Abnormal qEEG in TBI patients. (a) Average normalized power spectrum representation of all TBI patients and controls that underwent qEEG. Note the significant increase in delta power and the decrease in the alpha band in TBI patients compared to controls (inset). (b) Power spectrum averages of patient subgroups according to the occurrence of seizures. While both the PTE and the non-epileptic group had elevated delta power compared to controls, only PTE patients had a significant reduction of alpha and increase of theta power. *= .