Adjunctive Donepezil Therapy and Genetic Risk Factors of Cognitive Dysfunction in Brain Tumor Survivors

A significant number of brain tumor patients who received radiation or chemotherapy have thinking problems as a result of their treatment. The purpose of this study is to find out if treatment with Aricept (donepezil) may improve some aspects of thinking abilities in patients with brain tumors who received radiation or chemotherapy. This research will also study whether persons having particular genes for a blood-borne substance called apolipoprotein E (APOE) are more likely to have thinking problems after radiation or chemotherapy treatment for their brain tumors. The findings of this study will help us find out whether Aricept can improve thinking abilities after cancer treatment, and whether some of the thinking difficulties may be in part related to having certain genes.

A significant proportion of brain tumor patients treated with radiation or chemotherapy who are in disease remission experience cognitive sequelae from their treatment. Cognitive dysfunction can be of sufficient severity to interfere with their ability to function at premorbid professional and social levels. There are, however, no approved pharmacological interventions for improving cognitive functions in cancer patients who display treatment-related cognitive deficits. Donepezil, an acetylcholinesterase inhibitor, has been shown to provide cognitive and functional benefits in patients with Alzheimer's disease, vascular dementia, and in patients with other neurological diseases without known cholinergic deficiency. The proposed pilot study will examine the efficacy of donepezil in improving cognitive functions in adult brain tumor patients treated with radiation and/or chemotherapy who have mild to moderate cognitive difficulties. Neuropsychological measures of executive, psychomotor speed, attention, and memory abilities will be administered prior to, during and following donepezil therapy. The proposed study will also test the hypothesis that the apolipoprotein E (APOE) e-4 allele correlates with the development of cognitive impairment after radiation or chemotherapy treatments. The proposed investigation is unprecedented and may provide preliminary information about (1) a pharmacological therapy that could improve cognitive functions in this population, and (2) a genetic risk factor that may increase vulnerability to radiation or chemotherapy-induced cognitive decline.

Eligibility Criteria:
Inclusion Criteria:

* diagnosed with a brain tumor and treated with cranial irradiation and/or chemotherapy, and in stable remission of their disease at the time of enrollment.
* completed radiation and/or chemotherapy treatment at least 6 months prior to being enrolled in the study.
* who obtain a Mini-Mental Status Examination (MMSE) score ranging from 18 to 28 at the time of enrollment.
* are at least 18 years of age.
* are English speaking.
* have capacity to give consent

Exclusion Criteria:

* Patients with active or progressive disease on recent MRI of the brain either at the time of enrollment, or during the study period.
* with a pre-existing uncontrolled seizure disorder, or significant renal or hepatic impairment.
* taking the following medications: antipsychotics, psychostimulants.
* patients who have been on selective serotonin re-uptake inhibitors (SSRIs) for less than 3 months at the time of enrollment.
* with uncontrolled behavioral or mood disturbances.
* have their anticonvulsant medication(s) or dosage(s) changed less than 30 days prior to enrollment.
* currently receiving donepezil or other cholinesterase inhibitors.
* who is pregnant.
* unable to cooperate or complete cognitive tests.