Neuronal and Network Mechanisms of Electrocortical Stimulation

Launched by NORTHWESTERN UNIVERSITY · Apr 25, 2024

Keywords

ClinConnect Summary

This is an observational study that aims to learn how electrocortical stimulation mapping (ECS) works in the brain, especially for language areas. ECS is used during brain surgeries (such as tumor removal or epilepsy monitoring) to identify parts of the brain important for speech and language so doctors can avoid harming them. The researchers will study how ECS affects brain signals at the stimulation site and how it may influence broader language networks, including a comparison with a cooling method that mainly affects the outer brain surface. The plan is to better understand the brain mechanisms behind ECS, which could someday help shorten surgeries and improve outcomes for future patients. The main goal is to see how accurately researchers can identify critical language areas from brain data during stimulation; a secondary goal is to observe language function during the procedures.

Who can participate and what to expect: Adults up to age 80 who already need awake, cortical mapping during brain tumor surgery or during implantation of intracranial electrodes for epilepsy may join. To be eligible, they must be able to speak English and not have major language problems or cognitive issues that would prevent testing, and the tumor or electrodes must not be too close to key language areas. Participants will undergo the usual surgical procedures with ECS (and possibly brief cooling) and will perform simple language tasks like reading or naming pictures during the operation. This study does not test a new drug or device; it collects information from standard care to learn more about language networks in the brain. It is conducted at Northwestern University (Chicago), Johns Hopkins University (Baltimore), and the University of Iowa, with about 65 participants planned and results expected through 2030.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Requiring awake, cortical mapping for brain tumor resection or implantation of intracranial electrodes for extraoperative monitoring for epilepsy
• • For extraoperative patients: Planned electrode coverage including at least parts of frontal and temporal or parietal lobes, preferably both anterior (inferior frontal gyrus) and posterior language areas (superior temporal gyrus) in the language dominant hemisphere
• • For intraoperative patients: Planned craniotomy including parts of both frontal and temporal anterior and posterior language areas in the language dominant hemisphere.
• Exclusion Criteria:
• • Significant language or speech impairment, including but not limited to aphasia, dysarthria, and apraxia of speech, consistently preventing patient from speaking words
• • Non English-speaking (because this is a study of language networks, and second language could be encoded differently)
• • Impaired cognitive function, as determined by neurological testing, such that the patient cannot follow test instructions or provide written informed consent
• • Tumor infiltrating, or within 1 cm of, multiple of the cortical or subcortical areas studied in this proposal (inferior frontal gyrus, precentral gyrus, superior temporal gyrus)
• • Ferromagnetic implants that are MRI incompatible or other contraindications to MRI
• • Pregnancy