Category: Neurology

Categories : Mental Health NeurologyTags :

Repurposed Drug Exploits Ion Channel in The Brain To Treat Depression

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Researchers from the Icahn School of Medicine at Mount Sinai Hospital have repurposed a drug to treat depression by using an ion channel that is a completely different mechanism than regular antidepressants.

A study demonstrated that a drug called ezogabine, which opens KCNQ2/3 type of potassium channels in the brain, is linked to significant improvements in depressive symptoms and anhedonia (a lack of ability to feel pleasure) in patients with depression. Anhedonia is a complex, core symptom of depression and is associated with poor outcomes such as increased risk of suicide and reduced responsiveness to antidepressants.
Ezogabine is an anticonvulsant for epilepsy treatment; this novel application in treating depression opens up the investigation of the KCNQ2/3 channel as a potential drug target.

“Our study is the first randomized, placebo-controlled trial to show that a drug affecting this type of ion channel in the brain can improve depression and anhedonia in patients. Targeting this channel represents a completely different mechanism of action than any currently available antidepressant treatment,” said Professor James Murrough, MD, PhD, at the Icahn School of Medicine at Mount Sinai, and senior author of the paper.

The KCNQ2/3 channel belongs to the KCNQ (or Kv7) family of ion channels which are important controllers of brain cell excitability and function in the central nervous system, affecting brain cell function by controlling electrical charge flow across the cell membrane in the form of potassium (K+) ions. Previous research in mice also showed involvement of KCNQ2/3 in depression. Mice that were more resilient to stress had increased KCNQ2/3 channels in their brains.

“We viewed enhanced functioning of the KCNQ channel as a potential molecular mechanism of resilience to stress and depression,” said Ming-Hu-Han, PhD, who also discovered that by increasing the activity of this channel, such as by administering ezogabine, to depressed mice, the drug acted as an antidepressant.

A trial with adult human patients showed that, compared to placebo, those treated with ezogabine showed a large reduction in a number of key measures of depression severity, anhedonia, and overall illness severity.
“The fundamental insight by Dr Han’s group that a drug that essentially mimicked a mechanism of stress resilience in the brain could represent a whole new approach to the treatment of depression was very exciting to us,” said Dr Murrough.

In collaboration with Dr Han, Dr Murrough carried out a series of human studies, with an initial open-label (no placebo) study in patients with depression providing initial evidence that ezogabine could improve symptoms of depression and anhedonia.

“I think it’s fair to say that most of us on the study team were quite surprised at the large size of the beneficial effect of ezogabine on clinical symptoms across multiple measures related to depression. We are greatly encouraged by these findings and the hope they offer for the prospect of developing novel, effective treatments for depression and related disorders. New treatments are urgently needed given that more than one-third of people suffering from depression are inadequately treated with currently approved therapeutics.”

Source: Eureka Alert

Categories : Gender NeurologyTags :

LGBTQ Concerns Put Brain Imaging Study on Hold

On By ModernMedia
Person holding rainbow-themed cake slice. Photo by Sharon McCutcheon on Unsplash.

A study investigating brain functions of gender dysphoria at UCLA’s Semel Institute for Neuroscience & Human Behavior, has been put on hold after concerns from LGBTQ groups.

According to the Diagnostic and Statistical Manual of Mental disorders, gender dysphoria is a “marked incongruence between their experienced or expressed gender and the one they were assigned at birth.” Gender Justice LA and the California LGBTQ Health and Human Services Network released a joint statement, citing major ethical concerns.

Study leader Jamie Feusner, MD, a psychiatrist, told MedPage Today that he has asked UCLA’s Institutional Review Board to “re-review our entire protocol to ensure that it meets all ethics and safety standards.”

He added that his team is “actively engaged with members of the LGBTQ community” to help inform potential adjustments to study protocols. It wasn’t clear whether the entire study is on hold or just enrollment of new participants.

Ezak Perez, executive director of Gender Justice LA, wrote that the “research design unapologetically aims to cause mental health distress to trigger ‘dysphoria’ to an already marginalised and vulnerable community.”

