The electroencephalogram (EEG) is a physiologic measure of cerebral function that has been used by some to assess coma and prognosticate survival and global outcome after traumatic brain injury (TBI). Surface recordings of the brain's electrical activity reveal distinct patterns that indicate injury severity, depth of unconsciousness, and patient survival. The data produced with traditional qualitative studies, however, does not allow resolution and quantification of the wave frequency spectrum present in the brain. As a result, conventional EEG typically has only been used for gross and qualitative analyses and is not practical for use in long-term patient monitoring or as a sophisticated prognostic tool. One area of investigation that is working to address the limitations of conventional EEG has been the development and implementation of Fourier Transform (FT) EEG which resolves and quantifies frequency bands present in the brain. When FT analysis is applied to EEG, it provides concurrent and continuous monitoring, resolution, and quantification of all frequencies emitted. This review discusses the history and significance of conventional EEG and provides a review of how FT-EEG, commonly referred to as Quantitative EEG (QEEG), is being used in the clinical setting. The specific applications and significance of QEEG methods regarding treatment of patients with TBI are discussed in detail. The advantages, disadvantages, and future directions of QEEG in TBI are also discussed.
Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina (Wallace)
Instructor, Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania (K. Wagner)
Lecturer, Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania (P. Wagner)
Chairman and Medical Director, Department of Physical Medicine and Rehabilitation, Charlotte Institute of Rehabilitation, Charlotte, North Carolina (McDeavitt)
Address correspondence to: Amy K. Wagner, MD, Department of Physical Medicine and Rehabilitation, University of Pittsburgh, 3471 5th Avenue, Kaufmann Building, Suite 901, Pittsburgh, Pennsylvania 15213. Email firstname.lastname@example.org.