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The Timed Up & Go (TUG) test is a simple test for gait and balance that requires no special equipment and can be part of a routine clinical examination. Combined with the development of motion capture technologies, the possibilities of assessing individual TUG sub-components (i.e. sit-to-stand, gait, turn, turn-to-sit) are increasing. The clinical evaluation of an instrumented TUG requires reliable values. We analysed the intra-session repeatability of the iTUG sit-to-stand, gait and turn parameters in three conditions: (1) single, (2) cognitive dual-tasks, and (3) manual dual-tasks in older adults and Parkinson's disease (PD) patients. The repeatability coefficient (RC) was calculated for each of the 18 parameters. The repeatability varied across subject groups, the performed tasks, and the TUG subcomponent. The gait subcomponent had 6 non-repeatable spatio-temporal parameters and 2 non-repeatable parameters for the arm swing. The parameters of the turn subcomponent can be considered as non-repeatable in both groups under the manual dual-task condition and in HC under the single-task condition. When comparing PD to HC, the repeatability of the majority of the single-task parameters was higher in PD whereas lower under dual-tasks. In PD, the major part of gait parameters had a higher repeatability under single-tasks than dual-tasks. In contrast, HC exhibited better repeatability of dual-tasks than single-tasks. Repeatability can be used to assist researchers and clinicians to select adequate parameters with respect to the purpose of motion assessment.

Exploration of motor cortex activity is essential to understanding the pathophysiology in Parkinson's Disease (PD), but only simple motor tasks can be investigated using a fMRI or PET. We aim to investigate the cortical activity of PD patients during a complex motor task (gait) to verify the impact of deep brain stimulation in the subthalamic nucleus (DBS-STN) by using Near-Infrared-Spectroscopy (NIRS). NIRS is a neuroimaging method of brain cortical activity using low-energy optical radiation to detect local changes in (de)oxyhemoglobin concentration. We used a multichannel portable NIRS during finger tapping (FT) and gait. To determine the signal activity, our methodology consisted of a pre-processing phase for the raw signal, followed by statistical analysis based on a general linear model. Processed recordings from 9 patients were statistically compared between the on and off states of DBS-STN. DBS-STN led to an increased activity in the contralateral motor cortex areas during FT. During gait, we observed a concentration of activity towards the cortex central area in the "stimulation-on" state. Our study shows how NIRS can be used to detect functional changes in the cortex of patients with PD with DBS-STN and indicates its future use for applications unsuited for PET and a fMRI.

Turning is an essential part of human movement. Turning manoeuvres are affected by age, neurological disorders, or frailty. Analyses of the walking turn and its alterations could provide valuable information about functional independence. Most studies involving wearable sensors quantify the turn by descriptive statistical values such as the mean or maximum of the signal. Along with growing interest in walking turn analysis, new parameters should be proposed. From statistics we adapted a parameter, referred to as waveform skewness, that describes the shape of the 180 ° turn signal. This parameter is then compared to established ones and an intraclass-correlation is calculated. The mutual relationship between the proposed parameter and established ones is investigated via correlation. In addition, the effect of different circumstances (temporal alignment, signal scaling and time shift) to the proposed parameter is quantified. Waveform skewness showed a moderate intra-class correlation and a high correlation with the signal peak value. The results showed that waveform skewness is not sensitive to the time shift but is sensitive to signal scaling and temporal alignment. Comparing the waveform skewness between the two subject groups revealed significant differences between Parkinson disease patients and the control group. Quantitative assessment of the 180 ° turn may allow for more objective and sensitive determinations of movement disorders and pathologies.

The Timed Up & Go test (TUG) is functional test and is a part of routine clinical examinations. The instrumented Timed Up & Go test enables its segmentation to sub-tasks: sit-to-stand, walking forward, turning, walking back, stand-to-sit, and consequently the computation of task-specific parameters and sub-tasks separately. However, there are no data on whether walking forward parameters differ from the walking back parameters. This study tested the differences between walking forward and walking back in the TUG extended to 10 m for 17 spatio-temporal gait parameters. All parameters were obtained from a GAITRite® pressure sensitive walkway (CIR Systems, Inc.). The differences were assessed for healthy controls and Parkinson's disease (PD) patients. None of investigated parameters exhibited a difference between both gait subtasks for healthy subjects group. Five parameters of interest, namely velocity, step length, stride length, stride velocity, and the proportion of the double support phase with respect to gait cycle duration, showed a statistically significant difference between gait for walking forward and walking back in PD patients. Therefore, we recommend a separate assessment for walking forward and walking back rather than averaging both gaits together.

