Personalized, parcel-guided rTMS for the treatment of major depressive disorder: Safety and proof of concept

BACKGROUND

Not all patients with major depressive disorder (MDD) benefit from the US Food and Drug Administration-approved use of repetitive transcranial magnetic stimulation (rTMS) at the dorsolateral prefrontal cortex. We may be undertreating depression with this one-size-fits-all rTMS strategy.

METHODS

We present a retrospective review of targeted and connectome-guided rTMS in 26 patients from Cingulum Health from 2020 to 2023 with MDD or MDD with associated symptoms. rTMS was conducted by identifying multiple cortical targets based on anomalies in individual functional connectivity networks as determined by machine learning connectomic software. Quality of life assessed by the EuroQol (EQ-5D) score and depression symptoms assessed by the Beck Depression Inventory (BDI) were administered prior to treatment, directly after, and at a follow-up consultation.

RESULTS

Of the 26 patients treated with rTMS, 16 (62%) attained remission after treatment. Of the 19 patients who completed follow-up assessments after an average interval of 2.6 months, 11 (58%) responded to treatment and 13 (68%) showed significant remission. Between patients classified with or without treatment-resistant depression, there was no difference in BDI improvement. Additionally, there was significant improvement in quality of life after treatment and during follow-up compared to baseline.

LIMITATIONS

This review is retrospective in nature, so there is no control group to assess the placebo effect on patient outcomes.

CONCLUSION

The personalized, connectome-guided approach of rTMS is safe and may be effective for depression. This personalized rTMS treatment allows for co-treatment of multiple disorders, such as the comorbidity of depression and anxiety.

NCOG-12. IMPACT OF TUMOR-RELATED SEIZURES ON MENTAL HEALTH DISORDER ORDER IN LOW-GRADE GLIOMA

INTRODUCTION

Majority of LGG patients experience seizures during their disease course, requiring anti-epileptic drugs (AEDs). Frequent seizures negatively impact health-related quality of life (HRQoL). AEDs, moreover, are hypothesized to have mood-modulating effects. As survival for LGG patients has been improving, it is essential that the impact of seizure burden and AEDs on mental health disorders (MHD) be considered. The objective was to measure an association of tumor-related seizures with MHD onset among LGG patients.

METHODS

This retrospective cohort study queried data from the IBM Watson Health MarketScan® Claims and Encounters Database (2005-2014) to identify LGG patients without prior MHD history who experienced glioma-related seizures. Presence of seizures was determined by anti-epileptic drug fills within one year following LGG diagnosis. Patients with new onset of MHDs were identified using ICD-9 codes for MHDs and psychotropic drug fills in the 12 months post-LGG diagnosis period. Unadjusted odds ratios measured associations between seizures and MHD prevalence.

RESULTS

11,458 LGG patients with no history of MHD were included; 1,799 (15.7%) experienced seizures within 12 months of LGG diagnosis. Among them, 494 (27.5%) developed MHD in the post-LGG diagnosis period. Patients who experienced seizures were more likely to develop an MHD compared to patients who did not (OR, 2.19, 95% CI, 1.95–2.47). MHD incidence was significantly associated with female gender (OR, 1.14, 95%, 1.03–1.26) and age range of 35–44 (OR, 1.20, 95%, 1.03–1.39) compared to 18–34.

CONCLUSION

These findings demonstrated that tumor-related seizures were associated with MHD onset. This highlights the burden of seizures and regular AED use on mental health. The psychosocial and neurological aspects related to seizures and AEDs likely contribute to the multifaceted mental health disorder onset seen among these LGG patients. Proactive counseling, diagnosis, and management of MHDs in LGGs, particularly those with seizures, is warranted.

