2024, Volume 30, Issue 4
MODAFINIL AND GALANTAMINE FOR COUNTERACTING WAKEFULNESS-RELATED FATIGUE: ASSESSMENT VIA CRITICAL FLICKER FUSION
RAFAŁ LEWKOWICZ1, ANNA PRZEWODZKA1, JOANNA ŁASZCZYŃSKA1
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1Military Institute of Aviation Medicine
Autor korenspondencyjny: RAFAŁ LEWKOWICZ; Military Institute of Aviation Medicine; email: rlewkowicz@wiml.waw.pl
Streszczenie
Introduction: The critical flicker fusion (CFF) threshold is a well-established neurophysiological marker of temporal visual resolution and cortical excitability, with higher thresholds reflecting increased alertness and wakefulness. This study aimed to evaluate the effects of modafinil and galantamine on central nervous system arousal during sustained wakefulness using CFF as an objective measure of stimulant-induced modulation of perceptual processing.
Methods: Twelve healthy male volunteers (mean age = 24 years) participated in a randomized, double-blind, placebo-controlled, crossover study consisting of three non-consecutive test sessions: modafinil (100 mg), galantamine (10 mg), and placebo. Each session included four testing points and simulated prolonged wakefulness. The drug was administered after ~27 hours of continuous wakefulness. CFF thresholds were measured in both ascending (flicker-to-fusion) and descending (fusion-to-flicker) directions using a validated CFF device under controlled environmental conditions.
Results: Modafinil significantly elevated CFF thresholds compared to placebo in both ascending and descending paradigms, indicating enhanced cortical arousal. Galantamine showed a significant increase in the descending threshold at only one measurement point relative to placebo. No stimulant–measurement interaction emerged, suggesting that the effect did not vary significantly across sessions. However, time-course analyses showed a non-monotonic profile: after a 10:30 dose, CFF rose toward late morning then attenuated by early afternoon, likely reflecting circadian/homeostatic influences and individual pharmacokinetics/pharmacodynamics.
Conclusions: Modafinil, but not galantamine, increased CFF thresholds in both ascending and descending paradigms, consistent with enhanced cortical arousal. Operationally, dosing time and mission phase are critical considerations; aligning administration with rising circadian drive and pairing pharmacological treatment with non-pharmacological countermeasures may help sustain benefits.
Słowa kluczowe
sleep deprivation, fatigue, alertness, military aviation, circadian rhythms, stimulants