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

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.

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.