NCOG-46. PERSONALIZED, PARCEL-GUIDED RTMS FOR NEURO-REHABILITATION AFTER TUMOR NEUROSURGERY: SAFETY AND PROOF OF CONCEPT

Deficits in neurological and psychocognitive function are common for patients who have undergone surgical removal of primary tumors. Repetitive Transcranial Magnetic Stimulation (rTMS) is an emerging non-invasive tool used for the treatment of neuropsychiatric disorders. We present a retrospective review of individualized, targeted rTMS in thirteen patients who presented with post-operative neurological deficits following craniotomy for tumor resection. Multiple cortical targets were selected based on the patient’s neurological disorder, the networks associated with the deficit, and anomalies in the functional connectivity of the patient’s brain as determined by machine-learning. TMS treatment was performed for 5 consecutive days. EuroQol quality of life (EQ-5D), functional extremity scales, and neuropsychiatric questionnaires related to the patient’s deficit were assessed prior to rTMS treatment, after treatment, and during follow-up. Five patients (38.5%) had glioblastomas; four patients (30.8%) had oligodendrogliomas; two patients (15.4%) had astrocytoma; one patient (7.7%) had ganglioglioma; and one patient (7.7%) had a pineal cyst. All thirteen patients reported significantly improved quality of life after rTMS treatment (p = 0.0065) and during follow-up (p = 0.0038) as compared to baseline. For patients with functional deficits, lower extremity functional scale (LEFS) was significantly improved one week after rTMS treatment (p = 0.0205). Upper extremity function scale (UEFS) showed non-significant trend in improvement after rTMS treatment (p = 0.0777). In the two patients who developed post-craniotomy depression, they showed a 26% and 88% reduction in depressive symptoms based on the Beck’s Depression Inventory (BDI) at two-month follow-up. These results suggest that the personalized, functional connectivity approach to rTMS target and treatment may be effective for patients with post-craniotomy functional impairments and neuropsychiatric disorders. This method of post-operative interventional neuro-rehabilitation is safe, noninvasive, and allows for the simultaneous treatment of multiple symptoms.

MODL-37. DISCERNIBLE INTERINDIVIDUAL PATTERNS OF GLOBAL EFFICIENCY DECLINE DURING THEORETICAL BRAIN SURGERY

Resection of infiltrating brain tumors, such as diffuse gliomas, generally involves resecting a portion of a lobe of the brain. While the concept of localized functions, and the risk to removing these areas, is well established in neurosurgical thinking, the potential that the overall global efficiency of the connectome could be disproportionately disturbed by an intervention in ways which are not immediately obvious have not been formally studied. The current article provides evidence that structural patterns exist in the impact resection of various lobes of the brain has, which also differs between subjects. We utilized diffusion tractography to create structural connectivity graphs from the brains of 80 healthy adults, and then performed every plausible brain surgery in every gross anatomic region of the cerebrum by deleting every possible combination of nodes in the graph which were adjacent to each other, and measured the drop in global efficiency (GE) at each nodal deletion. Not surprisingly, the deletion of some nodes was worse than others, such that in every lobe we studied in every subject, there were combinations of deletions which were worse for GE than removing a greater number of nodes in a different part of the brain. Interestingly, while the worst nodes differed between subjects, there were specific nodes which typically showed up as particularly detrimental regardless of which node was the worst in that person, but that there were patterns of so-called ―connectotype, which could determine which nodes were the worst. Progressive removal of a lobe of the brain leads to patterns of global efficiency decline which are reasonably predictable, but which are not the same between subjects. Given evidence that global efficiency relates to specific neuro-cognitive abilities, this provides a path towards reducing the cognitive footprint of brain surgery.

Association of Low-Grade Glioma Diagnosis and Management Approach with Mental Health Disorders: A MarketScan Analysis 2005-2014

Simple Summary

Low-grade gliomas (LGGs) comprise 13–16% of glial tumors. As survival for LGG patients has been improving, it is important to consider the effects of diagnosis and treatment on mental health. The aims of this retrospective cohort study were to determine the incidence, prevalence, and risk factors of mental health disorders (MHD) in LGG patients. In our analysis including 20,432 LGG patients, we identified an MHD prevalence of 60.9%. Of those with no history of prior MHD, 16.9% of LGG patients developed a new onset of MHD within 12 months of LGG diagnosis. Risk factors included female gender, ages 35–54, presence of seizures, and first-line surgical treatment. Therefore, proactive surveillance and counseling surrounding MHDs are recommended among LGG patients. Impact of surgery on brain networks affecting mood should also be considered.

Abstract

Low-grade gliomas (LGGs) comprise 13–16% of glial tumors. As survival for LGG patients has been gradually improving, it is essential that the effects of diagnosis and disease progression on mental health be considered. This retrospective cohort study queried the IBM Watson Health MarketScan^® Database to describe the incidence and prevalence of mental health disorders (MHDs) among LGG patients and identify associated risk factors. Among the 20,432 LGG patients identified, 12,436 (60.9%) had at least one MHD. Of those who never had a prior MHD, as documented in the claims record, 1915 (16.7%) had their first, newly diagnosed MHD within 12 months after LGG diagnosis. Patients who were female (odds ratio (OR), 1.14, 95% confidence intervals (CI), 1.03–1.26), aged 35–44 (OR, 1.20, 95% CI, 1.03–1.39), and experienced glioma-related seizures (OR, 2.19, 95% CI, 1.95–2.47) were significantly associated with MHD incidence. Patients who underwent resection (OR, 2.58, 95% CI, 2.19–3.04) or biopsy (OR, 2.17, 95% CI, 1.68–2.79) were also more likely to develop a MHD compared to patients who did not undergo a first-line surgical treatment. These data support the need for active surveillance, proactive counseling, and management of MHDs in patients with LGG. Impact of surgery on brain networks affecting mood should also be considered.

