scholarly journals Gamma Knife surgery for tumor-related trigeminal neuralgia: targeting both the tumor and the trigeminal root exit zone in a single session

2016 ◽  
Vol 125 (4) ◽  
pp. 838-844 ◽  
Author(s):  
Sung Kwon Kim ◽  
Dong Gyu Kim ◽  
Young-Bem Se ◽  
Jin Wook Kim ◽  
Yong Hwy Kim ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Cranial Nerve ◽  
Single Session ◽  
Tissue Volume ◽  
Root Exit Zone ◽  
Facial Numbness ◽  
Trigeminal Root

OBJECTIVE Gamma Knife surgery (GKS) represents an alternative treatment for patients with tumor-related trigeminal neuralgia (TRTN). However, in previous studies, the primary GKS target was limited to mass lesions. The authors evaluated whether GKS could target both the tumor and the trigeminal root exit zone (REZ) in a single session while providing durable pain relief and minimizing radiation dose–related complications for TRTN patients. METHODS The authors' institutional review board approved the retrospective analysis of data from 15 consecutive patients (6 men and 9 women, median age 67 years, range 45–79 years) with TRTN who had undergone GKS. In all cases, the radiation was delivered in a single session targeting both the tumor and trigeminal REZ. The authors assessed the clinical outcomes, including the extent of pain relief, durability of the treatment response, and complications. Radiation doses to organs at risk (OARs), including the brainstem and the cranial nerve VII–VIII complex, were analyzed as doses received by 2% or 50% of the tissue volume and the tissue volume covered by a dose of 12 Gy (V12Gy). RESULTS The median length of clinical follow-up was 38 months (range 12–78 months). Pain relief with GKS was initially achieved in 14 patients (93.3%) and at the last follow-up in 13 patients (86.7%). The actuarial recurrence-free survival rates were 93%, 83%, and 69% at 1, 3, and 5 years after GKS, respectively. Persistent facial numbness was observed in 3 patients (20.0%). There were no complications such as facial weakness, altered taste function, hearing impairment, and balance difficulties indicating impaired function of the cranial nerve VII–VIII complex. The V12Gy in the brainstem was less than or equal to 0.24 cm3 in all patients. There were no significant differences in any OAR values in the brainstem between patients with and without facial numbness after GKS. CONCLUSIONS The strategy of performing GKS for both tumor and trigeminal REZ in a single session is a safe and effective radiosurgical approach that achieves durable pain control for TRTN patients.

NONISOCENTRIC RADIOSURGICAL RHIZOTOMY FOR TRIGEMINAL NEURALGIA

Neurosurgery ◽  
2009 ◽  
Vol 64 (suppl_2) ◽  
pp. A84-A90 ◽  
Author(s):  
John R. Adler ◽  
Regina Bower ◽  
Gaurav Gupta ◽  
Michael Lim ◽  
Allen Efron ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Symptom Relief ◽  
Complete Response ◽  
Patient Reported ◽  
High Incidence ◽  
Facial Numbness ◽  
Prescription Dose ◽  
Trigeminal Root

