Future directions in psychiatric neurosurgery: Proceedings of the 2022 American Society for Stereotactic and Functional Neurosurgery meeting on surgical neuromodulation for psychiatric disorders.

OBJECTIVE: Despite advances in the treatment of psychiatric diseases, currently available therapies do not provide sufficient and durable relief for as many as 30-40% of patients. Neuromodulation, including deep brain stimulation (DBS), has emerged as a potential therapy for persistent disabling disease, however it has not yet gained widespread adoption. In 2016, the American Society for Stereotactic and Functional Neurosurgery (ASSFN) convened a meeting with leaders in the field to discuss a roadmap for the path forward. A follow-up meeting in 2022 aimed to review the current state of the field and to identify critical barriers and milestones for progress. DESIGN: The ASSFN convened a meeting on June 3, 2022 in Atlanta, Georgia and included leaders from the fields of neurology, neurosurgery, and psychiatry along with colleagues from industry, government, ethics, and law. The goal was to review the current state of the field, assess for advances or setbacks in the interim six years, and suggest a future path forward. The participants focused on five areas of interest: interdisciplinary engagement, regulatory pathways and trial design, disease biomarkers, ethics of psychiatric surgery, and resource allocation/prioritization. The proceedings are summarized here. CONCLUSION: The field of surgical psychiatry has made significant progress since our last expert meeting. Although weakness and threats to the development of novel surgical therapies exist, the identified strengths and opportunities promise to move the field through methodically rigorous and biologically-based approaches. The experts agree that ethics, law, patient engagement, and multidisciplinary teams will be critical to any potential growth in this area.

Current Applications of Ablative Therapies for Trigeminal Neuralgia.

Trigeminal neuralgia (TN) is a syndrome consisting of episodic neuropathic facial pain. Although the precise symptoms vary across individuals, TN is typically described as lancinating electrical shocks triggered by sensory stimuli (light touch, talking, eating, and brushing teeth) that improve with antiepileptic medication (especially carbamazepine), remit spontaneously for weeks to months (pain-free intervals), and do not involve any changes in baseline sensation. The etiology of TN has not been definitively established, but many cases are associated with compression of the trigeminal nerve by a blood vessel at the trigeminal root entry zone adjacent to the brainstem. Patients who do not respond to medical management and who are not candidates for microvascular decompression often benefit from focal therapeutic injury to the trigeminal nerve at some point along its course. Many lesions have been described, including peripheral neurectomies that target distal branches of the trigeminal nerve, rhizotomies of the Gasserian ganglion of the nerve within Meckel's cave, radiosurgery of the trigeminal nerve at its root entry zone, partial sensory rhizotomy at the root entry zone, tractotomy of the spinal nucleus of the trigeminal nerve, and DREZotomy of the trigeminal nucleus caudalis, Though the latter two interventions are seldom done for TN and more commonly performed for trigeminal neuropathic pain. This article reviews the relevant anatomy and lesioning procedures for the treatment of trigeminal neuralgia.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Neuroablative Procedures for Patients With Cancer Pain.

BACKGROUND: Managing cancer pain once it is refractory to conventional treatment continues to challenge caregivers committed to serving those who are suffering from a malignancy. Although neuromodulation has a role in the treatment of cancer pain for some patients, these therapies may not be suitable for all patients. Therefore, neuroablative procedures, which were once a mainstay in treating intractable cancer pain, are again on the rise. This guideline serves as a systematic review of the literature of the outcomes following neuroablative procedures. OBJECTIVE: To establish clinical practice guidelines for the use of neuroablative procedures to treat patients with cancer pain. METHODS: A systematic review of neuroablative procedures used to treat patients with cancer pain from 1980 to April 2019 was performed using the United States National Library of Medicine PubMed database, EMBASE, and Cochrane CENTRAL. After inclusion criteria were established, full text articles that met the inclusion criteria were reviewed by 2 members of the task force and the quality of the evidence was graded. RESULTS: In total, 14 646 relevant abstracts were identified by the literature search, from which 189 met initial screening criteria. After full text review, 58 of the 189 articles were included and subdivided into 4 different clinical scenarios. These include unilateral somatic nociceptive/neuropathic body cancer pain, craniofacial cancer pain, midline subdiaphragmatic visceral cancer pain, and disseminated cancer pain. Class II and III evidence was available for these 4 clinical scenarios. Level III recommendations were developed for the use of neuroablative procedures to treat patients with cancer pain. CONCLUSION: Neuroablative procedures may be an option for treating patients with refractory cancer pain. Serious adverse events were reported in some studies, but were relatively uncommon. Improved imaging, refinements in technique and the availability of new lesioning modalities may minimize the risks of neuroablation even further.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/guidelines-on-neuroablative-procedures-patients-wi.