OS14.4.A The Neuroplastic Potential of the Human Brain before and After Glioma Surgery: Towards “Interventional Neurorehabilitation

INTRODUCTION

The human brain is a highly neuroplastic ‘complex’ network: it self-organises without a hard blueprint, adapts to evolving circumstances, and can withstand insults. However, similar to other naturally occurring networks, brain networks can only endure a finite amount of damage before cognitive processes are affected. In this study, we first sought to establish the brain networks governing domain-general cognition (DGC) in healthy individuals across the lifespan. We then sought to map, track, and potentially rehabilitate networks governing DGC through connectomics and non-invasive brain stimulation (NIBS) when damaged by low-grade gliomas (LGG) and surgical oncology.

METHODS

Using MRI and cognitive data from n=629 individuals (aged 18–88, Female= 51%), we assessed the structural, functional, and topological relevance of the spatially-distributed multiple-demand (MD) system for DGC. Next, in n=17 patients undergoing glioma surgery, we longitudinally acquired connectomic and cognitive data at multiple time points: pre-surgery and post-surgery Day 1, Month 3, Month 12. In an independent cohort of n=34 patients, we sought to establish the safety profile for “interventional neurorehabilitation”: connectome-driven NIBS in the acute post-operative period to accelerate cognitive recovery.

RESULTS

In healthy individuals, the MD system across multiple scales of biological organisation was positively associated with higher-order cognition (Catell’s fluid intelligence). In our patients, pre-operative LGG infiltration into the structural MD system was negatively associated with the number of long-term cognitive deficits, suggesting a functional reorganisation. Mixed-effects modelling demonstrated the resilience of the functional MD system to infiltration and resection, while the early post-operative period was critical for effective neurorehabilitation. Graph analyses revealed increased perioperative modularity can distinguish patients with long-term cognitive improvements at one-year follow-up. Finally, NIBS within two weeks post-craniotomy had a 90% (n=31/34) recruitment rate into the trial. There were no seizures or serious complications due to NIBS in this patient population. Transient headaches and tingling were reported in a minority of patients.

CONCLUSION

For the first time, we elucidate long-term cognitive and network trajectories following LGG surgery while establishing a positive safety-profile for NIBS in the acute post-operative period. We argue that “mesoscale” brain mapping serves as a robust biomarker for intervention-related plasticity for future clinical trials. While we performed these experiments in the context of neurosurgery, connectomics and NIBS could be adopted across diverse neuro-oncological care pathways (i.e. chemotherapy/radiation).

A Phase 2 Randomised Clinical Trial Assessing the Tolerability of Two Different Ratios of Medicinal Cannabis in Patients With High Grade Gliomas

Background

Cannabis for cancer is very topical and, given the use of illicit cannabis preparations used in this vulnerable population, research investigating standardised, quality-assured medicinal cannabis is critical to inform clinicians and assist patient safety.

Methods

A randomized trial involving adult patients diagnosed with a high-grade glioma, no history of substance abuse, liver or kidney damage or myocardial infarction were eligible for inclusion in a tolerability study on two different ratios of medicinal cannabis. Baseline screening of brain morphology, blood pathology, functional status, and cognition was conducted. A retrospective control group was used for comparison for secondary outcomes.

Results

Participants (n=88) were on average 53.3 years old. A paired t-test assessed the Functional Assessment of Cancer Therapy for Brain Cancer (FACT-Br) between groups from baseline to week 12 found that the 1:1 ratio favoured both physical (p=0.025) and functional (p=0.014) capacity and improved sleep (p=0.009). Analysis of changes from baseline to week 12 also found 11% of 61 participants had a reduction in disease, 34% were stable, 16% had slight enhancement, and 10% had progressive disease. No serious adverse events occurred. Side effects included dry mouth, tiredness at night, dizziness, drowsiness.

Conclusion

This study demonstrated that a single nightly dose of THC-containing medicinal cannabis was safe, had no serious adverse effects and was well tolerated in patients. Medicinal cannabis significantly improved sleep, functional wellbeing, and quality of life.

Clinical Trial Registration

Australian New Zealand Clinical Trials Registry (ANZCTR) http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373556&isReview=true, identifier ACTRN12617001287325.