Disorders of gait seriously affect the functional state and quality of life of patients with Parkinson’s disease (PD). Impaired brain function underlies disorders of movement control in PD, however functional brain imaging with magnetic resonance (fMRI) is not feasible during gait. Near-Infrared Spectroscopy (NIRS) is a portable imaging method for measuring brain activity. It uses low-energy optical radiation to detect local changes of (de)oxyhemoglobin concentration in the cerebral cortex, like a fMRI. We included 8 patients with advanced PD chronically treated with DBS STN. Brain activity was recorded with the NIRSport. Gait was examined in 10 cycles, during which the active and resting phases alternated. Changes in oxyhemoglobin concentration were calculated from the native NIRS signal using a modified transformation of the Lambert-Beer Law. The signals were filtered in the 0.015–0.3 Hz band and the least-squares algorithm was fitted with the HRF function for each cycle separately, from which the median was finally calculated. The activity of the motor cortex was significantly higher during gait in the OFF compared to ON state (p = 0.02). In contrast, in other regions no differences were found. A higher motor cortex activity shown in the DBS OFF compared to ON state may reflect the impairment of gait control in PD. In general terms, the present study demonstrates the potential utility of the NIRS method in detecting functional changes of the brain during gait in patients with PD.

Head tremor is a common clinical manifestation in essential tremor (ET) and can also occur as dystonic tremor (DT) in cervical dystonia. The clinical differentiation of head tremor due to ET and DT is not easy. Therefore, we developed instrumental methods using an accelerometer and an optical motion capture system to precisely measure and analyze head and hand tremor, and for distinguishing between ET and DT. Head tremor was measured with a Wireless XSens accelerometer and hand tremor by the Optitrack V120 Trio (MOCAP) and the tremor amplitude was computed. We included 24 patients fulfilling the criteria for ET (12 M, 12 F, mean age 58, SD 10) and 26 patients with cervical dystonia (5 M, 21 F mean age 64, SD 10). In supine position, visible head tremor disappeared in 5 out of 13 ET (38%) and in 8 out of 20 DT patients (40%). In ET patients, we found a strong correlation between the amplitudes of head tremor in sitting and supine position (rho=0.91, p Measurement of hand tremor with MOCAP confirmed the predicted difference in tremor of the upper limbs in patients with ET and DT. In the contrary, the analysis of head tremor amplitude did not confirm the hypothesis that head tremor disappears in supine position in patients with ET. The correlations show that the ET is just suppressed and depends on its amplitude. DT suppression is unpredictable.

Clinical benefits of pallidal deep brain stimulation (GPi DBS) in dystonia increase relatively slowly suggesting slow plastic processes in the motor network. Twenty-two patients with dystonia of various distribution and etiology treated by chronic GPi DBS and 22 healthy subjects were examined for short-latency intracortical inhibition of the motor cortex elicited by paired transcranial magnetic stimulation. The relationships between grey matter volume and intracortical inhibition considering the long-term clinical outcome and states of the GPi DBS were analysed. The acute effects of GPi DBS were associated with a shortening of the motor response whereas the grey matter of chronically treated patients with a better clinical outcome showed hypertrophy of the supplementary motor area and cerebellar vermis. In addition, the volume of the cerebellar hemispheres of patients correlated with the improvement of intracortical inhibition which was generally less effective in patients than in controls regardless of the DBS states. Importantly, good responders to GPi DBS showed a similar level of short-latency intracortical inhibition in the motor cortex as healthy controls whereas non-responders were unable to increase it. All these results support the multilevel impact of effective DBS on the motor networks in dystonia and suggest potential biomarkers of responsiveness to this treatment.