The advocacy groups said that researchers from the Semel Institute reached out to the transgender, gender non-conforming, and intersex community in the region to take part in a meeting to help the study design. When they expressed concerns during this meeting and realised the study was already underway with approval from the IRB, leaders from Gender Justice LA and the California LGBTQ Health and Human Services Network wrote a letter to UCLA’s Office of the Human Research Protection Program.

“The researchers are falsely advertising this study without clarity about the expectations of participants and without consideration of the need for direct access to mental health after care,” wrote Perez and Dannie Cesena, program manager of LGBTQ Health and Human Services Network.

The call for participants was for looking for transgender, nonbinary, and cisgender adults to complete an assessment and one or more MRI scans. Participants would also be “photographed from the neck down while wearing a unitard,” a point of contention cited by Perez in his statement. The enrollment announcement also noted that participants who experience discomfort during this process could withdraw from the study at any point. Requirements included not being psychiatric medications, and that trans and nonbinary participants could not already be on hormone therapy or have had gender-affirming surgery. Participants would be paid a small amount and have expenses reimbursed.

The study in question would use the ‘body morph’ test, designed in 2015 by Feusner and colleagues. During the test, participants are photographed from various angles in a nude-colored, full-body unitard, with faces, hand and feet cropped out.. Participant images are then morphed with pictures of different bodies.

Writing to MedPage Today, Feusner and co-researcher Ivanka Savic-Berglund, MD, PhD, wrote that at the time that Feusner created the ‘body morph’ test, “experiences of body-self incongruence were not easily understood. The test uses images to estimate the degree of alignment between individuals’ body perception and their gender-specific self-identity.”

Perez and Cesena strongly objected to the idea that capturing the neurological response of gender dysphoria through brian imaging could provide any scientific data that could ‘help’ trans people.

“It is suggestive of a search for medical ‘cure,’ which can open the door for more gatekeeping and restrictive policies and practices in relation to access to gender-affirming care,” the letter stated.

Feusner and Savic-Berglund, however, explained that “by demonstrating that body-self incongruence was linked to brain structure and function, we aimed to help provide a biological basis and increase empathy for the life stories of transgender individuals. From the beginning, the aim was to help increase acceptance of transgender individuals.”

Source: MedPage Today

Categories : Ageing NeurologyTags :

Jump-Starting Neural Stem Cells in Aged Brains

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As we age, neural stem cells lose the ability to divide and create new neurons, resulting in a decline in memory. Now, research led by Sebastian Jessberger, a professor at the Brain Research Institute of the University of Zurich, explains why this happens.

The new neurons are used all over the brain, including the hippocampus which is responsible for memory. Declines here from age and Alzheimer’s mean fewer neurons are produced here, impacting memory functions.

“As we get older, stem cells throughout the body gradually lose their ability to proliferate. Using genetic engineering and cutting-edge microscope technology, we were able to identify a mechanism that is associated with this process,” explained doctoral candidate and first author Khadeesh bin Imtiaz. The results were published in the journal Cell Stem Cell.

The study used a mouse model to show that as organisms age, neurons’ ability to divide becomes impaired. Protein structures ensure that accumulated harmful proteins are laid out unequally among the two daughter neurons, important for the longevity of neurons. As the neurons age, the amount of nucleic proteins changes, resulting in impaired distribution of proteins, reducing the number of newly generated neurons in the brains of older mice.

The researchers identified a nuclear protein called lamin B1, levels of which decrease as people age. When lamin B1 was increased in aged mice, there was an improvement in stem cell division and the number of neurons increased.

The study was part of wider research into ageing and stem cells. “While our study was limited to brain stem cells, similar mechanisms are likely to play a key role when it comes to the ageing process of other stem cells,” said Prof Jessberger.

The latest findings represent an important step in understanding how brain stem cells change with age. “We now know that we can reactivate aging stem cells in the brain. Our hope is that these findings will one day help increase levels of neurogenesis, for example in older people or those suffering from degenerative diseases such as Alzheimer’s. Even if this may still be many years in the future,” concluded Prof Jessberger.

