Neurosurgery Blog

Neurosurgery 72:749–754, 2013

Outcomes studies use patient-reported outcome (PRO) measurements to assess treatment effectiveness, but can lack direct clinical meaning. Minimum clinically important difference (MCID) calculation provides a point estimate of the critical threshold needed to achieve clinically relevant treatment effectiveness. MCID remains uninvestigated for microvascular decompression (MVD), a common surgical procedure for trigeminal neuralgia. OBJECTIVE: We aimed to determine MCID for the most commonly used PRO measures of pain after MVD: Visual Analog Scale (VAS) and Barrow Neurological Institute Pain Scale (BNI-PS).

METHODS: Sixty consecutive patients with classic trigeminal neuralgia who decided to undergo MVD by a single surgeon were prospectively assessed with VAS and BNI-PS preoperatively and 2 years postoperatively. Three anchors were used to assign each patient’s outcome. We then used 3 well-established, anchor-based methods to calculate MCID.

RESULTS: Patients experienced significant improvement in both VAS (9.9 vs 2.0, P < .001) and BNI-PS (5.0 vs 1.9, P < .001) after MVD. The area under the receiver-operating characteristic curve was greater for BNI-PS than for VAS for all 3 anchors, indicating that BNI-PS is probably better suited for calculating MCID. The 3 MCID calculation methods generated a range of MCID values for each of the PROs (VAS: 1.40-8.87, BNI-PS: 0.95-3.26).

CONCLUSION: MVD-specific MCID is highly variable based on calculation technique. Some of these calculations appear to either overestimate or underestimate the patients’ preoperative expectations. When the different MCID methods are averaged, the results are clinically appropriate and consistent with preoperative expectations. The average MCID for VAS is 6.25 and for BNI-PS is 2.44.

Acta Neurochir (2013) 155:863–868

The aim of this prospective study was to evaluate whether the cerebellopontine angle (CPA) cistern area and trigeminal nerve cisternal length play a role in the pathogenesis of trigeminal neuralgia (TN).

Methods High-resolution 1.5 T magnetic resonance imaging of the posterior fossa was performed in 26 patients with TN and 18 age-matched healthy controls. Axial T2- weighted, three-dimensional constructive interference in steady-state (3D-CISS) was used to measure bilaterally the cross-sectional area of the CPA cistern and trigeminal nerve cisternal length.

Results In patients, the cross-sectional area of the CPA cistern and trigeminal nerve cisternal length was smaller on the affected side (p=0.04). Healthy controls tended to have larger cisternal areas and longer trigeminal nerve lengths than patients (p=0.059, p=0.071, respectively). Larger CPA cisternal areas tended to be seen in older patients. There was a strong correlation between the crosssectional area of the CPA cistern and the length of the trigeminal nerve (p=0.000).

Conclusions Smaller CPA cisterns and short cisternal trigeminal nerves impact the pathogenesis of essential TN by facilitating the neurovascular conflict, especially in younger patients. Trigeminal nerve cisternal measurement provides an easy and direct estimation of the CPA area. This information can be used for surgical planning and potentially for outcome prediction.

Neurosurgery 72[ONS Suppl 1]:ons27–ons34, 2013

Percutaneous radiofrequency cordotomy (PRFC) involves controlled ablation of the anterolateral quadrant of the spinal cord, thereby relieving pain. Evolving from a morbid open surgery, the procedure has been modernized through the application of physiological target confirmation, well-regulated thermal ablation, and improved intraoperative imaging.

OBJECTIVE: To evaluate the utility in PRFC of a new high-resolution, portable flatpanel fluoroscopic imaging technology, the O-arm Imaging System. The O-arm allows traditional 2-dimensional fluoroscopy in addition to axial and 3-dimensional reconstructed computed tomography imaging.

METHODS: PRFC was performed using the O-arm Imaging System in 6 patients with unilateral cancer pain.

RESULTS: Patients experienced 90% to 100% initial pain relief, with 50% to 100% sustained pain relief at the time of death at 2 to 12 months. There were no complications.

CONCLUSION: Portable flat-panel fluoroscopy allows high-resolution, readily updated computed tomography and fluoroscopic image guidance during PRFC. Use of this new technology may assist neurosurgeons in providing an important analgesic intervention at centers possessing the imaging technology.

