BACKGROUND: Radiofrequency rhizotomy (RFR) is a commonly used, effective procedure for trigeminal neuralgia (TN), but a subset of patients experiences pain recurrence and requires subsequent surgeries. Currently, the rhizotomy temperature and duration of application are empirically determined, and there is no consensus on what settings are most beneficial. In this study, we analyzed patients who underwent trigeminal RFR and had subsequent surgeries to identify whether rhizotomy parameters were associated with the duration of pain relief. METHODS: Single-center, retrospective analysis of patients undergoing RFR for TN from 1995 to 2016. The primary endpoint was subsequent procedure. Associations with rhizotomy parameters and covariates were assessed using Cox regression analysis. RESULTS: The study included 338 patients, average age 65 years; 61% were women. Temperature was significantly associated with both the degree of immediate postoperative pain relief and the duration of pain relief, and in subgroup analyses by multiple sclerosis status and RFR procedural count. Ablation duration was also independently significant, though not when analyzed alongside age, sex, and race. Duration of pain relief was generally shorter in patients with multiple sclerosis and in repeated RFR. CONCLUSIONS: Higher temperatures may be necessary to achieve pain relief in some patients, given the progressive nature of the facial pain, but they are not associated with longer duration of pain relief in patients who have recurrent pain. Modulation of the ablation duration does not seem to affect the short-term or long-term outcomes.

OBJECTIVE Trigeminal neuralgia (TN) is characterized by intermittent, paroxysmal, and lancinating pain along the distribution of the trigeminal nerve. Microvascular decompression (MVD) directly addresses compression of the trigeminal nerve. The purpose of this study was to determine whether patients undergoing MVD as their first surgical intervention experience greater pain control than patients who undergo subsequent MVD.METHODS A retrospective review of patient records from 1998 to 2015 identified a total of 942 patients with TN and 500 patients who underwent MVD. After excluding several cases, 306 patients underwent MVD as their first surgical intervention and 175 patients underwent subsequent MVD. Demographics and clinicopathological data and outcomes were obtained for analysis.RESULTS In patients who underwent subsequent MVD, surgical intervention was performed at an older age (55.22 vs 49.98 years old, p < 0.0001) and the duration of symptoms was greater (7.22 vs 4.45 years, p < 0.0001) than for patients in whom MVD was their first surgical intervention. Patients who underwent initial MVD had improved pain relief and no improvement in pain rates compared with those who had subsequent MVD (95.8% and 4.2% vs 90.3% and 9.7%, respectively, p = 0.0041). Patients who underwent initial MVD had significantly lower rates of facial numbness in the pre- and postoperative periods compared with patients who underwent subsequent MVD (p < 0.0001). The number of complications in both groups was similar (p = 0.4572).CONCLUSIONS The results demonstrate that patients who underwent other procedures prior to MVD had less pain relief and a higher incidence of facial numbness despite rates of complications similar to patients who underwent MVD as their first surgical intervention.

OBJECTIVE:Percutaneous treatments for trigeminal neuralgia are safe, simple, and effective for achieving good pain control. Procedural risks could be minimized by using noninvasive imaging techniques to improve the placement of the radiofrequency thermocoagulation probe into the trigeminal ganglion. Positioning of a probe is crucial to maximize pain relief and to minimize unwanted side effects, such as denervation in unaffected areas. This investigation examined the use of laser speckle imaging during probe placement in an animal model.METHODS:This preclinical safety study used nonhuman primates, Macaca nemestrina (pigtail monkeys), to examine whether real-time imaging of blood flow in the face during the positioning of a coagulation probe could monitor the location and guide the positioning of the probe within the trigeminal ganglion.RESULTS:Data from 6 experiments in 3 pigtail monkeys support the hypothesis that laser imaging is safe and improves the accuracy of probe placement.CONCLUSIONS:Noninvasive laser speckle imaging can be performed safely in nonhuman primates. Because improved probe placement may reduce morbidity associated with percutaneous rhizotomies, efficacy trials of laser speckle imaging should be conducted in humans.

