Effect of Namenda on Short Term Memory and Attention in Patients With Mild to Moderate Traumatic Brain Injury

Inclusion Criteria:

1. Patients will have persistent memory and attention deficits due to a closed traumatic brain injury not less than one year prior to entrance in the study.
2. Meet or exceed American Congress of Rehabilitation Medicine (ACRM) criteria for mild TBI.
3. Mini-Mental State Exam (MMSE) score of 20 to 27 at the screening visit or a California Verbal Learning Test (CVLT) score for trials 1-5 one standard deviation lower than the age matched normative score. The CVLT score from the medical record may be used for entry criteria if it was obtained one year or more post-TBI and within two years of study entry.
4. Galveston Orientation and Amnesia Test (GOAT) score of at least 75.
5. Be of sufficient cognitive ability to complete neuropsychological tests.
6. Male or female, 18-50 years of age.
7. Females of childbearing potential must use acceptable means of birth control and have a negative screening b-HCG pregnancy test. Acceptable birth control includes hormonal birth control (such as oral birth control pills, implanted or injected contraceptives), an intrauterine device (IUD), surgical sterilization (such as tubal ligation or hysterectomy), a spermicide with barrier methods (condoms or diaphragm), or a partner who has had a vasectomy.
8. Patients taking donepezil (Aricept) or rivastigmine (Exelon) must be at a steady state dose for a minimum of six months.
9. Patients taking any other medication(s) affecting cognition must be at a steady state dose for a minimum of two months.
10. Able to provide written informed consent.
11. Able to read, write, and speak in English.
12. Willing and able to comply with the physician's instructions for all aspects of the study.

Exclusion Criteria:

1. Patients must not have any medical or psychiatric disorder that in the opinion of the PI would interfere with or bias the assessment of efficacy or place their health at risk when placed on the memantine (Namenda) regimen.
2. Patients with a history of seizure are excluded.
3. Patients with a history of severe renal insufficiency are excluded.
4. Patients must not have taken any experimental drug within the last 30 days prior to entering the protocol.
5. Patients must not have taken any drug known to have major organ system toxicity within the last 30 days prior to entering the protocol.
6. Women who are pregnant, nursing, or intend to become pregnant during the study are excluded.
7. Patients with a penetrating TBI are excluded.
8. Patients whose screening laboratory values are 1.5 times greater than ULN are excluded.
9. Patients with systolic blood pressure greater than 180 mm Hg or less than 90 mm Hg or diastolic blood pressure greater than 105 mm Hg or less than 50 mm Hg at the screening visit are excluded.
10. Concomitant use of amantadine (Symmetrel) is prohibited and a washout period of 4 weeks is required before study entry.