Stereotactic and Functional Neurosurgery Convection-Enhanced Delivery of Autologous Cerebrospinal Fluid Enhances Basal Ganglia Visualization during MRI-Guided Deep Brain Stimulation Surgery.

INTRODUCTION: The aim of this study was to determine the safety and feasibility of convection-enhanced delivery of autologous cerebrospinal fluid (CSF) for enhancing intraoperative magnetic resonance imaging (MRI) of the basal ganglia during stereotactic neurosurgery. METHODS: This pilot study was conducted in 4 patients with Parkinson's disease (PD) who underwent MRI-guided deep brain stimulation of the globus pallidus internus (GPi). CSF was obtained via lumbar puncture after general anesthesia and prior to incision. A frameless stereotaxy system was installed, and an infusion catheter was inserted to the GPi using intraoperative MRI. Infusion of autologous CSF was performed at a convective rate of 5 µL/min with a maximum volume of infusion (Vi) of 500 mL. T2-weighted MRI scans were obtained every 15 min up to a maximum of 105 min in order to calculate the volume of distribution (Vd). Safety was assessed with adverse event monitoring, and clinical outcomes were measured with changes in unmedicated UPDRS part III and PDQ-39 scores from baseline to 6 months postoperatively. RESULTS: All four infusions were safe and without adverse events. The mean unmedicated UPDRS part III and PDQ-39 scores improved by 24% and 26%, respectively. The Vd:Vi ratio ranged from 2.2 to 2.8 and peaked 45 min from the onset of infusion, which is when the borders of the GPi could generally be visualized based on T2-weighted MRI. Two patients underwent refinement of the stereotactic targeting based on infusion-enhanced images. CONCLUSIONS: The convective administration of autologous CSF to deep brain structures appears safe and feasible for enhancing intraoperative MRI during stereotactic procedures. Infusion-enhanced imaging with target-specific infusates could be developed to visualize neurochemical circuits or cellular regions that currently are not seen with anatomic/structural MRI.

Patient-Reported Outcomes and Predictive Factors following Focused Ultrasound Thalamotomy for Essential Tremor.

INTRODUCTION: The objectives of this study were to determine long-term patient-reported outcomes with magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy for medication-refractory essential tremor (ET) and to identify risk factors for a poor clinical outcome. METHODS: We administered a telephone or mail-in survey to patients who consecutively underwent unilateral MRgFUS thalamotomy for ET at our institution over an 8-year period. Patients were asked to self-report measures of hand tremor improvement, degree of overall postprocedure improvement, activities of daily life, side effects, and willingness to undergo the procedure again. Specific patient characteristics, ultrasound treatment parameters, and postoperative radiological findings from magnetic resonance imaging performed 1 day after the procedure were analyzed, and multivariable linear regression was used to determine if these factors could serve as predictors of clinical outcome. RESULTS: A total of 85 patients were included in this study with a mean follow-up time of 3.0 years (range 2 months to 1 8.4 years). The mean patient-reported improvement in hand tremor at last follow-up was 66%, and 73% of patients reported meaningful change in their overall condition after the procedure. The percentages of patients reporting normal or only minimal limitations with feeding, drinking, and writing ability at last follow-up were 60%, 71%, and 48%, respectively. In the position of their former selves, 89% of patients would again choose to undergo the procedure. Larger lesions were correlated with a higher risk of adverse events. DISCUSSION/CONCLUSION: While subjective hand tremor improvement declines with time, willingness to undergo the procedure again following MRgFUS thalamotomy for ET remains very high even several years after the procedure.

Reduced occurrence of primary rod fracture after adult spinal deformity surgery with accessory supplemental rods: retrospective analysis of 114 patients with minimum 2-year follow-up.

