Göttingen, Universiẗat, Diss., 2004.

Zugl.: Tübingen, Univ., Diss., 2009

Zugl.: München, Univ., Diss., 2009

Konstanz, Univ., Diplomarbeit, 1998.

Die zervikale spondylotische Myelopathie kann zu schweren neurologischen Funktionsstörungen führen. Vor allem durch die Störung der Feinmotorik und des Gangbilds kann es zu einer Beeinträchtigung im alltäglichen Leben kommen. Eine operative Dekompression des Rückenmarks kann ein Fortschreiten der neurologischen Symptome verhindern oder abmildern. Ziel dieser Studie war die Erfassung unterschiedlicher neurologischer Dysfunktionen bei zervikaler Myelopathie präoperativ sowie die Evaluierung der funktionellen Veränderung nach operativer Dekompression. Hierbei wurden verschiedene - objektive und subjektive - Messmethoden angewandt. Die Erfassung der feinmotorischen Dysfunktion lag dabei im Vordergrund, da diese in der Literatur bis jetzt nur unzureichend untersucht und beschrieben wurden. Daneben wurde die Regeneration der kernspintomographisch gemessenen Schädigung des Myelons nach operativer Dekompression untersucht. In dieser Studie wurde ein digitales Graphiktablett zur quantitativen und objektiven Erfassung der feinmotorischen Dysfunktion bei zervikaler Myelopathie benutzt. Eine Beeinträchtigung der Feinmotorik wurde vor allem bei komplexen Schreibaufgaben festgestellt, welche am ehesten Schreibaufgaben im alltäglichen Leben entsprechen. Im Einklang mit früheren Studien wurde auch in dieser Studie eine Störung des Gangbilds bei Patienten mit zervikaler Myelopathie festgestellt. Die Dauer der Symptome bis zur Operation konnte als einziger signifikanter Einflussfaktor für den Schweregrad der feinmotorischen Dysfunktion ausgemacht werden. Das Geschlecht, der BMI, der Beruf und Sport hatten in dieser Analyse weder einen Einfluss auf den klinischen noch auf den neuroradiologischen Schweregrad der zervikalen Myelopathie. Nach operativer Dekompression verbesserten sich die feinmotorische Funktion sowie das Gangbild der Patienten. Auch die subjektiven Scores zur Erfassung der neurologischen Funktion (European Myelopathy Score, Nurick-Score) sowie die Schmerzen (Numerische Rating-Skala) verbesserten sich postoperativ. Zudem nahm die Länge des pathologischen Signals im MRT ab. Faktoren, die einen Trend zur Korrelation mit den postoperativen Veränderungen der Funktion zeigten, waren das Alter der Patienten und die Symptomdauer. In dieser Studie konnte kein Einfluss des BMIs, der Anzahl der operierten Höhen oder der Art des Operationszugangs festgestellt werden. Obwohl die Anzahl der untersuchten Patienten begrenzt war, gestaltete sich die Gruppe heterogen (Alter, Geschlecht, BMI, Dauer der Symptome). So konnte ein möglichst breites Spektrum an Patienten mit zervikaler Myelopathie untersucht werden. Die wichtigste Limitation dieser Studie war die hohe drop-out Rate in den postoperativen Verlaufsuntersuchungen. Daher konnten die Ergebnisse der Längsschnittanalyse nur an einer kleinen Patientengruppe ermittelt werden und bei der Untersuchung von Einflussfaktoren für das postoperative Ergebnis nur Tendenzen erkannt werden. Ob diese Faktoren einen prognostischen Wert für das postoperative Ergebnis haben, müsste in weiteren Studien an einem größeren Kollektiv untersucht werden. / Spondylotic cervical myelopathy may lead to severe neurological dysfunction. Especially fine motor dysfunction and gait disturbance can cause impairment in everyday life. Operative decompression of the myelon can prevent or attenuate a progression of neurological symptoms. The goal of this study was the assessment of different neurological dysfunctions in cervical myelopathy preoperative and the evaluation of functional changes after operative decompression. Various, objective and subjective, methods of measurement where used. The assessment of fine motor dysfunction was predominant because it has not been investigated and described in detail yet. Furthermore postoperative recovery of pathological findings in MRI after operative decompression was assessed. In this study a digital graphic tablet was used to investigate quantitatively and objectively fine motor dysfunction in cervical myelopathy. Impairment of fine motor function was predominantly found in complex writing tasks, which correspond to writing tasks in everyday life. As shown in previous studies we found a gait disturbance in patients with cervical myelopathy. Duration of symptoms until operation was found to be the only significant factor influencing the severity of fine motor dysfunction. Sex, BMI, occupation and sports habits had no affect on the clinical or neuroradiological severity of cervical myelopathy. After operative decompression, fine motor function and gait pattern improved. Also, subjective scores, which assess neurological function (European Myelopathy Score, Nurick score) and pain (numeric rating scale) improved postoperatively. In addition, the length of pathological signal in MRI decreased. Factors that showed a tendency to correlation with postoperative changes of function were age and duration of symptoms. In this study no influence of BMI, number of operated levels or ventral vs. dorsal approach was found. Although the number of patients was limited (n = 28), the group was heterogeneous (age, sex, BMI, duration of symptoms). Thus a relatively broad spectrum of patients with cervical myelopathy could be assessed. The most important limitation of this study was the high drop out rate in the postoperative follow-up. Therefore the results of the longitudinal analysis could only be assessed in a small group of patients, and in the assessment of factors influencing the postoperative changes only tendencies could be found. If these factors have a prognostic value for the postoperative outcome should be investigated in further studies with a larger group of patients.

