Postherpetic craniofacial dysaesthesiae: their management by stereotaxic trigeminal nucleotomy

Outcome of Surgical Treatments of Chronic Pain Caused by Trigeminal Neuropathy

BACKGROUND

Trigeminal neuropathy represents a subset of several facial pain syndromes that are difficult to diagnose and treat. Although many surgical modalities are available, outcomes remain suboptimal. The aim of this study is to present our experience in management of trigeminal neuropathy with a focus on the effectiveness and long-term efficacy of the different surgical procedures.

METHODS

A single-center retrospective cohort study was conducted from December 2012 until February 2020.

RESULTS

Twenty-eight patients (19 females, 9 males) were included in this study. They had 40 surgical interventions. At last follow-up, 1 patient (33.3%) treated by spinal cord stimulation (SCS) had no pain recurrence and 2 patients (66.6%) had their devices removed because of therapeutic failure. Median time to pain recurrence after SCS was 19.5 months (interquartile range [IQR], 29.79 months). Six patients were treated with peripheral nerve stimulation (PNS). At last follow-up, 2 patients had satisfactory pain relief, whereas half of the patients had no improvement. For the 17 patients treated with computed tomography-guided trigeminal tractotomy/nucleotomy, true failure occurred 7 times in 6 patients. Median time to pain recurrence was 5.6 months (IQR, 6.2). Of the 6 patients treated with caudalis DREZ, 3 (50%) had satisfactory pain relief for >1 year and the median time to pain recurrence was 3.9 months (IQR, 29.53).

CONCLUSIONS

Trigeminal neuropathy is a difficult to treat entity of facial pain syndromes. The long-term efficacy of available interventions does not meet patients' satisfaction. More organized prospective studies with longer follow-up are needed to define the patient population best served by each surgical modality.

Microsurgical Pontine Descending Tractotomy in Cases of Intractable Trigeminal Neuralgia

BACKGROUND

Current treatment strategies in patients with trigeminal neuralgia (TN) include trials of medical therapy and surgical intervention, when necessary. In some patients, pain is not adequately managed with these existing strategies.

OBJECTIVE

To present a novel technique, ventral pontine trigeminal tractotomy via retrosigmoid craniectomy, as an adjunct treatment in TN when there is no significant neurovascular compression.

METHODS

We present a nonrandomized retrospective comparison between 50 patients who lacked clear or impressive arterial neurovascular compression of the trigeminal nerve as judged by preoperative magnetic resonance imaging and intraoperative observations. These patients had intractable TN unresponsive to previous treatment. Trigeminal tractotomy was performed either alone or in conjunction with microvascular decompression. Stereotactic neuronavigation was used during surgery to localize the descending tract via a ventral pontine approach for descending tractotomy.

RESULTS

Follow-up was a mean of 44 months. At first follow-up, 80% of patients experienced complete relief of their pain, and 18% had partial relief. At the most recent follow-up, 74% of patients were considered a successful outcome. Only 1 (2%) patient had no relief after trigeminal tractotomy. Of those with multiple sclerosis-related TN, 87.5% experienced successful relief of pain at their latest follow-up.

CONCLUSION

While patient selection is a significant challenge, this procedure represents an option for patients with TN who have absent or equivocal neurovascular compression, multiple sclerosis-related TN, or recurrent TN.

Percutaneous trigeminal tractotomy–nucleotomy with use of intraoperative computed tomography and general anesthesia: report of 2 cases

For confirming the correct location of the radiofrequency electrode before creation of a lesion, percutaneous CT-guided trigeminal tractotomy–nucleotomy is most commonly performed with the patient prone and awake. However, for patients whose facial pain and hypersensitivity are so severe that the patients are unable to rest their face on a support (as required with prone positioning), awake CT-guided tractotomy-nucleotomy might not be feasible. The authors describe 2 such patients, for whom percutaneous intraoperative CT-guided tractotomy-nucleotomy under general anesthesia was successful. One patient was a 79-year-old man with profound left facial postherpetic neuralgia, who was unable to tolerate awake CT-guided tractotomy-nucleotomy, and the other was a 45-year-old woman with intractable hemicranial pain that developed after a right frontal lesionectomy for epilepsy. Each patient underwent a percutaneous intraoperative CT-guided tractotomy-nucleotomy under general anesthesia. No complications occurred, and each patient reported excellent pain relief for up to 6 and 3 months after surgery, respectively. Percutaneous intraoperative CT-guided tractotomy-nucleotomy performed on anesthetized patients is effective for facial postherpetic neuralgia and postoperative hemicranial neuralgia.

