Motor Training After Stroke: Electrical Stimulation and Mirror Therapy

Upper limb disability and loss of motor function are mainly caused by a stroke. Recovering motor function after stroke has been a continuous challenge for rehabilitation and treatments. The success of physical therapy and rehabilitation therapy depends on the severity of the stroke and the area of the brain affected by the stroke. Several studies have investigated if other factors combined with motor training enhance motor recovery, or if there is no difference at all. A study done by Pan et al. investigated the use of electrical stimulation along with physical functional training in the recovery of motor function in stroke patients. A separate study done by Madhoun et al. combined mirror therapy and motor functions to investigate if there was any difference between the combined therapy and physical therapy in general.

Pan et al. demonstrated that stroke survivors that received electrical stimulation prior to physical functional training improved upper limb function. This type of motor training along with electrical stimulation facilitated corticomuscular functional connectivity. Electrical stimulation provided a steady somatosensory input. This was an ideal approach to appropriately stimulate the motor cortex. The median nerve was the specific target in this study due to its role in the flexion of three fingers in the hand which account for the majority of functions in the hand. This study demonstrated that in four weeks, the experimental group that received the electrical stimulation along with the physical functional training performed better at motor tasks than those of the control group, the group that did physical functional training without the electrical stimulation. In eight weeks, there was a significant improvement in hand function. The goal of this study was to demonstrate how electrical stimulation could facilitate and strengthen limb function and corticomuscular functional connectivity in chronic stroke patients. 

The goal of the Madhoun et al. study was to investigate the effects of task-based mirror therapy in subacute stroke patients compared to the effects of occupational therapy. The study compared two groups, those that did the task-based mirror therapy, and the control group that only did the occupational therapy. The task-based mirror therapy group placed their unaffected limb on the anterior side of the mirror, while the affected limb was hidden, allowing the patient to only observe the unaffected limb. The patients then did various tasks, such as flexion of the fingers and wrist with different types of objects simultaneously with both limbs. The results of this study showed that both types of therapy demonstrated improvement in motor function and recovery but that the results from the task-based mirror therapy group were significantly better than the control. 

In the Pan et al. study, the majority of the subjects that underwent electrical stimulation were at the chronic stage of stroke and they showed significant improvement in motor function. This was a type of improvement that many rehabilitation programs were not able to accomplish with stroke patients in the chronic stage. The results of the study demonstrated the importance of timing and the type of therapy in recovering motor function of stroke patients. The Madhoun et al. study did acknowledge some of its limitations. First, the study was conducted looking at results from subacute stroke patients, unlike the Pan et al. study that had results from chronic stroke patients. The long-term effects of task-based mirror therapy were also not investigated. It is important to keep in mind that the relationship between motor function and corticomuscular coherence differs between individuals due to its influence on the severity of the stroke and the area of the brain where the stroke occurred. Both studies demonstrated that physical therapy along with other therapeutic stimulation may enhance motor recovery after stroke. 

References:

Madhoun, H. Y., Tan, B., Feng, Y., Zhou, Y., Zhou, C., & Yu, L. (2020). Task-based mirror therapy enhances the upper limb motor function in subacute stroke patients: a randomized control trial. European journal of physical and rehabilitation medicine, 56(3), 265–271. https://doi.org/10.23736/S1973-9087.20.06070-0

 

Pan, LL.H., Yang, WW., Kao, CL. et al. Effects of 8-week sensory electrical stimulation combined with motor training on EEG-EMG coherence and motor function in individuals with stroke. Sci Rep 8, 9217 (2018). https://doi.org/10.1038/s41598-018-27553-4

DMN’s Importance in Mental Health

 

    “What is the Default Mode Network”  

Do you ever just drift off and someone suddenly snaps you back to reality. Ever had moments where you just mindlessly think about the future, the past, or even just completely “zone out.” Well, that is caused by your Default Mode Network (DMN), and not many people know the role the DMN plays in the brain. In the field of neuroscience, the default mode network (DMN) is composed of numerous systems in the brain including the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), precuneus, and the angular gyrus. These brain regions play critical roles in memory collection and formation, attention, self-processing, information processing, emotion regulation, metalizing, and various other cognitive tasks. The DMN has been linked to various forms of mental illness, these include patients with Alzheimer’s Disease (AD), along with those who suffer from Parkinson’s Disease (PD), and individuals who suffer from posttraumatic stress disorder (PTSD). Throughout this blog post, we will be looking over the connections between the DMN and mental health problems.