KEY WORDS:

J Neurosurg 118:329–336, 2013

Patients with trigeminal neuralgia due to multiple sclerosis (TN-MS) and idiopathic TN (ITN) who underwent glycerol rhizotomy (GR) and radiofrequency thermocoagulation with glycerol rhizotomy (RFTC-GR) were compared to investigate the effectiveness of these percutaneous ablative procedures in the TN-MS population.

Methods. Between 1998 and 2010, 822 patients with typical TN were evaluated; 63 (8%) had TN-MS and 759 (92%) had ITN. Pain relief comparisons were made between 22 GR procedures in patients with TN-MS and 470 GR procedures in patients with ITN; 50 RFTC-GR procedures in patients with TN-MS and 287 RFTC-GR procedures in patients with ITN were compared. Analysis of time to recurrence included only procedures that achieved complete pain relief without medications.

Results. After 15 of the GR procedures (68%) in patients with TN-MS and 315 of the procedures (67%) in those with ITN, the patients were pain free without medications (p = 0.736). After 36 of the RFTC-GR procedures (72%) in patients with TN-MS and 210 of the procedures (73%) in those with ITN, the patients were pain free without medications (p = 0.657). The difference in pain relief between GR and RFTC-GR for patients with TN-MS was not significant (p = 0.447). The median time to failure of GR was 20 months in patients with TN-MS compared with 25 months in those with ITN (p = 0.403). The median time to failure of RFTC-GR was 26 months in the TN-MS population compared with 21 months in the ITN population (p = 0.449). Patients with TN-MS experienced similar times to recurrence whether they were treated with GR or RFTC-GR (p = 0.431).

Conclusions. Pain relief and durability of relief outcomes of GR and RFTC-GR were similar in patients with TN-MS and ITN, reinforcing their use as preferred treatments of TN-MS. The GR and RFTC-GR achieved comparable outcomes in patients with TN-MS, suggesting that both can be used to good effect.

Acta Neurochir (2012) 154:1627–1633

Trigeminal neuralgia (TN) is primarily diagnosed by symptoms and patient history. Magnetic resonance (MR) imaging can be helpful in visualizing the neurovascular compression of the trigeminal nerve in TN patients, but the current parameters used as diagnostic markers for TN are less than optimal. The aim of this study is to assess whether the angle between the trigeminal nerve and the pons (the trigeminal-pontine angle) on the affected side of patients with idiopathic TN differs from that of the unaffected side and that found in controls without TN.

Methods A case-control study of 30 clinically diagnosed idiopathic TN patients aged 30 to 79 years and 30 age- and sexmatched controls was conducted.We compared the trigeminalpontine angle and trigeminal nerve atrophy via fast-imaging employing steady-state acquisition (FIESTA) MR imaging.

Results A sharp trigeminal-pontine angle was observed in 25 patients (25/30) on the affected side. As such, the mean angle of the trigeminal nerve on the affected side (40.17) was significantly smaller than that on the unaffected side (48.91, p=0.001) and that in the control group (52.02, p<0.001).

Conclusions A sharp trigeminal-pontine angle on the affected side was found in idiopathic TN patients by FIESTA imaging. This suggests that a sharp trigeminal-pontine angle increases the chance of neurovascular compression on the medial side of the trigeminal nerve.

Acta Neurochir (2012) 154:1089–1095 DOI 10.1007/s00701-012-1324-2

Microvascular decompression (MVD) is a non-ablative technique designed to resolve the neurovascular conflict responsible for typical idiopathic trigeminal neuralgia (TN).

Method With the patient in a supine position, a small elliptical retrosigmoid craniectomy is used to approach the cerebellopontine angle and the trigeminal nerve. After careful exploration of the trigeminal root entry zone, the offending vessel is identified and moved away. Oxidized regenerated cellulose is used to keep the vessel in its new position far from the nerve.

Conclusion MVD represents the gold standard first line treatment for TN; its aim is to free the nerve from any contact.

Neurosurgery 70[ONS Suppl 2]:ons177–ons180, 2012 DOI: 10.1227/NEU.0b013e3182309448

We describe the use of an intraoperative CT scan obtained using the Medtronic O-arm (Littleton, Massachusetts) for image-guided cannulation of the foramen ovale not previously accessible with the use of fluoroscopy alone. Unlike previously described procedures, this technique does not require placement of an invasive head clamp and may be used with an awake patient.

