Background: Electroencephalography may provide useful information about consciousness and cognitive processing in patients who have traumatic brain injury. Sleep disturbance after traumatic brain injury may impair cognitive function and affect rehabilitation.
Methods: In 15 patients who had chronic diffuse axonal injury after traumatic brain injury, electroencephalography and neuropsychologic tests were performed. In 8 patients who had subacute and chronic diffuse axonal injury and 7 healthy control subjects, electroencephalography, magnetoencephalography, and neuropsychologic tests were performed to evaluate sleep spindles and cognitive function.
Results: In the chronic stage of diffuse axonal injury, the mean peak frequency of alpha activity was significantly slower in patients who had abnormal than normal electroencephalography. The mean peak frequency of fast spindles, amplitude, and cortical activation source strength in precentral and postcentral regions were significantly slower in patients who had subacute diffuse axonal injury than healthy participants, and these parameters increased from the subacute to the chronic stage of diffuse axonal injury. After neurocognitive rehabilitation, cognitive functions were improved in all patients.
Conclusion: Alpha activity reflects the severity of disturbed consciousness in the acute stage after
traumatic brain injury. Spindles will be an indicator of the recovery of consciousness in the chronic stage.
Electroencephalographic makers may be useful in the diagnosis and prognosis of traumatic brain injury.