electrical stimulation

 Intramuscular injection (IM) of medications is an invasive and painful procedure for many patients. Various forms of electrical stimulation may play a role in pain modulation. The aim of this study was to assess the effects of cathodal and anodal direct current (DC) on reducing pain caused by IM injections.

This study was conducted as a triple-blinded, randomized clinical trial on 120 patients who were candidates for IM. Patients in the control group did not receive any intervention. In the cathodal and anodal groups, direct current (DC) with a current intensity of 5 mA was applied via a connection to the needle tip during the injection. In the anesthetic group, EMLA ointment was applied locally. The pain level was measured based on the Visual Analog Scale (VAS) immediately after the injection and at 1,3-, and 5-minutes post-injection. Heart rate changes, injection duration, and injection frequency were also recorded. Data were analyzed using one-way and two-way analysis of variance (ANOVA) tests, as well as repeated measures.

There was no statistically significant difference between the groups in terms of age (P=0.2), gender (P=0.83), and body mass index (P=0.056). The pain level was significantly lower in the groups receiving anesthetic ointment (P<0.01), anodal (P<0.001), and cathodal (P<0.0001) direct current stimulation compared to the control group. Moreover, pain levels in the cathodal group were significantly lower than those in the anodal group (P<0.01) and the anesthetic group (P<0.05). The injection time was significantly shorter in the intervention groups than in the control group (P<0.0001), while there was no significant difference in the frequency of attempts required to perform a successful injection between the groups (P>0.05). The increase in heart rate was significantly lower in the intervention groups than in the control group during and after the injection (P<0.05), while no significant difference was observed between the intervention groups (P>0.05).

Applying electrical stimulation directly to the needle insertion area effectively reduced the pain and tachycardia caused by IM. Greater analgesic effects were observed with cathodal stimulation.

 (Clinical Trials Registry Number: IRCT20240123060780N1)

Mild Cognitive Impairment (MCI) is a cognitive profile of aging that requires attention and treatment. Among the types of cognitive rehabilitation therapies, non-invasive brain stimulation and cognitive training can be highlighted as interventions for mild cognitive impairment.

The present study aimed to evaluate the effectiveness of cognitive training interventions, cranial electrical stimulation, and their combination in attention and delayed memory of individuals with mild cognitive impairment. 

This research employs a single-case experimental design involving comparing multiple treatments with follow-up. The study population consists of elderly individuals with mild cognitive impairment attending the memory clinic at Modarres Hospital in Isfahan in 2023. According to the research design, two patients were selected through purposive sampling, and the three treatment modalities were implemented in the following sequence: cranial electrical stimulation, a combined treatment that includes cognitive training along with transcranial electrical stimulation, and cognitive training alone.

The results of the follow-up phase for the first and second participants regarding the attention variable were as follows: PND1 =100; RCI1 =19.05; PND2 =100; RCI2 =19.05. For the delayed memory variable, the first and second participants' results were: PND1 =100; RCI1 =13; PND2 =100; RCI2 =15. Therefore, the treatment arrangement of cranial electrical stimulation, combined therapy, and cognitive training has a significant positive effect on attention and delayed memory.

Cranial electrical stimulation influences neurotransmitters and neural networks, creating a foundation for cognitive training effects by establishing new synapses and alterations in dendritic configuration. Consequently, their synergistic effects contribute to the improvement of cognitive behaviors.

Control of inflammatory factors after myocardial infarction is one of the factors affecting the recovery of myocardial infarction patients due to lack of adequate myocardial blood flow. Therefore, this study aimed to investigate the effect of exercise rehabilitation with electrical stimulation on serum ICAM and VCAM levels in rats with myocardial infarction.

In this experimental study, 40 Wistar rats (8 weeks old, weight 220±30g) were randomly divided into four groups after infarction: infarction, infarction-exercise rehabilitation, infarction-electrical stimulation, and infarction-exercise rehabilitation-electrical stimulation. Myocardial infarction was induced by two subcutaneous injections of isoproterenol (150 mg/kg) 24 hours apart. The intervention groups underwent one session of exercise rehabilitation (treadmill at 20 m/min for 1 hour) and electrical stimulation (foot shock device at 0.5 mA for 20 minutes). Immediately after the intervention, the levels of ICAM and VCAM in the serum were determined by ELISA. One-way ANOVA and Tukey post hoc test were used to analyze the data at the significance level of P<0.05.