Pregnancy and parental leave among neurosurgeons and neurosurgical trainees.

OBJECTIVE: Despite recently heightened advocacy efforts relating to pregnancy and family leave policies in multiple surgical specialties, no studies to date have described female neurosurgeons' experiences with childbearing. The AANS/CNS Section of Women in Neurosurgery created the Women and Pregnancy Task Force to ascertain female neurosurgeons' experiences with and attitudes toward pregnancy and the role of family leave policies. METHODS: A voluntary online 28-question survey examined the pregnancy experiences of female neurosurgeons and perceived barriers to childbearing. The survey was developed and electronically distributed to all members of the American Association of Neurological Surgeons and Congress of Neurological Surgeons who self-identified as female in February 2016. Responses from female resident physicians, fellows, and current or retired practicing neurosurgeons were analyzed. RESULTS: A total of 126 women (20.3%) responded to the survey; 57 participants (49%) already had children, and 39 (33%) planned to do so. Participants overwhelmingly had or planned to have children during the early practice and senior residency years. The most frequent obstacles experienced or anticipated included insufficient time to care for newborns (47% of women with children, 92% of women planning to have children), discrimination by coworkers (31% and 77%, respectively), and inadequate time for completion of board requirements (18% and 51%, respectively). There was substantial variability in family leave policies, and a minority of participants (35%) endorsed the presence of any formal policy at their institution. Respondents described myriad unique challenges associated with pregnancy and family leave. CONCLUSIONS: Pregnancy and family leave pose significant challenges to the recruitment, retention, and advancement of women in neurosurgery. It is thus imperative to promote clear family leave policies for trainees and practitioners, address discrimination surrounding these topics, and encourage forethought and flexibility to tackle obstacles inherent in pregnancy and the early stages of child rearing.

Options: A Prospective, Open-Label Study of High-Dose Spinal Cord Stimulation in Patients with Chronic Back and Leg Pain.

BACKGROUND: Therapeutic approaches to spinal cord stimulation (SCS) continue to evolve and improve patient outcomes in patients receiving SCS therapy secondary to failed back surgery syndrome. OBJECTIVES: The aim of this study was to evaluate pain relief and other patient outcomes of SCS using selected high-dose programming parameters. STUDY DESIGN: This was a prospective cohort study. SETTING: This study took place at 11 centers in North America. METHODS: Forty-four SCS-naive patients underwent trialing, starting with 1,000 Hz frequency, 90 µs pulse width followed by 300 Hz frequency, 800 µs pulse width, if pain relief was inadequate. Patients with 50% or greater pain relief were eligible for permanent implantation. Patient's pain rating, global impression of change, health-related quality of life, functional disability, satisfaction/recommendation, stimulation perception, device programming, and adverse events were assessed at 3 months postimplant. RESULTS: There were significant improvements from baseline in mean Numeric Rating Scale (NRS-11) pain scores for overall pain (7.5 to 3.8; P < 0.01), back pain (7.2 to 3.4; P < 0.01), leg pain (7.2 to 3.1; P < 0.01), Oswestry Disability Index (ODI) score (51.5 to 32.1; P < 0.01), and European Quality of Life-Five Dimensions, version 5L score (EQ-5D-5L) (0.58 to 0.74; P < 0.01). Twenty-eight of 32 patients (88%) had significant, favorable improvement in Patient Global Impression of Change (PGIC). Eighty-four percent of patients were "satisfied," and 78.1% would "definitely" recommend SCS. Eighteen patients (56%) used 1,000 Hz frequency and 90 µs pulse width exclusively; these patients experienced mean NRS-11 overall pain score improvement of 4.7 points. Device-, therapy-, or procedure-related adverse events were experienced in 19 patients (40%, 19 of 48), and all events resolved without reoperation and were similar to those observed with traditional SCS systems. LIMITATIONS: There was no active or sham comparator group, and therefore the reported effects may not be solely attributable to therapy effects and may be related to other, nonspecific effects of SCS. CONCLUSIONS: Improvements in pain relief, PGIC, EQ-5D-5L, ODI, and patient satisfaction were all clinically relevant and statistically significant. Future studies are needed to understand how these high-dose parameters perform versus a standard comparator. KEY WORDS: Spinal cord stimulation, high-frequency electrical stimulation, failed back surgery syndrome, neurostimulation, prospective, nonrandomized study.

