Luigi Iuppariello

Gait patterns in parkinsonian patients with or without mild cognitive impairment

Although in recent years the relationship between cognition and gait in Parkinsons disease (PD) has received increasing attention, the specific connections between gait patterns and cognitive features are not fully understood. The objective of this study was to describe the gait patterns in patients affected by PD with or without mild cognitive impairment (MCI+ and MCI−, respectively). We also sought to find an association between gait patterns and specific cognitive profiles. Using a gait analysis system, we compared the gait patterns among MCI+ patients (n = 19), MCI− patients (n − 24), and age‐ and sex‐matched healthy subjects (HS; n = 20) under the following conditions: (1) normal gait, (2) motor dual task, and (3) cognitive dual task. In PD patients, gait parameters were evaluated in both the off and on states. Memory, executive, and visuospatial domains were assessed using an extensive neuropsychological battery. Compared with MCI− PD and HS, MCI+ PD patients displayed reduced step length and swing time and impairment of measures of dynamic stability; these dysfunctions were only partially reversed by levodopa. We also found that dual‐task conditions affected several walking parameters in MCI+ PD in the off and on states relative to MCI− PD and HS. Factor analysis revealed 2 independent factors, namely, pace and stability. The latter was strongly and directly correlated to the visuospatial domain. In conclusion, dysfunctions on specific gait parameters, which were poorly responsive to levodopa and highly sensitive to dual‐task conditions, were associated with MCI in PD patients. Importantly, visuospatial impairment was strongly associated with the development of instability and more generally with the progression of PD.

Frequency and Time Domain Analysis of Foetal Heart Rate Variability with Traditional Indexes: A Critical Survey

Monitoring of foetal heart rate and its variability (FHRV) covers an important role in assessing health of foetus. Many analysis methods have been used to get quantitative measures of FHRV. FHRV has been studied in time and in frequency domain and interesting clinical results have been obtained. Nevertheless, a standardized definition of FHRV and a precise methodology to be used for its evaluation are lacking. We carried out a literature overview about both frequency domain analysis (FDA) and time domain analysis (TDA). Then, by using simulated FHR signals, we defined the methodology for FDA. Further, employing more than 400 real FHR signals, we analysed some of the most common indexes, Short Term Variability for TDA and power content of the spectrum bands and sympathovagal balance for FDA, and evaluated their ranges of values, which in many cases are a novelty. Finally, we verified the relationship between these indexes and two important parameters: week of gestation, indicator of foetal growth, and foetal state, classified as active or at rest. Our results indicate that, according to literature, it is necessary to standardize the procedure for FHRV evaluation and to consider week of gestation and foetal state before FHR analysis.

Analysis of Foetal Heart Rate Variability Components by Means of Empirical Mode Decomposition

Foetal heart rate variability (FHRV) is important in foetal wellbeing assessment. However, a gold standard for its evaluation is not yet available. Here, a rather new methodology, the empirical mode decomposition (EMD), is proposed to decompose FHR signal in its components. To test the reliability of this methodology, we employed simulated FHR signals, “clean” and noisy, with characteristics defined a priori and computed two indices of foetal health, the sympatho-vagal balance (SVB) and the standard deviation of FHR signal (ASD). Results obtained in comparison between values set for the simulation and those estimated after EMD demonstrated that EMD could be useful for evaluation of FHRV components directly in time domain. The error in the indices estimation was on average just over 1% for SVB and zero for ASD. In presence of noise, the error in ASD estimation was below 8% whereas that in SVB evaluation increases becoming almost 30%.

