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.

Nucleotractotomy is a treatment of choice for patients with facial pain associated with malignancy, deafferentation, and neuropathic conditions. It may also be used as a treatment for complications of previous surgical treatment of trigeminal neuralgia. Nucleotractotomy is known to provide high rate of pain relief when used for proper clinical indications. There are two approaches for performing this operation: an open technique under general anesthesia and percutaneous computed tomography (CT) -guided technique under local anesthesia.

From 2016 to 2022, 13 trigeminal nucleotractotomies (7 open and 6 percutaneous) were performed in 12 patients (5 women and 7 men). The average age of patients was 55.9 years. Patient data are summarized in Table 1.

Table 1.

Patient data in our work

NoSexAge, yearsType of painApproachVAS before the operationVAS after the operationVAS in follow-upRecurrence period, monthsComplications
68 Trigeminal deafferentation Percutaneous 18 
67 Trigeminal deafferentation Open 10 Hemiataxia 
44 Trigeminal deafferentation Open 10 
48 Trigeminal deafferentation Open Paresis in the right hand up to 2–3 points, with regression to discharge. Hemiataxia 
Open 
68 Post-stroke pain Open 
54 Trigeminal deafferentation Open Hemiataxia, left-sided hemiparesis 4 points 
60 Trigeminal deafferentation Percutaneous 10 
44 Cancer pain Percutaneous 
55 Neuropathic pain following removal of an acoustic schwannoma Open 10 Hemiataxia 
10 25 Cancer pain Percutaneous 10 
11 60 Post-stroke pain Percutaneous 10 
12 32 Cancer pain Percutaneous 10 
NoSexAge, yearsType of painApproachVAS before the operationVAS after the operationVAS in follow-upRecurrence period, monthsComplications
68 Trigeminal deafferentation Percutaneous 18 
67 Trigeminal deafferentation Open 10 Hemiataxia 
44 Trigeminal deafferentation Open 10 
48 Trigeminal deafferentation Open Paresis in the right hand up to 2–3 points, with regression to discharge. Hemiataxia 
Open 
68 Post-stroke pain Open 
54 Trigeminal deafferentation Open Hemiataxia, left-sided hemiparesis 4 points 
60 Trigeminal deafferentation Percutaneous 10 
44 Cancer pain Percutaneous 
55 Neuropathic pain following removal of an acoustic schwannoma Open 10 Hemiataxia 
10 25 Cancer pain Percutaneous 10 
11 60 Post-stroke pain Percutaneous 10 
12 32 Cancer pain Percutaneous 10 

In 6 patients, nucleotractotomy was performed for deafferentation pain that occurred after surgical treatment of trigeminal neuralgia; in 3 – for chronic drug-resistant pain syndrome caused by malignancy in the facial region; in 2 – for pain after an ischemic vertebrobasilar stroke and 1 – for painful trigeminal neuropathy after removal of vestibular schwannoma.

Neurological examination was done in each patient 1 day before surgery, on the first day after surgery, and at the time of follow-up. The type of surgical intervention (transcutaneous or open) was selected individually in each case: the overall health status (the ability to survive a “large” open operation) was taken into account, and so was the cause of pain (transcutaneous procedure was recommended for patients with oncological pain). One of the important factors was the psychological status of the patient (the patient’s ability to go through a transcutaneous procedure, be awake during the operation, and deal with painful sensations during the destruction process). In the early postoperative period, patients underwent brain MRI (Fig. 1, 2); it was repeated during follow-up in several patients.

Fig. 1.

MRI images of patient #2 after open nucleotractotomy, 1 day in axial plane (a) and in sagittal plane (c), and 1 month in axial plane (b) and in sagittal plane (d) after the surgery. Note a decrease in the hyperintense zone occurring within a month after the nucleotractotomy.

Fig. 1.

MRI images of patient #2 after open nucleotractotomy, 1 day in axial plane (a) and in sagittal plane (c), and 1 month in axial plane (b) and in sagittal plane (d) after the surgery. Note a decrease in the hyperintense zone occurring within a month after the nucleotractotomy.

Close modal
Fig. 2.