Deep brain stimulation (DBS) of the globus pallidus interna is an effective tool for the treatment of dystonia with possible distant effects reaching beyond the basal ganglia network.We analyzed the cortical silent period (CoSP) to test inhibitory circuits at the cortical level, and the cutaneous silent period (CuSP) and the H-reflex to test inhibitory circuits at the spinal level.The upper limb muscles of 16 patients (9F, aged 54±(SD)16years) with generalized (N=9) and cervical (N=7) dystonia treated with DBS bilaterally were examined by the CoSP, CuSP and H-reflex in two states with random order: (i) in DBS ON and (ii) in DBS OFF condition two hours later, and compared with healthy controls.While the CuSP and H-Reflex did not differ between groups and remained unaffected by DBS, the CoSP was influenced significantly in dystonia. The CoSP onset latency was shortened (p0.05 corrected) and the CoSP duration prolonged (p0.01 corrected) in ON versus OFF condition. This effect was especially larger in generalized or phasic type of dystonia. Compared to healthy controls, the CoSP latency and duration became shorter in patients during the OFF condition only.The pallidal DBS did not affect the spinal inhibitory circuitry in dystonia. However, the abnormally low cortical inhibition was normalized after DBS possibly offering more efficient suppression of aberrant dystonic movements.

Introduction Pallidal stimulation (GPi DBS) is an effective treatment of dystonic syndromes with a relatively high variability of clinical benefit. As patients with dystonia typically have a lower ability to suppress unwanted movements, we expected a decreased intracortical inhibition of motor cortex, which can be potentially reversed by GPi DBS. Objectives To distinguish between patients with dystonia according to the clinical outcome of GPi DBS using short-latency intracortical inhibition (SICI) of the motor cortex assessed by paired transcranial magnetic stimulation (TMS). Patients & methods We examined 22 patients (mean age 51 ± 17 years) with dystonia of various distribution and origin treated by GPi DBS in different time intervals from implantation. Paired TMS with subthreshold conditioning stimulus followed by a supratreshold testing stimulus 2.5 ms later were applied to the motor cortex to elicit SICI in GPi DBS ON and GPi DBS OFF condition two hours later. The clinical effect (CE) was expressed as a change in the dystonic score (Burke-Fahn-Marsden Dystonia rating Scale or Toronto Western Spasmodic Torticollis Scale) between actual GPi DBS ON condition and the preoperative state. Results The SICI was less effective in patients than in controls regardless of the ON and OFF conditions (p Download : Download high-res image (206KB) Download : Download full-size image ). Non-responders (n = 9; 50% CE, p Download : Download high-res image (225KB) Download : Download full-size image Fig. 2a) and in addition, the shortest MEP onset latency was observed in non-responders (p Conclusions Our results suggest that the best responders to GPi DBS treatment exhibited a similar level of SICI as in healthy controls. On the contrary, non-responders were unable to increase their reduced cortical inhibition and effectively suppressed dystonic symptoms. We speculate that decreased intracortical inhibition with abnormally fast transmission volley is underpinned by the poor complexity of the motor network. Supported by the grant IGA MZ CR NT12282-5/2011.

Deep brain stimulation (DBS) of the human basal ganglia is an important therapeutical method of alleviating the symptoms of dystonias of various aetiology. Accurate targeting of the permanent stimulation electrode into the Globus Pallidus internus (GPi) is key to positive long-term effects. The suitability of the location is preoperatively assessed by microelectrodes that register single-unit neuronal activity. The aim of this paper is to analyse electrophysiological recordings of patient's neuronal activity with a focus on the identification of markers relevant to the patient's clinical state. Specific biomarkers may help determine targets and patient-specific protocols for neuromodulation therapy. In this study, 13 patients chronically treated with double-sided DBS GPi were examined with microrecordings. The signal (24 kHz) processing included bandpass filtering (0.5–5 kHz), automated detection of the artefacts, and feature extraction. The results show that the GPi was distinguished from its vicinity with p