Toward nonparametric diffusion- T1 characterization of crossing fibers in the human brain

PURPOSE

To estimate T 1 for each distinct fiber population within voxels containing multiple brain tissue types.

METHODS

A diffusion- T 1 correlation experiment was carried out in an in vivo human brain using tensor-valued diffusion encoding and multiple repetition times. The acquired data were inverted using a Monte Carlo algorithm that retrieves nonparametric distributions P ( D , R 1 ) of diffusion tensors and longitudinal relaxation rates R 1 = 1 / T 1 . Orientation distribution functions (ODFs) of the highly anisotropic components of P ( D , R 1 ) were defined to visualize orientation-specific diffusion-relaxation properties. Finally, Monte Carlo density-peak clustering (MC-DPC) was performed to quantify fiber-specific features and investigate microstructural differences between white matter fiber bundles.

RESULTS

Parameter maps corresponding to P ( D , R 1 ) 's statistical descriptors were obtained, exhibiting the expected R 1 contrast between brain tissue types. Our ODFs recovered local orientations consistent with the known anatomy and indicated differences in R 1 between major crossing fiber bundles. These differences, confirmed by MC-DPC, were in qualitative agreement with previous model-based works but seem biased by the limitations of our current experimental setup.

CONCLUSIONS

Our Monte Carlo framework enables the nonparametric estimation of fiber-specific diffusion- T 1 features, thereby showing potential for characterizing developmental or pathological changes in T 1 within a given fiber bundle, and for investigating interbundle T 1 differences.

SURG-29. LASER INTERSTITIAL THERMAL THERAPY COMPARED TO CRANIOTOMY FOR TREATMENT OF RECURRENT GLIOBLASTOMA

There have been publications that propose the use of laser interstitial thermal therapy (LITT) as a viable alternative to craniotomy for the treatment of glioblastoma (GBM). The aim of this study was to retrospectively compare outcomes after LITT versus craniotomy for patients with recurrent GBM. To adequately match the cohorts, we included only pre-treatment tumor volumes of under 15 cc. We retrospectively collected data on all patients presenting with recurrent GBM, with a recurrence volume under 15 cc. These patients were either treated with LITT or craniotomy by the senior author. Data included demographics, tumor location and volume, tumor markers, perioperative complications, re-initiation of adjuvant chemotherapy, and long-term follow up data. We performed 23 LITT treatments and 34 craniotomies for recurrent GBM in patients that met selection criteria. There was no significant difference in the patients’ age, tumor volume (6.38 for craniotomy versus 5.765 cc for LITT), location, and post-procedure KPS. Patients that underwent LITT had significantly reduced inpatient stays in comparison to craniotomy (1.7 versus 4.2 days). They also had less perioperative complications (13.0% versus 32.3% for craniotomy). It was found that 28 out of the 34 patients that underwent craniotomy were able to undergo adjuvant therapy; in comparison, 15 out of the 23 patients who underwent LITT had undergone adjuvant therapy. Of these patient’s that underwent adjuvant therapy, 87% of patients were able to receive bevacizumab or a clinical trial versus 42% after craniotomy. Progression-free survival (PFS) and overall survival (OS) after procedure were similar for LITT versus craniotomy, respectively: % PFS-survival at 6 months = 23.5% versus 21.7%. Overall survival did not significantly differ at 9 months versus 9.9 months respectively. LITT appears to be safe and may be as efficacious as craniotomy in achieving progression free survival for small to moderate volume recurrent GBM.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Surgical Resection for the Treatment of Patients With Vestibular Schwannomas

QUESTION 1

What surgical approaches for vestibular schwannomas (VS) are best for complete resection and facial nerve (FN) preservation when serviceable hearing is present?

RECOMMENDATION

There is insufficient evidence to support the superiority of either the middle fossa (MF) or the retrosigmoid (RS) approach for complete VS resection and FN preservation when serviceable hearing is present.

QUESTION 2

Which surgical approach (RS or translabyrinthine [TL]) for VS is best for complete resection and FN preservation when serviceable hearing is not present?

RECOMMENDATION

There is insufficient evidence to support the superiority of either the RS or the TL approach for complete VS resection and FN preservation when serviceable hearing is not present.

QUESTION 3

Does VS size matter for facial and vestibulocochlear nerve preservation with surgical resection?

RECOMMENDATION

Level 3: Patients with larger VS tumor size should be counseled about the greater than average risk of loss of serviceable hearing.

QUESTION 4

Should small intracanalicular tumors (<1.5 cm) be surgically resected?