Source: Medical Xpress

Journal information: Cell Stem Cell, DOI: 10.1016/j.stem.2021.01.015

Categories : NeurologyTags :

Long-term Anaesthesia Causes Changes in Neural Connections

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New research has shown that there may be neurological consequences after long-term anaesthesia.

Prolonged anesthesia, also known as medically induced coma, takes the brain to a state of deep unconsciousness beyond short-term anaesthesia for surgical procedures. It is used to treat refractory intracranial hypertension and status epilepticus.

Though they are life-saving practices performed in ICUs the world over, they are not without cognitive side effects. Family members often report that their loved ones are not quite the same when they are discharged from hospital following prolonged anaesthesia.

“It is long known that ICU survivors suffer lasting cognitive impairment, such as confusion and memory loss, that can languish for months and, in some cases, years,” said lead author Michael Wenzel, MD, a former postdoctoral researcher at Columbia University with experience as a physician in neuro-intensive care in Germany.

Dr Wenzel said cognitive dysfunction after hospitalisation will likely become more widespread in the wake of COVID, with large numbers of ventilated patients awakening from days to weeks of unconsciousness.

Senior author Rafael Yuste, a professor of Biological Sciences at Columbia and senior author of the paper said that to date there had been no research on the direct effects of anaesthesia on neural connections.

“This is because it is difficult to examine the brains of patients at a resolution high enough to monitor connections between individual neurons,” Yuste said.

Yuste and Wenzel sought to investigate the connections between neurons, or synapses, and related cognitive effects of prolonged anaesthesia, using mice. With a specially built miniature ‘ICU’ for mice, they performed continuous anaesthesia for up to 40 hours, much longer than the longest animal study so far.

The researchers used in vivo two-photon microscopy to observe cortical synapses in the sensory cortex, combined with repeated assessment of behaviour in the cortex.

They found that, contrary to the view that neural connections in adult brains are stable in short-term anaesthesia, in long-term anaesthesia there are significant changes in synaptic architecture at any age.

“Our results should ring an alarm bell in the medical community, as they document a physical link between cognitive impairment and prolonged medically induced coma,” Wenzel said.

Further study is needed, the researchers said, adding that it will be important to test a range of anesthetics, as well as the combination of anesthetics administered to patients. Anaesthetics are not tailored to patients in any systematic fashion.

“We are well aware that anaesthesia is a life-saving procedure,” Wenzel said. “Refining treatment plans for patients and developing supportive therapies that keep the brain in shape during prolonged anaesthesia would substantially improve clinical outcomes for those whose lives are saved, but whose quality of life has been compromised.”

Source: Medical Xpress

Journal information: Michael Wenzel et al, Prolonged anesthesia alters brain synaptic architecture, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2023676118

Categories : Injury & Trauma Neurology Pain ManagementTags :

New Surgery Improves Prosthetic Use and Reduces Pain

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A new type of surgery that links muscles together may improve the precision of prosthetic use and also relieve pain.

In typical amputations, the muscle pairs (such as triceps and biceps) that work together to control the joints are severed. However, an MIT team has discovered that reconnecting these muscles that are in an agonistic-antagonistic (‘push-pull’) relationship improves the sensory feedback and thus precision of the affected limb.

“When one muscle contracts, the other one doesn’t have its antagonist activity, so the brain gets confusing signals,” explained Srinivasan, a former member of the Biomechatronics group now working at MIT’s Koch Institute for Integrative Cancer Research. “Even with state-of-the-art prostheses, people are constantly visually following the prosthesis to try to calibrate their brains to where the device is moving.”

The 15 patients who received the AMI surgery were able to flex their prosthetic ankle joint with more precision than those without it, who were only able to fully extend or flex their joint.

“Through surgical and regenerative techniques that restore natural agonist-antagonist muscle movements, our study shows that persons with an AMI amputation experience a greater phantom joint range of motion, a reduced level of pain, and an increased fidelity of prosthetic limb controllability,” says Hugh Herr, a professor of media arts and sciences, head of the Biomechatronics group in the Media Lab, and the senior author of the paper.