            Looking at the article “Posttraumatic Stress Disorder in Associated with a Dysrhythmia across the Visual Cortex and the Default Mode Network,” Kevin Clancy and his team hypothesized that there is a connection between a decrease in alpha activity and the ability to filter out sensory input across the DMN hubs. The DMN pertains to the resting brain, while alpha activity is the main electrical component of the resting brain. The team found that with increased visual input, patients with PTSD demonstrated reduced alpha frequency directed connectivity with hubs of the DMN, the posterior cingulate cortex (PCC) and the medial prefrontal cortex (mPFC). This presents a therapeutic target for individual who suffer from PTSD. There are numerous studies focused on the connection between the DMN and mental health problems. Looking at the article “Default Mode Network Complexity and Cognitive Decline in Mild Alzheimer’s Disease,” Matthias Grieder and his team examined the connection between two hubs of the DMN in relation to Alzheimer’s Disease. They found disruptions when it comes to functional connectivity between two hubs of the DMN in patients with Alzheimer’s disease (AD), this disruption was a decrease in DMN functional connectivity between the posterior cingulate cortex (PCC) and the right side of the hippocampus. These disruptions lead to disturbance in information processing, transfer of information to different regions in the brain, processing personal information, decision making, spatial cognition, and inevitably, the processing of memories.

            Both these teams and articles focused on the connection between hubs of the DMN and mental illnesses such as PTSD and Alzheimer’s Disease. Clancy and his team looked the decrease in alpha connectivity in the PCC and the mPFC in patients with PTSD whereas Grieder and his team looked at disruptions in connectivity in the PCC and the right side of the hippocampus in patients with Alzheimer’s Disease. Different approaches but both found disruptions in connectivity involved in two different, but very important mental problems. More work is being done regarding the connection between the DMN and other mental problems such as chronic depression and Parkinson’s disease. There is deeper work to be done when looking at the disruptions in connectivity between hubs of the DMN and mental health problems as both teams have found, but for mental problems such as rumination and depression, there are various things to do to stay health. Activities to help boost positivity include reading, hiking, watching the sun or moon rise and set, swimming, and various other positive actives that allows you to leave your mind but do so in a positive way.

References:

Clancy, K. J., Andrzejewski, J. A., Simon, J., Ding, M., Schmidt, N. B., & Li, W. (2020). Posttraumatic Stress Disorder Is Associated with α Dysrhythmia across the Visual Cortex and the Default Mode Network. eNeuro, 7(4), ENEURO.0053-20.2020. https://doi.org/10.1523/ENEURO.0053-20.2020

Grieder, M., Wang, D. J. J., Dierks, T., Wahlund, L. O., & Jann, K. (2018). Default Mode Network Complexity and Cognitive Decline in Mild Alzheimer's Disease. Frontiers in neuroscience, 12, 770. https://doi.org/10.3389/fnins.2018.00770

Buckner R. L. (2013). The brain's default network: origins and implications for the study of psychosis. Dialogues in clinical neuroscience, 15(3), 351–358. https://doi.org/10.31887/DCNS.2013.15.3/rbuckner

 

Neurological Autism Detection Alongside the Pandemic

 Autism has fortunately become more and more easily diagnosable in the modern day through neurological and biological research alongside social and behavioral cues. But, the COVID-19 pandemic has thrown a slight wrench in progress being made as so many of these behavioral cues that one may display when at risk for an Autism diagnosis are becoming normalized through the generation of children who have lived through/were born into the pandemic times.

