Cognitive fatigue: an impaired cortical inhibitory replenishment.

PRIMARY OBJECTIVE: The present study explores the cause of cognitive fatigue in persons with traumatic brain injury (TBI), as also in persons with Multiple Sclerosis (MS). Since cognitive fatigue shares many symptoms with chronic sleep deprivation (best described as cumulative excess wakefulness), it was hypothesized that cognitive fatigue is caused by cumulative excess wakefulness because of an impaired sleep efficacy. Recent results about the nature of sleep advocate that sleep aims primarily to replenish the efficiency of cortical inhibitory synapses.

RESEARCH DESIGN: We extensively researched in the TBI and MS literature on cognitive fatigue facts that sustained, or invalidate, our hypothesis.

METHODS AND PROCEDURES: We primary focused on TBI, but cognitive fatigue has received much more interest from the MS research community. We therefore used results from the MS literature to consolidate our TBI findings.

MAIN OUTCOMES AND RESULTS: There are objective reasons related to TBI and MS disease to suppose that NonREM sleep's efficacy is impaired (despite a normal duration of sleep).

CONCLUSIONS: Strategies providing a more efficient NonREM sleep could demonstrate some therapeutic action against cognitive fatigue.