Hana Brozová - Academia.edu (original) (raw)

Papers by Hana Brozová

Neurologie pro praxi, 2020

While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio air... more While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio aircraft, they are not as attractive for use in lower bypass-ratio systems and on aircraft that will fly supersonically. The noise of such propulsion systems is also dominated by jet noise, making the study and noise reduction of these exhaust systems very important, both for military aircraft and future civilian supersonic aircraft. This paper presents particle image velocimetry of internally mixed nozzle with different area ratios between core and bypass, and nozzles that are ideally expanded and convergent. Such configurations independently control the geometry of the internal mixing layer and of the external shock structure. These allow exploration of the impact of shocks on the turbulent mixing layers, the impact of bypass ratio on broadband shock noise and mixing noise, and the impact of temperature on the turbulent flow field. At the 2009 AIAA/CEAS Aeroacoustics Conference the authors presented data and analysis from a series of tests that looked at the acoustics of supersonic jets from internally mixed nozzles. In that paper the broadband shock and mixing noise components of the jet noise were independently manipulated by holding Mach number constant while varying bypass ratio and jet temperature. Significant portions of that analysis was predicated on assumptions regarding the flow fields of these jets, both shock structure and turbulence. In this paper we add to that analysis by presenting particle image velocimetry measurements of the flow fields of many of those jets. In addition, the turbulent velocity data documented here will be very useful for validation of computational flow codes that are being developed to design advanced nozzles for future aircraft.

Movement Disorders, 2021

BackgroundExcessive daytime sleepiness (EDS) is a frequent and disabling symptom of Parkinson&#39... more BackgroundExcessive daytime sleepiness (EDS) is a frequent and disabling symptom of Parkinson's disease (PD) without approved treatment. THN102 is a novel combination drug of modafinil and low‐dose flecainide.ObjectiveThe aim of this study is to evaluate the safety and efficacy of THN102 in PD patients with EDS.MethodsThe method involved a randomized, double‐blind, placebo‐controlled, crossover trial testing two doses of THN102 (200 mg/d modafinil with 2 mg/d [200/2] or 18 mg/d flecainide [200/18]) versus placebo; 75 patients were exposed to treatment. The primary endpoint was safety. The primary efficacy outcome was the change in Epworth Sleepiness Scale (ESS) score.ResultsBoth doses of THN102 were well tolerated. ESS significantly improved with THN102 200/2 (least square means vs. placebo [95% confidence interval, CI]: −1.4 [−2.49; −0.31], P = 0.012) but did not change significantly with the 200/18 dosage.ConclusionsTHN102 was well tolerated and showed a signal of efficacy at ...

PloS one, 2015

Falls are a common complication of advancing Parkinson's disease (PD). Although numerous risk... more Falls are a common complication of advancing Parkinson's disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The objective of this prospective study was to investigate clinical and instrumented tests of balance and gait in both OFF and ON medication states and to verify their utility in the prediction of future falls in PD patients. Forty-five patients with idiopathic PD were examined in defined OFF and ON medication states within one examination day including PD-specific clinical tests, instrumented Timed Up and Go test (iTUG) and computerized dynamic posturography. The same gait and balance tests were performed in 22 control subjects of comparable age and sex. Participants were then followed-up for 6 months using monthly fall diaries and phone calls. During the follow-up period, 27/45 PD patients and 4/22 control subjects fell one or more times. Previous falls, fear of falling, more severe motor impairment in the OFF s...

