Sensorimotor conditioning as a primary insomnia treatment

Chronic insomnia is a major public health problem afflicting millions of individuals along with their social environment. Even today little is known about the mechanisms, causes, clinical course, comorbidities, and consequences of chronic insomnia. Present evidence suggests that psychological disturbance and associated hyperarousal may play a key role in the aetiology and maintenance of chronic primary insomnia. Using instrumental sensorimotor rhythm conditioning (ISC) we will aim to directly address the cognitive hyperarousal associated with insomnia. Two early biofeedback studies from Peter Hauri (1981, 1982) indicate that SMR conditioning might be indeed efficient for treating "psychophysiological insomnia". Furthermore, recent data from our own laboratory indicate an increase in sleep spindle generation, a decrease in sleep onset time as well as a positive effect on declarative memory performance after ten sessions of ISC treatment in a young healthy student population. Although this evidence is encouraging a thorough evaluation of ISC for primary insomnia is still missing. Utilizing a placebo-controlled, cross-over counterbalanced within-subject design we will study the efficacy of non- pharmacological SMR treatment as compared to a placebo treatment (randomized frequency feedback) of identical intensity. Subjects will be blind to the treatment modality and will undergo ten hours of training within a 3-weeks period. At the beginning and the end (i.e., after 10 hrs) of each treatment condition we will extensively evaluate sleep and daytime functioning using various questionnaires, cognitive tasks, actigraphy as well as polysomnography (two nights pre- and two nights post- each treatment block). The two treatment modalities will be separated by a 3-months washout period to avoid carry-over effects. Besides evaluating treatment efficacy it is important to also study the neuronal key mechanisms which are disturbed or altered by the specific disease. Using full-head EEG montages and sophisticated analyses techniques (e.g., event-related synchronization and time-frequency analysis using wavelet transforms) the present project aims to identify altered brain oscillations and intends to evaluate their change in the course of treatment and symptom relief. Thereby, we hope to further elucidate the poorly understood pathophysiology of insomnia and provide clues which specific electrophysiological changes go in hand with subjective improvement in sleep quality or daytime functioning. The better we know which specific aspects of brain activity are altered by the disorder the better we will also be able to directly address these maladaptive changes and refine our treatment attempts (e.g, instrumental conditioning protocols) in the future. Altogether, SMR treatment might provide a promising alternative, especially in situations when pharmacotherapy is contraindicated such as for paediatric or geriatric patients, patients already using other medications, having existing medical conditions, or having a high risk for substance abuse or addiction.

Chronic insomnia is a major public health problem affecting millions of individuals along with their social environment. Even today little is known about the mechanisms, causes, clinical course, comorbidities, and consequences of chronic insomnia. Present evidence suggests that psychological disturbance and associated hyperarousal may play a key role in the aetiology and maintenance of chronic primary insomnia. In the present study we trained patients using sensorimotor rhythm (SMR) neurofeedback which is a method in which patients see their own brain activity (recorded with EEG electrodes) online on a computer screen. Whenever subjects succeed to enhance the SMR rhythm - a brain oscillation which is also known to be abundant during light sleep and especially during sleep onset (in form of so-called sleep spindles) - participants got a positive feedback. Using this technique we were able to enhance (over 10 learning sessions) SMR activity (study 1) during waking and also associated spindles during sleep in young (sub-clinical) insomnia patients. Most interestingly, it was found that also subjective sleep quality was enhanced when patients succeeded in that kind of biofeedback training. In a second study with older insomnia patients and more pronounced sleeping problems we then performed a more extensive long-term study over several months (12 times neurofeedback training, 12 times placebo training and 9 sleep laboratory nights). These patients appeared to increase the SMR rhythm - in the real neurofeedback but not the sham feedback placebo condition - over the brain region where feedback was provided. However, so far analyses did not reveal any beneficial effects on sleep quality or memory performance overnight. Subjective benefits were evident but not different from the placebo control condition. In addition, we could shed light on the question in how far sleep can help to better consolidate freshly encoded material. Data indicate that overnight forgetting is much more pronounced in the declarative (i.e., fact knowledge, like Vienna being the capital of Austria) than in the procedural memory domain (e.g., of a motor skill like tapping a complex sequence with fingers). Furthermore, it appears that insomnia patients can make up for most of their sleep-associated problems in attention and memory. Only when we introduced new interfering material in the morning in the declarative memory task (learning word-pairs) insomnia patients appeared to show stronger forgetting as compared to a healthy control group. In the procedural memory domain the insomnia patients on the other hand even appear to be quicker in learning a new motor skill. It is suspected that the unusual high motivation level and hyper-arousal of that subject group can explain these unexpected results. In concluding the data indicate that besides healthy individuals also young sub-clinical people suffering from primary insomnia can experience subjective as well as objective benefits from SMR neurofeedback. However, older and/or more strongly affected insomnia patients seem to lack a clear beneficial effect in sleep quality and memory performance. Overall we believe that it is important to emphasize the importance of sufficient sleeping time on a daily basis. Respecting basic "sleep hygiene" rules does not only support well-being the next morning but also helps to protect newly learned information against interfering material the following days.