The neurosurgical treatment of craniofacial pain syndromes: current surgical indications and techniques

Long-term outcomes of Gamma Knife radiosurgery in treating glossopharyngeal neuralgia

Glossopharyngeal neuralgia (GPN) is an unusual disorder causing severe, brief pain episodes in the areas supplied by the glossopharyngeal nerve. Initial treatment involves medications like carbamazepine, but if these are ineffective or cause side effects, interventional pain management techniques or surgery may be considered. Gamma Knife radiosurgery is becoming popular in managing GPN due to its lower risk of complications than surgical interventions like microvascular decompression or rhizotomy. In this retrospective case series, we examined the outcomes of Gamma Knife radiosurgery in eight patients with GPN. The decision to utilize Gamma Knife radiosurgery was made following specific criteria, including failed surgical interventions, patient preference against surgery, or contraindications to surgical procedures. Patients were administered radiation doses within the range of 80 to 90 Gy, targeting either the cisternal glossopharyngeal nerve or glossopharyngeal meatus of the jugular foramen. Evaluations were conducted before the Gamma Knife radiosurgery; at 3, 6, and 12 months after Gamma Knife radiosurgery; and annually thereafter. Pain severity was assessed using the modified Barrow Neurological Institute scale grades, with patients achieving grade I-IIIa considered to have a good treatment outcome and grade IV-V to have a poor treatment outcome. Pain control and absence of radiosurgery-related complications were primary endpoints. The median age of the patients was 46.5 years, varying from 8 to 72 years. The median duration of pain was 32 months (range, 12-120 months). All patients, except one, were on polydrug therapy. All cases exhibited preoperative grade V pain. The median follow-up duration after Gamma Knife radiosurgery was 54.5 months, varying from 14 to 90 months. The overall clinical assessments revealed a gradual neurological improvement, particularly within the first 8.5 weeks (range, 1-12 weeks). The immediate outcomes at 3 months revealed that all patients (8/8, 100%) experienced pain relief, with 25% (2/8) achieving a medication-free status (Grade I). Three patients (37%) experienced a recurrence during the follow-up and were managed with repeat Gamma Knife radiosurgery (n = 2) and radiofrequency rhizotomy (n = 1). At the last follow-up, 88% (7/8) of patients had pain relief (Grades I-IIIa), with three (37%) achieving a medication-free status (Grade I). No adverse events or neurological complications occurred. The patient who underwent radiofrequency rhizotomy continued to experience inadequately controlled pain despite medication (Grade IV). Gamma Knife radiosurgery is a non-invasive, efficacious treatment option for idiopathic GPN, offering short- and long-term relief without permanent complications.

Repeat Gamma Knife radiosurgery for recurrent trigeminal neuralgia in patients with multiple sclerosis: a single-center retrospective study

PURPOSE

Gamma Knife radiosurgery (GKRS) has emerged as an effective treatment option for trigeminal neuralgia (TN) in patients with multiple sclerosis (MS). To date, the outcomes of repeat GKRS for patients with TN and MS with recurrent pain have been investigated in a few patients. This study aims to report the outcomes and predictive factors of pain reduction for MS patients undergoing repeat GKRS for recurrent TN.

METHODS

Eighteen patients with MS underwent repeat GKRS for recurrent TN. A retrospective chart review and telephone interviews were conducted to determine background medical history, dosimetric data, and outcomes of the procedure. Facial pain and sensory function were evaluated using the Barrow Neurological Institute (BNI) scales.

RESULTS

Fifteen patients achieved a BNI pain score of IIIa or better, indicating pain reduction, within a median period of 21 days after repeat GKRS. The maximum dose for repeat GKRS ranged from 70 to 85 Gy. Pain recurred in 5 patients after a median period of 12 months after GKRS. Percentages of patients with pain reduction at 1, 2, 3, 5, and 7 years were 60%, 60%, 50%, 50%, and 50%, respectively. Older age at repeat GKRS predicted sustained pain reduction (P = 0.01). Seven patients developed facial sensory disturbances, which were bothersome in two patients.

