief from prior studies of cervical SCS are partly because of an overly caudal electrode placement which cannot therefore result in stimulation of a sufficient critical mass of the nucleus caudalis 17 . Moreover, this contention is further supported by studies on the “onion peel” somatotopy of the spinal trigeminal tract and nucleus; facial pain is primarily subserved by concentric dermatomes corresponding to the most cephalad portion of the nucleus caudalis 43‐45 …”

“…17 Moreover, this contention is further supported by studies on the "onion peel" somatotopy of the spinal trigeminal tract and nucleus; facial pain is primarily subserved by concentric dermatomes corresponding to the most cephalad portion of the nucleus caudalis. [43][44][45] The greater success of CMJ-S for facial pain syndromes as compared with occipital pain syndromes might also be explained by local anatomy and somatotopy. Although there is some sensory overlap and connections between the two, the dermatomes of the spinal trigeminal system tend to spare the occipital region which is primarily covered by the C2 dermatome and to a lesser extent the C3 dermatome.…”

Staged bilateral nucleus caudalis drez lesioning for persistent idiopathic facial pain: exceptional case report

“…Intraoperative studies have shown that changes in MEPs correlate strongly with postoperative neurological status (31,44). Usage of neurophysiological monitoring technologies may help the surgeon to locate and identify the targets as well as possible variant anatomy, thus avoiding such complications (15).…”

Trigeminal Nucleus Caudalis Anatomy: Guidance for Radiofrequency Dorsal Root Entry Zone Lesioning

“…One trend that can help the neurosurgeon craft the ideal lesion size for an individual patient is that a brainstem of smaller than average girth also has a smaller than average nucleus caudalis width. This is important, because if a lesion were made too wide or deep, corticospinal, cuneate fasciculus or cuneocerebellar fibers might be damaged [9,15] . We were unable to generate a convenient formula to estimate nucleus caudalis width based on a single measurement that could be found on preoperative CT or MR images, but imaging could help classify a patient's brainstem girth as being smaller or larger than average and allow the neurosurgeon to exercise caution against making excessively wide lesions that would injure neighboring structures.…”