Navigated Transcranial Magnetic Stimulation in Tumor Surgery

Study Overview
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Brief Summary
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Maximizing surgical removal of brain tumors while minimizing neurologic deficits is challenging. Functional brain tissue may reside close to or even within the abnormality, and inadvertent removal or disturbance of such areas can result in neurologic deficits. At present, the gold standard for identifying critical motor areas in tumor surgery is intraoperative invasive direct current stimulation (DCS) through a handpiece. More recently, new non-invasive preoperative method for brain mapping, functional magnetic resonance imaging (fMRI), may be used to identify the eloquent motor areas. fMRI signals used in localization of the motor areas are generated when the brain is activated during the performance of specific motor tasks. However, as fMRI signals are also generated by sensory input, the resulting fMRI map may include sensory as well as motor areas. Nexstim has developed a Navigated Brain Stimulation (NBS) system that uses TMS with a software based Navigational System that together may have more specific spatial accuracy. This study aims to determine whether navigated TMS is able to identify the eloquent motor cortical areas in patients with brain tumors and to determine the clinical accuracy of the procedure by comparing it to results obtained by intraoperative DCS and fMRI.

Official Title
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Preoperative Non-Invasive Motor Mapping in Tumor Surgery by Navigated Transcranial Magnetic Stimulation

Conditions
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Brain Tumors

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female subjects 18 years of age and over. A brain tumor in the vicinity of the central region. Mild (BMRC grade 4/5) or no paresis. Obscured anatomy of the central region due to the mass effect/infiltrating growth pattern of the lesion Scheduled for elective surgery under general or local anesthesia. No other known brain abnormalities by history or by structural MRI. Mentally and physically able to undergo MR imaging (fMRI, DTI) and navigated TMS studies Signed informed consent form. Exclusion Criteria: Implanted metallic parts of implanted electronic devices, including pacemakers, defibrillators, or implant medication pump. Pregnant or trying to become pregnant. History of alcohol abuse, illicit drug use or drug abuse or significant mental illness Hypertensive or hypotensive condition. Any condition that would prevent the subject from giving voluntary informed consent. An implanted brain stimulator. Aneurysm clip or other metal in the head (except mouth Enrolled or plans to enroll in an interventional trial during this study. Scalp wounds or infections. Claustrophobia precluding MRI Frequent seizures (>1/week)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Navigated TMS examination<br>20 patients with brain tumor in the vicinity of the central motor region scheduled for elective surgery will undergo pre-operative Navigated TMS examination to determine the localization of primary motor cortex and motor representation areas of specific muscles | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distance between motor representation area localization by NBS to that determined by DCS |  | immediate post-operative period | 
| Comparison of DTI results based on using NBS motor representations as seed to those obtained using DCS results as seeds |  | immediate post-operative period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the relative distance of NBS anf fMRI identified motor representations to those determined by DCS |  | immediate post-operative period | 
| Assess safety of navigated TMS in this patient population by capturing all Serious Adverse Events |  | During and after navigated TMS examination |