Attention and memory dysfunction after traumatic brain injury : cholinergic mechanisms, sensory gating and a hypothesis for further investigation

• Published in: Brain injury 1999, Vol.13 (1), p.1-13
• Main Authors: ARCINIEGAS, D, ADLER, L, TOPKOFF, J, CAWTHRA, E, FILLEY, C. M, REITE, M
• Format: Article
• Language: English
• Subjects: Acetylcholine - pharmacology; Acetylcholine - therapeutic use; Adult; Attention - drug effects; Attention - physiology; Biological and medical sciences; Biomarkers; Brain Injuries - complications; Brain Injuries - physiopathology; Cholinergic Fibers - physiology; Cognition Disorders - drug therapy; Cognition Disorders - etiology; Cognition Disorders - physiopathology; Discrimination (Psychology) - physiology; Emotions - physiology; Evoked Potentials, Auditory - physiology; Female; Hippocampus - physiopathology; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; Memory Disorders - drug therapy; Memory Disorders - etiology; Memory Disorders - physiopathology; Middle Aged; Neuropsychological Tests; Receptors, Cholinergic - physiology; Sensory Thresholds - physiology; Traumas. Diseases due to physical agents; Volition - physiology
• ISSN: 0269-9052; 1362-301X
• DOI: 10.1080/026990599121827

Traumatic brain injury (TBI) is a common occurrence, with a rate of nearly 400,000 new injuries per year. Cognitive and emotional disturbances may become persistent and disabling for many injured persons, and frequently involve symptomatic impairment in attention and memory. Impairments in attention and memory have been well characterized in TBI, and are likely related to disruption of cholinergic functioning in the hippocampus. Additionally, disturbances in this neurotransmitter system may also account for disturbances in sensory gating and discriminative attention in this population. The electroencephalographic P50 waveform of the evoked response to paired auditory stimuli may provide a physiologic market of impaired sensory gating among TBI survivors. The first application of this recording assessment to the TBI population is reported. Preliminary findings in three cases are presented, and the interpretation of impaired sensory gating in this population is discussed. Given the impact of TBI on cholinergic systems, the effects of cholinergic augmentation on attention and memory impairment, and the availability of an electrophysiologic marker of cholinergic dysfunction responsive to cholinergic agents, a testable cholinergic hypothesis for investigation and treatment of these patients is proposed.