Two pieces of work dive into not only the neurological components of Autism but also how society is handling the newfound stressors of the pandemic. The first, journal article “Cortical Source Analysis of the Face Sensitive N290 ERP Component in Infants at High Risk for Autism” published in the Brain Sciences Journal explores the neural mechanisms behind face processing in infants that are at high-risk for autism. To do this, the researchers examined the N290 event-related potential, which is known to be overly sensitive to face processing and has been found to be altered or modulated in individuals that have been diagnosed with autism. 58 infants aged 6-10 months at high risk of Autism (by having an older sibling already diagnosed). After undergoing EEG recordings while looking at images of faces and non-facial stimuli, results demonstrated that infants who were later diagnosed with Autism had reduced N290 amplitude in response to faces compared to those who were high-risk but did not develop Autistic symptoms and low-risk control participants. 

From here, the cortical analysis of the EEGs helped researchers identify the brain regions involved in facial processing in these infants who were at high risk. These regions demonstrated that reduced N290 amplitude in these high-risk infants was associated with decreased activation in the right fusiform gyrus (the fusiform face area). This study as a whole highlighted the potential successes in using EEG and cortical analysis to identify early neural biomarkers of autism in high-risk infants. 

This work, giving the ability to enhance early detection and intervention is crucial for making sure diagnoses are given and in improving the outcomes of those with Autism. Taking this one step further, the CNN article titled “Autism diagnosis has become more common, but the pandemic has disrupted early detection, CDC says” from CNNhealth takes this point and really drives it home. 

According to this article, in 2023 the CDC has found that the prevalence of Autism in the U.S. has increased to 1 in 44 children from 1in 54 children in 2016. However, the COVID-19 pandemic has hindered these diagnoses and has led to delays in routine screening as well as caused certain antisocial behaviors to become normalized through quarantine and isolation periods. This is now raising concerns in the diagnostic community about taking steps backward, leading to a surge in undiagnosed cases and delayed interventions. 

This CNN article presents yet another pressing issue that has arisen from the COVID-19 pandemic and how its impacts may follow society into losing the progress we have made in Autism intervention, causing long-term consequences for individuals with Autism and their families. But, the work Maggie Guy and her team have completed can be a saving grace in these hindrances as finding biological neural markers can aid the battle against delayed early intervention and behavioral shifts. Together, these two works demonstrate that with continued efforts and hypervigilance, we as a society can keep working towards improving the outcomes of individuals diagnosed with Autism and their families.

Guy, M. W., Richards, J. E., & Roberts, J. E. (2021). Cortical source analysis of the face-sensitive N290 ERP component in infants at high risk for autism. Brain Sciences, 11(3), 375. https://doi.org/10.3390/brainsci11030375

McPhillips, D. (2021, April 2). Autism diagnosis has become more common, but pandemic disrupted early detection, CDC says. CNN Health. https://www.cnn.com/2021/04/01/health/autism-diagnosis-covid-pandemic-wellness/index.html

Hormone Therapy & the Positive Cognition Correlation in Menopausal Women

    In an article titled “Perimenopausal use of hormone therapy is associated with enhanced memory and hippocampal function later in life”, Pauline Maki and her colleagues utilized hormone therapy (HT) methods during key menopausal periods to see if it affected certain areas of the brain. They found that women in the perimenopausal period undergoing HT had enhanced verbal memory and hippocampal functionality compared to women who never underwent HT. How have other forms of hormone therapy been used to affect women’s cognition? 

    Did you know that 2/3 of dementia diagnoses are women? When estrogen is lost in menopause, it can greatly accelerate neuropathology in women. In studies previously, uses of hormone replacement therapy have had mixed results, so in their paper “Hormone replacement therapy is associated with improved cognition and larger brain volumes in at-risk APOE4 women: results from the European Prevention of Alzheimer’s Disease (EPAD) cohort”, Saleh et al. explore the role of the APOE4 genotype and HRT inflation at specific ages, looking at the heterogeneity of the cognitive response when undergoing HRT. They used various tests of cognition and measured brain volumes using MRI. Their results indicated that when undergoing HRT, APOE4 carriers (women more likely to have cognitive decline/higher Alzheimer’s risk) have improved delayed memory and larger entorhinal and amygdala volumes. These results can suggest possible treatment plans that may target women based on their APOE4 genotype for the possibility of an improvement in their cognition. 