RECOMMENDATION

There are insufficient data to support a firm recommendation that surgery be the primary treatment for this subclass of VSs.

QUESTION 5

Is hearing preservation routinely possible with VS surgical resection when serviceable hearing is present?

RECOMMENDATION

Level 3: Hearing preservation surgery via the MF or the RS approach may be attempted in patients with small tumor size (<1.5 cm) and good preoperative hearing.

QUESTION 6

When should surgical resection be the initial treatment in patients with neurofibromatosis type 2 (NF2)?

RECOMMENDATION

There is insufficient evidence that surgical resection should be the initial treatment in patients with NF2.

QUESTION 7

Does a multidisciplinary team, consisting of neurosurgery and neurotology, provides the best outcomes of complete resection and facial/vestibulocochlear nerve preservation for patients undergoing resection of VSs?

RECOMMENDATION

There is insufficient evidence to support stating that a multidisciplinary team, usually consisting of a neurosurgeon and a neurotologist, provides superior outcomes compared to either subspecialist working alone.

QUESTION 8

Does a subtotal surgical resection of a VS followed by stereotactic radiosurgery (SRS) to the residual tumor provide comparable hearing and FN preservation to patients who undergo a complete surgical resection?

RECOMMENDATION

There is insufficient evidence to support subtotal resection (STR) followed by SRS provides comparable hearing and FN preservation to patients who undergo a complete surgical resection.

QUESTION 9

Does surgical resection of VS treat preoperative balance problems more effectively than SRS?

RECOMMENDATION

There is insufficient evidence to support either surgical resection or SRS for treatment of preoperative balance problems.

QUESTION 10

Does surgical resection of VS treat preoperative trigeminal neuralgia more effectively than SRS?

RECOMMENDATION

Level 3: Surgical resection of VSs may be used to better relieve symptoms of trigeminal neuralgia than SRS.

QUESTION 11

Is surgical resection of VSs more difficult (associated with higher facial neuropathies and STR rates) after initial treatment with SRS?

RECOMMENDATION

Level 3: If microsurgical resection is necessary after SRS, it is recommended that patients be counseled that there is an increased likelihood of a STR and decreased FN function.  The full guideline can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_8.

SURG-05. LASER INTERSTITIAL THERMAL THERAPY FOR MELANOMA BRAIN METASTASIS: A CASE SERIES

Stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT) have been established as non-invasive treatment modalities for intracranial metastasis from malignant melanoma, with SRS emerging as a safe and effective stand along therapy. However, either due to tumor regrowth or radiation necrosis, these radiation modalities can fail. MR-guided laser interstitial thermal therapy (LITT) has emerged as an option for these tumors. Clinical data for five patients at our institution was retrospectively reviewed. These were all the patients that had undergone LITT for intracranial metastatic melanoma after prior treatment failure that included a radiation modality. Demographics, prior treatments, surgical data, perioperative complications, adjuvant treatments, and follow imaging data were gathered. Of the five patients, one patient had received WBRT, three patients had received prior SRS to the area that underwent LITT, and one patient had a prior craniotomy with adjuvant SRS. Two of the tumors were located in the premotor area (frontal lobe), two tumors were located in the motor strip, and one tumor was located in the cerebellum. The average tumor volume was 4.32 cc (range 1.86 - 7.84 cc). Median time of hospital stay was 2 days (with a 2.6 day average). No perioperative complications were encountered. Three of the patients had received adjuvant therapy at our institution; these patients were not delayed in receiving adjuvant therapy. Of these three patients, only one patient had a BRAF mutation detected. Four patients received follow up imaging at our institution, with no patients demonstrating tumor regrowth in the site of LITT. Regrowth of intracranial metastasis of malignant melanoma is a known possibility of traditional radiation therapies. LITT should be considered as a safe, effective option for those that fail these traditional therapies, especially those located in areas difficult to access. The low complication rate allows patients to restart adjuvant therapies.

Common Disconnections in Glioma Surgery: An Anatomic Description

Within the surgical treatment of glioma, extended survival is predicated upon extent of resection which is limited by proximity and/or invasion of eloquent structures. Diffusion tensor imaging (DTI) tractography is a very useful tool for guiding supramaximal surgical resection while preserving eloquence. Although gliomas can vary significantly in size, shape, and invasion of functionally significant brain tissue, typical surgical disconnection patterns emerge. In this study, our typical surgical paradigm is outlined. We describe our surgical philosophy for resecting gliomas supramaximally summarized as define, divide, and destroy with the adjuvant utilization of neuronavigation and DTI. We describe the most common disconnections involved in glioma surgery at our institution; specifically, delineating tumor disconnections involving the medial posterior frontal, lateral posterior frontal, posterior temporal, anterior occipital, medial parietal, and insular regions. Although gliomas are highly variable, common patterns emerge in relation to the necessary disconnections required to preserve eloquent brain while maximizing the extent of resection. 