OBJECTIVE: Rod fracture (RF) after adult spinal deformity (ASD) surgery is reported in approximately 6.8%-33% of patients and is associated with loss of deformity correction and higher reoperation rates. The authors' objective was to determine the effect of accessory supplemental rod (ASR) placement on postoperative occurrence of primary RF after ASD surgery. METHODS: This retrospective analysis examined patients who underwent ASD surgery between 2014 and 2017 by the senior authors. Inclusion criteria were age > 18 years, ≥ 5 instrumented levels including sacropelvic fixation, and diagnosis of ASD, which was defined as the presence of pelvic tilt ≥ 25°, sagittal vertical axis ≥ 5 cm, thoracic kyphosis ≥ 60°, coronal Cobb angle ≥ 20°, or pelvic incidence to lumbar lordosis mismatch ≥ 10°. The primary focus was patients with a minimum 2-year follow-up. RESULTS: Of 148 patients who otherwise met the inclusion criteria, 114 (77.0%) achieved minimum 2-year follow-up and were included (68.4% were women, mean age 67.9 years, average body mass index 30.4 kg/m2). Sixty-two (54.4%) patients were treated with traditional dual-rod construct (DRC), and 52 (45.6%) were treated with ASR. Overall, the mean number of levels fused was 11.7, 79.8% of patients underwent Smith-Petersen osteotomy (SPO), 19.3% underwent pedicle subtraction osteotomy (PSO), and 66.7% underwent transforaminal lumbar interbody fusion (TLIF). Significantly more patients in the DRC cohort underwent SPO (88.7% of the DRC cohort vs 69.2% of the ASR cohort, p = 0.010) and TLIF (77.4% of the DRC cohort vs 53.8% of the ASR cohort, p = 0.0001). Patients treated with ASR had greater baseline sagittal malalignment (12.0 vs 8.6 cm, p = 0.014) than patients treated with DRC, and more patients in the ASR cohort underwent PSO (40.3% vs 1.6%, p < 0.0001). Among the 114 patients who completed follow-up, postoperative occurrence of RF was reported in 16 (14.0%) patients, with mean ± SD time to RF of 27.5 ± 11.8 months. There was significantly greater occurrence of RF among patients who underwent DRC compared with those who underwent ASR (21.0% vs 5.8%, p = 0.012) at comparable mean follow-up (38.4 vs 34.9 months, p = 0.072). Multivariate analysis demonstrated that ASR had a significant protective effect against RF (OR 0.231, 95% CI 0.051-0.770, p = 0.029). CONCLUSIONS: This study demonstrated a statistically significant decrease in the occurrence of RF among ASD patients treated with ASR, despite greater baseline deformity and higher rate of PSO. These findings suggest that ASR placement may provide benefit to patients who undergo ASD surgery.

Sacral insufficiency fractures after lumbosacral arthrodesis: salvage lumbopelvic fixation and a proposed management algorithm.

OBJECTIVE: Sacral insufficiency fracture after lumbosacral (LS) arthrodesis is an uncommon complication. The objective of this study was to report the authors' operative experience managing this complication, review pertinent literature, and propose a treatment algorithm. METHODS: The authors analyzed consecutive adult patients treated at their institution from 2009 to 2018. Patients who underwent surgery for sacral insufficiency fractures after posterior instrumented LS arthrodesis were included. PubMed was queried to identify relevant articles detailing management of this complication. RESULTS: Nine patients with a minimum 6-month follow-up were included (mean age 73 ± 6 years, BMI 30 ± 6 kg/m2, 56% women, mean follow-up 35 months, range 8-96 months). Six patients had osteopenia/osteoporosis (mean dual energy x-ray absorptiometry hip T-score -1.6 ± 0.5) and 3 received treatment. Index LS arthrodesis was performed for spinal stenosis (n = 6), proximal junctional kyphosis (n = 2), degenerative scoliosis (n = 1), and high-grade spondylolisthesis (n = 1). Presenting symptoms of back/leg pain (n = 9) or lower extremity weakness (n = 3) most commonly occurred within 4 weeks of index LS arthrodesis, which prompted CT for fracture diagnosis at a mean of 6 weeks postoperatively. All sacral fractures were adjacent or involved S1 screws and traversed the spinal canal (Denis zone III). H-, U-, or T-type sacral fracture morphology was identified in 7 patients. Most fractures (n = 8) were Roy-Camille type II (anterior displacement with kyphosis). All patients underwent lumbopelvic fixation via a posterior-only approach; mean operative duration and blood loss were 3.3 hours and 850 ml, respectively. Bilateral dual iliac screws were utilized in 8 patients. Back/leg pain and weakness improved postoperatively. Mean sacral fracture anterolisthesis and kyphotic angulation improved (from 8 mm/11° to 4 mm/5°, respectively) and all fractures were healed on radiographic follow-up (mean duration 29 months, range 8-90 months). Two patients underwent revision for rod fractures at 1 and 2 years postoperatively. A literature review found 17 studies describing 87 cases; potential risk factors were osteoporosis, longer fusions, high pelvic incidence (PI), and postoperative PI-to-lumbar lordosis (LL) mismatch. CONCLUSIONS: A high index of suspicion is needed to diagnose sacral insufficiency fracture after LS arthrodesis. A trial of conservative management is reasonable for select patients; potential surgical indications include refractory pain, neurological deficit, fracture nonunion with anterolisthesis or kyphotic angulation, L5-S1 pseudarthrosis, and spinopelvic malalignment. Lumbopelvic fixation with iliac screws may be effective salvage treatment to allow fracture healing and symptom improvement. High-risk patients may benefit from prophylactic lumbopelvic fixation at the time of index LS arthrodesis.