PURPOSE The aim of our study was to evaluate diffusion changes in main subtypes of Multiple Syste... more PURPOSE The aim of our study was to evaluate diffusion changes in main subtypes of Multiple System Atrophy (MSA): MSA-P (Parkinsonian) and MSA-C (cerebellar). We compared MSA patients to healthy subjects as well as MSA-C to MSA-P using TBSS. METHOD AND MATERIALS Patients with probable MSA-P (n=7, 1 Male, 6 Female, 58.8Y±5SD), MSA-C (n=10, 6 male, 4 female, 59.0Y±4SD; for MSA-C/MSA-P n=8, 5 male, 3 female, 58.6Y±5SD) and healthy volunteers (n=10, 5 male, 5 female, 58.6Y±5SD) were included. DWI was performed at 1.5T in 12 non-collinear gradient directions with an SS-EPI sequence. Eddy-current and motion correction, and tensor estimation was done in FSL and FA, MD, axial (AD) and radial (RD) diffusivity were calculated for each voxel and analyzed using TBSS (FA>0.3, 2500 permutations). RESULTS In both MSA-P and MSA-C widespread reduction of FA and increased MD/RD were observed. In the MSA-P group, both FA and RD were decreased in cerebellar peduncles, while MD/AD remained normal. RD...

Neuro endocrinology letters, 2009

We assessed the influence of gait disorders (GD) on quality of life (QOL) in Parkinson's dise... more We assessed the influence of gait disorders (GD) on quality of life (QOL) in Parkinson's disease (PD). In a survey including the PDQ-39 and a new 8-item questionnaire of GD (8-QGD), 491 PD patients estimated their gait at the worst state, the effect of their GD on activities of daily living, compared the severity of GD with the other PD symptoms, evaluated the occurrence of freezing of gait (FOG), levodopa-resistant FOG, falls, activity limitation due to fear of falling (FOF), and the occurrence of injuries. Significant differences in PDQ-39 scores were found between three groups of patients divided with respect to the severity of GD. Linear multiple regression analysis showed that FOF had the highest impact on PDQ-39 scores (r=0.32, p<0.001). These results confirm that GD have a substantial impact upon the QOL in PD and suggest that FOF plays a major role in QOL deterioration.

Assessment, 2014

The Grooved Pegboard Test (GPT) was conceived as a test of manual dexterity, upper-limb motor spe... more The Grooved Pegboard Test (GPT) was conceived as a test of manual dexterity, upper-limb motor speed, and hand-eye coordination. The aim of our study was to test the componential structure of the GPT on an archetypal model of motor impairment, Parkinson's disease (PD). A total of 45 PD patients (33 males, 12 females; age M = 67, range = 49-81; PD duration M = 10, range = 6-20 years; H/Y stage 2, range = 2-3) and 20 age- and education-matched controls (14 males, 6 females; age M = 66, range = 48-80) were included. All participants were investigated using the GPT, Short Falls Efficacy Scale-International, Frontal Assessment Battery (FAB), Montreal Cognitive Assessment (MoCA), and Non-Motor Symptom Scale. Patients were followed for 6 months, using fall diaries and monthly phone calls to define PD fallers (falls ≥ 1; n = 27) and PD nonfallers (falls = 0; n = 18). Using structural equation modeling, the GPT predicted performance on the MoCA (p < .001), but not on the FAB (p = .29)....

Functional neurology

We analysed clinical data in 80 genetically confirmed Huntington?s disease (HD) patients and meas... more We analysed clinical data in 80 genetically confirmed Huntington?s disease (HD) patients and measured the severity of the head of the caudate nucleus (HCN) atrophy using computed tomography-guided planimetry. The results were compared with measurements obtained in 43 age-matched healthy subjects. Mean planimetric measurements of the HCN differed significantly between the HD patients and healthy controls (p<0.001). We observed a significant inverse correlation between duration of HD and HCN planimetric values (p<0.001). Physiological atrophy of the HCN with age was also present in healthy controls, but did not overlap with values obtained in HD patients (p<0.01). Furthermore, we found in our patients a statistically significant inverse correlation between the number of CAG triplet repeats and the age at onset of HD (p<0.001). Neither the number of CAG triplet repeats, nor the age at onset of HD was found to be related to the character of the initial clinical symptoms (mot...