Effects of Wavelets Analysis on Power Spectral Distributions in Laser Doppler Flowmetry Time Series

The evaluation of endothelium function impairments are of great clinical interest in many vascular diseases and laser Doppler flowmetry (LDF) is the gold standard technique for its evaluation. LDF signals show low-frequency oscillations related to heartbeat, respiratory, myogenic and endothelial activities. Although wavelets analysis (WLT) of LDF has been shown as a better technique than Fourier (FFT) and Short Time Fourier Transform (STFT) in the resolution of these oscillatory components, the overall spectral power modifications have not yet been described. Aim of the paper is to study the effects of WLT analysis on power spectral distributions in LDF. We studied 20 min LDF recordings of 20 obese subjects by PeriFlux LDF system. Signals were detrended by moving average algorithms and transformed by FFT, STFT and WLT for spectral analysis. The spectral power has been calculated in bands I (0.6-2 Hz), II (0.145-06), III (0.052-0.145), IV (0.021-0.052), V (0.0095-0.021) and VI (0.005-0.0095) in percent values of the total spectral power. Results of the ANOVA tests between spectral powers in the six bands by the three different spectral analysis’ methods showed that WLT exhibited the highest F-value, reflecting significant difference (p<0.001) between II vs III and IV, III vs V and VI, IV vs V and VI bands. Moreover, while WLT values in I band are significantly lower of those of FFT and STFT, WLT values, both in IV and III band, are significantly higher than those of FFT and STFT (p<0.001). Therefore, the overall effects of WLT analysis on power spectral distributions in LDF time series in the studied population seem to limit the spectral power in the I band moving the power to the III and IV bands with the interesting effect to minimize heart rate variability spectral power enhancing myogenic and neurogenic sympathetic activity spectral power in LDF signals.

Submovements composition and quality assessment of reaching movements in subjects with Parkinson's Disease

The segmentation of seemingly continuous movements into segments has been theorized for many years. These segments may be considered as “primitive” movements, or building blocks of more complex movements. The existence of these fragments, or sub-movements as they are called, has been supported by a wide range of studies over the past 100 years. Evidence for the existence of discrete sub-movements underlying continuous human movement has motivated many attempts to “extract” them. Recently, the sub-movement theory gained a great appeal in the rehabilitation field. In fact, understanding movement deficits following CNS lesions, and the relationships between these deficits and functional ability, is fundamental to the development of successful rehabilitation therapies. So, here a novel sub-movements decomposition method is proposed; it is based on a constrained-Expectation-Maximization. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each signal into a weighted combination of 2D Gaussian functions. These can be used to assess the quality of reaching movements in subjects with Parkinsons Disease.

The effects of the vibratory stimulation of the neck muscles for the evaluation of stepping performance in Parkinson's Disease

The equilibrium system needs the coordination of three subsystems: sensory, skeletal and central nervous system. The central nervous system (CNS) counteracts equilibrium perturbations by means of compensatory and anticipatory postural adjustments (APA). While compensatory adjustments deal with actual perturbations of balance, the APA precede perturbations. The APA consist of preprogrammed activation of the muscles, according to task parameters [6] and are important to minimize the effects of planned postural perturbations. APA are specific to the movement, adapt to changes in external postural support by changing APA timing and magnitude. These APA are altered in Parkinson disease (PD) where have characterized by a reduced amplitude, an increased duration and a delayed onset of APA in tasks such as gait initiation. This study investigates the effects of a vibratory stimulus applied to the neck muscle groups in subjects with PD.

Comparison between clinical and instrumental assessing using Wii Fit system on balance control

The use of low-cost, commercial gaming systems for rehabilitation has received substantial attention in the last few years. Systems such as the Nintendo Wii encourage players to use natural actions to play games. The Wii systems has been integrated into rehabilitation programs and has gained the support of occupational therapists because it is easy to use and has a wide variety of games available. In this study we compare the benefits on balance control of Wii Fit use with traditional rehabilitation therapy in 15 patients (study group) with Spinal Cord Injuries (SCI) and in 15 normal subjects (control group). The performance on balance control of each subject was evaluate by the Berg Balance Scale(BBS) in order to establish the baseline. Similar measurement was repeated at the discharge. Moreover, we assess the improvements induced by the use of Wii Fit platform with quantitative posturographic analysis by means of parameters and objective metric indexes such as COP Area and Sway Path. Comparison between two groups was performed by means of paired t test and Mann Whitney test. Both groups showed improvements in the BBS and in the posturographic indexes at the discharge. Very interesting is to note that the wii fit training appears to improve much more the balance of the study group compared to the study group.