CONCLUSIONS

Repeat GKRS may be used as an effective treatment modality for prolonging the duration of pain reduction time in patients with MS and TN. After repeat GKRS, facial sensory disturbances are common; however, they are often not bothersome.

Occipital Nerve Stimulation for Recurrent Trigeminal Neuralgia Without Occipital Pain

OBJECTIVES

Trigeminal neuralgia (TN) is a severe, debilitating pain condition causing physical and emotional distress. Although the management of TN is well codified with medical and then surgical treatments, 15% to 30% of patients will experience intractable pain. Neuromodulation techniques have been scarcely used for refractory TN, with only small case series and short-term follow-up.

MATERIALS AND METHODS

We conducted a retrospective study of patients treated with occipital nerve stimulation (ONS) for medically and surgically resistant TN without painful trigeminal neuropathy. The effectiveness of the ONS was evaluated using the Barrow Neurological Institute (BNI) pain score and the pain relief (0%-100%) at best and at last follow-up.

RESULTS

Seven patients who have refractory TN were included. The mean age at ONS was 49 years. The mean pain duration was 8.6 years. The mean number of medical and surgical treatments before ONS was six and five, respectively. A percutaneous trial was performed in five of seven patients; all responded (pain relief > 40%), and four of five patients experienced pain recurrence after explantation. Eventually, six patients had a permanent ONS implantation. The average BNI pain score before implantation was V. The mean follow-up after implantation was 59 months. All patients reported an improvement after implantation. The average BNI score and mean pain relief at best were IIIa and 86.7%, respectively. At last follow-up, the average BNI score and mean pain relief were IIIa and 58.0%, respectively, with three patients experiencing pain recurrence. Adverse events were reported for four patients who required surgical revision for lead breakage (1), erosion (1), migration (1), or hardware-related discomfort (1). One patient finally underwent explantation because of infection.

CONCLUSIONS

Although ONS is not validated in this indication, these results suggest that it can induce an improvement in TN recurring after several surgical treatments, and the benefit of the stimulation can be sustained in the long term.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT01842763.

Gamma Knife Radiosurgery Targeting the Trigeminal Nerve for Tumor-Related Trigeminal Neuralgia: A Case Series

BACKGROUND

Tumor-related trigeminal neuralgia (TN) is a challenging condition to manage that is commonly treated by surgical resection of the tumor. Stereotactic radiosurgery targeting the tumor is used to control pain and tumor growth in patients unsuitable for surgery. Stereotactic radiosurgery targeting the trigeminal nerve has been explored as a viable treatment for patients with tumor-related TN who are unsuitable for surgical removal of the tumor or whose pain is refractory to radiation therapy targeting the tumor. Information regarding the efficacy of this procedure is limited to only a few studies. We report the outcomes of Leskell Gamma Knife radiosurgery (GKRS) targeting the trigeminal nerve for tumor-related TN from a case series.

METHODS

A retrospective review of our GKRS database identified 6 patients with unilateral tumor-related TN treated with GKRS targeting the trigeminal nerve between 2014 and 2020. Five patients had undergone previous radiation therapy targeting the tumor. Facial pain and sensory function were evaluated using the Barrow Neurological Institute scales.

RESULTS

Three patients achieved a Barrow Neurological Institute score of IIIb or better, indicating pain reduction, within a mean period of 4.3 months after GKRS. The maximum dose for GKRS ranged from 80 to 88 Gy. Pain recurred in 1 patient at 64 months after GKRS. No patient developed permanent facial sensory disturbances. No adverse event was recorded.

CONCLUSIONS

GKRS targeting the trigeminal nerve could be a safe and effective treatment for a subset of patients with tumor-related TN who are unsuitable for surgical removal of the tumor or whose pain is refractory to radiation therapy targeting the tumor.