Multilobar Insular-Involving Gliomas: Results with Hyperaggressive Resection

Objective

Hyperaggressive resection refers to a philosophy that maximal resection should be pursued in gliomas, wherever possible. In this study, we provide a detailed report of the outcomes with hyperaggressive surgery for multilobar insular-involving gliomas (MIGs). 

Methods

We report outcomes in patients with MIGs undergoing surgery aiming at gross total resection in all cases. Risk factors for neurologic deficits and survival were modeled using logistic and Cox regression.

Results

There were 72 consecutive patients, of whom 53 (74%) had undergone previous surgery. A greater than 90% resection was obtained in 67 patients (93%). Nineteen of 23 patients (83%) with Grade 2 tumors survived to the end of the follow-up period. Patients with Grade 3 tumors experienced 75% two-year survival rates and 48% four-year survival rates. Patients with Grade 4 tumors experienced 55% one-year survival rates and 33% two-year survival rates; eight of 33 patients (24%) lived longer than three years and three of 33 patients were alive at five years. Fifty-eight of 68 patients (85%) surviving to the three-month follow-up had a Karnofsky performance status (KPS) of 70 or greater, and 31 of 72 patients (43%) experienced improvement in KPS postoperatively. Permanent weakness occurred in 12 patients (17%), and permanent speech problems in three patients (13% of left-sided tumors).

Conclusion

Hyperaggressive surgical resection of MIGs yields rates of neurologic deficits within acceptable ranges and are lower than expected. In many cases, patients exceed the long-term survival expectations of conventional treatment.

Malignant Peripheral Nerve Sheath Tumor of the C2 Nerve Root: Case Report

Here we present the case of a 36-year-old man who was found to have a symptomatic malignant neural sheath tumor growing from the C2 nerve root following a period of progressively worsening headaches. The patient was successfully treated with surgical resection resulting in resolution of cranial nerve deficits. Though uncommon, malignant peripheral nerve sheath tumor must be considered in the differential diagnosis of tumors involving the cervical nerve roots and carotid space.

The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note

The success of awake craniotomies relies on the patient's performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities.

When Evaluating a New Thyroid Mass and a Ring-Enhancing Brain Lesion (When Two Presentations Collide)

We aimed to evaluate the clinical and pathologic features of two common medical illnesses and their appropriate workup and pathognomonic findings. A 57-year-old white male presented with a new onset expressive aphasia while traveling abroad. He was evaluated at an outside facility and underwent workup for a stroke. The evaluation included a CT and MRI of the brain demonstrating three new enhancing lesions, the largest of which was a 2.5 cm ring-enhancing cystic lesion. A CT of the chest noted a 4-cm cystic thyroid lesion that was diagnosed as a thyroid cancer with brain metastases. The patient was told that he had cancer and needed therapy. The patient elected to be treated closer to home and presented to our institution with a referral for brain irradiation. The patient was evaluated and his case was reviewed in a neuro/oncology tumor board, where several other possible diagnoses were considered. A complete workup was performed, including two separate FNAs of the thyroid mass along with a PET scan, CEA test, CBC test, CMP, CRP, sed rate, and SLE testing, along with a spinal tap (cytology, protein, and serology).

The MRI on further review showed that one of the lesions was a periventricular enhancing area and the largest lesion was an open ring with T2 and DWI enhancement. The fine needle aspiration (FNA) samples of the thyroid both showed benign histology. The laboratory evaluation was negative except for a mildly elevated CRP with no tumor markers identified and the spinal tap was positive for elevated protein and particularly oligoclonal bands. The PET scan showed no sites of fluorodeoxyglucose (FDG) avid masses including the thyroid. Multiple sclerosis (MS) represents 400,000 cases in the US and benign thyroid nodules noted on imaging range from 19-35% of the population. One pathognomonic finding of MS that is less common is the open rings called tumefactive lesions versus the closed rings seen with metastases. A cystic thyroid lesion can range from a benign process to a differentiated thyroid cancer. The rate of distant metastasis with these cancers ranges from 1-23% in the literature. Lung and bone metastasis are the most common sites with CNS metastasis only accounting for < 2% of the cases. A better understanding of these findings should allow physicians to have a higher degree of suspicion in these cases and provoke further inquiry to prevent unnecessary injury.