MRI images of patient #12 after percutaneous nucleotractotomy, 1 day in axial plane (a) and in sagittal plane (c), and 1 month in axial plane (b) and in sagittal plane (d) after the procedure. Note a decrease in the hyperintense zone occurring within a month after the nucleotractotomy.

Fig. 2.

MRI images of patient #12 after percutaneous nucleotractotomy, 1 day in axial plane (a) and in sagittal plane (c), and 1 month in axial plane (b) and in sagittal plane (d) after the procedure. Note a decrease in the hyperintense zone occurring within a month after the nucleotractotomy.

Close modal

All operations were performed according to established techniques previously described in the literature [1, 2]. Open nucleotractotomy is performed under endotracheal anesthesia. During open nucleotractotomy, we always use neurophysiological monitoring (motor-evoked potentials). After fixing the head in the three-point head holder, a linear incision is made along the midline from the occiput to the C3 spinous process. Posterior arch of C1 and lamina of C2 are skeletonized on both sides along with the inferior aspect of the occipital bone posterior to the foramen magnum. A suboccipital craniectomy is performed and the C1 posterior arch and the upper edge C2 lamina are resected. The dural opening is made along the midline from C2 to the foramen magnum and dural flaps are retracted away. Relevant anatomical structures are verified: the vertebral artery on the side of pain, the bilateral posterior inferior cerebellar arteries, the roots of the lower cranial nerves, and the obex of the fourth ventricle. After verification of the impedance (usually – 600–800 Ohm), radiofrequency thermolesioning of the trigeminal nucleus caudalis begins at a level just below the obex, using a curved 1.5-mm bare end radiofrequency electrode (KCTE, Cosman). The electrode insertion depth is marked at 4 mm to avoid over-penetration. A series of destructive lesions is performed along an imaginary line following the upper roots of C2 all the way up to the level of the 4th ventricular obex with a distance of 2 mm between the lesion locations, and temperature for each lesion was 80°C for 15 s. An additional series of lesions is performed above the obex up to the level of entry/exit of the vagus nerve roots when pain involves the perioral region. After each radiofrequency lesion, motor-evoked potentials are checked to confirm preservation of the motor pathways integrity. Hemostasis, duraplasty, and layer-by-layer wound closure are performed after the lesioning is completed.

Percutaneous nucleotractotomy starts with lumbar myelography: 10 mL of Omnipaque 350 mg/mL is injected under local anesthesia in the lateral position in the L3/L4 space. Once the presence of contrast in the subarachnoid space is confirmed on head and neck CT scan, the patient is turned into prone (“face down”) position, and the needle insertion point is chosen at the occiput-C1 level, paramedian on the side of pain. After administration of local anesthetic, the nucleotractotomy needle is inserted into the lateral subarachnoid space. The position of the needle during advancement is verified by a CT scan. After the subarachnoid space is entered, the needle is directed toward the upper lateral segment of the upper spinal cord (similar to dorsal root entry zone). A standard curved KCTE electrode (Cosman) is advanced through the needle and inserted into the spinal cord under continuous impedance measurement (600–800 ohms). Test stimulation (frequency 100 Hz, amplitude 0.1 Volt) is performed to trigger paresthesias in the face. If necessary, the position of the electrode is changed under CT control until concordant paresthesia coverage is obtained. Test lesion is carried out at 50°C for 30 s. Once the absence of neurological deficits is confirmed by examination, a definitive lesion is performed at a temperature of 70°C for 60 s. A neurological examination is then repeated. Upon completion of the procedure, the electrode and needle are removed, and the final CT scan is done to rule out hemorrhagic complications.

In schematic representation of the destruction area both types of operations is shown on Figure 3.

Fig. 3.

Schematic representation of the destruction area: the posterior side of the brain stem is shown; anatomical structures are indicated on the right. On the left, a gray ellipsoid indicates the destruction zone in open nucleotractotomy; on the right, a gray circle indicates the destruction zone in transcutaneous nucleotractotomy.

Fig. 3.

Schematic representation of the destruction area: the posterior side of the brain stem is shown; anatomical structures are indicated on the right. On the left, a gray ellipsoid indicates the destruction zone in open nucleotractotomy; on the right, a gray circle indicates the destruction zone in transcutaneous nucleotractotomy.