OBJECTIVE: To describe the use of intraoperative neuronavigation for accessing skull base foramina and, specifically, cannulating of the foramen ovale during percutaneous rhizotomy procedures using an intraoperative image guidance CT scanner (Medtronic O-arm, Littleton, Massachusetts).

METHODS: A noninvasive Landmark Fess Strap attached to a spine reference frame was applied to the heads of 4 patients who harbored a difficult-to-access foramen ovale. An intraoperative HD3D skull base scan using a Medtronic O-arm was obtained, and Synergy Spine software was used to create 3D reconstructions of the skull base. Using image guidance, we navigated the needle to percutaneously access the foramen ovale by the use of a single tract for successful completion of balloon compression of the trigeminal nerve.

RESULTS: All 4 patients (3 females and 1 male; ages 65-75) underwent the procedure with no complications.

CONCLUSION: Based on our experience, neuronavigation with the use of intraoperative O-arm CT imaging is useful during these cases.

Neurosurgery 70:1125–1134, 2012.  DOI: 10.1227/NEU.0b013e31823f5eb6

Percutaneous glycerol rhizotomy (GR) is used to treat trigeminal neuralgia (TN), with satisfactory pain relief lasting 2 to 3 years in most patients after the first intervention. The efficacy of subsequent GRs, however, has not been studied.

OBJECTIVE: To compare the pain relief and durability achieved by the first GR with those obtained after subsequent GRs in a retrospective cohort of TN patients.

METHODS: Between 1998 and 2010, 548 patients with TN underwent 708 GRs. After exclusions, 430 initial GRs (GR1) and 114 subsequent GRs (GR21) were compared in terms of initial pain relief, durability, sensory change, and complications. Durability was assessed by determining median time to treatment failure for all GRs achieving complete pain relief without medications (n = 375: 264 failures, 111 censored). Predictors of initial pain relief were assessed by logistic regression, and predictors of failure were assessed by Cox regression analysis.

RESULTS: After GR1, pain relief results were as follows: 285 patients (66%) were pain free without medications, 26 (6%) were pain free with medications, 66 (15%) improved, and 53 (12%) were unchanged. After GR21, results were as follows: 90 patients (79%) were pain free without medications, 6 (5%) were pain free with medications, 7 (6%) improved, and 11 (10%) were unchanged (P = .03). Median time to treatment failure was 26 months after GR1 and 25 months after GR21 (P = .34). On multivariate analysis, prior GR was a positive predictor of initial pain relief (odds ratio, 2.067; 95% confidence interval, 1.243-3.437; P = .005) and had no effect on durability.

CONCLUSION: TN patients experienced greater pain relief and equivalent durability after GR21 beyond the initial treatment.

Neurosurgery 70:407–413, 2012 DOI: 10.1227/NEU.0b013e318233a85f

Among the percutaneous procedures for the treatment of trigeminal neuralgia, percutaneous anhydrous glycerol rhizolysis (PRGR) and radiofrequency (RF) ablation of trigeminal neuralgia have stood the test of time.

OBJECTIVE: A prospective study was conducted to compare PRGR and RF ablation techniques in patients with trigeminal neuralgia in terms of (1) efficacy of pain relief, (2) duration of pain relief and (3) side effects.

METHODS: All patients presenting to our pain clinic for the first time for the treatment of trigeminal neuralgia were enrolled to receive either PRGR or RF ablation; the treatment was chosen by the patient. Demographic data, magnetic resonance imaging scan, relevant medical disease, amount of anhydrous glycerol, lesion temperature, and total duration of RF were noted. The presence or absence of cerebrospinal fluid egress, immediate pain relief, duration of pain-free period, need for repeat injection or additional peripheral nerve block, and recurrence of pain were also noted. The degree of pain relief was recorded every 3 months. Any complications during the procedure and side effects were also recorded.

RESULTS: Seventy-nine patients underwent either PRGR (n = 40) or RF thermocoagulation (n = 39). A total of 23 patients (58.9%) in the PRGR group and 33 patients (84.6%) in the RF group experienced excellent pain relief. The mean duration of excellent pain relief in the PRGR and RF groups was comparable. By the end of the study period, 39.1% patients in the PRGR group and 51.5% patients in the RF group experienced recurrence of pain.

CONCLUSION: Both PRGR and RF techniques can achieve acceptable pain relief with minimal side effects.

