Clinical EEG and Neuroscience

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

Abstract

Clinical EEG and Neuroscience
44(4) 273-285
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.
Research Professor
Dept. of Psychology & Neuroscience
Duke University
Durham, NC 2770

Neurofeedback: Introduction to the special issue

Editorial

It has long been a widely held belief that the brain once developed into adulthood, is an anatomically and physiologically static organ. In early childhood, critical periods of development were thought to exist in which the brain may undergo important changes, as was, for instance, demonstrated by Hubel and Wiesel (1970) for ocular dominance columns, but pathways were considered to be fixed once firmly established. Changes to the brain were only possible in very specific areas of the brain such as the cerebellum and hippocampus by environmental changes (learning). In the beginning of the 1980s, researchers began to develop different views, and evidence became available that the brain possessed self-organising principles, such as after differentiation of peripheral nerves (e.g. Merzenich & Kaas, 1982). This self-organising principle of the brain is now beyond doubt and has become known as neuroplasticity or brain plasticity. Anatomy aside, evidence that the electrophysiology of the brain can be influenced, predates the above findings by nearly half a century.

Neurofeedback entails learning to self-control brain activity largely based on operant conditioning principles, with the aim of improving mental states or processes, whether or not in clini- cal conditions. The finding that the human electroencephalogram (EEG) was susceptible to classical conditioning principles dates back to the 1930s (Durup & Fessard, 1935; Loomis, Harvey, & Hobart, 1936; Jasper & Shagass, 1941), and operant conditioning principles were first applied to the EEG in the 1960s (Kamiya, 1962; Nowlis & Kamiya, 1970; Sterman, Wyrwicka, & Roth, 1969). Ini- tial work on clinical application of neurofeedback was the most developed in the field of attention disorders such as ADHD (Lubar & Shouse, 1976; Elbert, Rockstroh, & Birbaumer, 1984; see Arns & Kenemans, 2013, for a recent review and a theoretical perspective). However, the field of neurofeedback has long been surrounded by an aura of mystery and sceptical antagonism that have hindered progress. Various factors, such as some failed replications, absent or poor control conditions in some early studies, insufficient insight into underlying mechanisms, overstatement of clinical benefits and premature popularisation in society at large, all may have con- tributed to a certain caution in the adoption of neurofeedback as a research theme by university laboratories.

This is now rapidly changing. The last decade has witnessed a sharp rise in the number of publications about neurofeedback (Fig. 1), and this can be interpreted as a sign that an increasing number of research groups are now recognising neurofeedback as a research topic. This seems to be especially the case in European university centres. Advances in technology have greatly simpli- fied the recording of the EEG, so that researchers could focus on more advanced topics, could use and develop more sophisticated research designs, and could apply the neurofeedback methods to a variety of clinical groups. These developments allowed the neu- rofeedback field to mature to where it is now, and this Society of Applied Neuroscience special issue is aimed at providing an overview of the current state of the field.

The Society of Applied Neuroscience (SAN, http://www.applied- neuroscience.org) was established in Europe as an international society to investigate the potential of neurofeedback, to pro- mote research on validation and to encourage cross fertilisation in applied neuroscience. This special journal issue is one of four, an initiative encouraged by Elsevier, which is a themed issue on neurofeedback at the journal editor’s invitation. The three others focus on applied neuroscience, one of which consists of theoret- ical and methodological aspects in the journal Neuroscience and Biobehavioural Reviews, and the other two issues are collections of empirical papers on psychobiology and on development and pathology published in the International Journal of Psychophysi- ology.

Here the focus is mainly on non-clinical applications of neu- rofeedback. Some research laboratories have started using novel techniques that go beyond conventional EEG measurements as input for the feedback process. Especially topographical infor- mation is thought to increase the specificity of neurofeedback techniques. Ruiz, Buyukturkoglu, Rana, Birbaumer, and Sitaram (2014) eloquently review the use of functional magnetic reso- nance imaging (fMRI) in neurofeedback, focussing on functional connectivity between different brain areas. Near-infrared spectog- raphy (NIRS) is used by Kober, Wood, Kurzmann, Friedrich, Stangl, Wippel, Väljamäe, and Neuper (2014) to increase motor-related brain activity, aimed at training patients with focal brain lesions. But even in conventional EEG, topographical information can be increased using techniques such as LORETA, as Maurizio, Liechti, Heinrich, Jäncke, Steinhausen, Walitza, Brandeis, and Drechsler (2014) beautifully demonstrate in the first controlled tomographic study into ADHD.