Impact of Dual-Layer Duraplasty During Hemicraniectomy on Morbidity and Operative Metrics of Cranioplasty: A Retrospective Case-Control Study Comparing a Single-Layer with a Dual-Layer Technique.

BACKGROUND: Dural substitutes used during hemicraniectomy provide a barrier and dissection plane during subsequent cranioplasty. A recent review by our group showed that use of dural substitutes in hemicraniectomy is associated with reduction in estimated blood loss (EBL) and operative time (OT). In our experience, the use of a dual-layer technique facilitates a dissection plane with minimal adhesions. We hypothesized that use of this dual-layer technique would show decreased OT and EBL in patients undergoing cranioplasty. METHODS: We conducted a retrospective case-control study comparing use of single-layer versus dual-layer duraplasty on cranioplasty operative outcomes. Data on dual-layer cases were collected from patients who underwent cranioplasty from 2013 to 2017. These data were matched to controls from 2008 to 2012. Patients were identified by query of a neurosurgical database of all procedures performed at our institution. Patients were included if they had complete surgical records for cranioplasty. Cases and controls were compared with a Student t test, χ2 test, or Fisher exact test. RESULTS: A total of 78 controls and 45 cases met inclusion criteria. All baseline characteristics between cohorts were similar except for surgical indication. Mean OT (102.97 minutes vs. 102.18 minutes) and mean EBL were not significantly different (204.66 mL vs. 190 mL) between cohorts. CONCLUSIONS: In this study, we did not detect any significant difference between EBL and OT with use of single-layer versus dual-layer duraplasty. Mean EBL was slightly higher in the controls compared with cases but this difference was not statistically or clinically significant. This concept would benefit from a prospective randomized study.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation for the Treatment of Patients With Parkinson's Disease: Executive Summary.

QUESTION 1: Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson's disease, as measured by improvements in Unified Parkinson's Disease Rating Scale, part III (UPDRS-III) scores? RECOMMENDATION: Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson's disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I). QUESTION 2: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson's disease? RECOMMENDATION: When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson's disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I). QUESTION 3: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson's disease? RECOMMENDATION: There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of "on" medication dyskinesias, the GPi should be targeted. (Level I). QUESTION 4: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson's disease? RECOMMENDATION: When considering improvements in quality of life in a patient undergoing DBS for Parkinson's disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I). QUESTION 5: Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease? RECOMMENDATION: If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS, then the clinician should consider using GPi DBS rather than STN DBS, while taking into consideration other goals of surgery. (Level I). QUESTION 6: Is bilateral STN DBS associated with a higher, lower, or similar risk of mood disturbance than GPi DBS in Parkinson's disease? RECOMMENDATION: If there is significant concern about the risk of depression in a patient undergoing DBS, then the clinician should consider using pallidal rather than STN stimulation, while taking into consideration other goals of surgery. (Level I). QUESTION 7: Is bilateral STN DBS associated with a higher, lower, or similar risk of adverse events compared to GPi DBS in Parkinson's disease? RECOMMENDATION: There is insufficient evidence to recommend bilateral DBS in 1 target over the other in order to minimize the risk of surgical adverse events. The full guideline can be found at: https://www.cns.org/guidelines/deep-brain-stimulation-parkinsons-disease.

Resection of Temporal Neocortex During Multiple Hippocampal Transections for Mesial Temporal Lobe Epilepsy Does not Affect Seizure or Memory Outcome.

BACKGROUND: Multiple hippocampal transection (MHT) is a surgical treatment for mesial temporal lobe epilepsy associated with improved postoperative neuropsychological outcomes compared with lobectomy. OBJECTIVE: To determine whether resection of the amygdala and anterior temporal neocortex during MHT affects postoperative seizure/memory outcome. METHODS: Seventeen patients with normal magnetic resonance imaging and stereo-electroencephalogram-proven drug-resistant dominant mesial temporal lobe epilepsy were treated with MHT. Nine patients underwent MHT alone (MHT-) and 8 patients underwent MHT plus removal of the amygdala and anterior 4.5 cm of temporal neocortex lateral to the fusiform gyrus (MHT+). Verbal and visual-spatial memory were assessed in all patients preoperatively and in 14 patients postoperatively using the Wechsler Memory Scale. Postoperative seizure control was assessed at 12 months for all patients. RESULTS: Overall, 11 of 17 patients (64.7%) were Engel class 1 at 1 year (6/9 MHT-, 5/8 MHT+, P = .38), and 10 of 14 patients (71.4%) had no significant postoperative decline in either verbal or visual memory (6/8 MHT-, 4/6 MHT+, P = .42). Verbal memory declined in 2 of 8 MHT- and 1 of 6 MHT+ patients, and visual memory declined in 1 of 8 MHT- and 2 of 6 MHT+ patients. Two patients had improved visual memory postoperatively, both in the MHT+ group. CONCLUSION: MHT on the dominant side is associated with high rates of seizure freedom and favorable memory preservation outcomes regardless of the extent of neocortical resection. Preservation of the temporal neocortex and amygdala during MHT does not appear to decrease the risk of postoperative memory decline, nor does it alter seizure outcome.

