Background: In this study, an active orthosis has been designed to rehabilitate patients with weak wrist flexor and extensor muscles. Methods: First, the mechanical design of the actuating mechanism ...with a linear servo motor to provide the desired wrist rotation, is performed in SolidWorks software. Also, to determine the force created by the actuator during flexion and extension of the wrist, the movement of the mechanism is simulated in Visual Nastran software. After molding the patient's wrist, the main body of the orthosis is made by forming the thermoplastic sheets on the mold, and the components of the mechanical part of the mechanism are installed on it. Then, the hardware part of the electronic circuits to drive the motor and to communicate between the control modules and the actuator is designed. For the programming of microcontrollers and synchronizing of deriver to the joystick, Bascom AVR software is used. The simulation of electrical circuit is performed in Proteus software and the printed board circuit is made in Altium Designer software. Results: The results of applying this orthosis on the wrist of a healthy subject indicate its proper performance in creating an acceptable angle range for the wrist extension and flexion. Conclusion: The use of the designed active wrist orthosis can improve the rehabilitation process of the patients with weakness in their wrist muscles.
Scoliosis is the abnormal sideways curve of the spine. Screening for scoliosis is controversial, and there has been significant heterogeneity between studies. In Iran, there is still no suitable ...device to screen sideways curves in spine.
To investigate the simple scolioscreen software for screening the students of elementary schools for detecting schoolchildren scoliosis. This students has been examined by trained medical student and data entered in scolioscreen application of an iPhone.
One hundred forty-four 7-12 years old students from primary schools in the 17th district of Tehran were randomly invited to participate. Initial screening of the students was done in schools by health care provider or medical student who has been trained by a pediatrician to undergo a vertebral examination. Scoliometer for iPhone's smartphone has been used for measuring the angle of deviation.
1.4% of students had overt scoliosis and 10.4% were suspected to have a kind of mild abnormality in spine curve. These individuals were referred to clinic for radiologic evaluation and it was confirmed that relative frequency of this abnormality was defined as 4.86% in our population study. There was no significant correlation between sex and degree of spinal curve.
Regarding the high rate of scoliosis in our population and approval of this screening test in different studies, routine use of this screening method is highly recommended in schoolchildren. It is cost beneficial and can be effective in prevention and early treatment of scoliosis.
Background
Brain oscillations known for handling various information across brain. The gamma rhythms observed in high‐level cognitive process (Fries et al., Trends in neurosciences 2018) and theta ...cycle observed to process sensory information and interact with gamma oscillations (Amemiya et al., Cell Reports 2018). Disruption in synchronization of gamma oscillations have been observed in Alzheimer’s disease patients (Uhlhaas et al., Neuron 2006). Gamma stimulation had been shown to reduce the mentioned dysfunction and reported to have therapeutic results (Martorell et al., Cell 2019; Suk et al. Alzheimer’s and Dementia 2020). This study examines the effect of gamma band activity induced by auditory chirp stimulation as a driver for other frequency sources. The chirp signal is designed to entrain 40Hz which had been shown to have therapeutics effects.
Method
33 participants were included in this study including 17 mild AD, 6 MCI and 10 healthy elderlies. A session consists of interleaved periods of forty second stimulation and twenty second silence. The stimulation is a 5kHz tone modulated by a 40Hz chirp at 0.1 duty cycle. EEG data were collected by a 10/20 system. Relative magnitude of the 40Hz oscillations with respect to neighbors’ magnitude during the stimulation was measured as an indicator of the entrained gamma oscillations. Total participants are categorized into entrained and not‐entrained group based on the indicator. Phase locking Value (PLV) is then calculated in theta frequency band.
Result
40Hz entrainment have been observed in healthy participants and also some Alzheimer’s disease patients. Based on the power spectral density (PSD) at forty hertz 23 entrained and 10 not‐entrained participants are separated and PLV analysis have been calculated for the two groups. Theta oscillatory asymmetry have been observed in posterior temporal cortex during auditory stimulation.
Conclusion
Entraining gamma oscillations using auditory stimulation results in cross frequency variation. Phase‐amplitude or phase‐phase coupling measures the simultaneous correlation between specific oscillations. This study suggests that despite the concurrent association of theta‐gamma frequencies, some brain network changes occur in response to gamma oscillation which should be more discussed in related researches.
Background
Non‐invasive 40Hz sensory‐induced brain entrainment has shown promising results in Alzheimer’s disease (AD) therapy (Chan et al., medRxiv, 2021; Chan et al., Alzheimer’s & Dementia, 2021). ...We previously reported on the network‐level mechanisms underlying the spatial and temporal coherence of the induced brain rhythms during gamma entrainment in dementia patients (Lahijanian et al., bioRxiv, 2021). Here, we posit that the induced gamma oscillations propagate as traveling waves circling each hemisphere of the cortex, and that the induction of such waves can explain the spatiotemporal coherence between the frontal and parietal/occipital regions reported to be involved in cognitive processes.