A second set of articles deals with EEG neurofeedback in improv- ing various aspects of human cognitive performance in non-clinical samples. Reiner, Rozengurt, and Barnea (2014) show that a single session of theta (4–7 Hz) neurofeedback, relative to beta (12–15 Hz) neurofeedback and control groups, increased motor performance in a finger tapping-task. A night’s sleep further improved perfor- mance, as has been found before, but only theta training led to further increases in performance, even lasting as long as a week. In a similar vein, a single session of mu (8–12Hz) suppression neurofeedback over the motor cortex was shown to speed up the acquisition of a procedural learning task by Ros, Munneke, Parkinson, and Gruzelier (2014). Interesting findings such as these cry out for further investigations in applied settings such as elite sports. Using frontal midline theta (4–8 Hz) activity and an ade- quate active control condition, the paper by Enriquez-Geppert, Huster, Scharfenort, Mokom, Zimmermann, and Herrmann (2014) provides information on how such training protocols can be indi- vidualised, and on how training progresses from session to session. The question of how training progresses between and within ses- sions was also studied by Dekker, Sitskoorn, Denissen, and Van Boxtel (2014) for the alpha frequency band, and they addition- ally found specificity in training lower (8–10Hz) versus upper (10–12 Hz) sub-bands. The question whether the healthy ageing brain is also susceptible to plasticity and learning is addressed by the paper of Staufenbiel, Brouwer, Keizer, and Van Wouwe (2014), who showed that this is indeed the case for beta (12–20 Hz) and gamma (36–44 Hz) neurofeedback. At the other end of nor- mal human development, Gruzelier, Foks, Steffert, Chen, and Ros (2014a) show that alpha/theta neurofeedback has a beneficial effect on creativity in normal 11-year old school children, which extends to sustained attention. Alpha/theta neurofeedback was also found to enhance musical creativity in both novice and elite music per- formance in an extensive and well-controlled study by Gruzelier, Holmes, Hirst, Bulpin, Rahman, Van Run, and Leach (2014b).

The above-mentioned studies all employed adequate designs, state-of-the-art methods of analysis and/or they validated their findings by correlating the psychophysiological changes with learn- ing indices (see for review Gruzelier, 2013a,b,c). These rigorous strategies have been developed predominantly in university lab- oratories in which normal healthy participants were used as test subjects. It is the result of the progress in the neurofeedback field that very few studies appear nowadays in which these issues are not handled adequately. Research in the clinical field lags behind in this respect, which is understandable for a variety of reasons, such as practical and ethical ones, but which is also undesirable Arns, Heinrich, and Strehl (2014) provide an important and well-written review of how methodological issues in ADHD research have pro- gressed over time, and provide advice on how to improve on this situation. The study reported by Meisel, Servera, Garcia-Banda, Cardo, and Moreno (2014) had applied many of their recommen- dations, and they found that children with ADHD benefited to an equal extent from forty theta/beta1 neurofeedback training sessions and from medication with methylphenidate, but only neu- rofeedback contributed to academic performance. In addition, the effects lasted for a period of at least six months. In another well- controlled clinical study, Schabus, Heib, Lechinger, Griessenberger,

Klimesch, Pawlizki, Kunz, Sterman, and Hoedlmoser (2014) showed that increasing the sensorimotor rhythm (SMR,12–15 Hz) over the central cortex improves sleep quality and memory performance in insomniacs.

Taken together, and other neurofeedback empirical reports in the SAN special issues (Bergstrom, Seinfield, Arroyo-Palacious, Slater, & Sanchez-Vives (this issue); Gruzelier, 2013d; Gruzelier, Thompson, Redding, Brandt, & Steffert, 2013; Peeters, 2013), the studies reported in this special issue provide an overview of impor- tant current developments in the field of neurofeedback. It is difficult if not impossible to dispute the effects of neurofeedback training after reading through the papers in this issue. However, which specific protocols to use in which clinical or non-clinical cases, how many training sessions should be applied before effects can be seen in those cases, how long these effects last, which exact brain mechanisms are involved, etcetera, are important questions that do not have clear answers in many specific instances, but which clearly warrant further investigations. In this sense, this special issue should be viewed not only as an overview of the current state of affairs, but also as a starting point for further study into neuroplasticity.

Acknowledgements

We are grateful to Prof. Ottmar Lipp for granting us the oppor- tunity to publish this special issue in Biological Psychology and to Elsevier for encouraging SAN to undertake special journal issues to promote the field of applied neuroscience.

Available online 8 December 2013