Gamma Knife radiosurgery for the treatment of cluster headache: a systematic review

Cluster headache (CH) is a severe trigeminal autonomic cephalalgia that, when refractory to medical treatment, can be treated with Gamma Knife radiosurgery (GKRS). The outcomes of studies investigating GKRS for CH in the literature are inconsistent, and the ideal target and treatment parameters remain unclear. The aim of this systematic review is to evaluate the safety and the efficacy, both short and long term, of GKRS for the treatment of drug-resistant CH. A systematic review of the literature was performed to identify all clinical articles discussing GKRS for the treatment of CH. The literature review revealed 5 studies describing outcomes of GKRS for the treatment of CH for a total of 52 patients (48 included in the outcome analysis). The trigeminal nerve, the sphenopalatine ganglion, and a combination of both were treated in 34, 1, and 13 patients. The individual studies demonstrated initial meaningful pain reduction in 60-100% of patients, with an aggregate initial meaningful pain reduction in 37 patients (77%). This effect persisted in 20 patients (42%) at last follow-up. Trigeminal sensory disturbances were observed in 28 patients (58%) and deafferentation pain in 3 patients (6%). Information related to GKRS for CH are limited to few small open-label studies using heterogeneous operative techniques. In this setting, short-term pain reduction rates are high, whereas the long-term results are controversial. GKRS targeted on the trigeminal nerve or sphenopalatine ganglion is associated to a frequent risk of trigeminal disturbances and possibly deafferentation pain.

Microvascular decompression for a unique case of glossopharyngeal neuralgia with provokable symptomatic bradycardia: 2-Dimensional operative video

Background:

Glossopharyngeal neuralgia is a rare neurovascular compression syndrome that can lead to paroxysmal craniofacial pain and sometimes cardiovascular symptoms.[1,2] The characteristic pathology involves a vessel (commonly a branch/loop of PICA) compressing the nerve at the root entry/exit zone at the brainstem.[1] Microvascular decompression is a commonly used treatment approach for patients that have failed conservative measures.[2]

Case Description:

A 72-year-old male presented to the ED following four episodes of syncope. The patient had a multi-year history of right-sided burning/stabbing pain involving the submandibular area and posterior throat. His syncope was related to symptomatic bradycardia that would occur during episodes of pain. His pain was exacerbated by speaking and swallowing and could be triggered by placing his finger in the right external auditory meatus. Interestingly, this maneuver would also trigger his bradycardia. The patient had failed previous pharmacotherapy, and a pacemaker had been placed to protect him from periods of hypotension. MRI/MRA of the brain and cervical spine were unremarkable. Due to his profoundly symptomatic status, the patient was offered a right retrosigmoid craniotomy for microvascular decompression of the right glossopharyngeal nerve. The patient had complete resolution of his pain and bradycardia immediately post-operatively. He was discharged on the second postoperative day and his pacemaker was ultimately removed. The patient continues to be pain free and off medication.

Conclusion:

Here we present a video case report of microvascular decompression with favorable outcome for an interesting presentation of glossopharyngeal neuralgia. The patient gave informed consent for surgery and video recording.

Preoperative evaluation of neurovascular relationships for microvascular decompression: Visualization using Brainvis in patients with idiopathic trigeminal neuralgia

OBJECTIVE

A precise and accurate evaluation of neurovascular relationships in patients with idiopathic trigeminal neuralgia (ITN) scheduled for microvascular decompression is necessary. Thus, we constructed and evaluated a fusion imaging technique combining multi-source heterogeneous imaging data from three-dimensional magnetic resonance (MR) and computerized tomography venoangiography (CTV), which enabled use of virtual reality to preoperatively assess the neurovascular relationships, in patients with ITN scheduled for microvascular decompression.