Comparison of measured and predicted reaching movements with a robotic rehabilitation device

As has been frequently observed, single-joint movements are characterized by single-peaked, bell-shaped speed profiles. This findings and the tendency of natural movements to be characteristically smooth and graceful led to suggest that motor coordination can be mathematically modeled by postulating that voluntary movements are made, at least in the absence of any other overriding concerns, to be as smooth as possible. Particularly the goal of the central nervous system (CNS) is to maximize smoothness and one measure of this feature is the integrated mean squared magnitude of jerk. Although in the past have been explored kinematic characteristics of reaching movements recorded with actigrafi or goniometric systems and potentiometers, few studies have evaluated the kinematic characteristics of these movements obtained with the new rehabilitative technologies, such as robot mediated therapy. In this paper we tested the applicability of the minimum-jerk model proposed to one join goal directed horizontal reaching movements performed by healthy subjects with a robotic shoulder rehabilitation device. Results show a good qualitative agreement between the measured trajectories and the predicted ones by the model.

Microvascular blood flow regulation impairments in hypertensive obese people

Hypertension causes several microvascular alterations, leading to inadequate blood supply to tissues and target-organ damage. The present study was aimed to investigate microvascular skin blood flow and related oscillations in hypertensive obese subjects. Twenty-eight controls and twenty-seven hypertensive patients were recruited from our Outpatient Clinics. Anthropometric measurements were evaluated and bioimpedance analysis was performed. Finally, skin microvascular blood flow was measured by a laser Doppler flowmeter and oscillations in blood flow were analyzed by power spectrum analysis. Newly diagnosed hypertensive subjects showed lower mean skin blood flow as well as lower related total power spectral density compared to the controls. In these patients, moreover, power spectral analysis of microvascular oscillations indicate a lower spectral density of the frequency component related to myogenic activity compared to controls. Therefore, hypertension appears to be associated to myogenic impairments, causing changes in microvascular modulation and tissue perfusion.

Kinematic Indexes’ Reproducibility of Horizontal Reaching Movements

Upper limb reaching movements are the most used motor task both in diagnosis and rehabilitation treatments of several movement disorders of the arm and the shoulder of various central and peripheral etiology. One of the most appealing features of these new technologies consists in the possibility to record and measure motions and mechanical indexes, allowing quantitative kinematics evaluations, while traditional clinical scales permit only qualitative and potentially disagreeing evaluations, since carried out by different therapists. Few papers have actually addressed this issue and aim of the study is the assessment the reproducibility of kinematics indexes of upper arm horizontal reaching movements in normal subjects during RMT. We studied 10 normal subjects (35±8 year old, males). Each subject underwent to 2 sessions, repeating each reaching protocol at four different target amplitudes of 15°, 20°, 25° and 30° and at three different target velocity, respectively of 20°/s, 30°/s and 40°/s, with at least intervals of 15’ of resting time between each trial. Reaching movements have been performed by a shoulder rehabilitation, the Multi-Joint-System (MJS) of the Tecnobody, equipped by a four freedom ranges mechanical arm, was used. Although all parameters generally showed a poor reproducibility, it can be noted that both kurtosys and symmetry indexes showed the lower bias values, ranging between 8 to 9% , while both symmetry and smoothness indexes showed doubled bias values. The kurtosys is also the parameter with the lower standard deviation of the bias and so it can be considered as the more reproducible kinematic index between the studied parameters. Bland-Altman plots showed that the scatter of all kinematic indexes measures around the bias line is not constant but getting larger as the average gets higher, like for example for the kurtosys, or getting larger as the average gets lower, like for example for the skewness.