INTRODUCTION: Trigeminal neuralgia (TN) is a pain disorder characterized by paroxysmal lancinating pain along the distribution of the trigeminal nerve. Mounting clinical evidence supports the neurovascular compression (NVC) theory, suggesting vascular compression results in the manifestation of debilitating pain. Microvascular decompression (MVD) is the only known surgical intervention that directly addresses this proposed etiology. METHODS: A retrospective review of patient records at the Johns Hopkins Hospital from 1998 to 2015 revealed 942 patients with TN and 500 patients who underwent MVD. A total of 306 patients who underwent MVD initially and 175 patients who underwent salvage MVD were included for analysis. Demographics, preoperative interventions, pain outcomes, pre- and postoperative sensory outcomes, and complications were collected. RESULTS: Patients who underwent salvage MVD were older (55.22 years vs 49.98 years, P < .001), and experienced symptoms longer (7.22 years vs 4.45 years, P <.001). Patients who underwent MVD initially experienced improved pain relief and no pain relief rates compared with those who had salvage MVD (95.8% and 4.2% vs 90.3% and 9.7%, respectively, P = .004). Patients who underwent MVD initially had significantly lower rates of facial numbness in the pre- and postoperative period compared with salvage MVD patients (P < .001). The number of complications between both groups was similar (P = .457). CONCLUSION: Our results suggest that patients who underwent procedures prior to MVD experienced less pain relief and a higher incidence of facial numbness despite similar rates of complications in comparison with patients who underwent MVD as their first surgical intervention.

AimChiari type I malformation (C1M) may be symptomatic or asymptomatic as an incidental finding. In this retrospective study, we applied diffusion tensor imaging (DTI) to study the brainstem and cerebellar white matter tracts in C1M.MethodDiffusion tensor imaging (DTI) data were acquired on a 1.5T MR‐scanner using balanced pairs of diffusion gradients along 20 non‐collinear directions. Measurements from regions of interest in each pontine corticospinal tract, medial leminscus, and middle cerebellar peduncle (MCP) and in the lower brainstem were obtained for fractional anisotropy and mean, axial, and radial diffusivity. Values in symptomatic and asymptomatic children, and children with and without hydromyelia were compared using analysis of variance.ResultsFifteen children with C1M (10 males, five females; six symptomatic [four with hydromyelia] and nine asymptomatic) were included. Median age was 6 years 5 months (range 2y 10mo–15y 4mo). No significant differences in DTI scalars were found in the lower brainstem. In both MCPs, axial diffusivity values were lower in symptomatic than in asymptomatic children (p=0.049 and p=0.035 respectively) and higher in children with hydromyelia versus without hydromyelia (p=0.018 and p=0.006 respectively). In the left MCP, mean diffusivity values were lower in symptomatic than in asymptomatic children (p=0.047).InterpretationOur results show that microstructural tissue alterations may be present in C1M. Additionally, our study suggests a specific role for the MCPs in C1M. Further large‐scale studies are warranted.

Objectives: Trigeminal neuralgia is a sensory nerve disorder characterized by lancinating pain and treated most commonly with carbamazepine, rhizotomy treatment, or open surgical management with microvascular decompression. We describe a novel technique to complement surgical treatment for trigeminal neuralgia via direct injection of the trigeminal nerve with glycerin in the cisternal portion of the nerve.Patients and methods: We performed a retrospective analysis of patients who received standard microvascular decompression and injection of glycerin to the inferior third of the cisternal portion of the nerve anterior to the root entry zone with lack of a compressive vessel on MRI as the primary indication. Fourteen patients were identified and demographic information, post-operative course and complications were recorded.Results: There were eleven females and three males with an average age at time of surgery of 54.8 years. 100% of patients reported that their trigeminal pain was significantly improved following surgical intervention. Four out of fourteen patients reported a 50-80% decrease from the pre-surgery baseline pain at one month and three month follow up. One patient developed a CSF leak, and no surgical site infections or motor deficits were observed.Conclusion: Intra-operative glycerin rhizotomy in conjunction with microvascular decompression can be used to safely treat patients suffering from trigeminal neuralgia. (C) 2013 Elsevier B.V. All rights reserved.

