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Hippocampal Radiation Exposure and Memory

This study has been completed.
Information provided by (Responsible Party):
University Health Network, Toronto Identifier:
First received: January 16, 2008
Last updated: June 21, 2016
Last verified: June 2016

Neurocognitive impairment as a result of gamma knife radiosurgery has not been well studied and is poorly understood. Radiosurgery to the base of skull for the treatment of benign and malignant disorders may consequently impair memory function. There is a need to evaluate changes in memory function that may be associated with such exposures.

In this pilot study, we will investigate changes in hippocampal-dependent memory function in 10 patients receiving a low SRS dose to the hippocampus. We will also investigate such changes in a no-dose control group and a high-dose control group. This study will provide preliminary estimates of variance in memory changes associated with radiation exposure, and will then permit us to design future studies with the appropriate sample size justification.

Arteriovenous Malformation Schwannoma Trigeminal Neuralgia

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Hippocampal Radiation Exposure and Memory: A Pilot Study

Resource links provided by NLM:

Further study details as provided by University Health Network, Toronto:

Enrollment: 1
Study Start Date: September 2007
Study Completion Date: December 2013
Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
(Experimental group): Receiving > 2 Gy SRS to left hippocampus (n=10)
(Low-dose control group): Receiving < 0.5 Gy SRS to left hippocampus (n=10)
(High-dose control group): Receiving whole brain PCI (n=10)


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Patients who have consented to GK radiosurgery or cranial radiation.

Inclusion Criteria:

  • Patients planned for radiosurgery for benign disorders (Groups 1&2).
  • Patients planned for prophylactic cranial irradiation (Group 3)

Exclusion Criteria:

  • Previous cranial radiation
  • Severe psychiatric disorder
  • Severe cognitive or memory impairment (MMSE < 21)
  • Non-English speaking, which will potentially make memory testing difficult and unreliable.
  • 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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00603694

Canada, Ontario
Joey & Toby Tanenbaum Gamma Knife Centre, Toronto Western Hospital
Toronto, Ontario, Canada, M5T 2S8
Sponsors and Collaborators
University Health Network, Toronto
  More Information

Responsible Party: University Health Network, Toronto Identifier: NCT00603694     History of Changes
Other Study ID Numbers: 07-0023-CE
Study First Received: January 16, 2008
Last Updated: June 21, 2016

Keywords provided by University Health Network, Toronto:

Additional relevant MeSH terms:
Trigeminal Neuralgia
Trigeminal Nerve Diseases
Facial Neuralgia
Congenital Abnormalities
Arteriovenous Malformations
Neurologic Manifestations
Nervous System Diseases
Peripheral Nervous System Diseases
Neuromuscular Diseases
Signs and Symptoms
Vascular Malformations
Cardiovascular Abnormalities
Cardiovascular Diseases
Vascular Diseases
Neoplasms, Vascular Tissue
Neoplasms by Histologic Type
Neuroendocrine Tumors
Neuroectodermal Tumors
Neoplasms, Germ Cell and Embryonal
Nerve Sheath Neoplasms
Neoplasms, Nerve Tissue
Facial Nerve Diseases
Mouth Diseases
Stomatognathic Diseases processed this record on September 21, 2017