The Timed Up and Go test (TUG) is widely used in both research and clinical settings. The most common parameter for quantification of functional decline is the duration of a performed TUG. Analysis of the turn part of the TUG could provide valuable information about functional decline. Notwithstanding, there are only a few studies that deals with the TUG turn processing. This study proposes a novelty parameter—wave kurtosis (WK) that provides quantitative metrics for describing and comparing turn patterns. The WK is designed to evaluate the shape of the signal waveform. The WK quantifies the peak of the signal, its position and tails. The TUG-turn angular rate was analysed. Intra-class correlations (ICC) of WK and the strength of a linear association between WK and established turn parameters (turn duration, peak angular rate, and mean angular rate) were calculated. The reliability of WK about the vertical axis was moderate (ICC > 0.50), while reliabilities of the frontal axis and sagittal axis varied according to the subject group. The WK about the vertical axis was moderately correlated with turn duration, mean value and peak value. Utilization of waveform parameters opens a new area of TUG turn analysis and may allow for a more sensitive determination of movement disorders or fall risk assessment. Therefore, future studies utilizing turn movement may benefit from the use of the wave kurtosis.

Exploration of motor cortex activity is essential to understanding the pathophysiology in Parkinson's Disease (PD), but only simple motor tasks can be investigated using a fMRI or PET. We aim to investigate the cortical activity of PD patients during a complex motor task (gait) to verify the impact of deep brain stimulation in the subthalamic nucleus (DBS-STN) by using Near-Infrared-Spectroscopy (NIRS). NIRS is a neuroimaging method of brain cortical activity using low-energy optical radiation to detect local changes in (de)oxyhemoglobin concentration. We used a multichannel portable NIRS during finger tapping (FT) and gait. To determine the signal activity, our methodology consisted of a pre-processing phase for the raw signal, followed by statistical analysis based on a general linear model. Processed recordings from 9 patients were statistically compared between the on and off states of DBS-STN. DBS-STN led to an increased activity in the contralateral motor cortex areas during FT. During gait, we observed a concentration of activity towards the cortex central area in the "stimulation-on" state. Our study shows how NIRS can be used to detect functional changes in the cortex of patients with PD with DBS-STN and indicates its future use for applications unsuited for PET and a fMRI.

We developed a software program, BradykAn, that computes motion characteristics and processes data acquired from compact optical motion capture systems (MoCap) such as Optitrack V120: Trio which provides accurate and easily acquired information about 3-dimensial movement. BradykAn has implemented algorithms and protocols for the evaluation of Unified Parkinson's Disease Rating Scale hand motor tests. The BradykAn was validated on a finger tapping test for patients with Parkinson Disease (PD), where the parameters describing repetitive movement speed, amplitude, and frequency were computed. We examined 55 PD patients (29M,26F), mean age 65 (46–85) years, H&Y stage 2 (1–2.5) and 59 (28M,31F) normal controls, mean age 65 (41–83) years. The analysis delivered significant results in most parameters. The best amplitude decrement parameter (p

Introduction Deep brain stimulation (DBS) of the globus pallidus interna (GPi) is an effective symptomatic treatment of farmacoresistant dystonic syndromes. The sensorimotor cortex of dystonia patients exhibits an exaggerated responsiveness to the TMS (transcranial magnetic stimulation) in conditioning protocols. The aim of our study was to analyse the excitability of the primary motor cortex (MI) in relation to modulation of input from the primary somatosensory cortex (SI) in dystonia patients treated by GPi DBS. Methods We examined 21 patients (mean age 51 ± (SD)17 years) with dystonia treated by GPi DBS. The SI was modulated in DBS ON and OFF conditions by a 2-min series of paired associative stimulation (PAS) with 5 Hz frequency, consisting of electrical stimulation of the median nerve followed by 20 ms of subthreshold TMS pulse. The excitability of the MI was tested by motor evoked potentials (MEP) applied before and after the PAS. The clinical effect (CE) was expressed as a change in the dystonic score between DBS ON condition and the preoperative state. Results The SI PAS caused a decrease of the MEP amplitude in dystonia patients with the GPi DBS ON state in comparison with GPi DBS OFF state ( p p N = 8, p p N = 13, >25% CE) had the MEP amplitude unchanged after the SI PAS in both of the GPi DBS conditions. Conclusion The SI PAS intervention applied over SI cortex affected motor cortex excitability in dystonia patients but not in healthy controls. The GPi DBS reduced the sensorimotor cortex plasticity of dystonia patients under level seen in the GPi DBS off state and even under the level seen in healthy controls. Surprisingly, only poor responders to GPi DBS therapy showed a loss of an inhibitory effect of the SI on the MI immediately after switching stimulation off in comparison with good responders and healthy controls. This may suggest, that the GPi DBS normalizes the excitability of MI through strengthening of the sensorimotor interaction and causes long lasting cortical plasticity changes in good responders which may contribute to better suppression of the dystonic symptoms. Supported by the grants GACR 16-13323S, PROGRES Q27/LF1 and MJFF11362.

