Unlike the well-examined cardiovascular changes during movement stimuli, changes of cerebral hemodynamics and cerebral metabolism in physical exercises have, as yet, rarely been studied. Our objective was to investigate whether there are changes in cerebral hemodynamics and cerebral metabolism caused by active and passive movement stimuli. Response to repetitive active and passive movement stimuli was studied in 14 volunteers (8 females, 6 males; mean age, 35.2+/-8 yr). Each volunteer was subjected to four measurement series while performing a defined active and passive exercise program of the right upper or right lower limb. Measurement series were designed according to Aaslid's "evoked flow test"; exercises were performed for 20 s, followed by a rest of 20 s. This sequence was repeated 10 times in each series. As a measure of cerebral hemodynamics mean and peak blood flow velocity of the middle cerebral artery were recorded by transcranial Doppler sonography (Multidop-X-DWL). In addition, cerebral metabolism was quantified in a subsample by means of oxygenic cytochrome aa3 (respiratory chain enzyme), cerebral oxygen saturation using near infrared spectroscopy (Critikon). As well, noninvasive blood pressure (Penaz method) and expiratory pCO2 were measured. Compared with resting measures, an increase in mean cerebral blood flow velocity of the middle cerebral artery of 3.8% (P = 0.003, paired t test) was observed after active exercises of the right lower limb and 3.5% after active exercises of the right upper limb. Respective changes were 3.4% (P = 0.004) for passive exercises of the lower limb and 4.6% (P = 0.007) for passive exercises of the right upper limb. Peak cerebral blood flow velocity of the middle cerebral artery showed an even more pronounced increase during passive and active exercises in all cases, with values of between 12.2% (P < 0.001) and 13.6% (P < 0.001). Significant increases (1.5-3%) of cytochrome aa3 and cerebral oxygen saturation were observed during active and passive exercises. These studies show that active as well as passive exercises are followed by an increase of cerebral blood flow velocity. We attribute the increase of cerebral hemodynamic and cerebral metabolism to cerebral activation and autoregulative mechanisms.

The purpose of the study contained herein was to investigate the effects of old traditional physiotherapeutic treatments on cerebral autoregulation. Treatment consisted of complete body immersion in cold or warm water baths. Fifteen volunteers were investigated by means of transcranial Doppler sonography and a servo-controlled noninvasive device for blood pressure measuring. One group of 8 volunteers (mean age, 27.2+/-3.5 yr; gender, 3 females/5 males) was subjected to cold baths of 22 degrees C for 20 min Another group of 7 volunteers (mean age, 52.1+/-8.5 yr; gender, 4 females/3 males) took hyperthermic baths at rising water temperatures from 36 degrees to 42 degrees C, increased by 1 degree C every 5 min. Each volunteer in both groups underwent autoregulation tests two to four times before, during, and after the thermic bath. Dynamic autoregulation was measured by the response of cerebral blood flow velocity to a transient decrease of the mean arterial blood pressure, induced by rapid deflation of thigh cuffs. The autoregulation index, i.e., a measure of the speed of change of cerebral autoregulation, was used to quantify the response. Further parameters were core temperature, blood pressure (mm Hg) and CO2et. During hypothermic baths, core temperature decreased by 0.3 degrees C (P = 0.001), measured between preliminary phase and the end of the bath; the autoregulation index decreased significantly (P < 0.05) from 5.3 before the bath to 4.25 during the bath. During hyperthermic baths, the autoregulation index increased from 6.0 to 7.5 and 8.9 (P < 0.001), with an increase of core temperature of 0.4 degrees C. The main cerebral autoregulation system is dependent on changes of core temperature, provoked by hypothermic or hyperthermic whole-body thermostimulus. Application of hyperthermic baths increased the autoregulation index, and hypothermic baths decreased the autoregulation index. Further studies are needed to prove the positive effects of thermo-stimulating water applications on cerebral hemodynamics in patients with cerebral diseases.

SUMMAR Y This study assessed the main, curvilinear, interactive and gender-dependent effects of job demands, job control and social support in the prediction of sleep quality. Participants were 348 male and 76 female executives and managers from Germany, Austria and Switzerland. A multiple regression controlling for age, occupational hierarchy and various health behaviors was computed. On the level of the main effects of the Job-Demand-Control-Support (JDCS) model, the results indicate a sleeppromoting effect of social support. A significant three-way interaction of job demands, job control and social support was observed. This interaction confirms the buffering effect of high job control and high social support on high job demands. Further, this three-way interaction of the JDCS dimensions is moderated by gender as indicated by a significant four-way interaction. The directions of the significant interactions suggest that female executives are especially prone to react with impaired sleep quality when exposed to isolated high-strain jobs. The study seems to imply that the JDCS model is a suitable framework for the prediction of sleep quality among executives and managers. The results suggest that the JDCS model might contribute to a better understanding of the higher prevalence of poor sleep amongst female executives. Further, the results imply that high job control and high social support might help executives to maintain good sleep quality despite experiencing high job demands.k e y w o r d s gender, industrial psychology, sleep, stress

Although research is needed to improve reliability and to test validity further, the DUSOI was shown in the present study to be a methodology that is reasonable for consideration as an international classification of health problems by their severity in primary care patients.