Close modal

The average pain intensity score before surgery, assessed by the 11-point (0–10) visual analog scale (VAS) before nucleotractotomy, was 9.3, in the group before percutaneous nucleotractotomy VAS was 9.5, and in the group before open nucleotractotomy was – 9.14. In all patients, except for no. 8, 10, and 12 (patients with craniofacial tumors), numbness was observed at the preoperative level on the half of the face corresponding to the side of pain. In patients 3, 7, and 9, neurological examination showed anesthesia of the face on the side of pain, which can be interpreted as anesthesia dolorosa. The mean VAS value in the early postoperative period was 2.07. In the group of patients who underwent percutaneous nucleotractotomy, the mean postoperative VAS was 2.66. The effectiveness of open interventions was somewhat higher; the average VAS value in the early postoperative period was 1.57. 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: we achieved only a minimal reduction in pain (VAS reduction from 10 to 8) in a patient after percutaneous nucleotractotomy for deafferentation pain after surgical treatment of trigeminal neuralgia.

In 1 case (patient #4), the patient developed a relapse before discharge from the hospital after open nucleotractotomy which resulted in great pain relief on the first postoperative day (from 9 to 3 on VAS). Due to relapse, we decided to repeat this procedure, and a month later, the patient underwent another open nucleotractotomy with a significant and lasting decrease in pain down to 2. This is the only case in this series when the procedure had to be repeated.

In 4 cases (33.3%), hemiataxia was noted in the early postoperative period after open nucleotractotomy (patients #2, 4, 6, 9), with a gradual resolution by the day of discharge and during the follow-up period. In patients after the percutaneous procedure, this complication was not observed. In the open nucleotractotomy group, several patients had a motor deficit: one (patient #4) developed monoparesis in the right hand down to 2–3/5 points with resolution before discharge; another one had hemiparesis of 4/5 points, also with resolution by the end of hospital stay (patient #6).

According to MRI in the early postoperative period in the percutaneous nucleotractotomy group, the average length of the visualized area of signal change was 16 mm in sagittal plane (range – 2–16 mm), and the diameter was 3.75 mm in axial plane (range – 2–7 mm). In the open nucleotractotomy group, the extent of radiographic change was more significant: the average length was 21.5 mm in sagittal plane (range – 11–32 mm), and the average diameter was 3.75 mm in axial plane (range – 3–4 mm).

During the postoperative period, we obtained long-term follow-up in 10 patients (average follow-up – 40 months, range – 1–71 months). Pain recurred in 3 patients (30%): 2 patients (patients #1 and #12) after percutaneous nucleotractotomy (3 and 18 month after surgery) and in 1 patient 4 months after the open surgery (patient #3). The mean VAS score at the last follow-up was 2.6.

In 1937, Sjöqvist performed the first trigeminal tractotomy. He made an incision in the posterolateral part of the medulla oblongata, next to the vagus nerve root, at a depth of 3.5–4 mm and 8–10 mm above the level of the obex of the rhomboid fossa [3]. In his work, Sjöqvist confirmed that after this operation, pain and temperature sensitivity was lost along the entire length of the trigeminal nerve, while tactile sensitivity was preserved. Later, Grant and Weinberger published a series of 12 patients [4] who underwent tractotomy, with a clinical improvement in all patients. The difference from the original technique was the myelotomy level: 4–5 mm below the obex. In this location, the trigeminal tract occupies the most dorsolateral part of the medulla oblongata and is covered by a thin layer of arcuate fibers. Olivecrona [5], in 1942, recommended making an incision directly at the level of the obex to reduce the likelihood of the restiform nucleus damage and fibers of the dorsal spinocerebellar tract. In his series, complete or partial regression of the pain syndrome was achieved in 27 out of 30 patients.