OBJECT: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.

This review examined Dr. Harvey Cushing’s cases in the surgical records of Johns Hopkins Hospital, from 1896 to 1912. 41 patients who underwent cortical stimulation for intra-operative motor mapping were selected for further analysis. We demonstrate that Cushing used cortical stimulation to define primary motor and sensory cortices in the treatment of tumors, trauma, and epilepsy, within adult and pediatric populations. In addition, he performed stimulation of sub-cortical white matter during 4 of these surgeries, setting the stage for contemporary use of this technique in improving post-operative outcomes. This review of Cushing’s early intra-operative motor mapping illuminates his contributions, and clarifies his influence on the evolution of cortical mapping from an experimental technique to a staple of contemporary neurosurgery.

OBJECTChoroid plexus tumors (CPTs) are rare intracranial neoplasms that constitute approximately 2%-5% of all pediatric brain tumors. Most of these tumors present with severe hydrocephalus. The optimal perioperative management and oncological care remain a matter of debate. The authors present the epidemiological and clinical features of CPTs from a 20-year single-institutional experience.METHODSA total of 39 consecutive patients with pathologically proven CPTs (31 choroid plexus papillomas [CPPs] and 8 choroid plexus carcinomas [CPCs]) were included in this series. Patient demographics, clinical presentation, comorbidities, indications for surgery, radiological studies, tumor location, and all operative variables were reviewed for each case. Multivariate regression analysis was performed to identify independent predictors of tumor recurrence and survival.RESULTSThe overall mean age (± SD) was 13.13 ± 19.59 years (15.27 ± 21.10 years in the CPP group and 3.66 ± 3.59 years in the CPC group). Hydrocephalus was noted at presentation in 34% of patients. The most common presenting symptoms were headache (32%) and nausea/vomiting (26%). Gross-total resection (GTR) was achieved in 86% of CPPs and in 71% of CPCs (p = 0.57). There was 100% survival in patients with CPPs observed at the 5- and 10-year follow-up and 71% survival in patients with CPCs at the 5-year follow-up. In a multivariate regression analysis, a diagnosis of papilloma, preoperative vision changes, or hydrocephalus; right ventricle tumor location; and GTR were all independently associated with a decreased likelihood of tumor recurrence at last follow-up.CONCLUSIONSThe authors' study suggests that patients with CPCs are more likely to experience local recurrence and metastasis; hence, GTR with chemotherapy and radiotherapy, particularly for CPCs, is pivotal in preventing recurrence and prolonging survival. While GTR was important for local control following resection of CPPs, it had a minimal effect on prolonging survival in this patient cohort.

Pediatric trigeminal neuralgia (TN) is a rare entity. The purpose of this study was to retrospectively analyze a small series of pediatric patients diagnosed with TN and surgically treated with microvascular decompression (MVD) at a single center.

A review of Dr. Harvey Cushing’s surgical cases at the Johns Hopkins Hospital provided insight into his early work on trigeminal neuralgia (TN). There was perhaps no other affliction that captured his attention in the way that TN did, and he built a remarkable legacy of successful treatment. At the time, surgical interventions carried an operative mortality of 20%.