Method
EEG data were recorded from two healthy young adults during multi‐trial visual entrainment sessions with 22Hz flickering light. Due to the harmonic property of the brain’s entrained response (Jones et al., Journal of Alzheimer’s Disease, 2019), gamma entrainment was achieved at 44Hz. Separately, EEG data were recorded from 11 dementia patients in multi‐trial auditory entrainment sessions with 40Hz chirp input. The phase of the spatiotemporal pattern at the target gamma frequency was calculated across the entire scalp as an indicator of traveling waves.
Result
Shortly after the stimulation onset in the young healthy adults, a circling traveling wave is observed in each hemisphere (Fig. 1). The onset and the homogeneity of the induced wave pattern is modulated by the power of the 44Hz entrained oscillations (Fig. 2). The dementia patients can be divided into two groups of entrained and non‐entrained according to the induced gamma power (see Lahijanian et al., bioRxiv, 2021), and the travelling wave effect can be occasionally observed during the stimulation in the entrained group and not in the non‐entrained group.
Conclusion
Cortical traveling waves modulate the brain dynamics and play a critical role in functions ranging from sensory processing to memory consolidation (Muller et al., Nature Reviews Neuroscience, 2018). Gamma entrainment induces traveling waves that connect the occipital/parietal regions of the cortex to the frontal region through the temporal region. The traveling wave promotes spatiotemporal coherence across the brain and hence can serve as a network‐level mechanism for explaining the therapeutic effects of gamma entrainment.
Unknown noise and artifacts present in medical signals with non-linear fuzzy filter will be estimated and then removed. An adaptive neuro-fuzzy interference system which has a non-linear structure ...presented for the noise function prediction by before Samples. This paper is about a neuro-fuzzy method to estimate unknown noise of Electrocardiogram signal. Adaptive neural combined with Fuzzy System to construct a fuzzy Predictor. For this system setting parameters such as the number of Membership Functions for each input and output, training epochs, type of MFs for each input and output, learning algorithm and etc. is determined by learning data. At the end simulated experimental results are presented for proper validation.
Behavioral and psychological symptoms of dementia (BPSD) are observed in more than 90% of patients with Alzheimer's disease (AD). BPSDs are remediable if detected early and managed appropriately. ...Behavioral Pathology in Alzheimer's disease Rating Scale (BEHAVE-AD) and Empirical BEHAVE-AD (E-BEHAVE-AD) were designed to identify BPSD. The aim of this study is to validate and prepare BEHAVE-AD and E-BEHAVE-AD in Persian language for clinical and research applications.
120 patients were selected through a combination of intentional and convenience sampling. All participants should fulfill the NINCDS-ADRDA Work Group criteria for a clinical diagnosis of Alzheimer's disease. Functional Assessment Staging Tool (FAST) was used to determine the rate of AD progression. All patients were evaluated using the BEHAVE-AD and E-BEHAVE-AD questionnaires, as well as the Persian version of the Neuropsychiatric Inventory Questionnaire (NPI-Q) and Mini-Mental State Examination (MMSE). The Content Validity Index (CVI) is determined based on the compatibility of the Persian and the original version of the two scales according to the opinion of expert panels. Correlation of MMSE with BEHAVE-AD and E-BEHAVE-AD as well as the BPSD pattern on AD progression continuum by FAST were considered as indices of construct validity. Concurrent validity was estimated by correlating NPI-Q scores with BEHAVE-AD and E-BEHAVE-AD scores. For both scales, interrater reliability was extracted as a reliability index.
Pearson correlation coefficients for the BEHAVE-AD scale were as follows: with NPI-Q (r = 0.77, p-value <0.01), with MMSE (r = −0.34, p-value <0.01), indicating concurrent and construct validity, respectively. The result for E-BEHAVE-AD was as follows: with NPI-Q-total (r = 0.59, p-value <0.01), and with MMSE (r = 0.31, p-value <0. 01). BEHAVE-AD and E-BEHAVE-AD scores increased in parallel with AD severity according to FAST, but not on the most severe AD stage. The area under the curve was estimated to be 0.84 (p-value <0.001) for BEHAVE-AD and 0.78 (p-value <0.001) for E-BEHAVE-AD. Correlation between BEHAVE-AD and E-BEHAVE-AD scores ranged from 0.45 to 0.63. The inter-rater reliability index ranged from 0.88 to 0.99 for BEHAVE-AD and from 0.74 to 0.95 for E-BEHAVE-AD.
The Persian version of BEHAVE-AD and E-BEHAVE-AD is valid and reliable for the assessment of BPSD in patients with AD.
Slow-gamma (35-45 Hz) phase synchronization and the coupling between slow-gamma and low-frequency theta oscillations (4–8 Hz) are closely related to memory retrieval and cognitive functions. In this ...pilot study, we assess the Phase Amplitude Coupling (PAC) between theta and slow-gamma oscillatory bands and the quality of synchronization in slow-gamma oscillations using Phase Locking Value (PLV) on EEG data from healthy individuals and patients diagnosed with amnestic Mild Cognitive Impairment (aMCI) and Alzheimer's Disease (AD) during an oddball olfactory task. Our study indicates noticeable differences between the PLV and PAC values corresponding to olfactory stimulation in the three groups of participants. These differences can help explain the underlying processes involved in these cognitive disorders and the differences between aMCI and AD patients in performing cognitive tasks. Our study also proposes a diagnosis method for aMCI through comparing the brain's response characteristics during olfactory stimulation and rest. Early diagnosis of aMCI can potentially lead to its timely treatment and prevention from progression to AD.
