Neoplasms

Nervous System Diseases

All Conditions

Brain Neoplasms

Central Nervous System Neoplasms

Nervous System Neoplasms

Brain Diseases

Central Nervous System Diseases

pre-operative and intra-operative brain mapping to identify eloquent areas

brain mapping

Michele R Aizenberg Ansari, MD

Accurate identification of areas of eloquent brain function is vital to surgical decision making and to preservation of independence as patients with brain tumors who are higher functioning have better survival outcomes. Eloquent brain is defined as a region controlling language, motor, or sensory function such that without its proper input, a person would be left with significant neurologic deficits. Imaging technology has evolved to provide multiple non-invasive modalities for pre-operative testing of eloquent brain function. Studies have shown that these non-invasive mapping modalities provide useful information, however, the information provided inconsistently predicts distribution of eloquent function.

Direct electrical stimulation (DES) at surgery allows assessment of eloquent function directly from the brain surface (invasive) and is considered the gold standard in brain mapping. Therefore, in order to determine the true clinical applicability of the non-invasive mapping technologies, this study proposes to assess the predictive value of functional MRI (fMRI) and magnetoencephalography (MEG) for sensorimotor and language functions by comparing results to DES and determine whether fMRI or MEG provides the most consistent and accurate information. The rationale for the proposed research is that understanding the reliability of our current technology will allow us to perform safer surgeries and to preserve neurologic function.

It is unknown whether imaging technologies have broad applications in brain mapping due to limited knowledge of the value of the results. Accurate identification of areas of eloquent brain function is vital to surgical decision making and to preservation of independence as patients with brain tumors who are higher functioning have better survival outcomes. Imaging technology has evolved to provide multiple non-invasive modalities for pre-operative testing of eloquent brain function and include functional MRI (fMRI) and magnetoencephalography (MEG). Eloquent brain is defined as a region controlling language, motor, or sensory function such that without its proper input, a person would be left with significant neurologic deficits. Studies conducted have shown that these non-invasive mapping modalities provide useful information, however, the information provided inconsistently predicts distribution of eloquent function.

Direct electrical stimulation (DES) at the time of surgery allows assessment of eloquent function directly from the brain surface (invasive) and is considered the gold standard in brain mapping. Therefore, in order to determine the true clinical applicability of the non-invasive mapping technologies, this study proposes to: (1) assess the predictive value of fMRI and MEG for sensorimotor and language functions by comparing their results to DES and (2) determine whether fMRI or MEG provides the most consistent and accurate information. These aims will be accomplished by by co-registering all mapping data (invasive and non-invasive) in a modifiable 3D rendering. In this way, the DES to fMRI and MEG can be evaluated as well as fMRI to MEG compared. The rationale for the proposed research is that understanding the reliability of our current technology will allow for safer surgeries and preservation of neurologic function. The expected outcomes for the work proposed in Aims 1 and 2 are identification of a predictive value for fMRI and MEG and determination if one modality should be utilized over the other pre-operatively for the most accurate information. The results of this study are expected to have an important positive impact because identification of accurate pre-operative non-invasive mapping modalities will allow tailored testing and possibly lead to negation of the need for intra-operative mapping in certain cases. It will also enhance patient outcomes by improving patient safety. Furthermore, it will serve as the basis for a multi-institutional mapping data bank.

Multi-modality Localization of Eloquent Brain Function

Multi-modality Localization of Eloquent Brain Function-A Comparison of Technologies for Improved Applicability

Assess the predictive value of fMRI for language and sensorimotor function by evaluating the location in the brain where the activity was found. The pre-operative locations will be compared to the intra-operative locations which are considered the gold standard. If the fMRI activations indicate the same gyrus/gyri as the intra-operative mapping, it is considered accurate. This is accomplished with special techniques integrating multiple data time points and types.

Assess the predictive value of MEG for language and sensorimotor function by evaluating the location in the brain where the activity was found. The pre-operative locations will be compared to the intra-operative locations which are considered the gold standard. If the MEG activations indicate the same gyrus/gyri as the intra-operative mapping, it is considered accurate. This is accomplished with special techniques integrating multiple data time points and types.