Management of Intracranial Meningiomas Using Keyhole Techniques

Background: Keyhole craniotomies are increasingly being used for lesions of the skull base. Here we review our recent experience with these approaches for resection of intracranial meningiomas.

Methods: Clinical and operative data were gathered on all patients treated with keyhole approaches by the senior author from January 2012 to June 2013. Thirty-one meningiomas were resected in 27 patients, including 9 supratentorial, 5 anterior fossa, 7 middle fossa, 6 posterior fossa, and 4 complex skull base tumors. Twenty-nine tumors were WHO Grade I, and 2 were Grade II. 

Results: The mean operative time was 8 hours, 22 minutes (range, 2:55-16:14) for skull-base tumors, and 4 hours, 27 minutes (range, 1:45-7:13) for supratentorial tumors. Simpson Resection grades were as follows: Grade I = 8, II = 8, III = 1, IV = 15, V = 0. The median postoperative hospital stay was 4 days (range, 1-20 days). In the 9 patients presenting with some degree of visual loss, 7 saw improvement or complete resolution. In the 6 patients presenting with cranial nerve palsies, 4 experienced improvement or resolution of the deficit postoperatively. Four patients experienced new neurologic deficits, all of which were improved or resolved at the time of the last follow-up. Technical aspects and surgical nuances of these approaches for management of intracranial meningiomas are discussed. 

Conclusions: With careful preoperative evaluation, keyhole approaches can be utilized singly or in combination to manage meningiomas in a wide variety of locations with satisfactory results.

Meningiomas of the Anterior Clinoid Process: Is It Wise to Drill Out the Optic Canal?

Introduction: Meningiomas of the anterior clinoid process are uncommon tumors, acknowledged by most experienced surgeons to be among the most challenging meningiomas to completely remove. In this article, we summarize our institutional experience removing these uncommon and challenging skull base meningiomas.

Methods: We analyzed the clinical outcomes of patients undergoing surgical removal of anterior at our institution over an 18-year period. We characterized the radiographic appearance of these tumors and related tumor features to symptoms and ability to obtain a gross total resection. We also analyzed visual outcomes in these patients, focusing on visual outcomes with and without optic canal unroofing.

Results: We identified 29 patients with anterior clinoid meningiomas who underwent surgical resection at our institution between 1991 and 2007. The median length of follow-up was 7.5 years (range: 2.0 to 18.6 years). Similar to others, we found gross total resection was seldom safely achievable in these patients. Despite this, only 1/20 of patients undergoing subtotal resection without immediate postoperative radiosurgery experienced tumor progression. The optic canal was unroofed in 18/29 patients in this series, while in 11/29 patients it was not. Notably, all five patients experiencing visual improvement underwent optic canal unroofing, while three of four patients experiencing visual worsening did not.

Conclusions:  These data provide some evidence suggesting that unroofing the optic canal in anterior clinoid meningiomas might improve visual outcomes in these patients.

Central nervous system metastasis in gynecologic cancer: symptom management, prognosis and palliative management strategies

INTRODUCTION

CNS metastasis (CNSmet) with gynecologic malignancy (GM) is associated with poor prognosis and symptom burden. Two prognostic indices, the recursive partitioning analysis (RPA) and graded prognostic assessment (GPA), used in other solid tumors to guide intervention options were evaluated among GM patients.

METHODS

Retrospective chart review was performed to identify patients with primary GM diagnosed with CNSmet from 2005-2014. RPA and GPA were applied and evaluated for goodness of fit. Long-term survivors (LTS) were those with survival time from CNSmet ≥9 months.

RESULTS

35 patients were identified with median age of 62 years (range, 41-78). The majority had ovarian cancer (54%). Median survival was 4.5 months (0.1-25.9), and median time from initial diagnosis was 2.6 years (0-19.6). Presenting symptoms varied but headache (57%) and altered mental status (23%) were most common. 37% had a solitary CNS lesion, 31% had 2-8, and 31% >8. 57% were treated with WBRT, 14% with stereotactic radiosurgery (SRS), and 20% with combinations of treatments, and 2 elected for hospice. 27% (9/33) of the patients were LTS. The GPA was not significantly associated with patient outcome (p=0.46). The RPA predicted time to death (p=.0010).

CONCLUSION

Prognostic indices used to guide therapeutic interventions perform poorly in GM. Detection and aggressive symptom management are critical in maintaining QOL. Multidisciplinary consultation is critical to optimize outcomes and symptom control.

