In the field of neurobehavioral therapy for seizures, promising research is taking place through the Eberhard-Karls-University of Tübingen at the Institute of Medical Psychology and Behavioral Neurobiology. It is at the University of Tübingen where the techniques for measuring and teaching self-regulation of slow cortical potentials were first developed by Dr. Niels Birbaumer.
Licensed clinical psychologist Dr. Ute Strehl is one of the scientists active in the ongoing research and development of neurobehavioral treatments for seizure disorders in T,bingen. An Assistant Professor on the medical faculty there, she teaches psychology for medical students. In addition to teaching and research, Dr. Strehl is also one of the institute's administrators.
Dr. Strehl brings to her work a background in Behavioral Therapy, Rational Emotive Therapy, and Client Centered Psychology. In 1994 she received the Neuropharmaka Award for Behavioral Research in Parkinson's disease. Her area of research is in developing behavioral treatments for neurological disorders such as Parkinson's and seizures.
ZL: Dr. Strehl, a major component of the behavioral approach to managing seizures is identifying seizure triggers, those things which may lower or raise the seizure threshold, then changing behaviors to raise the seizure threshold. Where do you recommend someone start in this process?
US: It is important to have a detailed behavioral analysis. The ways to keep the seizure threshold high are multifold and have to be individually tailored.
ZL: In the United States the idea of learning self-control of seizures is still met with much skepticism. In general, people with seizure disorders are led to believe they are helpless victims of a neurological disorder over which they are powerless. Responsibility for the control of one's seizures falls into the hands of the treating physician. A behavioral approach implies that seizures are at least somewhat a learned behavior which can be modified or even overcome. A study about slow cortical potentials (SCPs) indicates that what we think is "autonomic" activity of the cerebral cortex, may to some degree be learned. This seems to imply the cerebral cortex may be as pliable and amenable to conscious conditioning as blood pressure and heart rate. How is it that seizures can be learned?
US: The "problem" with the brain, in contrast to blood pressure, heart rate or muscle tension, is that the brain does not tell us anything about itself, i. e., it is mute. There are no receptors for self-perception. But consciousness is not a prerequisite of conditioning. Normally people don't realize when they (i. e., their behaviors) are under operant conditioning schedules. In clinical feedback trials of course, the feedback is perceived consciously, but the process of learning and memory is thought to be 'implicit'.
ZL: Are people with seizures really as helpless as it may sometimes appear, or do they have the ability to influence their seizures more than is typically acknowledged?
US: They are helpless only at the moment when they experience a seizure. Apart from that, many patients report that they are able -- sometimes and with more or less success -- to prevent seizures, to stop them or at least to postpone them.
ZL: One goal of behavioral therapy is to reduce seizure frequency by learning to raise the seizure threshold. What is involved in making a behavioral analysis and what are some of the typical strategies used?
US: From the behavioral therapy point of view, to control one's behavior requires detailed knowledge about the circumstances under which this behavior occurs. The question: "Why do I have seizures?" is changed to "when and where -- under which circumstances -- do I have seizures?" In our program, patients with seizures are encouraged to use diaries and self- observation. If they go into the details, they may learn a lot about how to prevent or control seizures.
As JoAnne Dahl pointed out in her book Epilepsy -- a Behavior Medicine Approach to Assessment and Treatment in Children (1992), antecedents of seizures can be environmental factors (especially important in reflex epilepsies), intrinsic (genetic predisposition, circadian factors, tissue and metabolic factors) as well as extrinsic (sleep deprivation, drug abuse, withdrawal of medication, social isolation / over-excitation...). Identifying eliciting stimuli, high risk situations, together with bodily sensations, emotional state, and state of arousal, should help to prevent seizures by avoiding or coping (if you can't avoid them) with antecedents. In addition to the antecedents, behavioral analysis stresses consequences: what happens after a seizure subsides? Attention, care, avoidance of demanding tasks, can reinforce seizures! Behavioral therapy then focuses on teaching seizure inhibiting techniques and on changing environmental contingencies.
ZL: Can you explain a little about the development of Slow cortical potentials (SCPs) measurement and techniques for training self- regulation of them?