Neurosurgical advances in cancer pain management

Neurosurgical procedures to treat pain are mainly destructive and involve the spinal cord and occasionally the brain. Targets include the spinothalamic tract, the trigeminal tract nucleus, the midline ascending visceral pain pathway, the brainstem spinal lemniscus, the thalamus, and the cingulate gyrus. Since the introduction of intrathecal opioids, the need for neurosurgical destructive procedures has been in decline. In recent years, cordotomy, trigeminal tractotomy, and dorsal root entry zone (DREZ) operations are the neurosurgical procedures most often utilized to treat cancer pain. The addition of CT guidance to spinal cord pain pathway ablation was a major addition and refinement to the procedure. Here the authors review the latest techniques and recently published results for CT-guided cordotomy, CT-guided trigeminal tractotomy, and DREZ operations utilized to treat cancer pain.

Destructive procedures for the treatment of nonmalignant pain: a structured literature review

OBJECT

Nonmalignant pain has been treated in the past century with ablative, or more appropriately, destructive procedures. Although individual outcomes for these procedures have previously been described in the literature, to the authors' knowledge this is the first comprehensive and systematic review on this topic.

METHODS

A US National Library of Medicine PubMed search was conducted for the following ablative procedures: cingulotomy, cordotomy, DREZ (also input as dorsal root entry zone), ganglionectomy, mesencephalotomy, myelotomy, neurotomy, rhizotomy, sympathectomy, thalamotomy, and tractotomy. Articles related to pain resulting from malignancy and those not in peer-reviewed journals were excluded. In reviewing pertinent articles, focus was placed on patient number, outcome, and follow-up.

RESULTS

A total of 146 articles was included in the review. The large majority of studies (131) constituted Class III evidence. Eleven Class I and 4 Class II studies were found, of which nearly all (13 of 15) evaluated radiofrequency rhizotomies for different pain origins, including lumbar facet syndrome, cervical facet pain, and Type I or typical trigeminal neuralgia. Overall, support for ablative procedures for nonmalignant pain is derived almost entirely from Class III evidence; despite a long history of use in neurosurgery, the evidence supporting destructive procedures for benign pain conditions remains limited.

CONCLUSIONS

Newly designed prospective standardized studies are required to define surgical indications and outcomes for these procedures, to provide more systematic review, and to advance the field.

Computed Tomography-guided Percutaneous Trigeminal Tractotomy-nucleotomy

Objective:

The destruction of the descending trigeminal tractus in the medulla is known as trigeminal tractotomy (TR), whereas the lesioning of the nucleus caudalis is known as trigeminal nucleotomy (NC). Trigeminal TR and/or NC procedures can be used in a large group of pain syndromes, such as glossopharyngeal, vagal, and geniculate neuralgias, atypical facial pain, craniofacial cancer pain, postherpetic neuralgias, and atypical forms of trigeminal neuralgia.

Methods:

In this study, anatomic and technical details of the procedure and the experience gained from 65 patients over the course of 20 years are discussed. Patients’ pain scores and Karnofsky Performance Scale scores were evaluated pre- and postoperatively (postoperative Day 1).

Results:

The best results were obtained in the second-largest group (vagoglossopharyngeal neuralgia, n = 17) and in geniculate neuralgia (n = 4). Patients with atypical facial pain (n = 21; 13 women, eight men) accounted for the largest group to undergo computed tomography-guided TR-NC surgery; pain relief was achieved in 19 of these patients. In the third-largest group (craniofacial and oral cancer pain, n = 13), 11 of 13 patients were successfully treated with TR-NC. Four of five patients with failed trigeminal neuralgia were also effectively treated with TR-NC.

Conclusion:

We propose that computed tomography-guided TR-NC provides direct visualization of the target-electrode relation and can be considered a first-step procedure in patient management. In view of its high efficacy, low complication rate, and minimal invasiveness, computed tomography-guided trigeminal TR-NC is a safe and effective procedure in the treatment of intractable facial pain syndromes.

Percutaneous computed tomography-guided radiofrequency ablation of upper spinal cord pain pathways for cancer-related pain

OBJECTIVE

The author presents data to support the continued need for ablative procedures, particularly cordotomy, in the management of cancer-related pain.

METHODS

Fifty-one patients with cancer-related body or face pain were treated with computed tomography-guided radiofrequency ablation of the spinothalamic tract or trigeminal tract nucleus in the upper cervical region of the spinal cord. Forty-one patients underwent a unilateral cervical cordotomy, and 10 patients underwent a trigeminal tractotomy-nucleotomy. Three methods to assess patient pain were used: degree of pain relief, Visual Analog Scale, and total sleeping hours. The Karnofsky scale was used to measure the patient's level of function pre- and postprocedure.

RESULTS

After surgical intervention, patients reported initial and 6-months follow-up pain relief as 98 and 80%, respectively.