Abstract OBJECTIVE Although stereotactic radiosurgery is an established procedure for treating trigeminal neuralgia (TN), the likelihood of a prompt and durable complete response is not assured. Moreover, the incidence of facial numbness remains a challenge. To address these limitations, a new, more anatomic radiosurgical procedure was developed that uses the CyberKnife (Accuray, Inc., Sunnyvale, CA) to lesion an elongated segment of the retrogasserian cisternal portion of the trigeminal sensory root. Because the initial experience with this approach resulted in an unacceptably high incidence of facial numbness, a gradual dose and volume de-escalation was performed over several years. In this single-institution prospective study, we evaluated clinical outcomes in a group of TN patients who underwent lesioning with seemingly optimized nonisocentric radiosurgical parameters. METHODS Forty-six patients with intractable idiopathic TN were treated between January 2005 and June 2007. Eligible patients were either poor surgical candidates or had failed previous microvascular decompression or destructive procedures. During a single radiosurgical session, a 6-mm segment of the affected nerve was treated with a mean marginal prescription dose of 58.3 Gy and a mean maximal dose of 73.5 Gy. Monthly neurosurgical follow-up was performed until the patient became pain-free. Longer-term follow-up was performed both in the clinic and over the telephone. Outcomes were graded as excellent (pain-free and off medication), good (>90% improvement while still on medication), fair (50–90% improvement), or poor (no change or worse). Facial numbness was assessed using the Barrow Neurological Institute Facial Numbness Scale score. RESULTS Symptoms disappeared completely in 39 patients (85%) after a mean latency of 5.2 weeks. In most of these patients, pain relief began within the first week. TN recurred in a single patient after a pain-free interval of 7 months; all symptoms abated after a second radiosurgical procedure. Four additional patients underwent a repeat rhizotomy after failing to respond adequately to the first operation. After a mean follow-up period of 14.7 months, patient-reported outcomes were excellent in 33 patients (72%), good in 11 patients (24%), and poor/no improvement in 2 patients (4%). Significant ipsilateral facial numbness (Grade III on the Barrow Neurological Institute Scale) was reported in 7 patients (15%). CONCLUSION Optimized nonisocentric CyberKnife parameters for TN treatment resulted in high rates of pain relief and a more acceptable incidence of facial numbness than reported previously. Longer follow-up periods will be required to establish whether or not the durability of symptom relief after lesioning an elongated segment of the trigeminal root is superior to isocentric radiosurgical rhizotomy.

Gamma Knife surgery used as primary and repeated treatment for idiopathic trigeminal neuralgia

2008 ◽  
Vol 109 (Supplement) ◽  
pp. 179-184 ◽  
Author(s):  
Chuan-Fu Huang ◽  
Hsien-Tang Tu ◽  
Wen-Shan Liu ◽  
Shyh-Ying Chiou ◽  
Long-Yau Lin
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Repeated Treatment ◽  
Maximal Dose ◽  
Idiopathic Trigeminal Neuralgia ◽  
Facial Numbness ◽  
The Mean

Object The purpose of this study was to assess the outcome of idiopathic trigeminal neuralgia (TN) treated with Gamma Knife surgery (GKS) as a primary and repeated treatment modality with a mean follow-up of 5.7 years. Methods Between July 1999 and September 2005, a total of 89 patients with idiopathic TN underwent GKS as a primary treatment. The entry zone of the TN was targeted with a 4-mm collimator and treated with a maximal dose of 60–90 Gy (mean 79 Gy). The dose to the pontine margin was always kept < 15 Gy. Twenty patients received repeated GKS for recurrent or residual pain with a maximal dose of 40–76 Gy (mean 52 Gy). For the second procedure, the target was positioned at the same location as the first treatment. Results The mean follow-up period was 68 months (range 32–104 months). Sixty-nine (77.5%) of the 89 patients experienced a favorable response, as follows: 50 (56%) had excellent, 12 (13.5%) had good, and 7 (7.8%) had fair outcomes. The mean time to pain relief was 1.1 months (range 2 days–6 months). No significant correlation, but more likely a tendency, was found between the dose and pain relief (p = 0.08). Also, no correlation was noted for facial numbness (p = 0.77). The mean follow-up period after repeated GKS was 60 months (range 32–87 months). Outcomes after repeated GKS were excellent in 11 patients (55%) and good in 1 (5%). Seven patients experienced facial numbness. No correlation was found between the additive dose and pain relief (p = 0.24) or facial numbness (p = 0.15). Final outcomes of primary and repeated GKS were excellent in 61 (68.5%), good in 13 (14.6%), and fair in 7 (7.9%). In total, 91% of the patients were successfully treated with this method. There was no statistical significance for efficacy between primary and repeated GKS (p = 0.65), but there was a significant difference for facial numbness (p = 0.007). Conclusions Gamma Knife surgery established durable pain relief when used as a primary and repeated surgery. Treatment was successful for a total of 91% of patients at a mean follow-up of 5.7 years, but facial numbness was also relatively higher.