The results showed that electrical stimulation caused a significant increase (P=0.021) in serum ICAM levels in infarct samples. However, serum VCAM levels showed a significant decrease in the electrical stimulation (P=0.040) and electrical stimulation-exercise rehabilitation (P=0.038) groups.

According to the results, it is not yet possible to determine with certainty the direction of the effect of acute exercise rehabilitation and electrical foot shock stimulation on adhesion molecules.

Objectives:

 Considering the negative effects of aging on bimanual motor skills, attention has been drawn to various non-invasive brain stimulation methods for the improvement of these skills. This study aimed to investigate the effects of online transcranial alternating current stimulation (tACS) over the right posterior parietal cortex (P4) and supplementary motor area (SMA) on bimanual coordination in elderly women. 

Methods :

This is a quasi-experimental study. The study population includes all healthy elderly women aged 60-75 years in Tehran, Iran, of whom 31 were selected using a convenience sampling method and were subjected to tACS over P4, tACS over SMA, and sham tACS along with performing the Purdue pegboard task (4 trials) in three sessions with a one-week interval.  Data were analyzed byby 3(condition)*4(trials) ANOVA with repeated measures.

Results:

 The results of ANOVA showed that only the main effect of trial was statistically significant (P<0.001); The main effect of condition and the interaction effect of condition and trial were not significant (P>0.05). Therefore, although bimanual coordination increased significantly in all three conditions in different trials, there was no significant difference in bimanual coordination among different conditions.

Conclusion :

The online tACS over P4 or SMA has no short-term effect on the bimanual coordination of elderly women. Further studies are recommended to assess the long-term effects of tACS in other areas of the cerebral cortex using different protocols.

Controlling inflammatory factors after myocardial infarction (MI), due to the lack of sufficient myocardial blood flow, is one of the factors influencing the recovery of infarction patients. Therefore, it is very necessary to know the causes of MI as one of the main causes of death in worldwide. The disease affects nearly three million people global and kills more than one million people in the United States each year (1) and cardiovascular problems caused by MI are the most common cause of MI (2). Research has shown that adhesion molecules play an important role in the pathogenesis of MI. New markers of intercellular adhesion molecule (ICAM) and vascular adhesion molecule (VCAM) have high sensitivity and accuracy in predicting and identifying the risk of heart damage and play an important role in the Prevalence of heart problems (2). It seems that the reduction of inflammatory markers has a positive effect on improving the condition of MI patients (4). Also, finding appropriate training methods and different training intensities has been the focus of researchers in the field of exercise physiology in recent years. There are conflicting studies between endurance training and the expression of ICAM and VCAM genes (5, 6). Also considering that electrical stimulation (ES) is used as a new and effective modality in the treatment of ischemia (8). Therefore, it was used as another intervention in the present study. According to research, it is expected that ES is a rehabilitation method for people who participate in exercise training (10) and also patients with heart failure (HF) (11). However, in other studies, the positive effects of exercise and ES on various aspects of heart health in patients with MI have been noted. For that reason, the researchers of the present study intend to investigate the exercise rehabilitation response with electrical stimulation on serum ICAM and VCAM levels of rats with myocardial infarction.

In this experimental study, 40 Wistar rats (8 weeks old with an average weight of 220 ± 30 g) were randomly divided into 4 infarction groups, infarction-exercise rehabilitation, infarction electrical stimulation and infarction-exercise rehabilitation-electrical stimulation groups were divided. Then, MI was induced using two subcutaneous injections of Isoproterenol (ISO) (150 mg/kg) with an interval of 24 hours in the infarcted groups. This substance is one of the common methods of inducing MI in animal models, especially rats (14). In this study, heart infarction was confirmed based on electrocardiographic changes (ST segment elevation) along with the increase of cardiac enzyme cTnI (344.01 pg/ml). The intervention groups underwent exercise rehabilitation (treadmill at a speed of 20 m/min for 1 hour) and ES (foot shock device for 0.5 mA and 20 minutes) for one session. Groups were anesthetized and killed immediately after the end of the training protocol with a combination of ketamine (75 mg/kg) and xylazine (10 mg/kg). Blood sampling was done directly from the right atrium of the rat. The serum levels of ICAM and VCAM were checked by ELISA method. After confirming the normal distribution of the data using the Shapiro-Wilk test, one-way ANOVA and Tukey's post hoc test were used to analyze the data at a significance level of P<0.05.