CONCLUSION

Computed tomography-guided ablation of the upper cervical spinal cord is a safe and effective procedure to treat cancer pain involving the body or face. There remains a need for ablative procedures, in particular cordotomy, in the management of cancer-related pain.

Management of chronic severe pain: spinal neuromodulatory and neuroablative approaches

The spinal cord is the target of many neurosurgical procedures used to treat pain. Compactness and well-defined tract separation in addition to well understood dermatomal cord organization make the spinal cord an ideal target for pain procedures. Moreover, the presence of opioid and other receptors involved in pain modulation at the level of the dorsal horn increases the suitability of the spinal cord. Neuromodulative approaches of the spinal cord are either electrical or pharmacological. Electrical spinal cord modulation is used on a large scale for various pain syndromes including; failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), neuropathic pain, angina, and ischemic limb pain. Intraspinal delivery of medications e.g. opioids is used to treat nociceptive and neuropathic pains due to malignant and cancer pain etiologies. Neuroablation of the spinal cord pain pathway is mainly used to treat cancer pain. Targets involved include; the spinothalamic tract, the midline dorsal column visceral pain pathway and the trigeminal tract in the upper spinal cord. Spinal neuroablation can also involve cellular elements such as with trigeminal nucleotomy and the dorsal root entry zone (DREZ) operation. The DREZ operation is indicated for phantom type pain and root avulsion injuries. Due to its reversible nature spinal neuromodulation prevails, and spinal neuroablation is performed in a few select cases.

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.

The surgical treatment of chronic pain: destructive therapies in the spinal cord

Stereotactic pain surgery is accepted as a group of procedures. These are usually highly sophisticated and technically risky procedures. In practice, the most important part of this discipline is not the technical abilities of the surgeon, but selection of the most appropriate patients for the available procedures. We must remember that we are performing all these procedures with the cooperation of patients. The energy that is used for lesioning can be stopped when desired. The target we want to approach can be definitely and anatomically visualized and demonstrated, and the function of the target is evaluated with neurophysiologic impedance techniques and stimulation. Thus, if we are able to understand the language of the central nervous system, these are available, effective, and safe procedures in neurosurgical practice. We must remember that if intractable pain can be controlled by minimally invasive destructive techniques, the patients will not be dependent on implantable systems, drugs,and medical units. This independent lifestyle is a critical goal central to quality of life for patients having intractable pain.

Computed tomography-guided trigeminal tractotomy-nucleotomy in the management of vagoglossopharyngeal and geniculate neuralgias

OBJECTIVE

Vagoglossopharyngeal and geniculate neuralgias are less frequently seen types of cranial neuralgias. Their causes and symptomatology are similar to those of trigeminal neuralgia; however, the complex anatomic relationship between the intermedius, vagal, and glossopharyngeal nerves leads to difficulties in the diagnosis and management of neuralgias originating from these cranial nerves. Numerous procedures have been used to treat intractable neuralgias of the VIIth, IXth, and Xth cranial nerves: 1) extracranial sectioning of the cranial nerves, 2) percutaneous thermal rhizotomy, 3) intracranial glossopharyngeal and vagal rhizotomies, 4) microvascular decompression, and 5) percutaneous trigeminal tractotomy-nucleotomy (TR-NC) or nucleus caudalis dorsal root entry zone operation. We propose that computer-guided TR-NC may be the first-choice operation for patients with glossopharyngeal, vagal, or geniculate neuralgia.

PATIENTS AND METHODS

Nine patients suffering from idiopathic vagoglossopharyngeal neuralgia (six patients) and geniculate neuralgia (three patients) were managed at our clinic. Computed tomography-guided percutaneous trigeminal TR-NC was performed for these nine patients.

RESULTS

Excellent (six patients) or good (three patients) pain control was obtained in each patient. Complications included temporary ataxia in two patients after TR-NC.

CONCLUSION

The risk:benefit ratio should be evaluated individually to select the appropriate treatment procedure for patients with vagoglossopharyngeal and geniculate neuralgias. Computed tomography-guided percutaneous TR-NC is an effective and minimally invasive procedure for such patients.

Diametral measurements of the upper spinal cord for stereotactic pain procedures: experimental and clinical study

BACKGROUND

Stereotactic percutaneous pain procedures, percutaneous cordotomy, trigeminal tractotomy, and extralemniscal myelotomy are routinely performed with computed tomography (CT) guidance. This new imaging technique enables one to measure the spinal cord diameters for each patient uniquely. Significant differences have been recognized between the measurements obtained with CT and the reference values given for such procedures.