    In another study titled “Lifetime estrogen exposure and Cognition in late life: the Cache County Study” Joshua Matyi et al. examined the relationship between estrogen and cognitive decline in a 12-year population-based study involving over 2,000 women. Their methodology revolved around a women’s health questionnaire which asked about reproductive history, and HT usage. It was analyzed on the metric of endogenous estrogen exposure (EEE), and calculated depending on the reproductive age at puberty and at the age of menopause with additional adjustments based on whether the women had become pregnant or breastfed. The results indicated a strong positive correlation between EEE and cognitive status, as well as another positive correlation between longer HT use and cognition. There are a few things to note including that HT had a greater benefit on women who were older and the soonest after menopause had happened (within the first 5 years of menopause).

    These studies show the importance of the use of different hormone therapies during certain menopausal periods and how they can affect cognition, mainly improving it. We all know women in our lives, and we all want the best for them and their lives as they get older. Knowing these studies we can make a positive impact on the cognition of many women when HT is used at optimal times for optimal impact. 

References:

Maki, P. M., Dennerstein, L., Clark, M., Guthrie, J., LaMontagne, P., Fornelli, D., Little, D., Henderson, V. W., & Resnick, S. M. (2011). Perimenopausal use of hormone therapy is associated with enhanced memory and hippocampal function later in life. Brain Research, 1379, 232–243. https://doi.org/10.1016/j.brainres.2010.11.030

Matyi, J. M., Rattinger, G. B., Schwartz, S., Buhusi, M., & Tschanz, J. T. (2019). Lifetime estrogen exposure and cognition in late life: the Cache County Study. Menopause (New York, N.Y.), 26(12), 1366–1374. https://doi.org/10.1097/GME.0000000000001405

Saleh, R.N.M., Hornberger, M., Ritchie, C.W. et al. Hormone replacement therapy is associated with improved cognition and larger brain volumes in at-risk APOE4 women: results from the European Prevention of Alzheimer’s Disease (EPAD) cohort. Alz Res Therapy 15, 10 (2023). https://doi.org/10.1186/s13195-022-01121-5

How We Perceive Certain Features Neurologically Can Harm Mental Health

Where do our senses of like and dislike come from regarding physical appearances of the objects and people around us? Is it genetic? Learned? Is it taught to us by society? There are neurological mechanisms at play every time we perceive a person or thing that determine whether or not we are attracted to whatever it is we're looking at. In "Is Beauty in the Eye of the Beholder or an Objective Truth," Grcywacz et. al suggest that, evolutionarily, we have developed our senses of like and dislike through the rewards systems in the brain, as one bad perceptive decision could mean life or death. They state that "in biological contexts symmetry is often a signal of good health and disruption of symmetry can signal genetic or natural abnormalities." These concepts are exemplified through various art mediums, as Dietrich et. al explore in "(Neuro)Aesthetics: Beauty, ugliness, and ethics." They suggest that the complexity of nature is simplified through art. We can understand art in this context because it has a nueroaesthetic foundation. "From a neuroaesthetic point of view, characteristics such as beautiful or ugly can be examined from the concept of art on the basis of the perception of art. Ethical implications of aesthetic experiences can be derived." Exaggeration is one of the eight heuristics introduced by Ramachandran and Hirstein that were created to explain how we perceive art, Dietrich et. al claim. "This is primarily intended to map the central characteristics of an object and thus to evoke strong responses. This occurs especially in caricatures, where physical features are deliberately exaggerated to be better recognized and to trigger a reaction on the part of the viewer." This can be one method of how beauty standards are developed, but ethically, it can cause issues with how certain groups are perceived in society, as many traits are held to similar standards throughout a certain area. Grcywacz et. al suggest that our "objective" sense of what is beautiful and what isn't as a collective society comes from our shared cognitive responses to certain features. If the traits of certain ethnic groups are not seen as beautiful by a collective society, it can lower the overall self-esteem of the people belonging to those groups because they are not correctly or morally represented in the forms of media they consume. This is not the fault of any one specific individual, but the gradual but noticeable narrowing of what is seen as beautiful can be extremely harmful for many people. 