US: SCPs are changes in the polarization of the electroencephalogram (EEG) lasting from 300 milliseconds to several seconds. On the scalp, the amplitude of SCPs ranges from several micro- volts to more than 100 micro- volts during seizures. Negative SCPs result from synchronous postsynaptic potentials in the apical dendrites; positive SCPs are thought to result from inhibitory sources. These neurophysiological considerations suggest an important role for SCPs in the modulation of excitation thresholds of cortical pyramid cells by their apical dendrites. Negative SCPs increase firing probabilities, whereas positive SCPs dysfacilitate [inhibit] the respective cell assembly. Negative Potentials could be observed in animal studies as well as in humans before epileptic seizures which are followed by positive potential shifts after their abatement. In the treatment of epilepsies, patients observe their own SCPs over an interval of 6 - 8 seconds on a screen. Two discriminating stimuli, such as letters or tones, are presented to indicate the required polarity. An object representing the actual SCP (as measured with one electrode on Cz against two linked electrodes behind the ears) moves across the screen. If the required polarity is achieved, the object reaches a goal and positive reinforcement is provided. About 100 trials of operant feedback training are usually performed in a 1 hour session. Trials without feedback are added where patients have to produce positive or negative SCPs contingent on the discriminative stimuli only. Later on, patients train to produce positive SCPs in everyday life situations, especially in those identified with a low seizure threshold.
ZL: What relationship, if any, have you found between SCPs, self-regulation training of SCPs, and cerebral blood flow, which, like other brain activity, is altered during seizures?
US: In a pilot study we explored the cortical activation during SCP-self- regulation with functional imaging (fMRI). Results show that two patients consistently activated the superior and medial frontal cortex during the negativity condition. Moreover, specific activation patterns were found, which presumably depend on the cognitive strategy used by the patients to change their cortical potentials. This shows that regulation of SCPs corresponds with regional cerebral blood flow.
ZL: Many with seizures experience auras, warning of an impending seizure. It seems SCPs training is teaching an individual to recognize a seizure coming on at its earliest stage, even before an aura manifests, then changing the activity to avert a seizure from developing. Is this an accurate perception? What is the subject learning when training to influence the SCPs for seizure control?
US: With the SCP-training the patient learns to inhibit cortical over-excitation. This is central for our treatment program, although there are other important goals concerning self-control of antecedents and consequences as discussed above.
ZL: When was this training first applied to controlling seizures? Was this one of your studies?
US: The training was first applied in the ninteen eighties and published in the early nineties (e.g. Rockstroh et al.*). We replicated this study and extended the treatment program by introducing daily sessions of behavioral therapy (e.g. Kotchoubey et al,**).
ZL: How effective has SCPs training been as a seizure treatment? In what settings is it most and least effective as the only, or as an adjunctive therapy? What about patients who cannot tolerate drugs or who do not want to use them?
US: I would not mind taking patients into the program who don't take AEDs [antiepileptic drugs] at all. They may have even a better prognosis because of lack of side effects of the AEDs. The patients in our studies had partial seizures, they were classified as medically intractable, and were on antiepileptic drugs. Follow up studies have demonstrated a 50% average reduction of seizures. As regards to the single patient, we found some without any change and a few who became seizure free. Patients with extremely negative SCP values before training respond less favorably.
ZL: Do you think behavioral therapy has a larger role in the treatment of seizures than it is now given? What are its strong and weak points?
US: Yes, definitively. Its strength has been demonstrated in many studies. Addressing 'weak points' may be the active role the patient has to play in this process -- but these features are essential to successful behavioral therapy.
ZL: Can you describe any research on SCPs training for seizures now being carried out?
US: Functional MRI [fMRI] and SCP-feedback; and there are several other questions we would like to examine: effects of therapy in patients who don't take drugs; training with children; after training, why do patients show a substantial increase in their IQs?
ZL: What role do you see for SCPs training in the future as a treatment for seizures?
US: If the system (hardware) can be miniaturized and if neurologists as well as psychologists lose their reluctance to deal with neurological diseases, [so behavioral medicine approaches for neurological disorders can advance,] this would be great!
In Germany, patients should contactDr. Strehl.
In the United States contact the Association of Applied Psychophysiology and Biofeedback.
The homepage of the Eberhard-Karls-University of T,bingen, Institute of Medical Psychology and Behavioral Neurobiology can be reached by clicking here
**K,bler, A., Kotchoubey, B., Kaiser, J., Wolpaw,
J. & Birbaumer, N. Brain-computer communication: unlock the locked-in.
Psychological Bulletin (in press).
K,bler, A., Neumann, N., Kaiser, J.,
Kotchoubey, B., Hinterberger, T. & Birbaumer, N. Brain-computer
communication: self-regulation of slow cortical potentials for verbal
communication. Archives of Physical Medicine and Rehabilitation (in press).
For an historical survery of attempts to control seizures click here.
© 2001 Zoë L. Langley