Percutaneous transoral clivoplasty and upper cervical vertebroplasties for multifocal skeletal lymphangiomatosis resulting in complete resolution of pain: case report.

Lymphangiomatosis is a rare congenital disorder that results in multiorgan system lymphatic invasion. Symptoms due to axial skeletal involvement can range from chronic bone pain to severe deformity resulting in radiculopathy, myelopathy, and even paralysis. The authors present a case of lymphangiomatosis of the clivus, C-1, and C-2, resulting in chronic pain. The patient was successfully treated with percutaneous transoral clivoplasty and vertebroplasty, without disease progression or return of symptoms at 2 years.

Tailored disconnection based on presurgical evidence in catastrophic epilepsy: report of 2 cases.

Catastrophic epilepsy in infants, often due to extensive cortical dysplasia, has devastating consequences with respect to brain development. Conventional lobar, multilobar, or hemispheric resection in these infants is challenging, carrying an increased operative risk compared with that in older children. Removing a larger tissue volume versus removing or disconnecting the epileptogenic region does not always guarantee better seizure outcome. The authors describe 2 infants with catastrophic epilepsy who benefited from individually tailored disconnections based on a hypothesized epileptogenic zone following intensive presurgical evaluation. Two infants with catastrophic epilepsy and epileptic spasms underwent leukotomies between 3 and 12 months of age. They were followed up postoperatively for 19-36 months. Both patients had 90%-100% seizure reduction and a significantly improved neurodevelopmental outcome without postoperative complication. Cortical malformation was seen in both patients. Modifications of established surgical disconnection techniques, tailored to each patient's specific epileptogenic zone, optimized seizure and neurodevelopmental outcomes while minimizing the risks associated with more extensive resections.

Electrical Stimulation of the Trigeminal Ganglion and Intrathecal Drug Delivery Systems for the Management of Corneal Neuropathic Pain.

PURPOSE: This case study reports on 2 novel neuromodulatory approaches in the management of a particularly recalcitrant case of corneal neuropathic pain. METHODS: Report of a case RESULTS: : A 32-year-old woman presented with intractable bilateral dry eye-like symptoms and corneal neuropathic pain after undergoing laser in situ keratomileusis surgery. Extensive ocular and systemic therapies were unsuccessful. Implantation of an electrode for the electrical stimulation of the trigeminal ganglion resulted in complete resolution of symptoms, but pain recurred after lead migration. Implantation of an intrathecal infusion system for fentanyl and bupivacaine delivery at the C1-C2 level resulted in control of her symptoms with excellent pain relief for more than 1 year. CONCLUSIONS: Electrical stimulation of the trigeminal ganglion and a high cervical intrathecal pain pump can be used in the management of corneal neuropathic pain unresponsive to ocular and systemic approaches.

Intensity Modulation: A Novel Approach to Percept Control in Spinal Cord Stimulation.

