Doi R, Morita K, Shigemori M, Tokutomi T, Maeda H: Characteristics of cognitive function in patients after traumatic brain injury assessed by visual and auditory event-related potentials. Am J Phys Med Rehabil 2007;86:641–649.
Using auditory and visual stimuli including facial affective stimuli, we analyzed the P300 components of event-related potentials (ERPs) in patients after traumatic brain injury (TBI) to assess their cognitive characteristics.
Twenty TBI patients and 32 age-matched control subjects were recruited. Using conventional oddball paradigms, visual ERPs were recorded using images of crying and smiling babies as visual stimuli. Auditory ERPs were obtained using 2-kHz tones as stimuli without affective stimuli. The peak amplitude and latency for P300, and the latency for N200, were recorded.
In visual ERPs, the P300 amplitudes were significantly smaller in patients than in controls for the crying baby, but the amplitudes were similar between groups for the smiling baby. Controls showed smaller P300 amplitudes for the smiling baby than for the crying baby, but patients showed no difference. In patients, the P300 latency for both smiling and crying babies was longer than in the controls. Patients' auditory ERPs showed smaller P300 amplitudes but similar P300 latencies compared with controls. The N200 latency in patients was significantly longer than in controls only for the crying baby.
Visual ERPs are a potentially useful marker for evaluating cognitive dysfunction in patients after TBI.
From the Departments of Neurosurgery (RD, MS, TT), Cognitive and Molecular Research Institute (KM), and Neuropsychiatry (HM), Kurume University, School of Medicine, Kurume City, Japan.
This work was supported by grants from Ministry of Health, Labor and Welfare in Japan.
All correspondence and requests for reprints should be addressed to K. Morita, MD, PhD, Cognitive and Molecular Research Institute, Kurume University, School of Medicine, Asahimachi67, Kurume City, Fukuoka, #830-0011, Japan.