Objectives-To quantify the treatment effect oflocal botulinum toxin injections in writer's cramp a newly developed rating scale of writing performance and a computer assisted analysis of writing speed were used in 31 patients undergoing botulinum toxin therapy.Methods-Baseline data of the writer's cramp rating scale (WCRS, see appendix) and computer based writing speed analysis were compared with those obtained at the time of subjective best response as recorded during follow up visits. Results-The mean dose injected per session was 133-2 units DysportR divided between two forearm muscles. Of all 124 injection sessions during mean follow up of one year 76% produced a good improvement. The most common side effect was weakness (72% of the follow up visits). The WCRS scores as assessed by a blinded videotape review by four independent raters showed good reliability between raters and a significant improvement after treatment (P < 0.001).

For the calculation of changes in oxyhaemoglobin, deoxyhaemoglobin and the redox state of cytochrome-c-oxidase from attenuation data via a modified Beer-Lambert equation the wavelength dependence of the differential pathlength factor (DPF(lambda)) has to be taken into account. The DPF, i.e. the ratio of the mean optical pathlength and the physical light source-detector separation at each wavelength, determines the crosstalk between the different concentrations and is therefore essential for a sensitive detection of chromophore changes. Here a simple method is suggested to estimate the wavelength dependence of the DPF(lambda) from pulse-induced attenuation changes measured on the head of adult humans. The essence is that the DPF is the ratio of the attenuation changes over absorption coefficient changes, and that the spectral form of the pulse correlated absorption coefficient change can be assumed to be proportional to the extinction coefficient of blood. Indicators for the validity of the DPF(lambda) derived for wavelengths between 700 and 970 nm are the stability of the calculated haemoglobin and cytochrome signals with variations of the wavelength range included for their calculation and its overall agreement with the data available from the literature.

From the ECG trace of the sleep polygrams the heart rate Yariability (HRW is derived by determining the intervals between the R peaks, During sleep, transitions of heart rate can be observed in HRV signal which are relevant to changes in the autonomic regulation. For better insight into the vegetative background of sleep, the spectrum analysis of HRV signal and its parameters has been calculated. In particular LF/HF (ratio between the powers in low frequency range over high frequency range) is considered the measure of ympathohagal balance. A trend of such a ratio is compared with the parameters obtained in differen t vegetative tests (Rest to Stand, Valsalva-maneuver etc.). The HR V signal showed characteristic patterns in the time and in the frequency domains in the different sleep states. The presented method offers a pronounced sensibility to explore the autonomic regulatory activities during sleep. IntroductionIn man, alterations of Autonomic Nervous System ( A N S ) function has generally been studied by means of measuring the functional state of different end organs, in particular of the heart. A number of simple tests based on cardiovascular refleses have been developed and used especially in individuals with diabetis mellitus. Most of these tests are provoking a tachycardiac transient episode followed by a bradycardiac one. Determining the ratio of the longest over the shortest R-R interval a crude quantification of the autonomic regulation capacities can be obtained. In 'steady state' condition also spontaneous fluctuations of the heart rate can be observed in man. Many authors have tried to extract more detailed information from the beat to beat oscillations of the heart rate, the goal being to obtain a marker of the 'tonic' regulation activities of both the sympathetic and parasympathetic (or vagal) nervous system. In several papers the sympatho-vagal balance obtained from the power spectral density (PSD) of the heart rate variability (HRV, R-R interval series, as detected from 02'76-6547/93 $3.00 0 1993 IEEE an ECG lead) has been widely demonstrated. Three main frequency components have been established by the current literature, in accordance with various hypothesis on their physiological meaning:The 'respiratory' rhythm of heart period variatiqn, defined as high-frequency (HF) spectral component, is generally considered a marker of vagal modulation;the rhythm corresponding to vasomotor waves and present in heart period and arterial pressure (also referred to as Mayer waves) variabilities, defined as the low-frequency (LF) component, is always increased in condition of sympathetical stimulation and therefore is considered a prevalent marker of sympathetic activation; the very low frequency (VLF) component, due probably to long term regulatory mechanisms, such as humoral factors, temperature and other slow components; a reciprocal relation exists between the power of the LF and HF rhythms, that is similar to that characterising the sympatho-vagal balance: it is then possible to quantify such balance ...

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