- Patients planned for radiosurgery for benign disorders (Groups 1&2).
- Patients planned for prophylactic cranial irradiation (Group 3)
- Previous cranial radiation
- Severe psychiatric disorder
- Severe cognitive or memory impairment (MMSE < 21)
- Non-English speaking, which will potentially make memory testing difficult and
- Other medical conditions deemed by the PI or associates to make the patient
ineligible for protocol procedures
- Patients on steroid medications.
- Left hand dominant patients
- Dose exposure to left hippocampus >0.5Gy and <2Gy. We will attempt to estimate dose
to hippocampus prior to enrollment using pre-planning on diagnostic imaging to
minimize exclusion of patients due to dose exposure >0.5 Gy and < 2Gy following
baseline memory testing.
- Benzodiazepine or narcotics given on the day of radiotherapy/radiosurgery prior to
completion of the study procedures
- Previous brain surgery within one year prior to radiosurgery
- Pregnant women