METHODS

A single-center observational study. In total, eight patients with ITN scheduled for microvascular decompression were included. Patients underwent three-dimensional MR imaging with time-of-flight (TOF) and fast imaging employing steady state acquisition (FIESTA) sequences and CTV before microvascular decompression. A fusion imaging technique, combining MR-TOF, MR-FIESTA, and CTV images, was used to construct a three-dimensional model with information regarding the facial and auditory nerves, brain tissue, skull, arteries and veins. The positions of the trigeminal nerve and the responsible vessels were observed. The agreement between intraoperative neurovascular compression findings and preoperative evaluation results, and the duration required to determine the neurovascular relationships, were evaluated.

RESULTS

The neurovascular relationships as determined with the fusion imaging technique were consistent with intraoperative neurovascular compression findings in all patients. Moreover, the assessment duration was significantly shorter with the fusion imaging technique than with the three-dimensional MR (P<0.05). The rate of an accurate assessment was significantly higher with the fusion imaging technique than with three-dimensional MR (P<0.05).

CONCLUSIONS

The fusion imaging technique is a useful tool for the diagnosis and decision-making process based on neurovascular relationships in patients with ITN scheduled for microvascular decompression.

Gamma Knife Radiosurgery for the Treatment of Trigeminal Neuralgia in Patients with Multiple Sclerosis: A Single-Center Retrospective Study and Literature Review

OBJECTIVE

Trigeminal neuralgia (TN) in patients with multiple sclerosis (MS) is a challenging condition to manage that is treated with Gamma Knife radiosurgery (GKRS). The aim of this report is to assess the safety, efficacy, and durability of GKRS for the treatment of TN in patients with MS. Our findings are compared with those of the existing literature and discussed.

METHODS

We retrospectively reviewed all patients at our institution who underwent GKRS for the treatment of TN secondary to MS and had 1 or more years of follow-up. Preoperative and postoperative pain intensities and facial numbness were evaluated with the Barrow Neurological Institute scores. Durability of successful pain relief was statistically evaluated with Kaplan-Meier analysis. The prognostic role of perioperative factors was investigated and analyzed using Cox proportional hazards regression.

RESULTS

There were 29 patients with MS-TN who underwent GKRS at our institution. Two patients underwent bilateral treatment. Four patients underwent repeat GKRS for pain recurrence. The median period of follow-up assessment was 33 months. Rates of reasonable pain reduction at 1, 3, and 5 years were 70%, 57%, and 57% respectively. All patients who underwent repeat GKRS had durable pain reduction. No prognostic factor for successful pain reduction was found.

CONCLUSIONS

Our study shows that GKRS for the treatment of TN secondary to MS is a safe and effective procedure in controlling pain in the short term but often fails to provide long-term pain control. GKRS can be safely repeated to prolong the time of pain reduction.

Reoperation after failed microvascular decompression for glossopharyngeal neuralgia

BACKGROUND

Microvascular decompression (MVD) is known as a safe and effective procedure to treat glossopharyngeal neuralgia (GN). However, some patients experienced poor pain relief after MVD, for which the mechanism is not clear yet. Reviewing the intraoperative findings and postoperative effect of reoperation for patients who failed the first MVD, is helpful to figure out why the first MVD for GN failed.

METHODS

There were eight patients with GN who failed first MVD. The possibilities for secondary GN were eliminated by physical and radiological examination. The reoperation through the previous incision was conducted, and appropriately, treatment was provided according to the intraoperative findings. The video data and prognosis of the reoperation were retrospectively reviewed. The reasons for the invalid first MVD were analyzed.

RESULTS

To the end of follow-up, there were 7 patients of pain-free, and one patient with occasional mild pain attacks (VAS 2). There was one patient who experienced transient hoarseness in 3 months after the reoperation. We summarized the causes for failed first MVD which were omission of the offending vessel in 3 cases, inadequate decompression of the nerve root in 2 cases, and excessive decompression materials which caused iatrogenic nerve root compression in 3 cases.

