Neurosurgeons' Armamentarium for the Management of Refractory Postherpetic Neuralgia: A Systematic Literature Review.

BACKGROUND/AIMS: Postherpetic neuralgia (PHN) can be refractory to both medical and minimally invasive treatments. Its complex pathophysiology explains the numerous neurosurgical procedures that have been implemented through the years. Our objective was to summarize all available neurosurgical strategies for the management of resistant PHN and evaluate their respective safety and efficacy outcomes. METHODS: A comprehensive systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: A total of 38 studies comprising 811 patients with refractory PHN were included. The safety and efficacy of the following procedures were investigated: spinal cord stimulation (SCS), dorsal root entry zone (DREZ) lesioning, intrathecal drug delivery, caudalis DREZ lesioning, dorsal root ganglion (DRG) radiofrequency lesioning, peripheral nerve stimulation, gamma knife surgery, deep brain stimulation, cordotomy, percutaneous radiofrequency rhizotomy and Gasserian ganglion stimulation. CONCLUSIONS: There are several available neurosurgical approaches for recalcitrant PHN including neuromodulatory and ablative procedures. It is suggested that patients with resistant PHN undergo minimally invasive procedures first, including SCS, peripheral nerve stimulation or DRG radiofrequency lesioning. More invasive procedures should be reserved for refractory cases. Comparative studies are needed in order to construct a PHN neurosurgical management algorithm.

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.

Sudden falls as a persistent complication of selective dorsal rhizotomy surgery in children with bilateral spasticity: report of 3 cases.

Selective dorsal rhizotomy (SDR) surgery is a well-established treatment for ambulatory children with bilateral spastic paresis and is performed to eliminate spasticity and improve walking. The objective of this case report is to describe sudden falls as a persistent complication of SDR. The authors report on 3 patients with bilateral spastic paresis, aged 12, 6, and 7 years at the time of surgery. The percentage of transected dorsal rootlets was around 40% at the L2-S1 levels. Sudden falls were reported with a frequency of several a day, continuing for years after SDR. The falls were often triggered by performing dual tasks as well as occurring in the transition from sitting to standing, during running, after strenuous exercise, or following a fright. Patients also had residual hyperesthesia and dysesthesia of the foot sole. The authors hypothesize that the sudden falls are caused by a muscle inhibition reflex of the muscles in the legs, as an abnormal reaction to a sensory stimulus that is perceived with increased intensity by a patient with hyperesthesia. A favorable effect of gabapentin medication supports this hypothesis.

Trends in surgical treatment for trigeminal neuralgia in the United States of America from 1988 to 2008.

Current surgical treatments for refractory trigeminal neuralgia (TN) include microvascular decompression (MVD), percutaneous rhizotomy, and stereotactic radiosurgery (SRS). We aimed to map the trends of utilization of these procedures in the USA and examine factors associated with morbidities and discharge outcome. We performed a retrospective cohort study with time trends of patients admitted to US hospitals for TN between 1988 and 2008 who received MVD, percutaneous rhizotomy, or SRS as reported in the Nationwide Inpatient Sample. Univariate and multivariate analyses were conducted to examine patient demographics, hospital characteristics, and other hospitalization factors affecting complications and discharges. The use of MVD increased significantly by 194% from 1988 to 2008 while rhizotomy decreased by 92%. The use of radiosurgery, introduced in the early 1990s, peaked in 2004 and has declined since. Univariate analysis revealed patient age, length of hospitalization, hospital teaching status, and hospital patient volume to be associated with discharge and complications. Multivariate analysis showed that for MVD, younger age and high hospital volume were predictive of a good discharge outcome. For rhizotomy, age, median income, urban location, and hospital volumes were associated with discharge outcome, but only teaching status, urban location, and hospital volume were associated with complications. For SRS, patient age and length of stay were found to be important by multivariate analysis on discharge. Mortality rates for MVD (0.22%), rhizotomy (0.42%), and SRS (0.12%) were low. The clinical practices for surgical treatment of TN have evolved over time with the rise of MVD and dwindling of rhizotomy procedures.

Other surgical interventions.

Optimal management of patients with chronic neuropathic pain requires a multidisciplinary approach that may include surgery. Yet despite the fact that lumbosacral spinal surgery, for example, is performed in thousands of patients every year, there is very little controlled clinical data to support its use or that of other surgical techniques in the treatment of chronic nonmalignant pain, especially neuropathic pain. Nevertheless, there is evidence of some success for ablative techniques such as dorsal root entry zone lesioning for phantom limb pain and girdle-zone neuropathic pain, and sympathectomy for the treatment of complex regional pain syndrome, and a variety of operations for tic douloureux. However, before considering a surgical procedure, a nonsurgical approach should have been tried and the suitability of the patient must be carefully assessed. To fully establish the role of surgery in the treatment of chronic neuropathic pain, further well-designed, prospective, controlled trials are essential.