The most comprehensive analysis of that time was conducted by Guidetti [6] in 1950. He performed 124 trigeminal tractotomies and compared the Sjöqvist tractotomy group (40 patients) with the Olivecrona group (84 patients). The results of this work showed that performing a tractotomy at or below the obex level reduces the likelihood of complications, namely, the damage to the restiform nucleus and vagus nerve roots. It is important to mention that Guidetti defined a special role for tractotomy among the already existing surgical methods for treating trigeminal neuralgia (the Frazier [7] infratemporal trigeminal rhizotomy and the Dandy [8] transection of the sensory part of the trigeminal nerve). He also emphasized the importance of the candidate selection for this procedure.

In the 1970s, Kunc [9] came to the conclusion that trigeminal tractotomy at the obex level damages the first-order afferents that supply both the rostral and caudal parts of the nucleus of the spinal tract of the trigeminal nerve. Kunc [9] described “vertical partial nucleotomy of the trigeminal nerve” in his work. He was making not a horizontal but a vertical incision along the lateral border of the nucleus cuneatus. Thus, both first- and second-order afferent neurons were lesioned in the tract and nucleus, respectively. With this approach, the more caudally the incision was made, the further the border of analgesia from the midline of the face, while the more rostral, the closer to the center of the face was the analgesia.

In the late 1960s, Crue et al. [10] and Hitchcock [11] independently performed stereotactic percutaneous trigeminal tractotomies. They used radiofrequency electrodes to lesion the trigeminal nucleus. Regarding the location of destruction, it was assumed that the coordinates of neurons of the third branch of the trigeminal nerve are 3 mm ventral to the dorsal border of the spinal cord and 6 mm lateral to the midline. The neurons of the first branch are located ventrolaterally at 5 mm in depth from the dorsal edge of the medulla and 7.5 mm lateral to the midline.

Schvarcz [12] performed 104 stereotactic nucleotractotomies in 100 patients with a broad range of diagnoses (craniofacial tumors – 31, posttraumatic trigeminal neuropathy – 25, trigeminal neuralgia – 19, anesthesia dolorosa – 14, postherpetic neuralgia – 8, neuralgia IX and X nerves – 2, multiple sclerosis – 1) with a successful outcome in 72% of cases.

In 1971, Fox [13] described 18 cases of free-hand percutaneous nucleotractotomy without the use of a stereotaxic frame. In 1989, Kanpolat et al. [1] described free-hand percutaneous nucleotractotomy under CT guidance. The target point was located 3 mm anterior to the posterior surface of the spinal cord and 5–6 mm lateral to the midline at the level of the first cervical segment. Under local anesthesia, a 20 G needle is inserted in the first cervical vertebra, 5–8 mm lateral to the midline, and its tip is placed in the subarachnoid space. A 0.3-mm straight or curved electrode is inserted through it, directed toward the lateral third of the transverse diameter of the posterior half of the spinal cord. The final position of the tip is confirmed by CT scan, impedance measurement, and electrical stimulation. The patient can verbally confirm the location of the stimulation-induced sensation and its concordance with the area of pain.

Kanpolat et al. [1, 14‒16] subsequently produced the largest number of publications on the outcomes and complication rate of percutaneous trigeminal nucleotractotomy. In their studies, the majority of patients had deafferentation pain, craniofacial tumors, and atypical facial pain. The effectiveness of the atypical facial pain treatment is 44%, and the degree of pain reduction in other groups is much higher. The complication rate is low with percutaneous surgery, according to Kanpolat et al. [16]; the frequency of severe ataxia is just 10%.

In the 1980s and 1990s, Nashold and El-Naggar used the open nucleotractotomy using a radiofrequency electrode [2, 17]. During the procedure, the authors performed a series of destructions along the entire length of the subnucleus caudalis. Anatomical landmarks of the brain stem determine the location of the lesion: the subnucleus caudalis occupies a triangular area between the dorsolateral groove of the spinal cord and the exit point of the accessory nerve. At the level of the C2 root, the subnucleus caudalis merges with the posterior horn of the spinal cord and is dorsolaterally covered with a thin layer of descending trigeminal tract. Near the obex, it is covered with a layer of external arcuate and dorsal spinocerebellar fibers. According to Gorecki and Nashold et al., the overall efficacy of this approach is 74% [18].