Neurosurgical Focus Jan 2012 / Vol. 32 / No. 1 / Page E1. DOI: 10.3171/2011.10.FOCUS11248

Recent technological developments open the field of therapeutic application of focused ultrasound to the brain through the intact cranium. The goal of this study was to apply the new transcranial magnetic resonance imaging–guided focused ultrasound (tcMRgFUS) technology to perform noninvasive central lateral thalamotomies (CLTs) as a treatment for chronic neuropathic pain.

METHODS

In 12 patients suffering from chronic therapy-resistant neuropathic pain, tcMRgFUS CLT was proposed. In 11 patients, precisely localized thermal ablations of 3–4 mm in diameter were produced in the posterior part of the central lateral thalamic nucleus at peak temperatures between 51°C and 64°C with the aid of real-time patient monitoring and MR imaging and MR thermometry guidance. The treated neuropathic pain syndromes had peripheral (5 patients) or central (6 patients) origins and covered all body parts (face, arm, leg, trunk, and hemibody).

RESULTS

Patients experienced mean pain relief of 49% at the 3-month follow-up (9 patients) and 57% at the 1-year follow-up (8 patients). Mean improvement according to the visual analog scale amounted to 42% at 3 months and 41% at 1 year. Six patients experienced immediate and persisting somatosensory improvements. Somatosensory and vestibular clinical manifestations were always observed during sonication time because of ultrasound-based neuronal activation and/or initial therapeutic effects. Quantitative electroencephalography (EEG) showed a significant reduction in EEG spectral overactivities. Thermal ablation sites showed sharply delineated ellipsoidal thermolesions surrounded by short-lived vasogenic edema. Lesion reconstructions (18 lesions in 9 patients) demonstrated targeting precision within a millimeter for all 3 coordinates. There was 1 complication, a bleed in the target with ischemia in the motor thalamus, which led to the introduction of 2 safety measures, that is, the detection of a potential cavitation by a cavitation detector and the maintenance of sonication temperatures below 60°C.

CONCLUSIONS

The authors assert that tcMRgFUS represents a noninvasive, precise, and radiation-free neurosurgical technique for the treatment of neuropathic pain. The procedure avoids mechanical brain tissue shift and eliminates the risk of infection. The possibility of applying sonication thermal spots free from trajectory restrictions should allow one to optimize target coverage. The real-time continuous MR imaging and MR thermometry monitoring of targeting accuracy and thermal effects are major factors in optimizing precision, safety, and efficacy in an outpatient context.

Neurosurgery 69:1255–1260, 2011 DOI: 10.1227/NEU.0b013e31822ba315

Patients with medically unresponsive trigeminal neuralgia (TN) who are >70 years of age often undergo operations that typically provide pain relief for <5 years despite having a life expectancy that can exceed 15 years.

OBJECTIVE: To review the safety and efficacy of posterior fossa exploration (PFE) for TN patients >70 years of age.

METHODS: From 1999 to 2009, 67 TN patients >70 years of age (median, 74 years) underwent a PFE. Thirty-seven patients (55%) had failed ≥1 prior surgeries (median, 2). Fifty-nine patients (88%) had a microvascular decompression, and 8 patients (12%) underwent a partial sensory rhizotomy. Follow-up (median, 40 months) was censored at the time of last contact (n = 51), additional surgery (n = 12), or death (n = 4).

RESULTS: Complete pain relief (no pain, no medications) was 87% at 1 year and 78% at 5 years. Facial pain outcomes did not correlate with patient age, sex, prior surgery, or pain duration. Postoperative complications were noted in 10 patients (15%) and included ataxia (10%), hearing loss (5%), trigeminal dysesthesias (5%), facial weakness (3%), aseptic meningitis (2%), and pulmonary embolus (2%). Factors associated with postoperative complications were prior PFE (P = .01) and neurovascular compression from a dolicoectatic basilar artery (P = .03).

CONCLUSION: Posterior fossa exploration is safe and effective for physiologically healthy TN patients .70 years of age. It should be deferred in older patients with TN secondary to a dolicoectatic basilar artery and patients who have persistent/recurrent pain after a previous PFE unless simpler procedures prove ineffective at controlling their facial pain.

Neurosurgery 69:1015–1029, 2011 DOI: 10.1227/NEU.0b013e318229cfcd

A significant number of patients with major depressive disorder are unresponsive to conventional therapies. For these patients, neuromodulation approaches are being investigated.