Gamma Knife surgery for recurrent or residual trigeminal neuralgia after a failed initial procedure

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 172-177 ◽  
Author(s):  
Chuan-Fu Huang ◽  
Shyh-Ying Chiou ◽  
Ming-Fang Wu ◽  
Hsien-Tang Tu ◽  
Wen-Shan Liu
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Pain Control ◽  
Initial Treatment ◽  
Gamma Knife Surgery ◽  
Significant Difference ◽  
Facial Numbness ◽  
Initial Procedure

Object The purpose of this study was to assess outcomes of Gamma Knife surgery (GKS) as a second treatment for recurrent or residual trigeminal neuralgia (TN) after failure of 3 initial procedures: microvascular decompression (MVD), GKS, and percutaneous radiofrequency rhizotomy (PRR). Methods Between 1999 and 2008, 65 patients (31 men [48%] and 34 women [52%]) with recurrent TN were treated with GKS. All 65 patients had undergone previous medical procedures that failed to achieve sufficient pain relief: 27 patients (42%) had undergone MVD, 8 (12%) had undergone PRR, and 30 (46%) had undergone GKS as the initial treatment. The entry zone of the trigeminal nerve was targeted using a 4-mm collimator and treated with 35–90 Gy. The isocenter was positioned so that the brainstem surface was usually irradiated at an isodose no greater than 20% (59 patients) to 30% (6 patients). The median duration of TN symptoms in these patients was 39 months (range 1–192 months). Results At the clinical evaluation, 42 patients (65%) with idiopathic TN reported successful pain control at a median follow-up point of 64 months (range 18–132 months). Of these patients, 33 (51%) were no longer using medication. At the 1-, 2-, and 3-year follow-up examinations, 74%, 71%, and 66% of patients experienced successful pain control, respectively. There was no significant difference in pain relief in the initial MVD group compared with the initial GKS and initial PRR groups (74% vs 59% and 50%, respectively; p = 0.342). Recurrence of pain was noted in 23 patients. Twelve of these 23 patients underwent another GKS, resulting in pain control in 8 patients (67%); 8 other patients underwent MVD, resulting in pain relief in 7 patients (87.5%). The median time from GKS to pain recurrence was 7 months (range 3–48 months). There was no significant difference in new facial numbness among the 3 groups (p = 0.24); however, in the initial GKS group, facial numbness was significantly associated with freedom from pain (p = 0.0012). There was a significant correlation between the total radiation dose and facial numbness. The cutoff value for facial numbness ranged from 115 to 120 Gy (p = 0.037). Conclusions Gamma Knife surgery as a second treatment achieved acceptable levels of pain control in 65% of patients with residual or recurrent TN after long-term follow-up. Initial treatment was not a factor that affected pain control, but salvage surgery may be considered separately for each group.

Repeated Gamma Knife surgery for refractory trigeminal neuralgia

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 99-102 ◽  
Author(s):  
Chuan-Fu Huang ◽  
Jim-Chao Chuang ◽  
Hsien-Tang Tu ◽  
Long-Yau Lin
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Prospective Trial ◽  
Late Complications ◽  
Gamma Knife Surgery ◽  
Dose Effect ◽  
Duration Of Symptoms ◽  
Facial Numbness

ObjectRepeated Gamma Knife surgery (GKS) for trigeminal neuralgia (TN) is an acceptable method for refractory cases but not well established in terms of dose effect and nerve tolerance. The authors report their experience in 28 patients over 3.5 years of follow up.MethodsBetween 1999 and 2004, a total of 28 patients with recurrent or residual TN underwent repeated GKS. The median follow-up periods were 52 and 43 months after the first and repeated procedures, respectively. The entry zone of the trigeminal nerve was targeted using a 4-mm collimator and treated with 40 to 76 Gy as maximal dose. Additive doses ranged between 110 and 152 Gy. The median duration of symptoms was 4.86 years. There were 12 women (46%) and 16 men (54%).At the last evaluation, a total of 19 patients (68%) reported pain relief. Of these patients, 13 were no longer taking pain medications. Significant recurrent or residual pain was noted in nine patients after a median follow up of 12 months (range 6–48 months). New onset of facial numbness was noted in 10 patients. An additive dose above 115 Gy was found to be associated with facial numbness and nonfacial numbness (p = 0.047). No definite additive dose correlation with pain relief was noted (p = 0.23).Conclusions Repeated GKS established durable pain relief in a majority of patients, and a higher additive dose (> 115 Gy) tended to cause facial numbness. However, a prospective trial is needed to fully assess the efficacy and late complications of GKS.

