Nationwide Shift From Percutaneous Rhizotomy to Microvascular Decompression for Treatment of Trigeminal and Other Cranial Nerve Neuralgias.

OBJECTIVE: The aim of this study was to report the trends in the use of common surgical interventions over the past decade to treat cranial nerve neuralgias. METHODS: The Centers for Medicare and Medicaid Services Part B National Summary Data File from 2000 to 2016 were studied. RESULTS: A total of 57.1 million persons were enrolled in 2016, up from 39.6 million persons in 2000. Suboccipital craniectomy done for cranial nerve decompressions (including cranial nerves V, VII, and IX) increased by 33.9 cases per year so that in 2016 the number of cases was 167% of what it was 17 years earlier (ie, from 655 cases in 2000 to 1096 cases in 2016). The less commonly used subtemporal approach craniectomy to treat trigeminal neuralgia (TN) increased by 1.13 cases per year (ie, from 25 cases in 2000 to 46 cases in 2016). The less invasive percutaneous rhizotomy procedures, including glycerol and radiofrequency ablation, for treatment of TN decreased by 42.9 cases per year (64%; ie, from 2578 cases in 2000 to 1206 cases in 2016). CONCLUSIONS: Overall trends show increased use of open surgery and decreased use of percutaneous rhizotomy, including destruction of the trigeminal nerve using balloon compression, glycerol injection, or thermal injury. These trends may be related to differences in outcomes between treatment modalities.

Options in treating trigeminal neuralgia: Experience with 195 patients.

OBJECTIVE: For patients with medically unresponsive trigeminal neuralgia (TN), surgical options include microvascular decompression (MVD), radiofrequency rhizotomy (RF), and stereotactic radiosurgery (SRS). In an attempt to identify the risks and benefits and cost inherent with each of the three modalities, we performed a retrospective review of our experience with 195 cases of TN treated over the past 15 years. METHODS: Since 2001, 195 patients with previously untreated TN were managed: with MVD in 79, RF in 36, and SRS in 80. All patients reported herein underwent preoperative MRI. Women outnumbered men 122/73 (p=0.045). Follow-up after surgery was 32±46months. RESULTS: The patients qualifying for MVD were generally healthier and younger, with a mean age±SD of 57±14, compared to those undergoing RF (75±15) or SRS (73±13, p<0.0001). In case of relapse, medical treatment was always tried and failed prior to consideration of surgical intervention. A second surgical procedure was necessary in 2, 23, and 18 patients initially treated with MVD, RF, and SRS respectively (p<0.0001). In the patients treated with MVD, RF, and SRS, the average number of procedures per patient necessary to achieve pain control was 1.1, 2.0, and 1.3 respectively (p=0.001). There were 7 complications in the patients treated with MVD but no deaths. Numbness was present in 13, 18, and 29 patients treated with MVD, RF, and SRS respectively (p=0.008). CONCLUSION: MVD for TN is the treatment least likely to fail or require additional treatment. Patients who underwent MVD were younger than those undergoing RF or SRS. The highest rate of recurrence of TN was encountered in patients undergoing RF (64%). Facial numbness was least likely to occur with MVD (16%) compared to RF and SRS (50% and 36% respectively).

Effectiveness of repeat glycerol rhizotomy in treating recurrent trigeminal neuralgia.

BACKGROUND: 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 (GR2+) 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 GR2+, 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 GR2+ (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 GR2+ beyond the initial treatment.

Various surgical modalities for trigeminal neuralgia: literature study of respective long-term outcomes.

BACKGROUND: The literature contains many varying, often conflicting surgical results. However, there is no study comparing long-term effectiveness of all surgical procedures for trigeminal neuralgia (TN). The aim of the present analysis is to report the long-term outcomes of surgical options of TN since the development of electronic databases, to evaluate them with the same clinical and statistical criteria and determine the most appropriate treatment. METHOD: All studies that had a minimum 5 years or more (> or =5 years) mean duration of follow-up were included in the review. The identified studies were evaluated independently by two authors for quality using a modified inclusion criteria. The evaluated outcome measures of this study were, the initial acute pain relief (APR), follow-up pain free period and recurrence rates as well as complications. In comparisons of the data, the Student's t-test, Chi-square followed by Pearson's risk analysis tests were used. Kaplan-Meier actuarial analysis of pain free-survival curves were constructed for each surgical option that had enough data. FINDINGS: Twenty-eight studies, mostly including microvascular decompression (MVD) and radiofrequency thermorhizotomy (RF-TR), that met the inclusion criteria were included in the review. The efficacy of MVD and percutaneous balloon microcompression (PBC) were similar (Odds ratio = 0.15, P > 0.05), and their effects were superior to those of the other modalities (P < 0.001). Although RF-TR provided a high initial pain relief, its average pain free rate was 50.4% for a mean follow-up of 5 years. The recurrence rate was high after RF-TR (46%), while the lowest recurrence rate (18.3%) was after MVD (P < 0.001). Within the long-term follow-up period recurrence of pain affects at least 19% of patients who undergo any surgical treatment for TN. CONCLUSIONS: The study suggests that each surgical technique for treatment of trigeminal neuralgia has merits and limitations. However, MVD provides the highest rate of long-term patient' satisfaction with the lowest rate of pain recurrence.

Phosphorylated MAP1B is induced in central sprouting of primary afferents in response to peripheral injury but not in response to rhizotomy.

A peripheral nerve lesion induces sprouting of primary afferents from dorsal root ganglion (DRG) neurons into lamina II of the dorsal horn. Modifications of the environment in consequence to the axotomy provide an extrinsic stimulus. A potential neuron-intrinsic factor that may permit axonal sprouting is microtubule-associated protein 1B (MAP1B) in a specific phosphorylated form (MAP1B-P), restricted to growing or regenerating axons. We show here that both in rat and mouse, a sciatic nerve cut is rapidly followed by the appearance of MAP1B-P expression in lamina II, increasing to a maximum between 8 and 15 days, and diminishing after three months. Evidence is provided that sprouting and induction of MAP1B-P expression after peripheral injury are phenomena concerning essentially myelinated axons. This is in accordance with in situ hybridization data showing especially high MAP1B-mRNA levels in large size DRG neurons that give rise to myelinated fibers. We then employed a second lesion model, multiple rhizotomy with one spared root. In this case, unmyelinated CGRP expressing fibers do indeed sprout, but coexpression of MAP1B-P and CGRP is never observed in lamina II. Finally, because a characteristic of myelinated fibers is their high content in neurofilament protein heavy subunit (NF-H), we used NF-H-LacZ transgenic mice to verify that MAP1B-P induction and central sprouting were not affected by perturbing the axonal organization of neurofilaments. We conclude that MAP1B-P is well suited as a rapidly expressed, axon-intrinsic marker associated with plasticity of myelinated fibers.

Dorsal rhizotomy with anterior sacral root stimulation for neurogenic bladder.

A spinal cord lesion above the sacral micturition center results in a loss of voluntary control and development of bladder sphincter dysynergia with hyperreflexia of the detrusor and spasticity of the sphincter. Sacral rhizotomy and implantation of an anterior sacral root stimulator appears as an effective method for the treatment not only of voiding dysfunction but also of defecation and sexual disturbance. The surgical technique is described as are the clinical and electrophysiological controls. The results of our series of operated patients with intradural implantation and sacral deaffentation show a constant improvement. 90% have satisfactory continence and no longer require an incontinence appliance. Bladder capacity and compliance have increased to 120% and urethral closure pressure has decreased. 80% have complete voiding or a post-void residue of not more than 50 ml. So, urinary infection rate is dramatically decreased.