OBJECTIVE: To determine whether epidural cortical stimulation at the left dorsolateral prefrontal cortex is safe and efficacious for major depressive disorder through a safety and feasibility study.

METHODS: Twelve patients were recruited in this randomized, single-blind, shamcontrolled study with a 104-week follow-up period. The main outcome measures were Hamilton Depression Rating Scale-28 (HDRS), Montgomery-Asberg Depression Rating Scale (MADRS), Global Assessment of Function (GAF), and Quality of Life Enjoyment and Satisfaction (QLES) questionnaire. An electrode was implanted over Brodmann area 9/46 in the left hemisphere. The electrode provided long-term stimulation to this target via its connections to an implanted neurostimulator in the chest.

RESULTS: During the sham-controlled phase, there was no statistical difference between sham and active stimulation, although a trend toward efficacy was seen with the active stimulation group. In the open-label phase, we observed a significant improvement in outcome scores for the HDRS, MADRS, and GAF but not the QLES (HDRS: df = 7, F = 7.72, P < .001; MADRS: df = 7, F = 8.2, P < .001; GAF: df = 5, F = 16.87, P < .001; QLES: df = 5, F = 1.32, P . .2; repeated measures ANOVA). With regard to the HDRS, 6 patients had ≥40% improvement, 5 patients had ≥ 50% improvement, and 4 subjects achieved remission (HDRS , 10) at some point during the study.

CONCLUSION: Epidural cortical stimulation of the left dorsolateral prefrontal cortex appears to be a safe and potentially efficacious neuromodulation approach for treatment- refractory major depressive disorder.

J Neurosurg 115:202–209, 2011. DOI: 10.3171/2011.4.JNS101924

Microvascular decompression (MVD) offers an effective and durable treatment for patients suffering from trigeminal neuralgia (TN). Because the disorder has a tendency to occur in older persons, the risks of surgical treatment in the elderly have been a topic of recent interest. To date, evidence derived from several small retrospective and a single prospective case series has suggested that age does not increase the complication rate associated with surgery. Using a large national database, the authors aimed to study the impact of age on in-hospital complications following MVD for TN.

Methods. Using the Nationwide Inpatient Sample (NIS) for the 10-year period from 1999 to 2008, the authors selected all patients who underwent MVD for TN. The primary outcome of interest was the in-hospital mortality rate. Secondary outcomes of interest were cardiac, pulmonary, thromboembolic, cerebrovascular, and wound complications as well as the duration of hospital stay, total hospital charges, and discharge location. An elderly cohort of patients was first defined as those 65 years of age and older and then redefined as those 75 years and older.

Results. A total of 3273 patients who underwent MVD for TN were identified, having a median age of 57 years. Within this sample, 31.5% were 65 years and older and 10.7% were 75 years and older. The in-hospital mortality rate was 0.68% for patients 65 years or older (p = 0.0087) and 1.16% for those 75 years or older (p = 0.0026). In patients younger than 65 years, the in-hospital mortality rate was 0.13% (3 deaths among 2241 patients). As analyzed using the chi-square test (for both 65 and 75 years as the age cutoff) and the Pearson rank correlation coefficient, the risk of cardiac, pulmonary, thromboembolic, and cerebrovascular complications was higher in older patients (that is, those 65 and older and those 75 and older), but the risks of wound complications and CNS infection were not. The risk of any in-hospital complication occurring in a patient 65 years and older was 7.36% (p < 0.0001) and 10.0% in those 75 years and older (p < 0.0001). There was no difference in the total hospital charges associated with age. The duration of the hospital stay was longer in older patients, and the likelihood of discharge home was lower in older patients.

Conclusions. Microvascular decompression for TN in the elderly population remains a reasonable surgical option. However, based on data from a large national database, authors of the present study suggest that complications do tend to gradually increase in tandem with an advanced age. While age does not act as a risk factor in isolation, it may serve as a convenient surrogate for complication rates. The authors hope that this information can be of use in guiding older patients through decisions for the surgical treatment of TN.

Neurosurgery 69:15–26, 2011 DOI: 10.1227/NEU.0b013e318212bafa

High-resolution three-dimensional (3D) magnetic resonance imaging (MRI) has demonstrated its ability to predict fine trigeminal neurovascular anatomy.