Stereotactic gamma knife surgery for trigeminal neuralgia: detailed analysis of treatment response

2005 ◽  
Vol 102 (3) ◽  
pp. 442-449 ◽  
Author(s):  
Rabih G. Tawk ◽  
Mary Duffy-Fronckowiak ◽  
Bryan E. Scott ◽  
Ronald A. Alberico ◽  
Aidnag Z. Diaz ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Treatment Response ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Limiting Factors ◽  
Content Type ◽  
Facial Numbness ◽  
Fine Print

Object. The purpose of this study was to assess the durability and completeness of pain relief in patients treated using stereotactic gamma knife surgery (GKS) for trigeminal neuralgia (TN). Methods. Thirty-eight patients with refractory TN were treated with stereotactic GKS. All patients received a prescription radiation dose of 35, 40, or 45 Gy to the 50% isodose surface through a 4-mm collimator helmet. The group was assessed regularly based on physician-directed interviews for a median follow up of 24 months (range 6–27 months). Pain relief was classified as excellent (no pain without medication), good (well-controlled pain with continued medication), fair (decreased but residual pain with continued medication), or poor (unimproved or increased pain with the same or increased medication). Three months after treatment, pain relief was good or excellent in 71% of patients. By 24 months post-GKS, 50% of the original cohort had poor pain relief, 21% continued to have either excellent or good relief, 3% had fair relief, and 26% had not reached the 24-month follow up. Based on their status at the last follow up, 29% of patients had excellent and 16% had good pain relief. Thirty-seven percent experienced facial numbness, which was dose related. In addition, there was a significantly higher rate of complete pain relief in patients who had facial numbness following treatment (p = 0.003). Conclusions. Stereotactic GKS is an effective treatment in patients with TN; however, the durability of pain relief and the time to treatment response are limiting factors. As with other types of ablative treatment, facial numbness is strongly associated with better treatment response.

scholarly journals Gamma Knife radiosurgery for bilateral trigeminal neuralgia

2019 ◽  
Vol 131 (5) ◽  
pp. 1591-1598
Author(s):  
Corbin A. Helis ◽  
Emory McTyre ◽  
Michael T. Munley ◽  
J. Daniel Bourland ◽  
John T. Lucas ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Treatment Outcomes ◽  
Gamma Knife ◽  
Median Duration ◽  
Gamma Knife Radiosurgery ◽  
Persistent Symptoms ◽  
Significant Difference ◽  
Facial Numbness

OBJECTIVEA small subset of patients with trigeminal neuralgia (TN) will experience bilateral symptoms. Treatment in these patients is controversial because the population is heterogeneous and patients may have nonvascular etiologies of their pain. This study reports treatment outcomes in the largest cohort of patients with bilateral TN who have undergone Gamma Knife radiosurgery (GKRS) to date.METHODSA retrospective chart review identified 51 individual nerves in 34 patients with bilateral TN who were treated with GKRS at the authors’ institution between 2001 and 2015, with 12 nerves in 11 patients undergoing repeat GKRS for recurrent or persistent symptoms. Long-term follow-up was obtained by telephone interview. Pain outcomes were measured using the Barrow Neurological Institute (BNI) pain scale, with BNI IIIb or better considered a successful treatment.RESULTSThere was sufficient follow-up to determine treatment outcomes for 48 individual nerves in 33 patients. Of these nerves, 42 (88%) achieved at least BNI IIIb pain relief. The median duration of pain relief was 1.9 years, and 1-, 3-, and 5-year pain relief rates were 64%, 44%, and 44%, respectively. No patients experienced bothersome facial numbness, and 1 case of anesthesia dolorosa and 2 cases of corneal dryness were reported. Patients with a history of definite or possible multiple sclerosis were significantly more likely to experience BNI IV–V relapse. There was no statistically significant difference in treatment outcomes between patients in this series versus a large cohort of patients with unilateral TN treated at the authors’ institution. There was sufficient follow-up to determine treatment outcomes for 11 individual nerves in 10 patients treated with repeat GKRS. Ten nerves (91%) improved to at least BNI IIIb after treatment. The median duration of pain relief was 2.8 years, with 1-, 3-, and 5-year rates of pain relief of 79%, 53%, and 53%, respectively. There was no statistically significant difference in outcomes between initial and repeat GKRS. One case of bothersome facial numbness and 1 case of corneal dryness were reported, with no patients developing anesthesia dolorosa with retreatment.CONCLUSIONSGKRS is a safe, well-tolerated treatment for patients with medically refractory bilateral TN. Efficacy of treatment appears similar to that in patients with unilateral TN. GKRS can be safely repeated in this population if necessary.