•An oddball olfactory experiment was conducted on a cohort of healthy elderly and amnestic MCI and AD patients.•Indicators of spatial coherence and cross-frequency coupling in the oscillatory activity of the brain were extracted.•These indicators were proposed as topographical markers of aMCI and AD.•Network-level markers can complement other biomarkers based on behavioral, molecular, genetic, or structural assessment.•Differentiating aMCI status from normal and AD states allows for early intervention to decelerate its progress to AD.
Background
Altered gamma oscillations have been observed in patients of Alzheimer’s disease (AD). A large number of studies have linked the quality of gamma oscillations in the frontal cortex to the ...performance of memory retrieval tasks. Synchronization of gamma oscillations has a strong correlation with cognitive functions (Fell et al., Nature Reviews Neuroscience 2011), and deficit in gamma synchronization in the frontal cortex has been reported as a marker for AD (Sedghizadeh et al., PLOS One 2020). In this study, we examine the phase synchronization of gamma oscillations in the EEG data recorded from the frontal cortex during olfactory stimulation as a marker for AD.
Method
Twenty‐four elderly participants (13 Normal and 11 mild AD patients) participated in this study. The cognitive status of the participants was quantified using the MMSE test. Then, each participant underwent an olfactory stimulation session consisting of 120 trials of 2s stimuli presentation with a random selection of two odors (lemon as the frequent and rose as the rare odor) followed by 8s of rest. EEG data were simultaneously recorded and pre‐processed for artifact and noise removal and trial averaging. To analyze gamma band synchronization, the phase‐locking value (PLV) for lower gamma oscillations (35‐45Hz) was calculated between the Fz and Cz electrodes. Fig. 1 illustrates the measurement and processing flow.
Result
Our study shows that the PLV is significantly higher for normal participants compared to AD patients (Fig. 2). Also, the phase difference between the Fz and Cz electrodes in the lower gamma band remains unchanged across trials for normal participants while it widely varies between ‐180 and 180 degrees for AD patients (Fig. 3).
Conclusion
This study shows that there is a significant difference between normal participants and AD patients in terms of the synchronization of gamma oscillations in the frontal cortex in response to olfactory stimulation. These results suggest that the PLV between the Fz and Cz electrodes under olfactory stimulation can be used as a marker for AD diagnosis.
Clinical trial studies revealed conflicting results on the effect of Ashwagandha extract on anxiety and stress. Therefore, we aimed to evaluate the effect of Ashwagandha supplementation on anxiety as ...well as stress. A systematic search was performed in PubMed/Medline, Scopus, and Google Scholar from inception until December 2021. We included randomized clinical trials (RCTs) that investigate the effect of Ashwagandha extract on anxiety and stress. The overall effect size was pooled by random‐effects model and the standardized mean difference (SMD) and 95% confidence interval (CIs) for outcomes were applied. Overall, 12 eligible papers with a total sample size of 1,002 participants and age range between 25 and 48 years were included in the current systematic review and meta‐analysis. We found that Ashwagandha supplementation significantly reduced anxiety (SMD: −1.55, 95% CI: −2.37, −0.74; p = .005; I2 = 93.8%) and stress level (SMD: −1.75; 95% CI: −2.29, −1.22; p = .005; I2 = 83.1%) compared to the placebo. Additionally, the non‐linear dose–response analysis indicated a favorable effect of Ashwagandha supplementation on anxiety until 12,000 mg/d and stress at dose of 300–600 mg/d. Finally, we identified that the certainty of the evidence was low for both outcomes. The current systematic review and dose–response meta‐analysis of RCTs revealed a beneficial effect in both stress and anxiety following Ashwagandha supplementation. However, further high‐quality studies are needed to firmly establish the clinical efficacy of the plant.
Mild cognitive impairment (MCI) is known as an early stage of cognitive decline. Amnestic MCI (aMCI) is considered as the preliminary stage of dementia which may progress to Alzheimer’s disease (AD). ...While some aMCI patients may stay in this condition for years, others might develop dementia associated with AD. Early detection of MCI allows for potential treatments to prevent or decelerate the process of developing dementia. Standard methods of diagnosing MCI and AD employ structural (imaging), behavioral (cognitive tests), and genetic or molecular (blood or CSF tests) techniques. Our study proposes network-level neural synchronization parameters as topographical markers for diagnosing aMCI and AD. We conducted a pilot study based on EEG data recorded during an olfactory task from a group of elderly participants consisting of healthy individuals and patients of aMCI and AD to assess the value of different indicators of network-level phase and amplitude synchronization in differentiating the three groups. Significant differences were observed in the percent phase locking value, theta-gamma phase-amplitude coupling, and amplitude coherence between the groups, and classifiers were developed to differentiate the three groups based on these parameters. The observed differences in these indicators of network-level functionality of the brain can help explain the underlying processes involved in aMCI and AD.
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