Assess which mapping method provides the most consistent and accurate information in pre-operative mapping for language and sensorimotor function. Determination of the testing method that most often identifies the correct anatomic location of the eloquent function as dictated by the findings from outcomes 1 and 2.

University of Nebraska

Standard of care with brain mapping, pre-, intra-, and post-operative.

Brain mapping will be employed pre-, intra-, and post-operatively to evaluate specific functions.

Brain mapping

Dulce Maroni, PhD

Katie Maire, MS

Michele Aizenberg, MD

Purpose of the study:

AIM 1 Prospectively collect pre-operative (fMRI, DTI, MEG) and intra-operative mapping data in patients with intra-axial brain tumors to assess how well each modality predicts the location of eloquent brain function. In addition, each modality will be compared with the other.

AIM 2 Assess reorganization of eloquent brain function and plasticity in patients with intra-axial brain tumors. This will be accomplished by prospectively collecting post-operative mapping studies and neuropsychological tests to compare them to prior mapping studies as stated above.

Any patient with a primary or metastatic brain tumor in or near an eloquent area would be eligible for participation in the study assuming no contraindications to any of the studies or operative procedure.

Pre-operative:

Evaluation will include clinical evaluation, neuropsychological testing, MRI brain with and without contrast, fMRI, DTI tractograms, and MEG studies as well as standard pre-operative work-up.

Intra-operative:

All non-invasive pre-operative mapping data will be incorporated into the operative procedure with the imaging tools that we routinely use during neurosurgical procedures. Patients will have awake mapping performed. Our usual standards of care will be followed during craniotomy, mapping, and tumor resection or biopsy.

Post-operative:

Patients will have routine post-operative care and assessment consisting of clinical examinations and imaging obtained within 24 hours post resection. They will have routine follow-up outpatient appointments after surgery which will include neurologic assessment and follow-up imaging (MRI with and without contrast) for their tumors as appropriate. The experimental portion of the protocol is incorporating repeat neuropsychological testing and mapping studies (fMRI, DTI, MEG) studies at 2 and 6 months post-surgery into their routine follow-up.

Assessment of Eloquent Function in Brain Tumor Patients

Assessment of Reorganization and Plasticity of Eloquent Function in Patients With Brain Tumors

The location of the eloquent function of interest (motor, sensory, speech) will be assessed pre-operatively and intra-operatively. These will be compared. Then, at 2 and 6 months post-operatively, repeat non-invasive mapping studies will be performed to compare to the subjects' prior studies. This will allow for assessment of reorganization and plasticity of function. Addtionally, novel ways of identifying eloquent brain regions will be developed.

Rare Diseases

Brain Tumor, Adult

Maximum Grip Strength will be measured using a hand-held dynamometer (K-FORCE Grip dynamometer®. Kinvent Biomequanique S.A.S, Montpellier, France) during the preoperative, intraoperative (Awake craniotomy) and postoperative period.

Hand-held dynamometer

Kaisorn L Chaichana, M.D.

Lina C Marenco-Hillembrand, M.D.

Kaisorn Chaichana, MD

The primary purpose of this study is to assess the feasibility, safety and reliability of the use of handheld dynamometry in evaluating intraoperative motor function for patients undergoing awake craniotomy for the resection of brain lesions located within or adjacent to the motor cortex.

Handheld Dynamometer During Awake Craniotomy Pilot

Use of Handheld Dynamometer as a Novel Tool to Assess Motor Function During Awake Craniotomy for Brain Lesions Located Within or Adjacent to the Motor Cortex: A Single-Center Pilot Study

Maximum grip strength (KgF) will be measured using hand-held dynamometry every 2 minutes from the time the patient awakes until the end of surgery. Intraoperative maximum grip strength baseline is defined as the mean of 3 consecutive measures with \<10% variability.

To validate the use of hand-held dynamometry as an adequate tool to monitor intraoperative motor function during awake craniotomies (AC), maximum grip strength (KgF) will be measured every 2 minutes from the time the patient awakes to the end of surgery. The intra-individual variability will be defined as the percent difference between sets with 10% or greater defined as substantial variability.