Grzywacz, N. M., Aleem, H., Pombo, M., & Correa-Herran, I. (2019). Is Beauty in the Eye of the Beholder or an Objective Truth? A Neuroscientific Answer. Springer Nature Switzerland. https://doi.org/10.1007/978-3-030-24326-5_11

Dietrich, P., & Knieper, T. (2021). (Neuro)Aesthetics: Beauty, ugliness, and ethics. PsyCh Journal. https://doi.org/10.1002/pchj.478

The Search for an Earlier Autism Diagnosis

 Written by Bri Galvan

    Throughout your lifetime, have you ever encountered someone who has been diagnosed with autism? With the numbers on the rise, I am sure you have. Among 8-year-olds, one in 54 are diagnosed.1 Autism spectrum disorder, also known as ASD, is a neurological condition that affects development, communication, sensory processing, and interactions with others.1 The exact cause of the development of autism is unknown, although many people have generated their own ideas. Some people believe it is caused by a gene variant, others believe it could be environmental factors such as toxin exposures, or even imbalances in the intestinal microbiome. 

Countless studies have been done to support each of these possible causes. In support of environmental influences, recent research has found an association between ASD and a mother’s exposure to ozone pollution during the third trimester of pregnancy.1 Additionally, it was found that exposure to a specific type of air pollution known as particulate matter during a baby's first year of living can increase the likelihood of developing autism.1  In regards to genes and neurobiological factors, a recent study analyzed the DNA of more than 35,584 people worldwide, including 11,986 autistic individuals. The scientists identified variants in 102 genes linked with an increased probability of developing ASD.1 Additionally, there has been a correlation shown between a decrease in the formation of myelin sheaths via oligodendrocytes, which can possibly disrupt neural communication and harm normal brain development, later leading to autism.1 

It is important to physicians that we can start diagnosing autism earlier on in an infant's life as it can help in the long run. More recent research has been aimed at finding potential biomarkers of autism that will help with diagnosing earlier. A recent study done by Maggie Guy et al. aims to further understand information processing in those at high risk of developing autism, therefore potentially getting closer to identifying a biomarker. The participants in this study included those with siblings with autism spectrum disorder (referred to as ASIBs) and children with fragile X syndrome. This population of children was chosen as approximately a fifth of ASIBs and three out of five children with FXS will develop ASD in their lifetime.2 

This study worked to further understand facial processing in these children as atypical face processing is one of the most frequently observed forms of atypical attention in ASD.2 This was done via cortical source analysis by testing event-related potentials during facial recognition by understanding the N290 response in infants (which is closely linked with face processing). Overall, cortical source analysis of the N290 showed face specialization in groups both at risk and not risk, but mainly because of higher activation of brain regions when shown faces versus being shown toys. Although, infants with FXS displayed higher levels of activation to faces across all areas analyzed, while ASIBs show more muted levels of activation.2 This finding helped the field dig a little bit closer to identifying more specific causes of ASD but more research in this area is important to promoting increased understanding of cortical development associated with social information processing in neurodevelopmental disorders, including FXS and ASD.2 Hopefully one day there will be successful identification of a biomarker to indicate autism diagnosis earlier on. 