Grigoryan et al. [19] summarized their experience with 32 patients who underwent ultrasonic trigeminal nucleotractotomy for different forms of facial pain. The uniqueness of this procedure is the ultrasonic effect on the brain matter. Of the 17 patients with deafferentation pain, 14 achieved complete pain regression, and one had a significant decrease in pain syndrome. In 2 cases, the postoperative pain level was the same as before the procedure. In the long-term follow-up, no relapses of pain were observed.

In addition, Teixeira et al. [20] described endoscopic nucleotractotomy. This technique has the advantages of minimally invasive percutaneous nucleotractotomy and the possibility of direct visualization of the brain stem. This technique was used by Rahimpour and Patel [21] to perform surgery on 5 patients with good results achieved in four.

According to the literature, open nucleotractotomy leads to more complications than percutaneous. This is due to the extent of a lesion to structures: other nuclear structures of the trigeminal nerve, parts of the spinal cord and medulla oblongata can be damaged. Ipsilateral paresis is associated with injury of the corticospinal tract. Contralateral hypesthesia is associated with lesions of the spinothalamic tract. The most common complication is ataxia, resulting from an injury to the spinocerebellar tract and dorsal columns [18]. Ataxia of the upper and lower extremities develops in 30–39% [22, 23] and only the upper extremities in 17–61% [2, 17, 22, 23].

Nucleotractotomy as an approach for the surgical treatment of trigeminal neuralgia has evolved over time like all neurosurgery: through gradual development of the optimal technique for performing this procedure and the modernization of equipment to the emergence of minimally invasive percutaneous methods. Over time, this method has not enjoyed wide acceptance but rather has taken a unique niche in the surgical treatment of patients with intractable facial pain.

So far, in the 21st century, only few papers have been published on the outcomes of trigeminal nucleotractotomy. All articles on this topic published after 2001 are listed in Table 2.

Table 2.

Publications about trigeminal nucleotractotomy from 2001 to 2022

AuthorsPublication yearApproachPatients, NDiagnosisEfficiency, %
Husain et al. [242002 Open Postherpetic, posttraumatic neuropathy, etc. 80 
Teixeira et al. [252003 Percutaneous 58 Deafferentation, postherpetic, oncological, atypical pain 71.4–100 
Delgado-Lopez et al. [262003 Open Anesthesia dolorosa 83 
Kanpolat et al. [162004 Percutaneous 52 Anesthesia dolorosa, trigeminal neuralgia, oncological, postherpetic, atypical facial pain, glossopharyngeal neuralgia, geniculate neuralgia 44–82 
Kanpolat et al. [272008 Percutaneous 65 Anesthesia dolorosa, trigeminal neuralgia, oncological, postherpetic, atypical facial pain, glossopharyngeal neuralgia, geniculate neuralgia 95 
Kanpolat et al. [282008 Open 11 Trigeminal deafferentation, cancer pain, glossopharyngeal neuralgia, geniculate neuralgia 73 
Raslan [292008 Percutaneous 10 Oncological 80 
Chivukula et al. [302015 Open 16 Trigeminal deafferentation, postherpetic, posttraumatic pain, glossopharyngeal neuralgia 100 
Rahimpour and Patel [212015 Percutaneous Atypical facial pain, trigeminal deafferentation 80 
Tan et al. [312022 Percutaneous 23 Oncological, posttraumatic, odontogenic, postherpetic, idiopathic facial pain 100 
AuthorsPublication yearApproachPatients, NDiagnosisEfficiency, %
Husain et al. [242002 Open Postherpetic, posttraumatic neuropathy, etc. 80 
Teixeira et al. [252003 Percutaneous 58 Deafferentation, postherpetic, oncological, atypical pain 71.4–100 
Delgado-Lopez et al. [262003 Open Anesthesia dolorosa 83 
Kanpolat et al. [162004 Percutaneous 52 Anesthesia dolorosa, trigeminal neuralgia, oncological, postherpetic, atypical facial pain, glossopharyngeal neuralgia, geniculate neuralgia 44–82 
Kanpolat et al. [272008 Percutaneous 65 Anesthesia dolorosa, trigeminal neuralgia, oncological, postherpetic, atypical facial pain, glossopharyngeal neuralgia, geniculate neuralgia 95 
Kanpolat et al. [282008 Open 11 Trigeminal deafferentation, cancer pain, glossopharyngeal neuralgia, geniculate neuralgia 73 
Raslan [292008 Percutaneous 10 Oncological 80 
Chivukula et al. [302015 Open 16 Trigeminal deafferentation, postherpetic, posttraumatic pain, glossopharyngeal neuralgia 100 
Rahimpour and Patel [212015 Percutaneous Atypical facial pain, trigeminal deafferentation 80 
Tan et al. [312022 Percutaneous 23 Oncological, posttraumatic, odontogenic, postherpetic, idiopathic facial pain 100 

