Effects of physostigmine on scopolamine–induced changes in quantitative electroencephalogram and cognitive performance

✍ Scribed by Ulrike Ebert; Reinhard Oertel; Keith A. Wesnes; Wilhelm Kirch

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 184 KB
• Volume: 13
• Category: Article
• ISSN: 0885-6222
• DOI: 10.1002/(sici)1099-1077(199804)13:3<199::aid-hup974>3.0.co;2-3

✦ Synopsis

The eects of physostigmine on scopolamine-induced changes were investigated in a randomized, double-blind crossover study utilizing quantitative electroencephalogram (qEEG) and cognitive tasks. Ten healthy male volunteers received scopolamine 0 . 6 mg subcutaneously. After 90 min, single doses of either 0 . 5, 1 . 0 and 2 . 0 mg physostigmine salicylate or placebo were administered subcutaneously in randomized order. qEEG, cognitive function and the visual analogue scale were recorded before and at 1, 2, 3, 4, 6, and 8 h after scopolamine administration; that was 0 . 5, 1 . 5, 2 . 5, 4 . 5, and 6 . 5 h after physostigmine administration. Scopolamine produced an increase in delta (1 . 25±4 . 50 Hz) and theta power (4 . 75±6 . 75 Hz) in qEEG 1 h after administration compared to baseline, while physostigmine decreased the spectral delta power density in qEEG compared to placebo. The maximal eect of physostigmine was seen up to 1 . 5 h after injection. A dose-dependent reversal of the scopolamine induced decrements in cognitive performance was found 0 . 5 h after administration of physostigmine. Psychometric tests sensitively discriminated between the doses of physostigmine, and showed dose-and time-dependent eects. The results suggest that physostigmine may reverse the scopolamine-induced changes in both qEEG and cognitive function. This reversal was temporary and of short duration.