scholarly journals Results of a third Gamma Knife radiosurgery for trigeminal neuralgia

2020 ◽  
pp. 1-7
Author(s):  
Corbin A. Helis ◽  
Ryan T. Hughes ◽  
Michael T. Munley ◽  
J. Daniel Bourland ◽  
Travis Jacobson ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Treatment Success ◽  
Gamma Knife Radiosurgery ◽  
The Third ◽  
Significant Difference ◽  
Pain Outcomes ◽  
Facial Numbness

OBJECTIVEGamma Knife radiosurgery (GKRS) is a commonly used procedure for medically refractory trigeminal neuralgia (TN), with repeat GKRS routinely done in cases of pain relapse. The results of a third GKRS in cases of further pain relapse have not been well described. In this study, the authors report the largest series of patients treated with a third GKRS for TN to date.METHODSRetrospective review of institutional electronic medical records and a GKRS database was performed to identify patients who had been treated with a third GKRS at the authors’ institution in the period from 2010 to 2018. Telephone interviews were used to collect long-term follow-up data. Pain outcomes were measured using the Barrow Neurological Institute (BNI) pain intensity scale, with a score ≤ IIIb indicating successful treatment.RESULTSTwenty-two nerves in 21 patients had sufficient follow-up to determine BNI pain score outcomes. Eighteen of 22 cases had a successful third GKRS, with a median durability of pain relief of 3.88 years. There was no significant difference in the durability of pain relief after a third GKRS compared with those of institutional historical controls of prior series of first and second GKRS procedures. Ten cases had new or worsening facial numbness, with 1 case being bothersome. Four cases of toxicity other than facial numbness were reported, including 1 case of corneal abrasions and possible neurotrophic keratopathy. No cases of anesthesia dolorosa were reported. No factors predicting treatment success or the durability of pain relief were identified. Nonnumbness toxicity was more common in those with a proximally placed shot at the third GKRS.CONCLUSIONSA third GKRS is an effective treatment option for TN patients who have pain relapse after repeat GKRS. Pain outcomes of a third GKRS are similar to those following a first or second GKRS. Toxicity is tolerable in patients with a distally placed shot at the third GKRS.

Efficacy of Internal Neurolysis for Trigeminal Neuralgia without Vascular Compression

2021 ◽  
Author(s):  
Ming-Wu Li ◽  
Xiao-feng Jiang ◽  
Chaoshi Niu
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Chart Review ◽  
Vascular Compression ◽  
Internal Neurolysis ◽  
Facial Numbness ◽  
Relief Rate

Abstract Background and Objective Trigeminal neuralgia is a common neurologic disease that seriously impacts a patient's quality of life. We retrospectively investigated the efficacy and safety of internal neurolysis (nerve combing) for trigeminal neuralgia without vascular compression. Patients and Methods This study was a retrospective review of all patients with trigeminal neuralgia who were admitted between January 2014 and February 2019. A subgroup of 36 patients had no vascular compression at surgery and underwent internal neurolysis. Chart review and postoperative follow-up were performed to assess the overall outcomes of internal neurolysis. Results Thirty-six patients were identified, with a mean age of 44.89 ± 7.90 (rang: 31–65) years and a disease duration of 5.19 ± 2.61 years. The immediate postoperative pain relief (Barrow Neurological Institute [BNI] pain score of I or II) rate was 100%. The medium- to long-term pain relief rate was 91.7%. Three patients experienced recurrence. Facial numbness was the primary postoperative complication. Four patients with a score of III on the BNI numbness scale immediately after surgery had marked improvement at 6 months. No serious complications occurred. Conclusion Internal neurolysis is a safe and effective treatment for trigeminal neuralgia without vascular compression or clear responsible vessels.

scholarly journals Assessment of pain control, quality of life, and predictors of success after gamma knife surgery for the treatment of trigeminal neuralgia