To characterize a population of pediatric high-grade astrocytoma (HGA) patients by confirming the proportion with a correct diagnosis, and determine prognostic factors for survival in a subset diagnosed with uniform pathologic criteria. Sixty-three children diagnosed with HGA were treated at the Johns Hopkins Hospital between 1977 and 2004. A single neuropathologist (P.C.B.) reviewed all available histologic samples (n = 48). Log-rank analysis was used to compare survival by patient, tumor, and treatment factors. Median follow-up was 16 months for all patients and 155 months (minimum 54 months) for surviving patients. Median survival for all patients (n = 63) was 14 months with 10 long-term survivors (survival >48 months). At initial diagnosis, 27 patients were grade III (43%) and 36 grade IV (57%). Forty-eight patients had pathology slides available for review, including seven of ten long-term surviving patients. Four patients had non-HGA pathology, all of whom were long term survivors. The remaining 44 patients with confirmed HGG had a median survival of 14 months and prognostic analysis was confined to these patients. On multivariate analysis, five factors were associated with inferior survival: performance status (Lansky) <80% (13 vs. 15 months), bilaterality (13 vs. 19 months), parietal lobe location (13 vs. 16 months), resection less than gross total (13 vs. 22 months), and radiotherapy dose <50 Gy (9 vs. 16 months). Among patients with more than one of the five adverse factors (n = 27), median survival and proportion of long-term survivors were 12.9 months and 0%, compared with 41.4 months and 18% for patients with 0-1 adverse factors (n = 17). In an historical cohort of children with HGA, the potential for long term survival was confined to the subset with less than two of the following adverse prognostic factors: low performance status, bilaterality, parietal lobe site, less than gross total resection, and radiotherapy dose <50 Gy. Pathologic misdiagnosis should be suspected in patients who are long term survivors of a pediatric high grade astrocytoma.

Background: Spinal stenosis is a common complication of achondroplasia. To our knowledge, no study has evaluated a greater than 2-year outcome after surgical intervention for spinal stenosis in such children or compared decompression with and without instrumentation in relation to revision surgery. Our purpose was to assess the efficacy of lumbar decompression and instrumentation for symptomatic stenosis in children with achondroplasia.Methods: We retrospectively reviewed our institution's database to identify children (<= 18 y old) with achondroplasia undergoing initial spinal decompression for lumbar stenosis from 1995 through 2003. We identified 18 such patients and reviewed their medical records for demographic data, presenting signs and symptoms, and treatment and outcome data. Mean follow-up was 72.0 +/- 27.6 months. We determined each patient's symptom score (SS) based on presence of leg weakness, numbness, or pain; abnormal reflexes; incontinence; and walking intolerance (unable to walk >= 5 blocks). Each finding was scored 1 point (6 points maximum). Nine patients requiring revision surgery were assigned a revision postoperative SS. All patients were contacted at the end of data collection and assigned a final follow-up SS. Baseline SS values were compared with postoperative, revision postoperative, and final follow-up scores using a paired t test (alpha = 0.05).Results: The mean preoperative and final SS values were significantly different: 4.0 +/- 0.9 (most common symptoms, leg weakness and incontinence) and 1.6 +/- 1.7 (most common symptom, leg weakness), respectively. Nine patients underwent decompression with instrumentation initially; 9 did not; 7 of the latter required instrumentation during revision; and 2 of the former also required revision. Those without initial instrumentation were 3.5 times more likely (odds ratio = 12.3) to require revision.Conclusions: Surgical decompression with instrumentation significantly reduced the symptoms of lumbar stenosis and the likelihood of revision surgery in children with achondroplasia.