In addition to clinical papers, two literature reviews on trigeminal nucleotractotomy have been published by Teixeira and Fonoff [32], and Santyr et al. [33]. Available postoperative MRI data in our patients do not allow us to draw definitive conclusions about long-term postoperative outcomes of the surgery since not all patients had neuroimaging completed. Gurbani et al. [34] after analyzing the postoperative images of 4 patients who underwent transcutaneous nucleotractotomy, concluded that the ablation zone when performing this procedure according to the standard method corresponds to the anatomical location of the nucleus and tract of the trigeminal nerve. The availability of visualization techniques for the spinal nucleus of the trigeminal nerve will make it possible to identify individual differences in the electrode location during destruction [35]. Future research remains needed to determine the relationship between lesion volume and surgical outcomes.

Currently, there is not enough data that would allow us identify clear indications for a choice between open and percutaneous nucleotractotomy. Therefore, the choice of the method tends to depend on the preferences of the operating surgeon.

At our hospital, transcutaneous surgery is recommended for patients with craniofacial tumors and patients with severe medical conditions who have a high risk of not recovering well from the “major” open operation. However, an important factor when choosing a transcutaneous technique is the patient’s compliance with this type of surgery. Not every patient will be able to tolerate this procedure, given the high level of patient anxiety due to the lack of general anesthesia and the pain encountered during the stimulation for checking the correct position of the needle. At the moment, only these parameters might play a role in selecting a particular technique in each specific case.

Trigeminal nucleotractotomy is an effective treatment for intractable facial pain. Our experience and the available literature data suggest that this technique is highly effective in patients with drug-resistant pain caused by craniofacial tumors and deafferentation conditions after the treatment of trigeminal neuralgia. Nucleotractotomy can be performed by both open and percutaneous methods. Percutaneous nucleotractotomy appears to be equally effective to the open technique in terms of the degree of pain relief but has a higher relapse rate. A smaller area of the neural tissue destruction with the percutaneous method appears to correlate with a lower number of serious postoperative complications.

This study was approved by the Local Ethics Committee of the Federal Neurosurgery Center of Novosibirsk (No. 5 dated August 22, 2022). The patients gave their written voluntary consent to the use of their case histories and clinical examination data in this study. Informed written consent for surgical treatment was obtained from each patient.

The authors have no conflicts of interest to declare.

No funding was received for this work.

Conception: Konstantin V. Slavin, Jamil A. Rzaev, Egor D. Anisimov; investigation and data collection: Egor D. Anisimov, Galina I. Moysak, Alexander B. Dmitriev, and Konstantin V. Slavin; writing of original draft manuscript: Egor D. Anisimov, Konstantin V. Slavin; review and editing: Egor D. Anisimov, Irina E. Duff, Konstantin V. Slavin.

Data are not publicly available due to ethical reasons. Further inquiries can be directed to the corresponding author.