Revision thoracolumbar surgery for flat back deformity: staged ALIF and posterior column osteotomies to avoid three-column osteotomy.

Three-column osteotomies (3COs) can achieve significant alignment correction when revising fixed sagittal plane deformities; however, the technique is associated with high complication rates. The authors demonstrate staged anterior-posterior surgery with L5-S1 ALIF (below a prior L3-5 fusion) and multilevel Smith-Petersen osteotomies to circumvent the morbidity associated with 3CO. The patient was a 67-year-old male with three prior lumbar surgeries who presented with back and leg pain. Imaging demonstrated lumbar flat back deformity and sagittal imbalance. The narrated video details key radiological measurements, operative planning and rationale, surgical steps, and outcomes. The patient provided written, informed consent for publication of this illustrative case. The video can be found here: https://youtu.be/wv4W9D9fUPc.

Persistent post-discharge opioid prescribing after traumatic brain injury requiring intensive care unit admission: A cross-sectional study with longitudinal outcome.

Traumatic brain injury (TBI) is associated with increased risk for psychological and substance use disorders. The study aim is to determine incidence and risk factors for persistent opioid prescription after hospitalization for TBI. Electronic medical records of patients age ≥ 18 admitted to a neuroscience intensive care unit between January 2013 and February 2017 for an intracranial injury were retrospectively reviewed. Primary outcome was opioid use through 12 months post-hospital discharge. A total of 298 patients with complete data were included in the analysis. The prevalence of opioid use among preadmission opioid users was 48 (87%), 36 (69%) and 22 (56%) at 1, 6 and 12-months post-discharge, respectively. In the opioid naïve group, 69 (41%), 24 (23%) and 17 (19%) were prescribed opioids at 1, 6 and 12 months, respectively. Preadmission opioid use (OR 324.8, 95% CI 23.1-16907.5, p = 0.0004) and higher opioid requirements during hospitalization (OR 4.5, 95% CI 1.8-16.3, p = 0.006) were independently associated with an increased risk of being prescribed opioids 12 months post-discharge. These factors may be used to identify and target at-risk patients for intervention.

Gamma Knife Radiosurgery for Trigeminal Neuralgia Reduces Neurovascular Compression: A Case Report after 11 Years.

BACKGROUND: Trigeminal neuralgia (TN) is a rare and debilitating craniofacial pain syndrome often caused by vascular compression of the trigeminal nerve. Gamma Knife radiosurgery (GKRS) has been shown to offer a less invasive yet effective treatment method for pain reduction in TN. In this case report, we observed radiological evidence of resolved neurovascular compression after 11 years for a patient with recur-rent TN and prior GKRS. CASE REPORT: A 72-year-old -female presented with TN and radiological evidence of neurovas-cular compression on the affected side. She had complete resolution of her pain for 7 years after treatment with GKRS. The patient experienced recurrence and underwent repeat GKRS, this time resulting in another 3 years of pain relief. After the second recurrence, repeat intracranial imaging demonstrated resolution of neurovascular compression. DISCUSSION: GKRS is an important treatment option for TN, although the mechanisms behind pain relief from this procedure still remain unclear. While prior histological and radiological studies point to ablative mechanisms for pain relief, this case report suggests that GKRS may result in a decompressive effect in TN due to changes in neurovascular architecture. Despite this finding, TN is known to occur and recur in the absence of neurovascular compression; thus, further work is necessary to understand the etiology of TN and its treatments. CONCLUSION: In this case, we demonstrate that vessel-nerve relationships may change over time in TN patients treated with GKRS, which raises the possibility that GKRS could ease a neurovascular compression.