PLoS ONE, 2013

Fractional anisotropy (FA) is the most commonly used quantitative measure of diffusion in the bra... more Fractional anisotropy (FA) is the most commonly used quantitative measure of diffusion in the brain. Changes in FA have been reported in many neurological disorders, but the implementation of diffusion tensor imaging (DTI) in daily clinical practice remains challenging. We propose a novel color look-up table (LUT) based on normative data as a tool for screening FA changes. FA was calculated for 76 healthy volunteers using 12 motion-probing gradient directions (MPG), a subset of 59 subjects was additionally scanned using 30 MPG. Population means and 95% prediction intervals for FA in the corpus callosum, frontal gray matter, thalamus and basal ganglia were used to create the LUT. Unique colors were assigned to inflection points with continuous ramps between them. Clinical use was demonstrated on 17 multiple system atrophy (MSA) patients compared to 13 patients with Parkinson disease (PD) and 17 healthy subjects. Four blinded radiologists classified subjects as MSA/non-MSA. Using only the LUT, high sensitivity (80%) and specificity (84%) were achieved in differentiating MSA subjects from PD subjects and controls. The LUTs generated from 12 and 30 MPG were comparable and accentuate FA abnormalities.

Parkinsonism & Related Disorders, 2007

Movement Disorders, 2009

This study focused on the relationship between the asymmetry of initial motor symptoms of Parkins... more This study focused on the relationship between the asymmetry of initial motor symptoms of Parkinson's disease (PD) and premorbid handedness of patients. Structural equation modeling has been used for this purpose. The survey consisting of validated items measuring handedness and questions related to side of occurrence of initial symptoms was administered to 472 patients with PD [277 men, 195 women, mean age 66.5 (9.3), mean duration of the disease 10 (6.1) years]. The unidimensional model of handedness fits the data well (v 2 5 37.86, df 5 20, P 5 0.009, Root Mean Square Error of Approximation 5 0.044, Comparative Fit Index 5 1.00, Standardized Root Mean Square Residual 5 0.042) and side of initial motor symptoms is not significantly related to the factor of handedness (r 50.11, SE 5 0.07, P 5 0.14). In contrast to several other studies, the results indicate that the side of first occurrence of PD signs cannot be predicted from premorbid handedness of patients.

Movement Disorders, 2008

The aim of this study was to compare the Pull Test-Retropusion Test and the Push and Release Test... more The aim of this study was to compare the Pull Test-Retropusion Test and the Push and Release Test (P&R) as regards their ability to predict Parkinson (PD) fallers and nonfallers in relation to their medication state. Eighty-two PD patients participated in the study. Fallers (N 5 36) and nonfallers (N 5 46) were grouped on the basis of their fall history. Fallers were those who had fallen at least once within the last 6 months. The two groups were compared on the basis of the patients' performance in the Pull and the P&R tests, both in their ''OFF'' and ''ON'' medication state. The overall accuracy of the classification of PD patients as fallers and nonfallers was determined by means of binomial logistic regression (BLR) and the analysis of the ''area under the receiver operating characteristics curve'' (AUC). In the OFF medication state, the statistical analysis revealed that the Pull Test was accurate (methods BLR (AUC)) in 85.4% (0.87) of cases and the P&R Test in 86.6% (0.90). In the ON medication state, the Pull Test was only 76.8% (0.78) accurate, while the P&R Test was 87.8% (0.87) accurate. Both clinical tests are valid and relatively equivalent when assessing patients in their OFF medication state; however, the P&R Test is more accurate than the Pull Test in the ON state. This indicates that it is more widely applicable in clinical practice.

Journal of Neural Transmission, 2012

This study focused on the difference between pre-morbid and current hand preference of patients w... more This study focused on the difference between pre-morbid and current hand preference of patients with Parkinson's disease (PD). A survey instrument comprised items measuring pre-morbid and current hand preference and question related to the side of occurrence of initial symptoms. These questions were administered to 471 PD patients. The results show a significant change of premorbid right hand preference toward using the left when the side of PD onset was on the right hand and vice versa. Disease duration does not predict the amount of hand preference shift.

