Clinical Advantages of Quantitative Electroencephalogram (QEEG)−Electrical Neuroimaging Application in General Neurology Practice
J. Lucas Koberda, Andrew Moses, Paula Koberda and Laura Koberda
Clin EEG Neurosci 2013 44: 273 originally published online 26 March 2013 DOI: 10.1177/1550059412475291
J. Lucas Koberda1, Andrew Moses1,2, Paula Koberda1,2, and Laura Koberda1,2
Clinical EEG and Neuroscience
a EEG and Clinical Neuroscience Society (ECNS) 2013
Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1550059412475291 eeg.sagepub.com
QEEG-electrical neuroimaging has been underutilized in general neurology practice for uncertain reasons. Recent advances in computer technology have made this electrophysiological testing relatively inexpensive. Therefore, this study was conducted to evaluate the clinical usefulness of QEEG/electrical neuroimaging in neurological practice. Over the period of approximately 6 months, 100 consecutive QEEG recordings were analyzed for potential clinical benefits. The patients who completed QEEG were divided into 5 groups based on their initial clinical presentation. The main groups included patients with seizures, headaches, post-concussion syndrome, cognitive problems, and behavioral dysfunctions. Subsequently, cases were reviewed and a decision was made as to whether QEEG analysis contributed to the diagnosis and/or furthered patient’s treatment. Selected and representative cases from each group are presented in more detail, including electrical neuroimaging with addi- tional low-resolution electromagnetic tomography analysis or using computerized cognitive testing. Statistical analysis showed that QEEG analysis contributed to 95% of neurological cases, which indicates great potential for wider application of this mod- ality in general neurology. Many patients also began neurotherapy, depending on the patient’s desire to be involved in this treat- ment modality.
An objective test to help diagnose ADHD: Quantitative EEG
Like all psychiatric disorders, ADHD is diagnosed based on the presence of particular behavioral symptoms that are judged to cause significant impairment in an individual's functioning, and not on the results of a specific test. In fact, recently published ADHD evaluation guidelines from the American Academy of Pediatrics (AAP) explicitly state that no particular diagnostic test should be routinely used when evaluating a child for ADHD.
While most ADHD experts would agree that no single test could or should be used in isolation to diagnose ADHD, there are several important reasons why the availability of an accurate objective test would be useful.
First, many children do not receive a careful and comprehensive assessment for ADHD but are instead diagnosed with based on evaluation procedures that are far from optimal.
Second, although AAP guidelines indicate that specific diagnostic tests should not be routinely used, many parents are concerned about the lack of objective procedures in their child's evaluation. In fact, many families do not pursue treatment for ADHD because the the absence of objective evaluation procedures leads them to question the diagnosis. You can read a review of an interesting study on this issue at www.helpforadd.com/2006/january.htm
For these reasons an accurate and objective diagnostic test for ADHD could be of value in many clinical situations. Two important conditions would have to be met for such a test to be useful.
First, it would have to be highly sensitive to the presence of ADHD, i.e., individuals who truly have ADHD as determined by a comprehensive evaluation should score positive for ADHD on the test. If the test were 100% sensitive, every individual who has ADHD based on current diagnostic criteria would score positive on the test. As the sensitivity of a test drops, the number of "false negatives" - normal test results in individuals who truly have the disorder increase and its utility goes down.
Second, individuals who don't have ADHD should never score positive on the test, i.e., a positive result should occur only for individuals with ADHD and no one else. When a diagnostic test has high specificity, individuals without the condition rarely score positive on the test. When specificity is low, many individuals without the condition will score positive and may be incorrectly diagnosed as a result. This is referred to as a "false positive".
Although many psychological tests yield different results, on average, for individuals with and without ADHD, they are not sensitive or specific enough to be particularly useful when making individual diagnostic decisions. For example, a widely used objective test in ADHD evaluations are Continuous Performance Tests (CPTs). These tests provide a computerized measure of a child's ability to sustain attention and refrain from impulsive responding. Although average performance on CPTs for children with ADHD is below that of peers, and CPT data can be helpful when thoughtfully integrated with other diagnostic information, these tests yields too many false positives and false negatives to be useful as an "objective" diagnostic test for ADHD.
David Rabiner, Ph.D.
Dept. of Psychology & Neuroscience
Durham, NC 2770