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)