G-protein coupled receptor kinase (GRK)-5 regulates proliferation of glioblastoma-derived stem cells

Glioblastoma multiforme (GBM) is a grade IV malignant brain tumor with high mortality and has been well known to involve many molecular pathways, including G-protein coupled receptor (GPCR)-mediated signaling (such as epithelial growth factor receptor [EGFR] and platelet derived growth factor receptor [PDGFR]). G protein-coupled receptor kinases (GRK) directly regulate GPCR activity by phosphorylating activated agonist-bound receptors to desensitize signaling and internalize receptors through beta-arrestins. Recent studies in various cancers, including prostate and breast cancer, have highlighted the role of change in GRK expression to oncogenesis and tumor proliferation. In this study, we evaluated the expression of GRK5 in grade II to grade IV glioma specimens using immunohistochemistry and found that GRK5 expression levels are highly correlated with aggressiveness of glioma. We used culture conditions to selectively promote the growth of either glioblastoma cells with stem cell markers (GSC) or differentiated glioblastoma cells (DGC) from fresh GBM specimens. GSC are known to be highly invasive and mobile, and have the capacity to self-renew and are more resistant to chemotherapy and radiation compared to differentiated populations of GBM. We examined the expression of GRK5 in these two sets of culturing conditions for GBM cells and found that GRK5 expression is upregulated in GSC compared to differentiated GBM cells. To better understand the role of GRK5 in GBM-derived stem cells, we created stable GRK5 knockdown and evaluated the proliferation rate. Using an ATP chemiluminescence assay, we show, for the first time, that knocking down the expression of GRK5 decreased the proliferation rate of GSC in contrast to control.

Intracranial subdural osteoma: a rare benign tumor that can be differentiated from other calcified intracranial lesions utilizing MR imaging

We report the magnetic resonance (MR) imaging characteristics of subdural osteoma and other benign calcified intracranial lesions to highlight imaging features that differentiate between these disease entities. A 63-year-old woman presented with progressively altered mental status. Non-contrast CT demonstrated a densely calcified right middle cranial fossa extra-axial mass. MR imaging of the lesion demonstrated T1 and T2 hypointensity without evidence of contrast enhancement, parenchymal abnormality, or connection to adjacent venous structures. Diffusion weighted imaging demonstrated markedly decreased signal intensity and artificially reduced diffusion on apparent diffusion coefficient map. Histologically, the tumor was predominantly composed of lamellar bone and small fragments of residual dura consistent with subdural osteoma. This case demonstrates that radiological examination can provide additional insight into the origin of intracranial osteomas (extradural versus subdural versus sinonasal) and help distinguish from other diagnostic considerations including benign meningeal ossification and calcified meningioma prior to surgical resection.

The "yo-yo" technique to prevent cerebrospinal fluid rhinorrhea after anterior clinoidectomy for proximal internal carotid artery aneurysms

OBJECTIVE

Resection of the anterior clinoid process is important for the exposure of aneurysms on clinoidal and supraclinoidal segments of the internal carotid artery. Cerebrospinal fluid (CSF) rhinorrhea can complicate anterior clinoidectomy when the optic strut is pneumatized and its removal communicates the subarachnoid space with the sphenoid sinus. We present a technique for repairing this defect and preventing CSF rhinorrhea.

METHODS

A suture is secured around a strip of temporalis muscle, which is then pushed through the opening in the optic strut completely into the sphenoid sinus. The ends of suture that trail the muscle are used to retract the muscle from the sphenoid sinus back into the optic strut. The suture is trimmed and the repair is covered with sealant or fibrin glue.

RESULTS

During an 8-year period in which 127 patients with proximal internal carotid artery aneurysms that required anterior clinoidectomy were treated, pneumatized optic struts were encountered in 14 patients (11%). Four patients were treated with the "yo-yo" technique, none of whom experienced CSF rhinorrhea. Before using this technique, 10 patients were managed with standard packing techniques (wax, muscle, and gel foam) and four of these patients subsequently experienced CSF rhinorrhea (40%). In these four patients, all required reoperation with either craniotomy and packing with pericranium (one patient), Couldwell-Luc procedure (one patient), or endoscopic transnasal obliteration of the sphenoid sinus with fat (two patients).

CONCLUSION

The "yo-yo" technique of tightly wedging a muscle plug into the optic strut proved to be simple, fast, and effective, preventing CSF rhinorrhea in all patients in whom it was applied. Although experience with this technique is limited, reversing the direction of packing and pulling muscle from the sphenoid sinus into the optic strut eliminated a complication that occurred in 40% of patients with standard packing techniques.