Concurrent Venous Stenting of the Transverse and Occipito-Marginal Sinuses: An Analogy with Parallel Hemodynamic Circuits.

Nonthrombotic intracranial venous occlusive disease (NIVOD) has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH) and various non-IIH headache syndromes. Endovascular stenting of stenotic, dominant transverse sinuses (TSs) may reduce trans-stenosis pressure gradients, decrease intracranial pressure, and alleviate symptoms in a subset of NIVOD patients. We present a case in which concurrent stenting of the occipito-marginal sinus obliterated the residual trans-stenosis pressure gradient across an initially stented dominant TS. We hypothesize that this observation may be explained using an electric-hydraulic analogy, and that this patient's dominant TS and occipito-marginal sinus may be modeled as a parallel hemodynamic circuit. Neurointerventionalists should be aware of parallel hemodynamic drainage patterns and consider manometry and possibly additional stenting of stenotic, parallel venous outflow pathways if TS stenting alone fails to obliterate the trans-stenosis pressure gradient.

Low rates of complications after spinopelvic fixation with iliac screws in 260 adult patients with a minimum 2-year follow-up.

OBJECTIVERecent literature describing complications associated with spinopelvic fixation with iliac screws in adult patients has been limited but has suggested high complication rates. The authors' objective was to report their experience with iliac screw fixation in a large series of patients with a 2-year minimum follow-up.METHODSOf 327 adult patients undergoing spinopelvic fixation with iliac screws at the authors' institution between 2010 and 2015, 260 met the study inclusion criteria (age ≥ 18 years, first-time iliac screw placement, and 2-year minimum follow-up). Patients with active spinal infection were excluded. All iliac screws were placed via a posterior midline approach using fluoroscopic guidance. Iliac screw heads were deeply recessed into the posterior superior iliac spine. Clinical and radiographic data were obtained and analyzed.RESULTSTwenty patients (7.7%) had iliac screw-related complication, which included fracture (12, 4.6%) and/or screw loosening (9, 3.5%). No patients had iliac screw head prominence that required revision surgery or resulted in pain, wound dehiscence, or poor cosmesis. Eleven patients (4.2%) had rod or connector fracture below S1. Overall, 23 patients (8.8%) had L5-S1 pseudarthrosis. Four patients (1.5%) had fracture of the S1 screw. Seven patients (2.7%) had wound dehiscence (unrelated to the iliac screw head) or infection. The rate of reoperation (excluding proximal junctional kyphosis) was 17.7%. On univariate analysis, an iliac screw-related complication rate was significantly associated with revision fusion (70.0% vs 41.2%, p = 0.013), a greater number of instrumented vertebrae (mean 12.6 vs 10.3, p = 0.014), and greater postoperative pelvic tilt (mean 27.7° vs 23.2°, p = 0.04). Lumbosacral junction-related complications were associated with a greater mean number of instrumented vertebrae (12.6 vs 10.3, p = 0.014). Reoperation was associated with a younger mean age at surgery (61.8 vs 65.8 years, p = 0.014), a greater mean number of instrumented vertebrae (12.2 vs 10.2, p = 0.001), and longer clinical and radiological mean follow-up duration (55.8 vs 44.5 months, p < 0.001; 55.8 vs 44.6 months, p < 0.001, respectively). On multivariate analysis, reoperation was associated with longer clinical follow-up (p < 0.001).CONCLUSIONSPrevious studies on iliac screw fixation have reported very high rates of complications and reoperation (as high as 53.6%). In this large, single-center series of adult patients, iliac screws were an effective method of spinopelvic fixation that had high rates of lumbosacral fusion and far lower complication rates than previously reported. Collectively, these findings argue that iliac screw fixation should remain a favored technique for spinopelvic fixation.

Microsurgery Versus Stereotactic Radiosurgery for Brain Arteriovenous Malformations: A Matched Cohort Study.