To validate the use of hand-held dynamometry as an adequate tool to monitor intraoperative motor function during AC, each patient will be baselined (mean of 6 consecutive measurements) during the preoperative neuropsychology evaluation. Variability from preoperative baseline will be calculated as a percentile \[ (Preoperative Baseline/ Intraoperative Baseline)/ Preoperative Baseline) \* 100\]

Defined as the duration of the procedure from the initiation of skin incision to the completion of skin closure according to anesthesia records. Measured in minutes.

Concordance between hand-held dynamometer and manual motor testing will be evaluated using Spearmans' correlation coefficient.

Postoperative Maximum Grip strength (KgF) will be measured using hand-held dynamometer at day 1 and at 1 month follow-up.

Mayo Clinic

Principal Investigator

Analgesics

Central Nervous System Depressants

All Drugs and Chemicals

Dexmedetomidine

Propofol

Remifentanil

Hypnotics and Sedatives

Analgesics, Non-Narcotic

Adrenergic Agents

Adrenergic alpha-Agonists

Adrenergic Agonists

Neurotransmitter Agents

Anesthetics

Anesthetics, Intravenous

Anesthetics, General

Analgesics, Opioid

Narcotics

Group I. (propofol/remifentanil): Infusions begin at remifentanil (0.01-0.1 mcg/kg/min) and propofol (25-250 mcg/kg/min) for 15 min, and then titrated to effect.

Group II. (dexmedetomidine): The infusion begins at 0.3-0.4 mcg/kg/hr for 15 min, and then titrated down to 0.1-0.2 mcg/kg/hr.

The infusion begins at dexmedetomidine 0.3-0.4 mcg/kg/hr for 15 min, and then titrated down to 0.1-0.2 mcg/kg/hr.

The infusion begins at propofol 25-250 mcg/kg/min for 15 min, and then titrated to effect.

The infusion begins at remifentanil 0.01-0.1 mcg/kg/min for 15 min, and then titrated to effect.

Pirjo Manninen, MD, FRCPC

Nicolai Goettel, MD

Awake craniotomy for resection of brain tumor located in close proximity to areas of eloquent brain function, such as speech, motor and sensory, is an accepted procedure used to minimize neurological injury during resection. During awake craniotomy, anesthesia is usually provided using a combination of local anesthesia (regional scalp block and/or local infiltration) and intravenous (IV) agents to provide sedation, anxiolysis and analgesia. Propofol sedation, commonly in combination with a shorter acting opioid such as fentanyl, or remifentanil, is an effective and popular technique during awake craniotomy, achieving a high degree of patient satisfaction and acceptance. Most of the anesthetic agents are associated with some respiratory depression.

The anesthetic agent called dexmedetomidine is a potent, highly selective α2-adrenoceptor agonist. The effects of dexmedetomidine are anxiolysis, analgesia, sedation and sympatholysis, and it is not associated with respiratory depressive effect. Bekker et al. first reported the successful use of dexmedetomidine in awake craniotomy in 2001.

The purpose of this blinded, prospective, randomized study is to compare the efficacy of dexmedetomidine versus propofol-remifentanil based sedation in patients undergoing awake craniotomy for resection of tumors. The study hypothesis is that the efficacy of performing intra-operative brain mapping is identical between dexmedetomidine and the propofol-remifentanil based sedation. The primary end-points are to assess the ability to perform intraoperative mapping during awake craniotomy. Secondary end-points will assess the incidence of complications (respiratory depression, failure to provide adequate analgesia), as well as patient and surgeon satisfaction to the corresponding anesthetic technique.

Awake craniotomy for resection of brain tumor located in close proximity to areas of eloquent brain function, such as speech, motor and sensory, is an accepted procedure used to minimize neurological injury during resection. The level of sedation and analgesia during the different stages of surgery varies, but importantly, the patient needs to be awake and alert during brain mapping. During awake craniotomy, anesthesia is usually provided using a combination of local anesthesia (regional scalp block and/or local infiltration) and intravenous (IV) agents to provide sedation, anxiolysis and analgesia. There is considerable variation in the anesthetic management of the awake craniotomy in different institutions. Propofol sedation, commonly in combination with a shorter acting opioid such as fentanyl, or remifentanil, is an effective and popular technique during awake craniotomy, achieving a high degree of patient satisfaction and acceptance. However, the awake craniotomy remains one of the most challenging techniques of anesthesia care in terms of balancing an adequate depth of sedation and analgesia to combat the rapid changes of surgical stimulation yet having an alert patient for brain mapping. Furthermore, most of the anesthetic agents are associated with some respiratory depression.