OBJECTIVE: Spinal cord stimulation (SCS) can be effective for neuropathic pain, but clinical benefit is sometimes inadequate or is offset by stimulation-induced side-effects, and response can be inconsistent among patients. Intensity-modulated stimulation (IMS) is an alternative to tonic stimulation (TS) that involves continuous variation of stimulation intensity in a sinusoidal pattern between two different values, sequentially activating distinct axonal populations to produce an effect that resembles natural physiological signals. The purpose of this study is to evaluate the effect of IMS on the clinical effect of SCS. METHODS: Seven patients undergoing a percutaneous SCS trial for postlaminectomy syndrome were enrolled. Thresholds for perception, pain relief, and discomfort were measured and used to create patient-specific models of axonal activation and charge delivery for both TS and IMS. All participants underwent three two-min periods of blinded stimulation using TS, IMS, and placebo, and were asked to describe the effect on quality of the sensory percept and pain relief. RESULTS: All participants perceived IMS differently from placebo, and five noted significant differences from TS that resulted in a more comfortable sensation. TS was described as electric and tingling, whereas IMS was described as producing a focal area of deep pressure with a sense of motion away from that focus. The anatomic location of coverage was similar between the two forms of stimulation, although one participant reported better lower back coverage with IMS. Computer modeling revealed that, compared with TS, IMS involved 36.4% less charge delivery and produced 78.7% less suprathreshold axonal activation. CONCLUSIONS: IMS for SCS is feasible, produces a more comfortable percept than conventional TS, and appears to provide a similar degree of pain relief with significantly lower energy requirements. Further studies are necessary to determine whether this represents an effective alternative to tonic SCS for treatment of neuropathic pain.

Degree of distal trigeminal nerve atrophy predicts outcome after microvascular decompression for Type 1a trigeminal neuralgia.

OBJECT: Trigeminal neuralgia is often associated with nerve atrophy, in addition to vascular compression. The authors evaluated whether cross-sectional areas of different portions of the trigeminal nerve on preoperative imaging could be used to predict outcome after microvascular decompression (MVD). METHODS: A total of 26 consecutive patients with unilateral Type 1a trigeminal neuralgia underwent high-resolution fast-field echo MRI of the cerebellopontine angle followed by MVD. Preoperative images were reconstructed and reviewed by 2 examiners blinded to the side of symptoms and clinical outcome. For each nerve, a computerized automatic segmentation algorithm was used to calculate the coronal cross-sectional area at the proximal nerve near the root entry zone and the distal nerve at the exit from the porus trigeminus. Findings were correlated with outcome at 12 months. RESULTS: After MVD, 17 patients were pain free and not taking medications compared with 9 with residual pain. Across all cases, the coronal cross-sectional area of the symptomatic trigeminal nerve was significantly smaller than the asymptomatic side in the proximal part of the nerve, which was correlated with degree of compression at surgery. Atrophy of the distal trigeminal nerve was more pronounced in patients who had residual pain than in those with excellent outcome. Among the 7 patients who had greater than 20% loss of nerve volume in the distal nerve, only 2 were pain free and not taking medications at long-term follow-up. CONCLUSIONS: Trigeminal neuralgia is associated with atrophy of the root entry zone of the affected nerve compared with the asymptomatic side, but volume loss in different segments of the nerve has very different prognostic implications. Proximal atrophy is associated with vascular compression and correlates with improved outcome following MVD. However, distal atrophy is associated with a significantly worse outcome after MVD.

Multitract orthogonal microelectrode localization of the subthalamic nucleus: description of a novel technique.

BACKGROUND: Microelectrode recording helps surgeons accurately localize boundaries of the subthalamic nucleus (STN) and surrounding structures in deep brain stimulation. OBJECTIVE: To describe a novel adaptation of the Ben gun device to optimize efficient mapping. METHODS: Patients who underwent STN deep brain stimulation over a 3-year period were reviewed. For the final year, the Ben gun was rotated 45° and the target was offset 1.4 mm lateral and anterior in the plane orthogonal to the intended trajectory to allow for simultaneous parallel tracks at target, 2.8 mm anterior (localizing the front of STN), and 2.8 mm lateral (identifying the internal capsule). Before this step, the initial pass consisted of 1 to 2 tracks with the frame center targeted to STN. The primary outcome measure was the number of passes required for accurate localization of the nucleus and boundaries. RESULTS: Eighty-three electrodes were implanted in 45 patients (mean age, 62; range, 37-78 years), of which 29 electrodes were placed by the use of the new technique. One electrode (4%) required more than 1 pass using the new technique compared with 36 (67%) using the older technique (P < .01). The distance from original target to final electrode position increased from 0.67 ± 0.13 mm to 1.06 ± 0.15 mm (P < .05) with a greater tendency to move the final electrode position posteriorly. There was no statistically significant difference in benefit from neurostimulation. CONCLUSION: This technique facilitates reliable localization of the STN with fewer passes, possibly decreasing the risks associated with more passes and longer duration of surgery.

Depths and grids in brain tumors: implantation strategies, techniques, and complications.