Introduction Dystonia patients express less effective intracortical inhibition, which can potentially be restored with pallidal deep brain stimulation (DBS). The DBS-related clinical benefit in dystonia increases relatively slowly, suggesting an induction of slow plastic processes in regions involved with motor control. In our study, we explored the relationship between intracortical inhibition of the motor cortex, brain morphology, and DBS-related clinical effects. Methods Twenty-two patients (mean age 51 ± (SD)17 years) with dystonia of various distribution and etiology treated by chronic pallidal DBS and 22 healthy subjects were included in the study. Voxel-based morphometry of postoperative T1-weighted images (MPRAGE, 1 × 1 × 1 mm) was calculated for gray matter (GM) density in each voxel using CAT12/SPM12 software. Paired TMS with subthreshold conditioning stimulus followed by a supratreshold testing stimulus were applied to the motor cortex to elicit short-latency intracortical inhibition (SICI) of the motor evoked potential. The clinical effect of DBS was expressed as a change in the dystonic score (BFMDS or TWSTRS) between actual DBS ON condition and the preoperative state. Results Dystonia patients showed increased GM density in the supplementary motor area (SMA) and middle cingulate in comparison with healthy controls (p Conclusion Good responders to pallidal DBS treatment exhibited a similar level of SICI as healthy controls but non-responders were unable to increase it. Brain changes of treated patients possibly underwent grey matter rebuilding with cerebellar hypertrophy quantitatively related to the improvement of intracortical inhibition and with hypertrophy in the cortex involved in motor act preparation. All these results support the multilevel impact of effective DBS on motor networks in dystonia. Supported by the grants GACR 16-13323S.

Background Treatment efficacy of pallidal stimulation (GPi DBS) in dystonia varies and the benefit increases slowly, suggesting induction of slow plastic processes in regions involved with motor control. Methods We examined 19 patients (mean age 48 ± (SD)18 years) with cervical (N = 7) or generalized dystonia (N = 12) of various origin by chronic GPi DBS for 57 ± 28 months. Voxel-based morphometry of postoperative T1-weighted images was calculated for gray matter (GM) density in every patient and compared with 20 matched controls. Paired TMS was applied to the motor cortex to elicit short-latency intracortical inhibition (SICI) of the motor evoked potential. The clinical effect of GPi DBS was expressed as a change in the dystonic score (BFMDS or TWSTRS) between actual GPi DBS ON condition and the preoperative state. Results Dystonia patients showed increased GM density in the SMA and middle cingulate in comparison with healthy controls (p Conclusions Brain changes of chronically GPi DBS treated patients possibly reflect “hardwire” rebuilding of motor regions associated with functional improvement. Supported by the grant GACR 16-13323S.

This article describes the development of the measurement and controlling module that can be controlled through some mobile device (smartphone or tablet) application. The design was influenced by the experiences from the former development and user reactions of similar device that was commercially successful and with good reception. The goal was to create a low-end device that would be also very powerful and flexible. The whole system consists of the hardware, software for FPGA and RTOS and software for mobile devices.

The article explains the basic concepts of colorimetry and deals with issues of assessment reflectance quality of special plaster coatings in accordance with current methods of measuring spectral reflectance of the International Commission on Illumination (CIE). The results demonstrate that in the case of coatings with high gloss values leads to a linear increase of chroma depending on the lightness values in the case of measuring devices fitted diffusion geometry. Conversely, if the angle-measuring instrument fitted geometry values of specific purity correlated with values of specific brightness. Analysis BRDF, respectively BSRDF function showed that the previously used dichromatic spectral reflectance model must be extended by an additional parameter explaining the correlation between chroma and lightness at the di:8 measurement geometry.

