Schlaf, Rapid Eye Movement und Aufmerksamkeit bei Patienten mit Amyotropher Lateralsklerose

Ziel der vorliegenden Dissertation war es, die Schlafarchitektur, die schnellen Augenbewegungen im Schlaf (REM; rapid eye movement) und die Aufmerksamkeit bzw. Informationsverarbeitung in Patienten mit Amyotropher Lateraler Sklerose (ALS) zu untersuchen. Amyotrophe Laterale Sklerose und andere degenerative neurologische Erkrankungen haben meist milde bis schwere Schlafstörungen zur Folge, die auf direkte und indirekte Ursachen der Krankheit und deren Fortschreiten zurückzuführen sind. In der ersten Studie wurden Schlafmessungen bei zehn Patienten in verschiedenen Stadien von Amyotropher Lateraler Sklerose in drei Nächten durchgeführt und Tagesschläfrigkeit objektiv mittels EEG-basierten multiplen Schlaflatenzmessungen und Tests zur Aufrechterhaltung der Schlaflosigkeit während des Tages erfasst. Subjektive Schlafqualität und Tagesschläfrigkeit wurde mit Fragebögen erhoben. In der zweiten Studie dienten polysomnographische EOG (Elektrookulogramm) Messungen als Grundlage zur Analyse der schnellen Augenbewegungen im Schlaf, um eine mögliche Erhaltung der unwillkürlichen extraokulären Muskelbewegungen der Augen im REM Schlaf zu evaluieren. Die dritte Studie im Rahmen dieser Dissertation war darauf ausgerichtet, die Aufmerksamkeit und Informationsverarbeitung bei 14 ALS Patienten und einer gesunden Kontrollgruppe mit auditorisch und visuell evozierten P300 EEG Potentialen zu vier verschiedenen Tageszeitpunkten zu untersuchen. Die Ergebnisse der ersten Untersuchung zeigten, dass die Schlafeffizienz in ALS Patienten signifikant herabgesetzt ist, eine Verlängerung des Schlafstadiums I stattfindet und eine verkürzte REM Schlafphase zu finden ist. Mehr als die Hälfte der ALS Patienten leiden unter milder Tagesschläfrigkeit, während keiner der TeilnehmerIinnen Schwierigkeiten hatten im Laufe des Tages wach zu bleiben. Diese Ergebnisse spiegelten sich auch in den Resultaten der subjektiven Erfassung von Schlafqualität und Tagesschläfrigkeit wider mit berichteter schlechter Schlafqualität und mild ausgeprägter Schläfrigkeit während des Tages. Die Hauptursache könnte in dem häufig berichteten Auftreten von motorischen Symptomen und Blasenschwäche während der Nacht liegen. Im zweiten Teil der Dissertation konnte erfolgreich nachgewiesen werden, dass sich die Funktion der extraokulären Motoneuronen signifikant mit dem Fortschreiten der Krankheit verschlechtert, welches sich in der signifikanten Verminderung der REM Komponenten von Amplitude, Dichte und Dauer zeigte. Zuletzt wurde ein verändertes zeitliches Muster in der Aufmerksamkeit für die auditorisch evozierte P300 bei ALS Patienten gefunden, obwohl sich ALS Patienten und Gesunde nicht grundsätzlich unterscheiden.The aim of this dissertation was to investigate sleep architecture, rapid eye movement, and alertness in patients diagnosed with amyotrophic lateral sclerosis (ALS) at different stages of the disease including subjective and objective measures of sleep quality. Amyotrophic lateral sclerosis and other types of neurological diseases lead to mild to severe sleep disturbances resulting from direct and indirect factors due to the progression of the disease. First, 10 patients at varying stages of amyotrophic lateral sclerosis, some artificially ventilated and fed, were polysomnographically recorded over the course of three nights as well as for daytime sleepiness during the day by EEG-based Multiple Sleep Latency Tests (MSLT) and Maintenance of Wakefulness Tests (MWT). Subjective sleep quality and sleepiness were assessed by means of questionnaires. In the second study, polysomnographic electrooculogram (EOG) recordings served as the basis for the analysis of rapid eye movements (REM) to evaluate the possible preservation of involuntary extraocular eye movement muscles during REM sleep. The third study was aimed at investigating alertness/information processing in 14 ALS patients and matched healthy controls using auditory and visually evoked P300 EEG potentials over the course of four time points during the day. First, ALS patients demonstrated reduced sleep efficiency, significantly prolonged stage 1 sleep and decreased REM sleep. Six of ten ALS patients displayed mild daytime sleepiness (MSLT), but all had normal scores for daytime wakefulness as measured with the MWT. These results were reflected in subjective sleep quality and daytime sleepiness findings with reported poor sleep quality with mild daytime sleepiness likely caused by nocturnal motor symptoms and nocturia as the most prominent factors. Second, it was demonstrated that function of extraocular motor neurons significantly decline over the course of the progression of amyotrophic lateral sclerosis reflected by significant deterioration in REM components amplitude, density and duration. Finally, no significant differences between ALS patients and healthy controls could be found, but a different time pattern in alertness over the course of the day became apparent in patients with amyotrophic lateral sclerosis for auditory P300