BACKGROUND: Microsurgery (MS) and stereotactic radiosurgery (SRS) remain the preferred interventions for the curative treatment of brain arteriovenous malformations (AVM), but their relative efficacy remains incompletely defined. OBJECTIVE: To compare the outcomes of MS to SRS for AVMs through a retrospective, matched cohort study. METHODS: We evaluated institutional databases of AVM patients who underwent MS and SRS. MS-treated patients were matched, in a 1:1 ratio based on patient and AVM characteristics, to SRS-treated patients. Statistical analyses were performed to compare outcomes data between the 2 cohorts. The primary outcome was defined as AVM obliteration without a new permanent neurological deficit. RESULTS: The matched MS and SRS cohorts were each comprised of 59 patients. Both radiological (85 vs 11 mo; P < .001) and clinical (92 vs 12 mo; P < .001) follow-up were significantly longer for the SRS cohort. The primary outcome was achieved in 69% of each cohort. The MS cohort had a significantly higher obliteration rate (98% vs 72%; P = .001), but also had a significantly higher rate of new permanent deficit (31% vs 10%; P = .011). The posttreatment hemorrhage rate was significantly higher for the SRS cohort (10% for SRS vs 0% for MS; P = .027). In subgroup analyses of ruptured and unruptured AVMs, no significant differences between the primary outcomes were observed. CONCLUSION: For patients with comparable AVMs, MS and SRS afford similar rates of deficit-free obliteration. Nidal obliteration is more frequently achieved with MS, but this intervention also incurs a greater risk of new permanent neurological deficit.

Deep brain stimulation for the treatment of drug addiction.

Drug addiction represents a significant public health concern that has high rates of relapse despite optimal medical therapy and rehabilitation support. New therapies are needed, and deep brain stimulation (DBS) may be an effective treatment. The past 15 years have seen numerous animal DBS studies for addiction to various drugs of abuse, with most reporting decreases in drug-seeking behavior with stimulation. The most common target for stimulation has been the nucleus accumbens, a key structure in the mesolimbic reward pathway. In addiction, the mesolimbic reward pathway undergoes a series of neuroplastic changes. Chief among them is a relative hypofunctioning of the prefrontal cortex, which is thought to lead to the diminished impulse control that is characteristic of drug addiction. The prefrontal cortex, as well as other targets involved in drug addiction such as the lateral habenula, hypothalamus, insula, and subthalamic nucleus have also been stimulated in animals, with encouraging results. Although animal studies have largely shown promising results, current DBS studies for drug addiction primarily use stimulation during active drug use. More data are needed on the effect of DBS during withdrawal in preventing future relapse. The published human experience for DBS for drug addiction is currently limited to several promising case series or case reports that are not controlled. Further animal and human work is needed to determine what role DBS can play in the treatment of drug addiction.

Thalamic Deep Brain Stimulation Salvages Failed Focused Ultrasound Thalamotomy for Essential Tremor: A Case Report.

BACKGROUND: A recent randomized controlled trial investigating unilateral MRI-guided focused ultrasound (FUS) for essential tremor demonstrated efficacy. The long-term durability of this thalamotomy, however, is unknown. Furthermore, the feasibility of stimulating a previously lesioned target such as the thalamic nucleus ventralis intermedius (Vim) is poorly understood. We report a case of tremor recurrence, following an initially successful FUS thalamotomy, in which Vim-DBS was subsequently utilized to regain tremor control. METHODS: An 81-year-old right-handed female with medically refractory essential tremor (a Clinical Rating Scale for Tremor [CRST] value of 73) underwent left-sided FUS thalamotomy with initial abolition of right-upper extremity tremor. By the 6-month follow-up, there was complete recurrence of tremor (a CRST value of 76). The patient subsequently underwent left-sided Vim-DBS. RESULTS: Vim-DBS provided clinical improvement with a CRST value of 42 at the 3-month follow-up; the patient continues to do clinically well at the 6-month follow-up. This result mirrors previous reported cases of stimulation following radiofrequency and gamma-knife lesioning. Our literature review highlights several reasons for the waning of clinical benefit seen with lesional procedures. CONCLUSION: This case demonstrates that thalamic DBS can salvage a failed FUS thalamotomy and also the feasibility of stimulating a previously lesioned target.

Trends in intracranial monitoring for pediatric medically intractable epilepsy: 2000-2012.

