Cardenas et al. (1994)
Population: TBI; Mean Age= 29.5yr; Gender: Male=36, Female=0; Mean GCS=5.31; Mean Time Post Injury=4.33yr.
Treatment: Patients randomized to one of 4 treatment protocols: 1) scopolamine, oral physostigmine, washout, placebo (for scopolamine), then placebo (for physostigmine); 2) placebo (for scopolamine), oral physostigmine, washout, scopolamine, then placebo (for physostigmine); 3) placebo (for scopolamine), placebo (for physostigmine), washout, scopolamine, then oral physostigmine; and 4) scopolamine, placebo (for physostigmine), washout, placebo (for scopolamine), then oral physostigmine. Scopolamine was administered at 5µg/hr via a transdermal patch placed behind the ear. Oral physostigmine was administered initially at 2mg 3×/d, but titrated up to 4mg 3×/d over 1wk. Washout period was 1wk, and each treatment phase lasted 8d.
Outcome Measure: Selective Reminding Test (SRT), Wechsler Memory Scale I & II, Digit Symbol, Trail Making Test A & B, Memory Questionnaire, clinical balance tests, serum cholinesterase levels.
- A total of 16 (44%) participants had improved memory scores while taking oral physostigmine (improvement was defined as >50% increase on Long-term storage or Sum Consistent Long-term Retrieval of the SRT).
- Participants were divided into either responder (n=16) or non-responder (n=20) groups based on the SRT.
- Responders showed significantly improved standing time compared to non-responders (p<0.05), suggesting better balance.