1.
Kanpolat
Y
,
Deda
H
,
Akyar
S
,
Cağlar
S
,
Bilgiç
S
.
CT-guided trigeminal tractotomy
.
Acta Neurochir
.
1989
100
3–4
112
4
.
2.
Nashold
BS
Jr
,
Caputi
F
,
Bernard
E
.
Trigeminal DREZ: caudalis nuclear lesions for relief of facial pain
.
Neurosurgery
.
1984
;
19
:
150
.
3.
Sjoqvist
O
.
Studies on pain conduction in the trigeminal nerve: contribution to surgical treatment of facial pain
.
Acta Psychiatr Scand Suppl
.
1938
;
17
:
1
139
.
4.
Grant
FC
,
Weinberger
LM
.
Experiences with intramedullary tractotomy. IV. Surgery of the brain stem and its operative complications
.
Arch Surg
.
1941
;
42
:
747
54
.
5.
Olivecrona
H
.
Tractotomy for relief of trigeminal neuralgia
.
Arch Neurol Psychiatr
.
1942
;
47
(
4
):
544
654
.
6.
Guidetti
B
.
Tractotomy for relief of trigeminal neuralgia: observations in 124 cases
.
J Neurosurg
.
1950
;
7
(
6
):
499
508
.
7.
Frazier
C
.
Operation for the radical cure of trigeminal neuralgia: analysis of fove hundred cases
.
Ann Surg
.
1928 Sep
88
3
534
47
.
8.
Dandy
W
.
Concerning the cause of trigeminal neuralgia
.
Am J Surg
.
1934
;
24
(
2
):
447
55
.
9.
Kunc
Z
.
Vertical trigeminal partial nucleotomy
.
Adv Pain Res Ther
.
1979
;
3
:
325
9
.
10.
Crue
BL
,
Todd
EM
,
Carregal
EJA
,
Kilham
O
.
Percutaneous trigeminal tractotomy. Case report-utilizing stereotactic radiofrequency lesion
.
Bull Los Angeles Neurol Soc
.
1967
;
32
(
2
):
86
92
.
11.
Hitchcock
E
.
Stereotactic trigeminal tractotomy
.
Ann Clin Res
.
1970
;
2
:
131
5
.
12.
Schvarcz
JR
.
Spinal cord stereotactic techniques re trigeminal nucleotomy and extralemniscal myelotomy
.
Appl Neurophysiol
.
1978
41
1–4
99
112
.
13.
Fox
JL
.
Intractable facial pain relieved by percutaneous trigeminal tractotomy
.
JAMA
.
1971
;
218
(
13
):
1940
1
.
14.
Kanpolat
Y
,
Akyar
S
,
Cağlar
S
.
Diametral measurements of the upper spinal cord for stereotactic pain procedures: experimental and clinical study
.
Surg Neurol
.
1995
;
43
(
5
):
478
82
; discussion 482–3.
15.
Kanpolat
Y
,
Caglar
S
,
Akyar
S
,
Temiz
C
.
CT-guided pain procedures for intractable pain in malignancy
.
Acta Neurochir Suppl
.
1995
;
64
:
88
91
.
16.
Kanpolat
Y
,
Savas
A
,
Akyar
S
,
Cosman
E
.
Percutaneous computed tomography-guided spinal destructive procedures for pain control
.
Neurosurg Q
.
2004
;
14
(
4
):
229
38
.
17.
Nashold
BS
Jr
,
el-Naggar
AO
,
Ovelmen-Levitt
J
,
Abdul-Hak
M
.
A new design of radiofrequency lesion electrodes for use in the caudalis nucleus DREZ operation. Technical note
.
J Neurol
.
1994
;
80
(
6
):
1116
20
.
18.
Gorecki
JP
,
Nashold
BS
.
The Duke experience with the nucleus caudalis DREZ operation
.
Acta Neurochir Suppl
.
1995
;
64
:
128
31
.
19.
Grigoryan
YA
,
Slavin
KV
,
Ogleznev
KY
.
Ultrasonic lesion of the trigeminal nucleus caudalis for deafferentation facial pain
.
Acta Neurochir
.
1994
131
3–4
229
35
.
20.
Teixeira
MJ
,
de Almeida
FF
,
de Oliveira
YS
,
Fonoff
ET
.
Microendoscopic stereotactic-guided percutaneous radiofrequency trigeminal nucleotractotomy
.
J Neurosurg
.
2012 Feb
116
2
331
5
.