The results of the analysis of ICAM levels showed a statistically significant difference between MI and MI.ES groups (F=4.4 and P=0.021), MI.EX and MI.ES (F=5.9 and P=0.002). But this difference between MI with MI.EX (F=1.4 and P=0.762), MI with MI.EX.ES (F=1.17, P=0.838), MI.EX with MI.EX. ES (F=2.56, P=0.292) and MI.ES with MI.EX.ES (F=3.26, P=0.124) were not significant. The results of VCAM levels showed a statistically significant difference between MI and MI.ES groups (F=3.9 and P=0.040) and MI and MI.EX.ES groups (F=2.3 and P=0.038). But between the groups, MI with MI.EX (F=1.60 and P=0.659), MI.EX with MI.ES (F=2.4, P=0.343, MI.EX with MI.EX .ES (F=2.4, P=0.331) and MI.ES with MI.EX.ES (F=0.034, P=0.999), this difference was not significant.

Deficiency in the function of cell adhesion molecules is one of the main causes of pathological progress in many diseases, including cardiovascular disorders. Therefore, investigating inflammatory pathways and cellular and molecular processes involved in it is very necessary. The cholinergic anti-inflammatory pathway consisting of the Vagus nerve and its transporter acetylcholine play an important role in regulating the inflammatory response. When the body is injured, the excitability of the Vagus nerve increases, which causes the release of acetylcholine from peripheral nerve endings. This process can inhibit the release of pro-inflammatory cytokines such as IL-1, TNF-a, IL-6 and IL-17 and lead to the reduction of heart damage. Also, ES can change the function of inflammatory cells at the molecular level, thereby preventing the spread of inflammation by affecting the number of immune cells as a mediator. In general, it seems that according to the results of the present study, it is still not possible to determine with certainty the direction and direction of the effect of acute sports rehabilitation and foot shock electrical stimulation on adhesive molecules, and it needs more study.

The aim of this study was to compare the effect of direct cranial electrical stimulation and cognitive-behavioral therapy on cognitive functions and psychological well-being of methamphetamine-dependent patients.
This experimental study was a post-test pre-test by control group. The statistical population was all male patients dependent on methamphetamine referred to Gam Addiction Treatment Clinic in Ghaemshahr in 1399, from which 45 statistical samples were selected by convenience sampling method and randomly divided into 3 groups of 15 (Experiment 1, Experiment 2 and Control) were divided. Subjects in all three groups answered the Wechsler Form A (1945) and Reef (1989) psychological well-being questionnaires in three stages of pre-test, post-test and follow-up. For experimental group 1, direct electrical stimulation from the skull with a maximum current of 2 mA and a maximum voltage of 80 volts, and for the experimental group 2, sessions of cognitive-behavioral therapy on the protocol of cognitive-behavioral therapy (Bailing, McCabe, Anthony, 2011) It was performed for 12 sessions and the control group did not receive any treatment. SPSS24 software and descriptive and analytical statistics (Analyze of Covariance and Post-Hoc) were used to analyze the data.
The analysis showed that direct electrical stimulation from the skull and cognitive-behavioral therapy had a positive and significant effect on cognitive functions and psychological well-being (p < 0.05). But the effectiveness of cognitive-behavioral therapy was greater (p < 0.05).
Cognitive-behavioral therapy can be used to reduce psychological problems cognitive functions and improvement in methamphetamine-dependent patients.

The path of the center of pressure while walking reflects the general mechanics of the body. Also, the electrical stimulation system triggers movement units, including the lower limbs. The present study investigated the effect of the electrical stimulation system on gait and balance patterns in young athletes.

This research is applied and semi-experimental. In this study, 15 male athletes were selected by convenience sampling. The present study was performed in February 1400 at Shahriar Health Club. Participants were asked to walk at a self-selected speed. In the middle of the walking path, a foot-scanning device was placed, which recorded information about the path of the center of pressure, the relative duration of the stance phases, and the forward angle in both positions with and without the muscle stimulation vest. After checking the normality of the data using the Shapiro-Wilk test, paired sample t-test was used to analyze the data.