METHODS

To confirm the reliability of CT measurements, two experimental models were used. In the first stage, an artificial neck and spinal cord model was set up and diameters of the spinal cord were remeasured with CT. In the second stage, spinal cord diameters of the upper cervical region on 10 mongrel dogs were initially taken with CT, then standard laminectomy was performed and diameters of the same region were measured under the operating microscope.

RESULTS

The experimental studies confirmed that CT measurements of the upper cervical cord are reliable. In clinical application, diametral measurements of the spinal cord at occiput C-1 level were carried out in 30 patients who underwent percutaneous trigeminal tractotomy and extralemniscal myelotomy. The anteroposterior diameter at this level was measured at 7.0-12.8 mm and the transverse diameter ranges between 9.3-14 mm. At the level of C-1-C-2, these measurements were performed over 63 patients who experienced percutaneous cordotomy. In this group the anteroposterior (A-P) diameter was measured as 7.0-11.4 mm, and the transverse diameter as 9.0-14.0 mm.

CONCLUSIONS

Our clinical experiences and the results of the experimental measurements demonstrate that CT imaging gives accurate diametral values that would favorably influence the surgical procedures, and thus, with CT imaging it is possible to perform main stereotactic destructive pain procedures safely, effectively and selectively.

CT-guided pain procedures for intractable pain in malignancy

CT-guided stereotactic percutaneous destructive procedures, i.e. percutaneous cordotomy, trigeminal tractotomy, and extralemniscal myelotomy, have been routinely used for the treatment of localized intractable pain in malignancy since 1987. In 67 cases if local pain due to malignancy, CT guided percutaneous cordotomy was performed and in 97% complete pain control was achieved. In 45 of these cases, a "selective cordotomy" was performed meaning that analgesia was produced only in the painful region of the body. CT guided trigeminal tractotomy was applied to a total of 19 cases in 5 of which pain had been caused by malignancy. The results were satisfactory. 12 cases, suffering from visceral pain due to malignancy, were treated by CT-guided extralemniscal myelotomy and in 10 cases pain relief was achieved.

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.

CT-guided trigeminal tractotomy

Trigeminal tractotomy is an effective procedure in denervating pain areas of 5th, 7th, 9th and 10th nerves. The classical imaging technique is the x-ray method which visualizes the target electrode relation indirectly. The method of CT-guided trigeminal tractotomy demonstrates the target electrode relation directly.

Craniofacial postherpetic neuralgia managed by stereotactic spinal trigeminal nucleotomy

Postherpetic craniofacial neuralgias are notoriously difficult to deal with. Nevertheless, stereotactic spinal trigeminal nucleotomy seems to be a rational approach, as both experimental and clinical data strongly suggest the relevance of nucleus caudalis for certain facial neurogenic pain phenomena. From a series of 136 consecutive nucleotomies, 80 were performed for deafferentation pain. The long-term results of 25 such cases, who underwent this procedure for postherpetic neuralgia, are reported. Their pain was referred to the Vth, to the VII, IX and Xth, and to the C2-3 dermatomes. Abolition of the allodynia, and disappearance of, or marked reduction in, the deep background pain was achieved in 76% of the cases overall. The follow-up period ranged from 1 to 13 years. There was no untoward side-effects. Technical and electrophysiological data germane to accurate target placement are discussed. Spinal trigeminal nucleotomy is then a specially suitable procedure for postherpetic craniofacial dysaesthesiae.

Trigeminal somatosensory evoked responses in patients with facial anaesthesia dolorosa

The TSER of six patients with facial anaesthesia dolorosa showed shorter latencies and higher amplitudes of the late waves, which are believed to represent the processing of somatosensory input in the higher subcortical and cortical centres. Shorter latencies and higher amplitudes may reflect abnormal facilitation or decreased inhibition by these centres. The TSER also supplied an objective means of pain measurement, as the stimulating impulse at the affected side had to be reduced from 20 mA (the usual intensity used in patients without evoking pain or an unpleasant sensation) down to 9-12 mA, to avoid unbearable pain.

Chronic self-stimulation of the medial posterior inferior thalamus for the alleviation of deafferentation pain

Since current techniques yield uncertain results on deafferentation pain, chronic brain stimulation may presumably be a valuable alternative method, without deterrent side-effects. Disappointing results with stimulation of the somato-sensory structures prompted the selection of the medial posterior inferior thalamus and adjacent brain stem for chronic stimulation in pain states of central origin. Six such cases are reported. Abolition of the hyperpathia and marked reduction in the deep background pain was achieved in 2 cases, and disappearance of the hyperpathia and moderate reduction in the deep pain was obtained in another 2, but none had complete alleviation of pain. The follow-up time ranged between 6 and 42 months. Reversal of analgesia by naloxone was not observed. Acute experimentally-induced pain was not modified by stimulation.