Objectives To analyse the influence of the primary somatosensory cortex (SI) on the motor cortex (MI) in dystonia in regards to the effectiveness of deep brain stimulation (DBS) of the globus pallidus interna (GPi). Methods We examined 21 patients (mean age 51 ± (SD)17 years) with dystonia treated by GPi DBS. The SI was modulated in DBS ON and OFF conditions by a 2-min series of paired associative stimulation (PAS) with 5 Hz frequency, consisting of electrical stimulation of the median nerve followed by 20 ms of TMS pulse. The excitability of the MI was tested by motor evoked potentials (MEP) applied before and after the PAS. The clinical effect (CE) was expressed as a change in the dystonic score between DBS ON condition and the preoperative state. Results The SI PAS caused a decrease of the MEP amplitude in responders ( N = 8, >50% CE) and in partial responders ( N = 5, 25–50% CE) during both conditions which was indistinguishable from controls. In non-responders ( N = 8, p Discussion Non-responders showed a quick suppression of an inhibitory effect of the SI on the MI after switching stimulation off than when compared with the group of responders and controls. Conclusion GPi DBS normalizes the excitability of MI probably due to strengthening of the sensorimotor interaction, suggesting a longer lasting cortical plasticity in the responders. Significance The SI PAS reduces the excitability of the MI in dystonia according to effectiveness of GPi DBS. Supported by the grants GACR 16-13323S and PROGRES Q27/LF1 .

The relationship between gluconeogenesis from alanine and nitrogen balance after stomach resection was investigated in 13 patients. Partial stomach resection was done in eight patients and total stomach resection was done in five patients. Alanine turnover, carbon flux from alanine to glucose, and glucose turnover were determined by tracer methodology, using the single injection of [U-14C]alanine and [2-3H]glucose. The patients were divided in two groups according to the quantity of administered glucose. Six patients with partial stomach resection received 2.1 to 2.8 g glucose . kg-1 . day-1 and 0.07 to 0.09 g nitrogen . kg-1 . day-1, amounting to 11 to 13 kcal . kg-1 . day-1 (group 1). In group 2 the subjects received 5.4 to 8.2 g glucose . kg-1 . day-1 and 0.12 to 0.26 g nitrogen . kg-1 . day-1; five patients received also 1.2 to 1.8 g fat emulsion . kg-1 . day-1. Total caloric supply was 28 to 60 kcal . kg-1 . day-1. In group 1 the mean potential contribution of gluconeogenesis from alanine to nitrogen loss was between 31 and 67%; in group 2 this contribution was at least 7 to 63%. No correlation was found between nitrogen balance and carbon flux from alanine to glucose. A significant correlation (p less than 0.001) was found between nitrogen balance and, respectively, nitrogen intake and caloric supply. These results suggest that not gluconeogenesis from alanine but nitrogen and caloric demand are major factors influencing nitrogen balance after stomach resection.

Influence of total parenteral nutrition and operation on alanine turnover and venous alanine concentration was determined in 5 patients with stomach carcinoma using single injection technique of U- 14 C alanine. Every patient served as his own control. In the postabsorptive state alanine turnover was 1.63 ± 0.31 mgatC · min −1 , not different from a control group (1.84 ± 0.60 mgatC · min −1 ); during total parenteral nutrition alanine turnover increased to 3.21 ± 0.5g mgatC · min −1 with a rise in alanine concentration from 0.96 ± 0.17 mgatC · L −1 +0.69 ± 0.22 mgatC · L −1 . After surgery during the same total parenteral nutrition alanine turnover increased further to 3.78 ± 0.17 mgatC · min −1 with a lowering of alanine concentration to 1.44 ± 0.22 mgatC · L −1 . The present results show the distinct influence of TPH on alanine kinetics. The present data indicate that alanine turnover cannot be deduced from blood alanine concentration.