The results showed that the electrical muscle stimulation system had a favorable effect on the gait pattern of athletes compared to those without a vest. Electrical stimulation led to a slight increase in pressure center oscillations and improved displacement of pressure fluctuations (p=0.001) in the vest mode, which showed the effectiveness of this method.

The results of the present study showed that strengthening the muscles of the lower extremities by the electrical muscle stimulation system had favorable effects on athletes' gait pattern and foot pressure fluctuations.

Activation of inflammatory processes after a heart attack is necessary, but if it continues too long, it will facilitate the recurrence of myocardial infarction. Endurance training plays an important role in improving inflammation and the condition of heart attack patients. Accordingly, the present study aimed to investigate the acute response of sports rehabilitation with electrical stimulation on CA-125 and Cys-C in myocardial infarction rats.

In this experimental study with a control group of 50 Wistar rats (8 weeks old, weighing 220±30g) were randomly divided into 5 healthy groups: infarction, infarction-exercise rehabilitation, infarction-electrical stimulation and infarction-exercise rehabilitation-stimulation were electrically divided. Myocardial infarction was induced by subcutaneous injection of Isoproterenol (150 mg/kg) 24 hours apart in groups. The intervention groups underwent endurance training (treadmill at 20 m/min for 1 hour) and electrical stimulation (foot shock device with 0.5 mA for 20 minutes) for one session. Serum levels of CA-125 and Cys-C were assessed by ELISA immediately after the intervention. Data were analyzed by one-way ANOVA and Tukey post hoc at the significance level of P<0.05.

Induction of infarction significantly increases serum levels of CA-125 and Cys-C (P=0.0001). One session of electrical stimulation and exercise rehabilitation with electrical stimulation showed a significant decrease in serum CA-125 levels (P<0.05) but no significant changes were observed in serum Cys-C values (P˃0.05).

It seems that a session of electrical stimulation and exercise rehabilitation combined with electrical stimulation leads to the improvement of the inflammatory status of infarction patients.

Cardiovascular disease is the leading cause of one-third of all deaths worldwide, and by 2030 it will account for more than 30.5% of all deaths. Myocardial infarction (MI) is one of the most common causes of this disease. Different biomarkers are involved in these diseases, which lead to this complication by causing structural and molecular changes in heart cells and extracellular matrix. Numerous studies have shown an association between stress and cardiovascular disease. Stress increases the secretion of catecholamine’s and corticosteroids from the endocrine glands, and consequently high levels of these hormones potentially increase the risk of cardiovascular disease. MI necrosis stimulates the hypothalamic-pituitary-adrenal axis (HPA) and, as a stressor, increases cortisol (CORT) and catecholamine levels. High elevated CORT levels lead to higher mortality in MI patients. Stress reduces myocardial blood flow by increasing oxygen demand, increasing vascular resistance, and coronary artery contraction, and is a risk factor for cardiovascular patients. On the other hand, exercise has been an effective stimulant on the HPA axis and leads to increased secretion of adrenocorticotropin from the pituitary gland, which is the most important factor in the secretion of CORT. In sports activity studies, it significantly reduces CORT levels. Evidence also suggests that there is a direct relationship between CORT and cardiac troponin-I (cTnI) levels in patients with MI. Troponin is one of the most sensitive proteins in the diagnosis of MI damage. cTnI is more specific than the other two components due to the presence of 31 amino acids in its N-terminus and cTnI levels increase rapidly after the onset of myocardial injury, which can also occur in intense long-term and short-term continuous exercise. This has not been observed in some studies and exercise results in different responses in CORT and cTnI secretion. One of the non-clinical methods along with exercise is the use of electrical stimulation (ES) in the rehabilitation of cardiovascular patients. ES has also been shown to be used as a new and effective modality in the treatment of ischemia. Few studies have been performed on the effect of endurance training and electrical stimulation. On the one hand, little research has been done more on healthy people and so far the effect of endurance training and ES on changes in CORT and cTnI in infarction samples has not been investigated. Therefore, the present study aimed to determine changes in serum levels of troponin-I and CORT after a period of endurance training and electrical stimulation in infarcted rats as a problem can be proposed. The aim of this study was to determine the efficacy of troponin-I and CORT levels in rats induced myocardial infarction after a period of endurance training and acute electrical stimulation.