OBJECTIVE: To address the predictive value of 3-Tesla (3T) MRI in detecting and assessing features of neurovascular compression (NVC), particularly regarding the degree of compression exerted on the root, in patients who underwent microvascular decompression (MVD) for classic primary trigeminal neuralgia.

METHODS: This prospective study includes 40 consecutive patients who underwent MVD for classic primary trigeminal neuralgia. All patients underwent a preoperative 3T MRI with 3D T2-weighted driven equilibrium (DRIVE), 3D time-of-flight (TOF) magnetic resonance angiography (MRA), and 3D T1-weighted gadolinium-enhanced sequences in combination. Evaluations were performed by 2 independent observers and compared with the operative findings.

RESULTS: For prediction of NVC, image analysis corresponded with surgical findings in 39 cases. Of the 3 patients in whom image analysis did not show NVC, 2 did not have NVC at the time of intraoperative observation. MRI sensitivity was 97.4% (37/38), and specificity was 100% (2/2). The kappa coefficients (k) for predicting the offending vessel, its location, and the site of compression were 0.882, 0.813, and 0.942, respectively. Image analysis correctly defined the severity of the compression in 31 of the 37 cases. The k coefficients predicting the degree of compression were 0.813, 0.833, and 0.852, respectively, for Grades 1 (simple contact), 2 (distortion), and 3 (marked indentation).

CONCLUSION: 3T MRI using 3D T2-weighted DRIVE in combination with 3D TOF-MRA and 3D T1-weighted gadolinium-enhanced sequences proved to be reliable in detecting NVC and in predicting the degree of root compression, the outcome being correlated with the latter.

Acta Neurochir (2011) 153:1037–1042. DOI 10.1007/s00701-011-0957-x

Purpose To summarize our experience and lessons of microvascular decompression surgery for trigeminal neuralgia caused solely by venous compression.

Methods Fifteen patients with idiopathic trigeminal neuralgia caused by venous compression only underwent microvascular decompression. The entire course of the trigeminal root was explored thoroughly; and coagulating and cutting techniques were preferred in decompressing the culprit veins. Their clinical features, outcomes and operative complications were analyzed.

Results The compressing veins included the transverse pontine vein in five cases (33.3%), the transverse pontine vein and the vein of middle cerebellar peduncle in one (6.7%), the transverse pontine vein and the vein of cerebellopontine fissure in one (6.7%), the superior petrosal vein in three (20%), the pontotrigeminal vein in one (6.7%), the vein of the cerebellopontine fissure in two (13.3%), and the plexus venosus or venule in two (13.3%). After microvascular decompression, 11 cases (73.3%) had “excellent” or “good” pain relief. Four cases (26.7%) failed the first surgery; and two of them underwent re-operation and got “excellent” pain relief. Postoperative facial numbness appeared in four cases, due to injury to trigeminal nerve when coagulation.

Conclusion The transverse pontine vein is the most common offending vein. For this type of trigeminal neuralgia, coagulating and cutting techniques are preferred in decompressing the culprit veins. The entire course of the trigeminal root should be explored and decompressed. Following these principles, excellent or good pain relief could be achieved in most cases; and recurrence is rare. However, sometimes injury to the nerve is unavoidable when coagulating the culprit vein.

J Neurosurg 114:172–179, 2011. (DOI: 10.3171/2010.6.JNS10142)

Because the incidence of trigeminal neuralgia (TN) increases with age, neurosurgeons frequently encounter elderly patients with this disorder. Although microvascular decompression (MVD) is the only etiological therapy for TN with the highest initial efficacy and durability of all treatments, it is nonetheless associated with special risks (cerebellar hematoma, cranial nerve injury, stroke, and death) not seen with the commonly performed ablative procedures. Thus, the safety of MVD in the elderly remains a concern. This prospective study and systematic review with meta-analysis was conducted to determine whether MVD is a safe and effective treatment in elderly patients with TN.

Methods. In this prospectively conducted analysis, 36 elderly patients (mean age 73.0 ± 5.9 years) and 53 nonelderly patients (mean age 52.9 ± 8.8 years) underwent MVD over the study period. Outcome and complication data were recorded. The authors also conducted a systematic review of the English literature published before December 2009 and providing outcomes and complications of MVD in patients with TN above the age of 60 years. Pooled complication rates of stroke, death, cerebellar hematoma, and permanent cranial nerve deficits were analyzed.