2005 ◽  
Vol 18 (5) ◽  
pp. 1-7 ◽  
Author(s):  
Ajay Jawahar ◽  
Rishi Wadhwa ◽  
Caglar Berk ◽  
Gloria Caldito ◽  
Allyson Delaune ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Patient Satisfaction ◽  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Pain Control ◽  
Gamma Knife Surgery ◽  
Patient Satisfaction Score

Object There are various surgical treatment alternatives for trigeminal neuralgia (TN), but there is no single scale that can be used uniformly to assess and compare one type of intervention with the others. In this study the objectives were to determine factors associated with pain control, pain-free survival, residual pain, and recurrence after gamma knife surgery (GKS) treatment for TN, and to correlate the patients' self-reported quality of life (QOL) and satisfaction with the aforementioned factors. Methods Between the years 2000 and 2004, the authors treated 81 patients with medically refractory TN by using GKS. Fifty-two patients responded to a questionnaire regarding pain control, activities of daily living, QOL, and patient satisfaction. The median follow-up duration was 16.5 months. Twenty-two patients (42.3%) had complete pain relief, 14 (26.9%) had partial but satisfactory pain relief, and in 16 patients (30.8%) the treatment failed. Seven patients (13.5%) reported a recurrence during the follow-up period, and 25 (48.1%) reported a significant (> 50%) decrease in their pain within the 1st month posttreatment. The mean decrease in the total dose of pain medication was 75%. Patients' self-reported QOL scores improved 90% and the overall patient satisfaction score was 80%. Conclusions The authors found that GKS is a minimally invasive and effective procedure that yields a favorable outcome for patients with recurrent or refractory TN. It may also be offered as a first-line surgical modality for any patients with TN who are unsuited or unwilling to undergo microvascular decompression.

Gamma Knife radiosurgery for trigeminal neuralgia: the impact of magnetic resonance imaging–detected vascular impingement of the affected nerve

2010 ◽  
Vol 113 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Jason P. Sheehan ◽  
Dibyendu Kumar Ray ◽  
Stephen Monteith ◽  
Chun Po Yen ◽  
James Lesnick ◽  
...  
Keyword(s):  
Pain Relief ◽  
Mr Imaging ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Trigeminal Nerve ◽  
Gamma Knife Radiosurgery ◽  
Vascular Compression ◽  
Pain Intensity Score ◽  
The Impact

Object Trigeminal neuralgia is believed to be related to vascular compression of the affected nerve. Radiosurgery has been shown to be reasonably effective for treatment of medically refractory trigeminal neuralgia. This study explores the rate of occurrence of MR imaging–demonstrated vascular impingement of the affected nerve and the extent to which vascular impingement affects pain relief in a population of trigeminal neuralgia patients undergoing Gamma Knife radiosurgery (GKRS). Methods The authors performed a retrospective analysis of 106 cases involving patients treated for typical trigeminal neuralgia using GKRS. Patients with or without single-vessel impingement on CISS MR imaging sequences and with no previous surgery were included in the study. Pain relief was assessed according to the Barrow Neurological Institute (BNI) pain intensity score at the last follow-up. Degree of impingement, nerve diameter preand post-impingement, isocenter placement, and dose to the point of maximum impingement were evaluated in relation to the improvement of BNI score. Results The overall median follow-up period was 31 months. Overall, a BNI pain score of 1 was achieved in 59.4% of patients at last follow-up. Vessel impingement was seen in 63 patients (59%). There was no significant difference in pain relief between those with and without vascular impingement following GKRS (p > 0.05). In those with vascular impingement on MR imaging, the median fraction of vessel impingement was 0.3 (range 0.04–0.59). The median dose to the site of maximum impingement was 42 Gy (range 2.9–79 Gy). Increased dose (p = 0.019) and closer proximity of the isocenter to the site of maximum vessel impingement (p = 0.012) correlated in a statistically significant fashion with improved BNI scores in those demonstrating vascular impingement on the GKRS planning MR imaging Conclusions Vascular impingement of the affected nerve was seen in the majority of patients with trigeminal neuralgia. Overall pain relief following GKRS was comparable in those with and without evidence of vascular compression on MR imaging. In subgroup analysis of those with MR imaging evidence of vessel impingement of the affected trigeminal nerve, pain relief correlated with a higher dose to the point of contact between the impinging vessel and the trigeminal nerve. Such a finding may point to vascular changes affording at least some degree of relief following GKRS for trigeminal neuralgia.

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