Memantine for Neuroprotection and Cognitive Enhancement Following Traumatic Brain Injury

This is a pilot/feasibility study of memantine in severe traumatic brain injury (TBI)
persons, employing a randomized, double-blind, placebo-controlled, design. Outcome
evaluations will occur after 24 weeks of treatment (on medication) and 4 weeks after
treatment discontinuation.

Inclusion Criteria:

- 18-65 years old of age at time of enrollment

- Severe traumatic brain injury (TBI)

- Feeding access (e.g., orogastric (OG), nasogastric (NG), or percutaneous endoscopic
gastrostomy (PEG) tube) permitting delivery of memantine or placebo

- Availability of legally-authorized representative (LAR) to provide consent and
participate in some study activities (e.g., monitoring for side effects, providing
information about the patient)

Exclusion Criteria:

- Pre-existing history of serious neurological disorder

- Pre-existing history of serious psychiatric disorder (e.g., schizophrenia)

- Anticipated poor prognosis, based on the presence of bilaterally fixed and dilated
pupils, severe hemodynamic instability, severe elevations in intracranial pressure
refractory to interventions, or other factors leading to a determination of a
probable non-survivable injury

- Primarily penetrating mechanism of injury (e.g., gunshot wound to the head)

- Isolated epidural hematoma with anticipated good prognosis

- Low probability of participant being compliant or being able to finish study
procedures (e.g., present for outcome rating) in the judgment of the investigator

- Not English speaking (due to inability to complete outcome measure)

- Medical contraindications to memantine: Severe hepatic impairment (defined as albumin
> 15gm/dL, Alk Phos > 375 U/L, ALT > 150 U/L, AST > 120 U/L or bilirubin > 3mg/dL).
Moderate-to-Severe renal impairment (defined as creatinine clearance < 60)

- Pregnancy or breastfeeding