Results. Thirty-one elderly patients (86.1%) reported an excellent outcome after MVD (mean follow-up 20.0 ± 7.0 months). Twenty-five elderly patients with Type 1 TN were compared with 26 nonelderly patients with Type 1 TN, and no significant difference in outcomes was found (p = 0.046). Three elderly patients with Type 2a TN were compared with 12 nonelderly patients with Type 2a TN, and no significant difference in outcomes was noted (p = 1.0). Eight elderly patients with Type 2b TN were compared with 15 nonelderly patients with Type 2b TN, and no significant difference in outcomes was noted (p = 0.086). The median length of stay between cohorts was compared, and no significant difference was noted (2 days for each cohort, p = 0.33). There were no CSF leaks, no cerebellar hematomas, no strokes, and no deaths. Eight studies (1334 patients) met the inclusion criteria for the meta-analysis. For none of the complications was the incidence significantly more frequent in elderly patients than in the nonelderly.

Conclusions. Although patient selection remains important, the authors’ experience and the results of this systematic review with meta-analysis suggest that the majority of elderly patients with TN can safely undergo MVD.

Acta Neurochir (2010) 152:2125–2132. DOI 10.1007/s00701-010-0840-1

The study aims to assess the efficacy and safety of surgical treatment of trigeminal neuralgia (TN) in our department and to identify prognostic factors.

Methods Seventy patients receiving surgical treatment for TN during the period 2003–2004 were included in this retrospective study. The surgical procedures used were glycerol injection (GI), microvascular decompression (MVD), or rhizotomia (RIZ). All patients were divided into spontaneous onset TN type1 (brief lancinating pain) or TN type 2 (continuous pain component). Two patients had bilateral TN; each side was regarded as a separate case. These 70 patients had a total of 160 interventions (110 GI, 40 MVD, and ten RIZ) performed in the period 1998–2007. Data were obtained by chart review and telephone interview. Patients provided information about pre- and postoperative pain characteristics including subtype, duration, intensity, and the use of antiepileptic drugs. Outcome was evaluated using a pain vector diagram.

Results To quantify self-reported pain, we developed a new vector-based pain diagram. The subtype of TN was shown to be a very important prognostic factor. One year after MVD, 90% of patients with type 1 TN still had positive effect, whereas this was only true in 73% of patients with type 2 TN. After RIZ, the results were 71% and 33% for types 1 and 2, respectively. For comparison, GI had a significant lower effect but if the treatment led to hypoesthesia, 41% continued to have a positive effect 1 year after surgery, compared to only 24% if postoperative sensation was normal. Type 2 TN was found to be dominated by women with left-sided TN outside the V2 dermatome and with a lower probability of a neurovascular conflict. As expected, 1/5 of the cases developed postoperative hypoesthesia in the face following a nerve destructive procedure (RIZ and GI). Using MVD, the risk of serious side effects was about 4%. Complementary and alternative treatment had no general or permanent effect in the investigated population—quite the contrary.

Conclusions Regarding prognosis and outcome, we find that it is very important to classify TN in subgroups (types 1 and 2). Dealing with medically treatment-resistant type 1 TN, MVD and RIZ are reasonably safe and effective interventions. The surgical results dealing with type 2 TN are still very poor. All patients with medically treatmentresistant TN should be offered referral to a neurosurgical unit with experience in treating this painful disease. We recommend using a vector-based pain diagram when evaluating the outcome of multiple interventions.

Neurosurgery 67:633-639, 2010 DOI: 10.1227/01.NEU.0000377861.14650.98

Trigeminal neuralgia (TN) is the most common facial pain syndrome, with an incidence of approximately 27 per 100 000 patient-years.

OBJECTIVE: To prospectively compare facial pain outcomes for patients having either a posterior fossa exploration (PFE) or stereotactic radiosurgery (SRS) as their first surgery for idiopathic TN.

METHODS: Prospective cohort study of 140 patients with idiopathic TN who had either PFE (n = 91) or SRS (n = 49) from June 2001 until September 2007. The groups were similar with regard to sex, pain location, and pain duration. Patients who had SRS were older (67.1 vs 58.2 years; P < .001). The median follow-up after surgery was 38 months.