Background Cord retethering and other postoperative complications can occur after the surgical untethering of a first-time symptomatic tethered cord. It is unclear if using duraplasty vs. primary dural closure in the initial operation is associated with decreased incidence of either immediate postoperative complications or subsequent symptomatic retethering. It is also unclear if different etiologies are associated with different outcomes after each method of closure. We reviewed our pediatric experience in first-time surgical untethering of symptomatic tethered cord syndrome (TCS) to identify the incidence of postoperative complications and symptomatic retethering after duraplasty vs. primary closure.Materials and methods We retrospectively reviewed 110 consecutive pediatric (<18 years old) cases of first-time symptomatic spinal cord untethering at our institution over a 10-year period. Incidence of postoperative complications and symptomatic retethering were compared in cases with duraplasty vs. primary dural closure use.Results Mean age was 5.7 +/- 4.8 years old. "Complex" etiologies included lipomyelomeningocele or prior lipomyelomeningocele repair in 22 (20%) patients, prior myelomeningocele repair in 35 (32%), and concurrent lumbosacral lipoma in 18 (16%). "Noncomplex etiologies" included fatty filum in 26 (24%) and split cord malformation in five (4%). Seventy-five (68%) cases underwent primary dural closure vs. 35 (32%) with duraplasty. Twenty-nine (26%) patients experienced symptomatic retethering at a median [interquartile range (IQR)] of 30.5 [20.75-41.75] months postoperatively. There was no difference in incidence of postoperative cerebrospinal fluid leak, surgical site infection, or median [IQR] length of stay in patients receiving primary dural closure [4 (5%), 7 (9%), and 5 (4-6) days, respectively] vs. duraplasty [3 (9%), 3 (9%), and 6 [5-8] days, respectively], p>0.05. Complex etiologies were more likely to retether than noncomplex etiologies after primary closure (33.6% vs. 6.6%, p=0.05) but not after duraplasty (13.7% vs. 5.4%, p=0.33). Duraplasty graft type (polytetrafluoroethylene vs. bovine pericardium) was not associated with pseudomeningocele or retethering.Conclusion In our experience, the increased rate of symptomatic retethering observed with complex pediatric TCS (pTCS) etiologies after primary dural closures was not observed when duraplasty was instituted. Expansile duraplasty may be valuable specifically in the management of patient subgroups with complex pTCS etiologies.

BACKGROUND:Shunt infection is a morbid complication of CSF shunting. Though antibiotic-impregnated shunt (AIS) systems decrease shunt infections by preventing bacterial colonization following device implantation, their effectiveness in populations at high risk for infection has recently been disputed. We set out to determine whether the categorical switch to AIS systems at our institution has resulted in a decreased incidence of shunt infection in high-risk pediatric patients. METHODS:We retrospectively reviewed the records from all pediatric patients undergoing CSF shunt procedures at The Johns Hopkins Hospital over a 10-year period between January 1997 and December 2007. During the 5.75 years prior to October 2002, all CSF shunts included standard, non-AIS catheters. During the 4.25 years after October 2002, all CSF shunts included AIS catheters. High-risk subgroups were defined a priori as prematurity (<35 weeks gestational age), shunts placed immediately post-meningitis, conversion of external ventricular drains (EVD) to shunt, and replacement of nosocomial shunt infection in patients requiring prolonged hospital stay (>1 month). RESULTS:A total of 544 pediatric patients underwent 1,072 shunt placement procedures (502 AIS, 570 non-AIS). Of patients with non-AIS catheters, 64 (11.2%) experienced shunt infection, whereas only 16 (3.2%) patients with AIS catheters experienced shunt infection (p<0.001). AIS versus non-AIS was associated with decreased shunt infection in premature neonates [three (5.5%) vs. seven (20.0%), p=0.030], acutely following bacterial meningitis [two (5.7%) vs. nine (25.0%), p=0.043], when converting EVD to shunts [zero (0%) vs. four (13.3%), p=0.030], and in patients with prolonged hospital stay>1 month [three (5.3%) vs. 12 (18.5%), p=0.022]. Staphylococcus aureus was the most common infectious agent for both non-AIS (81.3%) and AIS (75.0%) systems. CONCLUSION:The introduction of AIS catheters into our institutional practice has reduced the incidence of shunt infection in pediatric populations at highest risk for infection. AIS catheters are effective instruments to prevent peri-operative colonization of CSF shunt components.