A new design of radiofrequency lesion electrodes for use in the caudalis nucleus DREZ operation. Technical note

Open and Percutaneous Trigeminal Nucleotractotomy: A Case Series and Literature Review

INTRODUCTION

Nucleotractotomy is an efficient surgical technique that provides a high pain relief rate for specific clinical indications. There are two main approaches for performing this operation: an open and percutaneous technique.

METHODS

In the Federal Center of Neurosurgery (Novosibirsk, Russia) from 2016 to 2022, 13 trigeminal nucleotractotomies (7 open and 6 percutaneous) were performed in 12 patients (5 women and 7 men). The indications for surgery were deafferentation pain and chronic drug-resistant pain syndrome caused by malignancy in the facial region. A neurological examination was done on each patient 1 day before the surgery, right after the surgery, and at the follow-up (examinations were done after 1, 6, and 12 months, or when the patient independently applied to our hospital). In the early postoperative period, patients underwent brain MRI.

RESULTS

The average pain intensity score before nucleotractotomy on the 11-point (0-10) visual analog scale (VAS) was 9.3. The effectiveness of open interventions was somewhat higher; the average VAS score in the early postoperative period for the open technique was 1.57, in the group of patients who underwent percutaneous nucleotractotomy were 2.66. Complete regression of the pain syndrome was achieved in 6 patients; in 5 patients, the pain in the face decreased by more than 50%. One case had an unsatisfactory outcome. In the open-surgery group in the early postoperative period, according to MRI, the average length of the visualized area of signal change was longer (21.5 mm, the average diameter was 3.75 mm) than in a percutaneous nucleotractotomy group (16 mm, the average diameter was 3.75 mm). During the postoperative period (average follow-up 40 months), the pain recurred in 3 patients (30%): 2 patients after percutaneous nucleotractotomy (3 and 18 months after surgery) and in 1 patient 4 months after the open surgery. The mean VAS score at the last follow-up was 2.6.

CONCLUSION

Trigeminal nucleotractotomy is an effective approach to the treatment of intractable facial pain. Our experience suggests this technique is highly effective in patients with drug-resistant pain caused by craniofacial tumors and deafferentation conditions after treating trigeminal neuralgia.

Dorsal root entry zone procedure and other surgeries for pain

Pain is a very common symptom that often serves a protective function. It is typically treated medically. When pain becomes chronic and intractable, it no longer serves a protective function and often requires more aggressive forms of treatment. Many types of surgeries can be performed for the management of pain. These surgeries can involve ablation (destruction) or augmentation (stimulation or facilitation) of some part of the nervous system. In many of these surgeries, neurophysiologic intraoperative monitoring (NIOM) is not needed, however, in others neuromonitoring serves a mapping and monitoring purpose. The prototype of pain surgery for this chapter is the dorsal root entry zone (DREZ) procedure. Both mapping and monitoring can help improve lesioning precision and outcomes in this surgery. In this chapter, the DREZ procedures and other surgeries for primarily pain relief in which NIOM is used are discussed. Surgeries, such as spinal stenosis, in which pain relief is important but not the sole purpose, are not discussed here and are covered elsewhere.

Surgical Options for Atypical Facial Pain Syndromes

Atypical neuropathic facial pain is a syndrome of intractable and unremitting facial pain that is secondary to nociceptive signaling in the trigeminal system. These syndromes are often recalcitrant to pharmacotherapy and other common interventions, including microvascular decompression and percutaneous procedures. Herein, the authors present two other viable approaches (nucleus caudalis dorsal root entry zone lesioning and motor cortex stimulation), their indications, and finally a possible treatment algorithm to consider when assessing patients with atypical facial pain.

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.

Management of a Hemidystonic Patient with Thalamotomy, Campotomy and Cervical Dorsal Root Entry Zone Operation

Several medical and surgical procedures have been presented for treatment of dystonia. Thalamotomy, pallidotomy, and campotomy are some of the surgical choices. This study presents a patient with dystonia who underwent a cervical dorsal root entry zone (DREZ) operation after thalamotomy and campotomy. A 23-year-old man who was resistant to medical treatment presented with left hemidystonia. Thalamotomy and campotomy were performed. The patient remarkably benefited from the procedure but dystonic complaints in his left arm continued. A cervical DREZ operation was performed 5 years after the first operation and the dystonic complaints decreased after the surgery. This article presents a new aspect for the treatment of dystonia. Based on the outcomes of the treatment, DREZ operation may be suggested as an alternative surgical treatment for patients with segmental dystonia located in the extremities.

The trigeminal tract and nucleus procedures in treatment of atypical facial pain

BACKGROUND

Atypical facial pain (AFP) is a throbbing pain situated deep in the eye and malar region, often radiating to the ear, neck, and shoulders. The pain generally is not within any dermatomal or anatomical boundaries. Atypical facial pain is distinct from trigeminal neuralgia and its variants. Therefore, the treatment of AFP should be specified. There is also no consensus in the treatment of AFP. Two different treatment procedures on the trigeminal tract and nucleus in a series of cases with AFP are presented.

METHODS

Between 1989 and 2005, 17 patients with AFP, in whom previous therapies had failed, underwent computed tomography (CT)-guided percutaneous trigeminal tractotomy-nucleotomy (TR-NC). One patient with unfavorable response to TR-NC underwent trigeminal dorsal root entry zone (DREZ) operation.

RESULTS

In the series with AFP, pain relief was achieved in all of the 17 cases. TR-NC provided maximum to inadequate degrees of pain relief in 16 of 17 patients. Dorsal root entry zone operation provided partial relief in 1 case. Neither mortality nor serious permanent complication was observed in the series.