CONCLUSIONS

For patients with recurrent or failed after MVD, a thorough examination should be carried out to eliminate the possibility of secondary GN. Reoperation through the previous incision is safe and effective. The bone window should be close enough to the sigmoid sinus to aid the exposure of the nerve root. The nerve transection could be adopted if no offending vessels were found. And a multi-site decompression could be used when the vertebral artery is the offending vessel.

CT-Guided Percutaneous Trigeminal Tractotomy-Nucleotomy for Intractable Craniofacial Pain

OBJECT

In this report, we aimed to analyze the outcome results of our patients who underwent percutaneous trigeminal tractotomy (TR) and nucleotomy (NC) procedures, which are defined as destructive procedures targeting the descending trigeminal tractus and nucleus caudalis of the spinal trigeminal nucleus, respectively, for intractable craniofacial pain.

METHODS

The medical records of a total of 12 patients who underwent a total of 14 computed tomography (CT)-guided TR-NC procedures at our clinics between 2005 and 2017 were retrospectively reviewed.

RESULTS

A significant increase in patients' performance status (p = 0.015) as well as a significant decrease in the VAS score (p < 0.001) were achieved. Grade I pain relief (VAS = 0, no pain) was established in 66.7% of the patients, whereas grade II pain relief was observed in the remaining patients. Two of the patients suffered from recurrent pain after the initial procedure. Both patients underwent a second trigeminal TR-NC procedure, and grade I pain relief was re-established. The mean VAS score at 3-month follow-up was 1.4 ± 1.1, whereas this score at 6-month follow-up was 2 ± 1.3. The trigeminal TR-NC procedure resulted in a significant decrease in patients' VAS scores at 3- and 6-month follow-up visits compared with preoperative VAS scores (p < 0.001). Transient ataxia was noted in only one patient (8.3%) early after the procedure.

CONCLUSIONS

The results presented in the current study support the efficacy of the percutaneous CT-guided trigeminal TR-NC procedure in the management of intractable facial pain in selected patients. The use of CT guidance allows direct visualization of the target area, thereby enhancing the safety and success of the procedure.

Craniofacial Peripheral Nerve Stimulation: Analysis of a Single Institution Series

OBJECTIVE

Objective real-world experience with peripheral nerve stimulation (PNS) is limited. Furthermore, the lack of robust outcome metrics, long-term follow-up and data comparing responders and nonresponders limit the refinement of selection criteria to better identify patients likely to benefit from PNS.

MATERIALS AND METHODS

We retrospectively analyzed 22 patients with craniofacial pain treated with PNS, and responders were classified as having ≥50% postoperative improvement in the numeric rating scale (NRS). In a subset of patients (n = 11), detailed prospective outcomes metrics were obtained preoperatively and postoperatively, including NRS, Beck Depression Index (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ).

RESULTS

About 59.1% (13 of 22) of subjects were classified as responders at a mean follow-up of 37.5 ± 5.27 months. Diagnoses included migraine (n = 6), occipital neuralgia (n = 9), trigeminal neuropathic pain (TNP; n = 6), and central poststroke pain (n = 1). Within the TNP subgroup, responders were more likely to have undergone two or more trigeminal neuralgia procedures prior to PNS (p < 0.05). In the 11 patients with comprehensive preoperative and postoperative outcome data, we noted significant improvement in NRS (p = 0.0005), BDI (p = 0.04), PCS (p = 0.01), as well as components of PCS (helplessness and magnification, p = 0.02) and MPQ (affective, p = 0.02).

CONCLUSIONS

The present study adds to the PNS literature by providing long-term data and multiple outcome metrics in a subset of patients. We suggest that BDI, PCS, and MPQ may provide more insight into meaningful response over time. Evaluating functional and quality of life outcomes in patients with craniofacial pain may be more informative than assessing benefit solely based on pain intensity and responder rates.