OBJECTIVE: To retrospectively examine nationwide trends in intracranial monitoring (ICM) for pediatric medically intractable epilepsy (MIE) from 2000 to 2012. METHODS: The Healthcare Cost and Utilization Project Kids' Inpatient Database was analyzed to identify admissions with ICD-9-CM codes corresponding to MIE and ICM from 2000 to 2012, inclusive. Associations between independent variables and outcomes were tested using χ2 test or Fisher exact test. A multivariate logistic regression analysis of variables associated with ICM was completed using stepwise selection. The Cochran-Armitage test was used to test for trend of a variable over the study period. RESULTS: The number of ICM procedures increased over the study period; however, secondary to large increases in the number of MIE admissions, the rate of ICM declined from 5.39% in 2000 to 2.56% in 2012 (p < 0.001). Despite this decline, ICM increasingly resulted in resective epilepsy procedures. In 2000, only 45.18% of ICM cases led to resective epilepsy surgery, which increased to 75.83% by 2012 (p < 0.001). ICM complication rates were comparable to, if not lower than, standard resective surgery. Disparities in access to ICM exist, with African American individuals and those with Medicaid significantly less likely to undergo ICM. CONCLUSION: In this nationwide characterization of pediatric ICM trends, we identified a slight, significant downward trend in the rate of utilization of ICM for MIE. This was secondary to substantial increases in the number of hospital admissions for MIE. Reasons for this large increase and why it has not led to increased rates of ICM warrant further investigation.

Transcranial magnetic resonance imaging-guided focused ultrasound thalamotomy for tremor: technical note.

Although the use of focused ultrasound (FUS) in neurosurgery dates to the 1950s, its clinical utility was limited by the need for a craniotomy to create an acoustic window. Recent technological advances have enabled efficient transcranial delivery of US. Moreover, US is now coupled with MRI to ensure precise energy delivery and monitoring. Thus, MRI-guided transcranial FUS lesioning is now being investigated for myriad neurological and psychiatric disorders. Among the first transcranial FUS treatments is thalamotomy for the treatment of various tremors. The authors provide a technical overview of FUS thalamotomy for tremor as well as important lessons learned during their experience with this emerging technology.

Magnetic resonance-guided, high-intensity focused ultrasound sonolysis: potential applications for stroke.

Stroke is one of the leading causes of death worldwide and a significant source of long-term morbidity. Unfortunately, a substantial number of stroke patients either are ineligible or do not significantly benefit from contemporary medical and interventional therapies. To address this void, investigators recently made technological advances to render transcranial MR-guided, high-intensity focused ultrasound (MRg-HIFU) sonolysis a potential therapeutic option for both acute ischemic stroke (AIS)-as an alternative for patients with emergent large-vessel occlusion (ELVO) who are ineligible for endovascular mechanical thrombectomy (EMT) or as salvage therapy for patients in whom EMT fails-and intracerebral hemorrhage (ICH)-as a neoadjuvant means of clot lysis prior to surgical evacuation. Herein, the authors review the technological principles behind MRg-HIFU sonolysis, its results in in vitro and in vivo stroke models, and its potential clinical applications. As a noninvasive transcranial technique that affords rapid clot lysis, MRg-HIFU thrombolysis may develop into a therapeutic option for patients with AIS or ICH. However, additional studies of transcranial MRg-HIFU are necessary to ascertain the merit of this treatment approach for thrombolysis in both AIS and ICH, as well as its technical limitations and risks.

Tremor Secondary to a Thalamic Glioma: A Case Report.

BACKGROUND AND IMPORTANCE: Tremor is the most prevalent movement disorder. While the exact pathophysiology remains to be elucidated, the importance of the thalamus in tremor circuitry is well recognized. Thalamic lesions from demyelination, trauma, ischemia, or neoplasm rarely cause isolated tremor. We report the case of a patient presenting with a tremor secondary to a thalamic grade II astrocytoma that improved with treatment. CLINICAL PRESENTATION: A 50-yr-old male presented with a 1-yr history of right-hand tremor. The presence of long tract signs prompted imaging that revealed a lesion within the left thalamus. Stereotactic biopsy revealed a World Health Organization grade II astrocytoma. Prior to biopsy, the patient's tremor was graded using the Clinical Rating Scale for Tremor. Immediately postoperatively the patient remained at his neurological baseline without improvement in his tremor. Subsequent fractionated radiotherapy with concomitant temozolomide followed by adjuvant temozolomide led to radiographic response as well as clinical improvement. The patient reported less tremor, which was confirmed objectively with improved Clinical Rating Scale for Tremor scores at 6 and 12 mo postoperatively. CONCLUSION: This case of a thalamic glioma presenting with isolated contralateral tremor highlights the role of the thalamus in the development of tremor. Moreover, this particular case contrasts with other published reports on the lack of additional symptoms and tremor response to chemoradiation.