Sources

1. Drake, Kimberly. (2021, April 16th). What is the latest research on autism?. Medical News Today. (Autism research: Recent findings (medicalnewstoday.com))

2. Guy, M.W.; Richards, J.E.; Roberts, J.E. Cortical Source Analysis of the Face Sensitive N290 ERP Component in Infants at High Risk for Autism. Brain Sci. 2022, 12, 1129. https://doi.org/10.3390/brainsci12091129

Endocannabinoids and Epilepsy: The Ups-and-Downs of Reducing Epilepsy Intensity Through Marijuana

    Throughout the years, the use of both recreational and medical marijuana has greatly increased within our society. More communities, celebrity figures, and even some political figures have begun to advocate for the legalization of marijuana and more flexible laws regarding marijuana. Within all these prospective areas, the biggest main thoughts for advocating for marijuana’s legalization tend to be regarding mental health or plain recreation/fun reasons. However, there is one area not many people think of when discussing legalizing marijuana, and that is its effect on reducing how intense seizures are and epilepsy.

    In a review article, ‘Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment,’ the authors Andrew Scheyer, Farhana Yasmin, Saptarnab, and Sachin Patel discus what exactly endocannabinoids (eBCs) are and how it is relevant to epilepsy. Based on the authors definition, endocannabinoids are “lipid neuromodulators that suppress neurotransmitter release, reduce postsynaptic excitability, activate astrocyte signaling, and control cellular respirations.” To put that into simpler terms, endocannabinoids can also be thought of as fatty acid analogs that are metabolites (substances made or used when our body breaks down food, drugs/chemicals, or even our own tissue) of membrane lipids. It was found that our eBCs system is largely implicated in the pathophysiology of seizures and epilepsy and that the one of our eBCs receptors, CB1Rs, have been shown to regulate and reduce epileptiform activity. Epileptiform activity is commonly seen when a seizure is taking place or about to happen. Alongside this information it was also revealed that 2-AG, a type of endocannabinoid, augmentation decreases excitability in the hippocampus by suppressing input to hippocampus granule cells, overall reducing the intensity of seizures. Seizures and epilepsy activity can be greatly regulated throughout the use of marijuana by reducing its intensity or strength of an individual’s seizure. Even though this is a very unconventional method that many of us would never imagine, this can provide great results and further medical research. With all this notable work, we still must consider the possible consequences as well.

    In a similar the web article ‘Endocannabinoid Release Calms Epileptic Seizures but Also Leads to Adverse After-Effects,’ the author (who is sadly unknown), discusses how Stanford University School of Medicine found evidence supporting how the release of   2-AG is related to the dampening of seizure intensity, along with the possible effects brought on by it. 2-AG, which as I stated earlier is an endocannabinoid compound, are our brains internal versions of the psychoactive chemicals in marijuana. While the release of 2-AG reduces the intensity of seizures, it was also discovered that due to our brain’s rapid breakdown of 2-AG, this results in a cascade of biochemical reactions focused within blood vessels and constricts the brains air and blood flow. When this occurs, it can result in amnesia and disorientation within an individual. Despite having it side effects that should not be ignored, the possibilities endocannabinoids encompass can further our medical findings, while also helping destigmatize the negative connotation surrounding marijuana wholly.

    In our present time, the medicinal and recreational use of marijuana has brought about a great movement in both the medical and personal world. Further research on how marijuana and endocannabinoids play a role in not only epilepsy and seizures, but also an array of areas such as stress, diet, and neurodevelopment can provide wonderful societal advancements. Through this, we can try all the possibilities to try and reduce the pain and discomfort the millions of people face from epilepsy, alongside other medical issues in our near future. So even though marijuana may not be everyone’s favorite topic, we cannot deny the contributions it has had in individual’s lives regarding feelings, such as pain and our medical world.

 

References:

(2021). Endocannabinoid Release Calms Epileptic Seizures but Also Leads to Adverse After-Effects. Genetic Engineering & Biotechnology News. https://www.genengnews.com/news/endocannabinoid-release-calms-epileptic-seizures-but-also-leads-to-adverse-after-effects/#:~:text=When%20excitatory%20neurons%2C%20secreting%20chemical,to%20chill%20out%20a%20little.

 

       Scheyer, A., Yasmin, F., Naskar, S., & Patel, S. (2022). Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment. Nature Journal. https://www.nature.com/articles/s41386-022-01438-7