In this experimental study, 50 Wistar rats (8 weeks old to weighing 130±30 g) purchased from Pasteur Institute were used with the control group. After adaptation to the standard research environment, the animals were randomly divided into 5 groups: healthy, infarction, infarction-endurance training, infarction-electrical stimulation and infarction-electrical stimulation-endurance training. Myocardial infarction was then induced in two infarct groups using two subcutaneous injections of Isoproterenol (150 mg/kg) 24 hours apart. Forty-eight hours after the last injection, several rats from each group were randomly selected and subjected to experimental conditions to ensure induction of infarction. Electrocardiographic changes and increased cardiac enzyme cTnI confirmed the complication of infarction. The intervention groups were exposed to electrical stimulation for one session (foot shock device for 0.5 mA for 20 minutes) and endurance training (treadmill at 20 m/min for 1 hour). Immediately after the protocol, they were anesthetized and killed with a combination of ketamine and xylazine, and blood samples were taken.  Then, serum levels of CORT and cTnI of the samples were evaluated in the laboratory by ELISA method according to the instructions of the manufacturer of kits of Eastbiofarm China. After examining the normal distribution of data, one-way ANOVA and Tukey post hoc tests were used to analyze it at a significance level of P <0.05.

The results showed that serum CORT levels in rats had a statistically significant difference between the healthy group and all groups (P=0.0001 with F=15.1). Also, CORT levels showed statistically significant differences between MI and MI.EX (P=0.008 and F= 5.2), MI and MI.ES (P=0.032 and F = 4.4) and MI with MI.EX.ES (P=0.044 and F=4.4). In different circumstances, Tukey test did not show a statistically significant difference between MI.EX and MI.ES groups (P=0.980 and F=0.8) and MI.ES with MI.EX.ES (P=0.982 and  F=0.1). The results showed that cTnI levels in healthy rats were significantly different from all groups (P=0.0001 with F=26.3). Also, cTnI levels were significantly different between MI and MI.EX groups (P=0.013 with F=4.9).  On the other hand, the difference between MI groups with MI.ES (P=0.476 and F=2.3) and MI.EX.ES (P=0.094 and F=3.7) was not significant. Also, Tukey post hoc test did not show significant differences between MI.EX and MI.ES groups (P=0.390 and F=2.5), MI.ES with MI.ES (P=0.911 and F=1.2) and MI.ES with MI.EX.ES (P=0.833 and F=1.3).

The results of the present study show that one endurance training session significantly reduces CORT and cTnI levels in infarct specimens. In this regard, Klapersky et al. Showed a significant reduction in serum CORT levels after endurance training. In contrast to the present study, Zhu et al. showed that acute aerobic exercise increases CORT levels in both males and females. The reason for the discrepancy between these studies and the present study was the difference in the intensity of physical activity. In the present study, the intensity of exercise was about 55% VO2max and was of moderate intensity. It has already been shown that moderate and low intensity physical activity does not cause significant changes in CORT, but high intensity physical activity stimulates the HPA axis. It may be followed by an increase in CORT. In this study, a significant decrease in cTnI levels was shown after one endurance training session in infarcted rats. Consistent with the results of the present study, Marefati et al. Showed that moderate-intensity interval training significantly reduced serum cTnI levels in ischemic rats, indicating a protective role of this type of exercise against ischemic injury. In contrast to this study, Nuano et al. showed that exercise significantly increased cTnI levels in rats with myocardial ischemia. The increase in cTnI secretion after intense and prolonged activity has not been accurately identified, but this increase may be due to oxidative stress, hypoxia, unstable secretion due to cytosolic leakage due to ischemia, changes in cell permeability and membrane permeability. Also, the difference in the measurement of cTnI level can be another reason for the contradiction of the mentioned studies with this research. The results of the present study showed that induction of ES in myocardial infarction rats significantly reduced CORT levels. In contrast to the present study, Digit et al. Investigated the acute and chronic effects of ES through death shock (0.8 mA and 20 min) on rats and showed that CORT levels increased significantly. The inconsistency may be due to differences in the intensity and duration of induced electrical stimulation in the study samples. The results of ES intervention on cTnI levels of infarcted rats did not show a significant difference.  Other results of this study showed that the combined effect of endurance training with ES significantly reduced CORT values in all study groups compared to MI. But changes in cTnI in the endurance training group with ES were not significant compared to the MI group.