Venous sinus stenting for reduction of intracranial pressure in IIH: a prospective pilot study.

OBJECTIVE Idiopathic intracranial hypertension (IIH) may cause blindness due to elevated intracranial pressure (ICP). Venous sinus stenosis has been identified in select patients, leading to stenting as a potential treatment, but its effects on global ICP have not been completely defined. The purpose of this pilot study was to assess the effects of venous sinus stenting on ICP in a small group of patients with IIH. METHODS Ten patients for whom medical therapy had failed were prospectively followed. Ophthalmological examinations were assessed, and patients with venous sinus stenosis on MR angiography proceeded to catheter angiography, venography with assessment of pressure gradient, and ICP monitoring. Patients with elevated ICP measurements and an elevated pressure gradient across the stenosis were treated with stent placement. RESULTS All patients had elevated venous pressure (mean 39.5 ± 14.9 mm Hg), an elevated gradient across the venous sinus stenosis (30.0 ± 13.2 mm Hg), and elevated ICP (42.2 ± 15.9 mm Hg). Following stent placement, all patients had resolution of the stenosis and gradient (1 ± 1 mm Hg). The ICP values showed an immediate decrease (to a mean of 17.0 ± 8.3 mm Hg), and further decreased overnight (to a mean of 8 ± 4.2 mm Hg). All patients had subjective and objective improvement, and all but one improved during follow-up (median 23.4 months; range 15.7-31.6 months). Two patients developed stent-adjacent stenosis; retreatment abolished the stenosis and gradient in both cases. Patients presenting with papilledema had resolution on follow-up funduscopic imaging and optical coherence tomography (OCT) and improvement on visual field testing. Patients presenting with optic atrophy had optic nerve thinning on follow-up OCT, but improved visual fields. CONCLUSIONS For selected patients with IIH and venous sinus stenosis with an elevated pressure gradient and elevated ICP, venous sinus stenting results in resolution of the venous pressure gradient, reduction in ICP, and functional, neurological, and ophthalmological improvement. As patients are at risk for stent-adjacent stenosis, further follow-up is necessary to determine long-term outcomes and gain an understanding of venous sinus stenosis as a primary or secondary pathological process behind elevated ICP.

Infundibular dilations of the posterior communicating arteries: pathogenesis, anatomical variants, aneurysm formation, and subarachnoid hemorrhage.

BACKGROUND: Cerebrovascular infundibular dilations (IDs) are triangular-shaped widenings less than 3 mm in diameter, which are most commonly found at the posterior communicating artery (PCoA). The aims of this systematic review are to elucidate the natural histories of IDs, determine their risk of progression to significant pathology, and discuss potential management options. METHODS: A comprehensive literature search of PubMed was used to find all case reports and series relating to cerebral IDs. IDs were classified into three types: type I IDs do not exhibit morphological change over a long follow-up period, type II IDs evolve into saccular aneurysms, while type III IDs are those that result in subarachnoid hemorrhage without prior aneurysmal progression. Data were extracted from studies that demonstrated type II or III IDs. RESULTS: We reviewed 16 cases of type II and seven cases of type III IDs. For type II IDs, 81.3% of patients were female with a median age at diagnosis of 38. All type II IDs were located at the PCoA without a clear predilection for sidedness. Median time to aneurysm progression was 7.5 years. For type III IDs there was no clear gender preponderance and the median age at diagnosis was 51. The PCoA was involved in 85.7% of cases, with 57.1% of IDs occurring on the left. Most patients were treated with clipping. Risk factors for aneurysm formation appear to be female gender, young age, left-sided localization, coexisting aneurysms, and hypertension. CONCLUSIONS: IDs can rarely progress to aneurysms or rupture. Young patients with type II or III IDs with coexisting aneurysms or hypertension may benefit from long-term imaging surveillance.

Neurological applications of transcranial high intensity focused ultrasound.

Advances in transcranial MRI-guided focused ultrasound have renewed interest in lesioning procedures in functional neurosurgery with a potential role in the treatment of neurological conditions such as chronic pain, brain tumours, movement disorders and psychiatric diseases. While the use of transcranial MRI-guided focused ultrasound represents a new innovation in neurosurgery, ultrasound has been used in neurosurgery for almost 60 years. This paper reviews the major historical milestones that have led to modern transcranial focused ultrasound and discusses current and evolving applications of ultrasound in the brain.