Patients with intracranial mass lesions are at increased risk of intractable epilepsy even after tumor resection due to the potential epileptogenicity of lesional and perilesional tissue. Risk factors for tumoral epilepsy include tumor location, histology, and extent of tumor resection. In epilepsy that occurs after tumor resection, the epileptogenic zone often does not correspond precisely with the area of abnormality on imaging, and seizures often arise from a relatively restricted area despite widespread changes on imaging. Invasive monitoring via subdural grids and/or depth electrodes can therefore be helpful to delineate areas of eloquence and localize the epileptogenic zone for subsequent resection. Subdural grids offer excellent contiguous coverage of superficial cortex and allow resection using the same craniotomy, facilitating understanding of anatomic relationships. Depth electrodes offer superior coverage of deep structures, are easier to use in cases where a previous craniotomy is present, are not associated with anatomic distortion due to brain shift, and may be associated with a lower complication rate. We review the biology of focal postoperative epilepsy and invasive diagnostic strategies for the surgical evaluation of medically refractory epilepsy in patients who have undergone resection of intracranial mass lesions.

The role of avastin in the management of recurrent glioblastoma.

Glioblastoma multiforme is a malignant primary brain tumor for which no cure has been developed. However, with aggressive surgical resection, radiation, and the advent of temozolomide, the overall survival of patients with glioblastomas has improved significantly. Despite this multimodal treatment, glioblastoma invariably recurs. Although treatment options for glioblastoma recurrence are limited, one promising therapy is bevacizumab (Avastin). The role of Avastin in the management of recurrent glioblastomas is reviewed.

Relapsed acute myelogenous leukemia of brachial plexus after marrow transplant.

We present a detailed description of brachial plexus infiltration by acute myelogenous leukemia (AML) in the setting of a remission bone marrow biopsy, without evidence of leukemia by flow cytometric analysis. This case illustrates the possibility of dormant leukemic cells in the peripheral nervous system (PNS) in a patient in apparent clinical remission. In patients with an unexplained brachial plexopathy and a history of AML, leukemic infiltrate of the PNS must be considered.

Long-term outcome after resection of brainstem hemangioblastomas in von Hippel-Lindau disease.

OBJECT: Brainstem hemangioblastomas are frequently encountered in patients with von Hippel-Lindau (VHL) disease. These tumors can cause significant morbidity, and their optimal management has not been defined. To better define the outcome and management of these tumors, the authors analyzed the long-term results in patients who underwent resection of brainstem hemangioblastomas. METHODS: Consecutive patients with VHL disease who underwent resection of brainstem hemangioblastomas with a follow-up of 12 months or more were included in this study. Serial functional assessments, radiographic examinations, and operative records were analyzed. RESULTS: Forty-four patients (17 male and 27 female) underwent 51 operations for resection of 71 brainstem hemangioblastomas. The most common presenting symptoms were headache, swallowing difficulties, singultus, gait difficulties, and sensory abnormalities. The mean follow-up was 5.9 ± 5.0 years (range 1.0-20.8 years). Immediately after 34 operations (66.7%), the patients remained at their preoperative functional status; they improved after 8 operations (15.7%) and worsened after 9 operations (17.6%) as measured by the McCormick scale. Eight (88.9%) of the 9 patients who were worse immediately after resection returned to their preoperative status within 6 months. Two patients experienced functional decline during long-term follow-up (beginning at 2.5 and 5 years postoperatively) caused by extensive VHL disease-associated CNS disease. CONCLUSIONS: Generally, resection of symptomatic brainstem hemangioblastomas is a safe and effective management strategy in patients with VHL disease. Most patients maintain their preoperative functional status, although long-term decline in functional status may occur due to VHL disease-associated progression.

Pleomorphic xanthoastrocytoma presenting with life-threatening hemorrhage in a child.

Pleomorphic xanthoastrocytomas are glial-based tumors that arise most frequently in young patients and usually follow a more benign and indolent clinical course than their other glial-based tumor counterparts. These tumors most frequently present with seizures, and only 3 previous case reports exist of hemorrhagic tumor as the clinical presentation. The authors present the first case of life-threatening intracerebral hemorrhage from pleomorphic xanthoastrocytoma in a child.

Multiple metachronous brain metastases from primary ureteral carcinoma.

Transitional cell carcinoma (TCC) of the ureter is an uncommon urologic malignancy, with approximately 150 cases diagnosed annually. Metastatic brain disease from ureteral TCC is exceedingly rare. To our knowledge, our case report represents only the second report of brain metastasis from ureteral TCC and the only reported patient to undergo resection of their TCC brain metastasis.