Journal of Neural Transmission, 2014

A distinctive alteration of speech has been reported in patients suffering from ephedrone-induced... more A distinctive alteration of speech has been reported in patients suffering from ephedrone-induced parkinsonism. However, an objective assessment of dysarthria has not been performed in ephedrone users. We studied 28 young Caucasian men from Georgia with a previous history of ephedrone abuse and compared them to 25 age-matched healthy controls. Speech examination, brain MRI, and NNIPPS-Parkinson plus scale were performed in all patients. The accurate differential diagnosis of dysarthria subtypes was based on the quantitative acoustic analyses of 15 speech dimensions. We revealed a distinct variant of mixed dysarthria with a combination of hyperkinetic and hypokinetic components representing the altered motor programming of dystonia and bradykinesia in ephedrone-induced parkinsonism. According to acoustic analyses, all patients presented at least one affected speech dimension, whereas dysarthria was moderate in 43 % and severe in 36 % of patients. Further findings indicated relationships between motor subscores of dystonia and bradykinesia and speech components of loudness (r =-0.54, p \ 0.01), articulation (r = 0.40, p \ 0.05), and timing (r =-0.53, p \ 0.01). In ephedrone-induced parkinsonism a prominent mixed hyperkinetic-hypokinetic dysarthria occurs that appears related to marked dystonia and bradykinesia and probably reflects manganese induced toxic and neurodegenerative damage to the globus pallidus internus and substantia nigra.

Neuro endocrinology letters, 2008

The dimensionality and reliability of the Motor Section of the Unified Parkinson Disease Rating S... more The dimensionality and reliability of the Motor Section of the Unified Parkinson Disease Rating Scale (UPDRS III) was studied with non-parametric Mokken scale analysis. UPDRS measures were obtained on 147 patients with PD (96 men, 51 women, mean age 61, range 35-80 yrs). Mokken scale analysis revealed a four-dimensional structure of the UPDRS III. Left-sided bradykinesia and rigidity appeared to co-occur with axial signs, gait disturbance, and speech/hypomimia, whereas right-sided bradykinesia and rigidity formed a second scale. Two further small scales were found consisting of right- and left-sided tremor. Results from the scale analysis reveal that all four subscales are strong. The reliability of the two tremor scales is low because they only contain three and four items, respectively.

Gait & Posture, 2011

20 HD patients were examined using: (1) The Unified Huntington's Disease Rating Scale (UHDRS... more 20 HD patients were examined using: (1) The Unified Huntington's Disease Rating Scale (UHDRS), (2) The Mini Mental State Examination (MMSE) and (3) six clinical tests for PI. Inter-scale and test correlations were inspected and uni-dimensionality, validity, and ...

Severe gait disturbances and freezing episodes (frequently resistant to optimal dopaminergic trea... more Severe gait disturbances and freezing episodes (frequently resistant to optimal dopaminergic treatment) often appear in advanced Parkinson disease (PD). Even several years after initiation, high-frequency subthalamic nucleus deep brain stimulation (STN-DBS) is still very effective for controlling segmental symptoms. However, there are no long-term data on the management of gait disorders and freezing in STN-DBS. To compare the effects of various STN-DBS parameters on freezing of gait and to determine whether such effects are more related to stimulation energy (usual voltages vs high voltages at 130 Hz) or frequency (130 Hz vs approximately half this frequency: 60 Hz). We blindly assessed STN-DBS parameters in 13 PD patients reporting severe gait disorders. We compared the effects on gait of two different voltages (the patient's usual voltage [median 3 volts] and a high voltage [median 3.7 volts]) and two different frequencies (60 and 130 Hz, while maintaining the same total energy delivered) vs "off-stimulation" conditions. The number of freezing episodes was significantly lower at the 60-Hz "high voltage/equivalent energy" and higher at the 130-Hz/high voltage than for "off stimulation." The slight improvement in the Unified Parkinson's Disease Rating Scale motor score observed (at 130 Hz) did not achieve statistical significance. Our results prompt consideration of a new strategy for two-stage subthalamic nucleus deep brain stimulation (STN-DBS) frequency optimization, with stimulation at 130 Hz and the usual voltage during the initial years of STN-DBS and then at 60 Hz at a high voltage in Parkinson disease patients who develop severe gait disorders.