RESULTS: Patients who had PFE more commonly were pain free off medications (84% at 1 year, 77% at 4 years) compared with the SRS patients (66% at 1 year, 56% at 4 years; hazard ratio = 2.5; 95% confidence interval, 1.4-4.6; P = .003). Additional surgery for persistent or recurrent face pain was performed in 14 patients after PFE (15%) compared with 17 patients after SRS (35%; P = .009). Nonbothersome facial numbness occurred more frequently in the SRS group (33% vs 18%; P = .04). No difference was noted in other complications between patients who had PFE (12%) (dysesthetic facial pain, n = 3; cerebrospinal fluid leakage, n = 3; hearing loss, n = 2; wound infection, n = 1; pneumonia, n = 1; deep vein thrombosis, n = 1) and patients who had SRS (8%) (dysesthetic facial pain, n = 4; P = .47).

CONCLUSION: PFE is more effective than SRS as a primary surgical option for patients with idiopathic TN

Neurosurgery 0:1–10, 2010 DOI: 10.1227/NEU.0b013e3181eb5230

Percutaneous balloon compression is an effective, low-cost, simple therapeutic modality with the special advantage of being the only percutaneous technique that can be simply performed with the patient under general anesthesia for the treatment of trigeminal neuralgia.

OBJECTIVE: To identify surgical and individual parameters that could influence outcome in patients with trigeminal neuralgia treated with percutaneous balloon compression.

METHODS: Within a 5-year period, 66 consecutive percutaneous balloon compressions were performed in 47 patients. The medical and surgical records of all patients were retrospectively reviewed and analyzed for a possible correlation between the following parameters and outcome: balloon shape, balloon volume, compression time, age, sex, type of pain, duration of disease, previous procedures, and trigeminal division affected. Univariate and multivariate analyses were used to test for statistical significance.

RESULTS: The initial success rate was 85%, and 36% of the responders are still pain free with a mean follow-up of approximately 20 months, whereas in 33 patients, trigeminal pain recurred after a mean of approximately 17 months. Of the investigated parameters, significant correlations were obtained between balloon shape and all aspects of outcome, previous operations and complication rate, pain type and complication rate, and compression time and postoperative numbness.

CONCLUSION: The balloon shape is a parameter with a very strong impact on outcome, and balloon volume should be adjusted to this parameter. Persistent elliptical balloon shapes should raise consideration of aborting the procedure. There were no differences in outcomes between 60 seconds and longer compression times. The number of previous operations did not correlate with pain relief, but seemed to increase the risk of complications. Patients with multiple sclerosis seemed to obtain similar benefit from the procedure as do patients with classic trigeminal neuralgia.

J Neurosurg 113:486–492, 2010.DOI: 10.3171/2010.1.JNS091106

The aim of this study was to compare percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizotomy (PRGR) in terms of effectiveness, complications, and technical aspects.

Methods. Sixty-six consecutive PBC procedures were performed in 45 patients between January 2004 and December 2008, and 120 PRGR attempts were performed in 101 patients between January 2006 and December 2008. The PRGR procedures were not completed due to technical reasons in 19 cases. Five patients in the Balloon Compression Group and 9 patients in the Glycerol Group were lost to follow-up and were excluded from the study. The medical records and the intraoperative fluoroscopic images from the remaining cases were retrospectively examined, and the follow-up was completed with telephone contact, when necessary. The 2 groups were compared in terms of initial effect, duration of effect, and rates of complications as well as severity and type of complications.

Results. The rates for immediate pain relief were 87% for patients treated with glycerol injection and 85% for patients treated with balloon compression. The Kaplan-Meier plots for the 2 treatment modalities were similar. The 50% recurrence time was 21 months for the balloon procedure and 16 months for the glycerol procedure. When the groups were broken down by the “previous operations” criterion, the 50% recurrence time was 24 months for the Glycerol First Procedure Group, 6 months for the Balloon First Procedure Group, 8 months for the Glycerol Previous Procedures Group, and 21 months for the Balloon Previous Procedures Group. The rates of complications (excluding numbness) were 11% for PRGR and 23% for PBC, and this difference was statistically significant (chi-square test, p = 0.04).

Conclusions. Both PRGR and PBC are effective techniques for the treatment of trigeminal neuralgia, with PRGR presenting some advantages in terms of milder and fewer complications and allowing lighter anesthesia without compromise of analgesia. For these reasons the authors consider PRGR as the first option for the treatment of trigeminal neuralgia in patients who are not suitable candidates or are not willing to undergo microvascular decompression, while PBC is reserved for patients in whom the effect of PRGR has proven to be short or difficult to repeat due to cisternal fibrosis.