CONCLUSION

Neurosurgical procedures such as TR-NC or trigeminal DREZ operation may be effective in the treatment of intractable AFP. The primary choice of operation should be TR-NC because this procedure is minimally invasive. Trigeminal DREZ operation, which affects a larger spread area, may follow if TR-NC fails. The indications and procedure of choice should be individually tailored, depending on the type of pain, underlying pathology, and experience of the surgeon.

Trigeminal nucleus caudalis dorsal root entry zone radiofrequency thermocoagulation for invalidating facial pain

INTRODUCTION

Facial pain syndromes occasionally result in desperate clinical settings completely unresponsive to any known therapy. Trigeminal nucleus caudalis dorsal root entry zone (DREZ) lesion is reported to be of benefit in such cases. In 1982 Nashold performed the first DREZ caudalis lesion in a patient with anaesthesia dolorosa.

PATIENTS AND METHODS

From 1994 to 2002 we have performed six DREZ caudalis lesions on five patients with extremely invalidating facial pain resistant to multiple pharmacological and surgical therapies. Pain was secondary to previous craniofacial surgery in all but one case. Pain presented as anaesthesia dolorosa or atypical facial pain so severe as to interfere with personal hygiene and even to prevent patients from oral feeding. A midline suboccipital approach was used and radiofrequency lesions (at the trigeminal nucleus caudalis in the cervicomedullary junction) were made at 1-mm intervals, 75 (o)C for 15 seconds each along the ipsilateral posterolateral sulcus from the cervical DREZ up to the obex.

RESULTS

Pain relief was complete and permanent in two patients. Three patients experienced significant improvement but pain recurred in two (weeks to a few months after the procedure). No patient's pain was made worse. A patient with persistent postoperative nasolabial pain was re-operated on (improving again but ultimately remaining unchanged). Air venous embolism related to the sitting position (3 patients) during surgery and bradycardia due to manipulation in medulla (2 patients) occurred during some of the procedures without any cardiovascular or neurological repercussion. Postoperative complications included mild and transient ataxia and monoparesia (3 patients).

DISCUSSION

Facial pain secondary to craniofacial surgery is known to be among the least responsive to treatment and a true challenge for pain clinicians. Actual indications for this procedure, operative technical details and the results of our series compared to previous reports are reviewed.

CONCLUSION

Trigeminal nucleus caudalis radiofrequency thermocoagulation is an effective neurosurgical procedure for the treatment of chronically debilitating and desperate facial pain syndromes with acceptable morbidity.

Microsurgical junctional DREZ coagulation for treatment of deafferentation pain syndromes

BACKGROUND

In the treatment of intractable deafferentation pain, different procedures in the DREZ have proved most effective. For most of the spot-like techniques special equipment is mandatory. In this study the technique and the results of junctional DREZ coagulation for treatment of different pain syndromes with the help of bipolar forceps is presented.

METHODS

In 40 patients with intractable deafferentation pain syndromes a junctional DREZ coagulation lesion along the entire dorsolateral fissure of the involved spinal cord segments was made using bipolar forceps. Etiologies of the pain included avulsion of the brachial plexus (21 cases), postherpetic pain (4 cases), phantom pain (3 cases), peripheral nerve injury (3 cases), reflex sympathetic dystrophy (2 cases), spinal cord transsection (1 case), and syringomyelia (6 cases).

RESULTS

Of 21 patients who underwent junctional DREZ surgery for pain because of brachial plexus avulsion 10 (47.6%) had complete, 7 (33.3%) excellent, 3 (14.3%) good, and 1 (4.7%) fair pain relief (follow-up 20 to 120 months). In the group of 19 patients (follow-up 6 to 84 months) with pain syndromes other than postavulsion pain we achieved excellent results in 10 cases (52.6%), good in 8 (42.1%) and no pain relief in 1 case (5.3%). Transient sensory neurological disturbances lasting up to 8 weeks were observed in 6 (15%) cases; permanent sensory and motor deficit in 1 (2.5%) case.

CONCLUSIONS

Clinical results of junctional coagulation DREZ lesion for the treatment of deafferentation pain syndromes are promising. There is no need for special equipment for creating DREZ lesions. The lesions are precisely placed with only a bipolar electrode. Postoperative complications are rare and transient. We believe that the junctional coagulation includes the entire dorsolateral sulcus and DREZ structures important for deafferentation pain.

The Duke experience with the nucleus caudalis DREZ operation

The nucleus caudalis DREZ operation has been performed in three phases at Duke. Between 1982 and 1988 radiofrequency (RF) lesions were made in the trigeminal nucleus extending from the C2 root to the obex using a straight electrode. Complications include ipsilateral arm ataxia due to spinocerebellar tract injury and ipsilateral lower limb weakness from the pyramidal tract. The former occurred at least transiently in 90% of cases. The electrode employed from 1988 to 1989 had proximal insulation protecting the spinocerebellar tract. Since 1989 a ninety degree bend has been added to the electrode to allow better placement. Two electrodes are used to accommodate the shape of the caudalis nucleus. A total of 101 procedures have been performed. The newest electrodes were used in 46 procedures. Ataxia is recognized in 39%. Overall pain relief was excellent in 34% and good in 40%. In post herpetic neuralgia 71% enjoyed excellent or good relief. Indications include post herpetic neuralgia, deafferentation pain (anaesthesia dolorosa, post-tic dysesthesia, stroke, MS, gasserian tumour, Gamma Knife radiation injury), facial trauma/surgery, atypical facial pain, and migraine/cluster headache. A study to compare this operation to deep brain stimulation prospectively for the above indications has been initiated.