Although fine motor performance declines with increasing age, older adults are able to improve their performance with motor practice. However, existing studies show mixed results regarding an effect of age on the amount of learning. Moreover, less is known about how age- and learning dependent behavioral changes are reflected on a neurophysiological level. Alpha and, especially, beta power assessed using electroencephalography (EEG) represent reliable markers of neurophysiological processes during motor task performance that need more attention in aging literature. Moreover, acute cardiovascular exercise has been shown to improve motor performance and trigger motor learning processes in young adults. However, this promising approach has not been considered in aging literature so far. Furthermore, the physical fitness level seems to be positively associated with motor performance and motor learning processes. But again, less is known about this association in healthy older adults. Both approaches might help to better understand or even counteract age-related changes in fine motor performance and motor learning. To explore these research topics, two empirical studies were conducted within this dissertation project. In both studies, motor performance and motor learning were assessed on a behavioral level using a precision grip force modulation task. The force modulation task required participants to match a visually presented sinusoidal target force by applying isometric force with the thumb and index finger to a force plate. Processes on a neurophysiological level were measured with an EEG and analyzed with a main focus on (alpha and) beta power. Study 1 aimed to further characterize age-related differences in fine motor performance and motor learning on a behavioral and neurophysiological level. Furthermore, key influencing factors that determine fine motor performance and motor learning in older adults on a behavioral level were investigated. Hence, a sample of young adults and older adults performed a short-term motor learning session, conducted a cardiovascular fitness test, motor fitness tests, and strengths tests. Study 2 focused on the effects of a session of acute exercise on fine motor performance and motor learning in a sample of healthy older adults. Participants were assigned to an experimental group (performing a session of acute cardiovascular moderate intensity exercise on a stationary bicycle) or a control group (listening to an audiobook). Both groups performed a motor learning experiment over two consecutive days. Young adults outperformed older adults in terms of performance variability, temporal precision, and force precision in the force modulation task. The lower behavioral performance was accompanied by higher beta activity in parietal and occipital areas. Although results were different with respect to the analyzed parameter, overall, the amount of motor learning in the force modulation task was not diminished in older adults compared to young adults. Beta power during motor performance was not affected by motor practice. However, beta power at rest increased from pre practice to post practice, especially in older adults. Fine motor performance of older adults was increased more directly after an acute cardiovascular exercise session than after rest. Moreover, frontal beta activity was higher directly after exercise, pointing to better cognitive resources to perform the task after exercise than after rest. Third, a high cardiovascular fitness level predicted a good fine motor performance in the force modulation task in older adults. Findings of the current dissertation project enhance the understanding of age-related changes in fine motor performance and motor learning using a precision grip force modulation task. Furthermore, approaches are presented that counteract age-related changes, improve motor functions, and determine good levels of fine motor performance in healthy older adults.