Circadian course of the P300 ERP in patients with amyotrophic lateral sclerosis - implications for brain-computer interfaces (BCI)

Background: Accidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). Brain-computer interfaces (BCI) based on electroencephalography represent an important approach to establish communication with these patients. The most common BCI for communication rely on the P300, a positive deflection arising in response to rare events. To foster broader application of BCIs for restoring lost function, also for end-users with impaired vision, we explored whether there were specific time windows during the day in which a P300 driven BCI should be preferably applied. Methods: The present study investigated the influence of time of the day and modality (visual vs. auditory) on P300 amplitude and latency. A sample of 14 patients (end-users) with ALS and 14 healthy age matched volunteers participated in the study and P300 event-related potentials (ERP) were recorded at four different times (10, 12 am, 2, & 4 pm) during the day. Results: Results indicated no differences in P300 amplitudes or latencies between groups (ALS patients v. healthy participants) or time of measurement. In the auditory condition, latencies were shorter and amplitudes smaller as compared to the visual condition. Conclusion: Our findings suggest applicability of EEG/BCI sessions in patients with ALS throughout normal waking hours. Future studies using actual BCI systems are needed to generalize these findings with regard to BCI effectiveness/efficiency and other times of day

Tracking risk profiles and outcome in a medium secure service for women: use of the HoNOS-secure

Female forensic mental health patients are a highly selected group who present exceptional clinical and behavioral challenges along with highly complex treatment needs. St. Andrew's Healthcare Women's Service offers a ‘best practice’ psychosocial treatment program in conditions of medium security. The outcomes of 60 women residents between 2003 to 2008 are described in terms of risk, behavior, symptomatology, and social functioning using HoNOS-secure. The instrument was sensitive to change in this population, including the security scale, which captured highly significant clinical improvements. Some of the challenges associated with measuring outcomes for this group are discussed. The needs of women in secure services can be effectively addressed, enabling movement to less secure settings and further improvement

Classifying EEG and ECoG Signals without Subject Training for Fast BCI Implementation: Comparison of Non-Paralysed and Completely Paralysed Subjects

We summarize results from a series of related studies that aim to develop a motor-imagery-based brain-computer interface using a single recording session of EEG or ECoG signals for each subject. We apply the same experimental and analytical methods to 11 non-paralysed subjects (8 EEG, 3 ECoG), and to 5 paralysed subjects (4 EEG, 1 ECoG) who had been unable to communicate for some time. While it was relatively easy to obtain classifiable signals quickly from most of the non-paralysed subjects, it proved impossible to classify the signals obtained from the paralysed patients by the same methods. This highlights the fact that though certain BCI paradigms may work well with healthy subjects, this does not necessarily indicate success with the target user group. We outline possible reasons for this failure to transfer