A newer anesthetic agent called dexmedetomidine (Precedex (TM), Hospira Healthcare Corporation, Saint Laurent, Québec, Canada) is a potent, highly selective α2-adrenoceptor agonist with an α2:α1 selectivity ratio of 1600:1. It has been available in the Canada since 2009 as a short-term sedative agent, and is available in the UHN. The use of dexmedetomidine has been in mechanically ventilated patients in ICU and for intra-operative sedation. The well-documented beneficial effects of dexmedetomidine are anxiolysis, analgesia, sedation and sympatholysis, and it is not associated with respiratory depressive effect.

Dexmedetomidine has been successfully used to provide sedation in dental procedures, awake fibreoptic intubation, bariatric surgery and morbidly obese patients, as well as obstructive sleep apnea patients. The pharmacokinetic properties of dexmedetomidine is very predictable and titratable, with a rapid distribution half-life (t1/2α) being approximately 5-6min and an elimination half-life (t1/2β) of approximately 2h. Bekker et al. first reported the successful use of dexmedetomidine in awake craniotomy in 2001. Subsequent case series published by Souter et al. demonstrated that dexmedetomidine can be used either as a sole agent or in combination with other agents such as fentanyl during seizure foci resection with accurate intraoperative brain mapping.

The hypnotic effect of dexmedetomidine is mediated by the hyperpolarization of noradrenergic neurons in the locus ceruleus, which proposed that dexmedetomidine converges on a natural sleep pathway to exert its sedative effect. Venn and co-workers, as part of a large European multicentre trial investigating dexmedetomidine for postoperative sedation in the ICU, reported that: "Patients are calmly and easily roused from sleep to allow excellent communication and cooperation while intubated and ventilated, and then similarly quickly return to sleep". This unique sedation state is very useful for awake craniotomy, which requires deep level of sedation during painful operative procedures, as well as easily rousable state during mapping of eloquent function.

The purpose of this blinded, prospective, randomized study is to compare the efficacy of dexmedetomidine versus propofol-remifentanil based sedation in patients undergoing awake craniotomy for resection of tumors. The study hypothesis is that the efficacy of performing intra-operative brain mapping is identical between dexmedetomidine and the propofol-remifentanil based sedation. The primary end-points are to assess the ability to perform intraoperative mapping during awake craniotomy. Secondary end-points will assess the incidence of complications (respiratory depression, failure to provide adequate analgesia), as well as patient and surgeon satisfaction to the corresponding anesthetic technique.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Multi-modality Localization of Eloquent Brain Function	NCT02795338	Brain Neoplasms	brain mapping	19 Years -	University of Nebraska
Multi-modality Localization of Eloquent Brain Function	NCT02795338	Brain Neoplasms	brain mapping	19 Years -	University of Nebraska
Assessment of Eloquent Function in Brain Tumor Patients	NCT01535430	Primary Brain T... Metastatic Brai...	Brain mapping	19 Years -	University of Nebraska
Assessment of Eloquent Function in Brain Tumor Patients	NCT01535430	Primary Brain T... Metastatic Brai...	Brain mapping	19 Years -	University of Nebraska
Handheld Dynamometer During Awake Craniotomy Pilot	NCT04742231	Brain Lesion Brain Tumor Adu... Brain Tumor	Hand-held dynam...	18 Years -	Mayo Clinic
Multi-modality Localization of Eloquent Brain Function	NCT02795338	Brain Neoplasms	brain mapping	19 Years -	University of Nebraska
Comparison of Dexmedetomidine and Propofol-Remifentanil Conscious Sedation for Awake Craniotomy for Tumor Surgery	NCT01545297	Brain Tumor	Dexmedetomidine Propofol Remifentanil	18 Years -	University Health Network, Toronto

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