Quantitative EEG analysis before and after liver transplantation.

Quantitative EEG has been shown to be effective for the assessment of hepatic encephalopathy. Initial quantitative EEG studies of patients who had undergone liver transplantation demonstrated improvement of frequency and the alpha-theta power ratio in the occipital area. This study involved the assessment of comprehensive quantitative EEG variables over the entire cortex following transplantation. Fourteen subjects underwent EEG recording prior to transplantation. Eight (6 without complications and 2 having problems with rejection) underwent the same recording between 3 and 6 months following transplantation. For all subjects, EEG variables showing significant changes from pre- to post-transplantation included posterior alpha frequency (increase, p < or = .03), central theta absolute power (decrease, p < or = .03), theta relative power over anterior, central, and posterior regions (decrease, p < or = .02, p < or = .01, p < or = .03, respectively), posterior beta absolute power (increase, p < or = .01), and central and posterior beta relative power (increase, p < or = .04, p < or = .04, respectively). When the two subjects with complications were removed from the analyses, these variables and also anterior alpha absolute power (increase, p < or = .02), alpha relative power over anterior, central, and posterior regions (increase, p < or = .05, p < or = .03, p < or = .04, respectively), and anterior and central theta absolute power (decrease, p < or = .05, p < or = .04, respectively) showed significant pre- to post-transplant changes. In conclusion, a combination of quantitative EEG parameters which are most affected by liver transplantation might provide an effective assessment tool for determining and quantitatively monitoring the cerebral status of post-transplant patients.