21.
Rahimpour
S
,
Patel
V
.
Endoscopic trigeminal nucleus caudalis doral root entry zone lesioning for atypical facial pain
.
Clin Neurosurg
.
2015
62
Suppl 1
205
.
22.
Bernard
EJ
Jr
,
Nashold
BS
Jr
,
Caputi
F
,
Moossy
JJ
.
Nucleus caudalis DREZ lesions for facial pain
.
Br J Neurosurg
.
1987
;
1
:
81
91
.
23.
Bernard
EJ
,
Nashold
BS
Jr
,
Caputi
F
.
Clinical review of nucleus caudalis dorsal root entry zone lesions for facial pain
.
Appl Neurophysiol
.
1988
51
2–5
218
24
.
24.
Husain
AM
,
Elliott
SL
,
Gorecki
JP
.
Neurophysiological monitoring for the nucleus caudalis dorsal root entry zone operation
.
Neurosurgery
.
2002
;
50
(
4
):
822
7
; discussion 827–8.
25.
Teixeira
MJ
,
Lepski
G
,
Aguiar
PHP
,
Cescato
VAS
,
Rogano
L
,
Alaminos
AB
.
Bulbar trigeminal stereotactic nucleotractotomy for treatment of facial pain
.
Stereotact Funct Neurosurg
.
2003
81
1–4
37
42
.
26.
Delgado-Lopez
P
,
Garcia-Salazar
F
,
Mateo-Sierra
O
,
Carrillo-Yague
R
,
Llaurado
G
,
Lopez
E
.
Trigeminal nucleus caudalis dorsal root entry zone radiofrequency thermocoagulation for invalidating facial pain
.
Neurocirugia
.
2003
;
14
(
1
):
25
32
; discussion 32.
27.
Kanpolat
Y
,
Kahilogullari
G
,
Ugur
HC
,
Elhan
AH
.
Computed tomography-guided percutaneous trigeminal tractotomy-nucleotomy
.
Neurosurgery
.
2008
63
1 Suppl 1
ONS147
53
; discussion ONS153–5.
28.
Kanpolat
Y
,
Tuna
H
,
Bozkurt
M
,
Elhan
AH
.
Spinal and nucleus caudalis dorsal root entry zone operations for chronic pain
.
Neurosurgery
.
2008
62
3 Suppl 1
235
42
; discussion 242–4.
29.
Raslan
AM
.
Percutaneous computed tomography-guided radiofrequency ablation of upper spinal cord pain pathways for cancer-related pain
.
Neurosurgery
.
2008
62
3 Suppl 1
ONS226
233
; discussion 233–4.
30.
Chivukula
S
,
Tempel
ZJ
,
Chen
CJ
,
Shin
SS
,
Gande
AV
,
Moossy
JJ
.
Spinal and nucleus caudalis dorsal root entry zone lesioning for chronic pain: efficacy and outcomes
.
World Neurosurg
.
2015
;
84
(
2
):
494
504
.
31.
Tan
H
,
Ward
E
,
Stedelin
B
,
Raslan
AM
.
Percutaneous CT-guided trigeminal tractotomy-nucleotomy under general anesthesia for intractable craniofacial pain
.
J Neurosurg
.
2022 Dec 2
1
9
.
32.
Teixeira
MJ
,
Fonoff
ET
.
Technique of trigeminal nucleotractotomy
. In:
Tasker
R
,
Lozano
A
,
Gildenbeg
P
, editors.
Stereotactic and functional neurosurgery
Springer-Verlag, Berlin/Heidelberg
2009
. p.
2097
124
.
33.
Santyr
B
,
Abbass
M
,
Chalil
A
,
Vivekanandan
A
,
Tindale
M
,
Boulis
NM
.
Surgical interventions targeting the nucleus caudalis for craniofacial pain: a systematic and historical review
.
Neuromodulation
.
2022 Sep 30
S1094
7159
.
34.
Gurbani
SS
,
Brandman
DM
,
Reeves
C
,
Boulis
NM
,
Weinberg
BD
.
Percutaneous trigeminal tractotomy for trigeminal neuralgia: postoperative MRI findings
.
J Neuroimaging
.
2022 Jan
32
1
57
62
.
35.
Burkett
DJ
,
Garst
JR
,
Hill
JP
,
Kam
A
,
Anderson
DE
.
Deterministic tractography of the descending tract of the spinal trigeminal nerve using diffusion tensor imaging
.
J Neuroimaging
.
2017 Sep
27
5
539
44
.