The surgery also had a completely unexpected benefit: the reduction of pain in the amputated area, which can be from neuromas or phantom limb pain. Phantom limb pain can occur in 80% of amputess. Six of the 15 AMI patients reported zero pain. This may be significant as in the five centuries since phantom limb pain was first described, there has not been much advancement in the understanding of it.

“Our study wasn’t specifically designed to achieve this, but it was a sentiment our subjects expressed over and over again. They had a much greater sensation of what their foot actually felt like and how it was moving in space,” Srinivasan says. “It became increasingly apparent that restoring the muscles to their normal physiology had benefits not only for prosthetic control, but also for their day-to-day mental well-being.”

To treat patients who had received the traditional amputation surgery, the team is also working on using muscle grafts to create a ‘regenerative AMI’ procedure that restores the effect of agonist and antagonist muscles.

Source: Medical Xpress

Journal information: Shriya S. Srinivasan el al., “Neural interfacing architecture enables enhanced motor control and residual limb functionality postamputation,” PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2019555118

Categories : NeurologyTags :

Short Window for Recovery After Stroke

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Researchers have found that there is a short window for brain repair to be most effective after a stroke, which peaked at two weeks after the incident.

Brain scans conducted by the study showed that the brains of stroke survivors retained plasticity and an improved ability to rewire itself, the first time this had been observed in humans. The study took place in Adelaide and London.

The researchers regularly scanned the brains of 60 stroke survivors as they recovered over a period of 12 months. To assess neural plasticity, the researchers repeatedly activated the brain’s motor cortex using continuous transcranial magnetic stimulation (cTBS). The laboratory in London tested the non-damaged motor cortex, which is also important for stroke recovery while the one in Adelaide tested the damaged motor cortex. In the first few days following an ischaemic stroke, the brain had greater plasticity.

“Earlier animal studies suggested this was the case, but this is the first time we have conclusively demonstrated this phenomenon exists in humans,” Dr Hordacre said.

Only eight minutes of daily rehabilitation time after a stroke is spent on the upper limbs.

“Delivering more treatment within this brief window is needed to help people recover after a stroke,” Dr Hordacre said. “The next step is to identify techniques which prolong or even re-open a period of increased brain plasticity, so we can maximise recovery.”

Source: News-Medical.Net

Journal information: Hordacre, B., et al. (2021) Evidence for a Window of Enhanced Plasticity in the Human Motor Cortex Following Ischemic Stroke. doi.org/10.1177/1545968321992330.

Categories : Neurology Obstetrics & GynaecologyTags :

Brain ‘Rewired’ by Sound Early in the Womb

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Playing music to foetuses in the womb to enhance their brain development is a popular practice even if thus far not grounded in science, but new research has shown that there may be some effect even at very early stages.

New research from John Hopkins University indicates that ‘wiring changes’ made in response to sounds occur even earlier than thought before. The ear canals of newborn mice only open after 11 days, while in humans, the ear canals open at 20 weeks’ gestation. The researchers used the mice as a model for human foetuses, and examined their neural connections at one week old.

“As scientists, we are looking for answers to basic questions about how we become who we are,” said Patrick Kanold, PhD, professor of biomedical engineering at The Johns Hopkins University and School of Medicine. “Specifically, I am looking at how our sensory environment shapes us and how early in foetal development this starts happening.”

Prof Kanold started out in electrical engineering before switching to neuroscience. His field of research is on the cortex, the outer layer of neurons underneath which lies the white matter which consists of connective neurons.

In developing foetuses, in the white matter, subplate neurons can be found at 12 weeks in human gestation and the second embryonic week in mice. This subplate neurons are the precursors to neurons and die off over a period lasting from before birth to several months old. Before they disappear, they make a connection between the thalamus, which is an important sensory gateway, and the middle layers of the cortex.

“The thalamus is the intermediary of information from the eyes, ears and skin into the cortex,” explained Prof Kanold. “When things go wrong in the thalamus or its connections with the cortex, neurodevelopmental problems occur.”

The subplate neurons respond to sound before the cortical neurons, prompting two questions for Prof Kanold: When sound signals reach the subplate neurons, does anything happen, and can a change in sound signals reflect changes in the brain circuits at these young ages?

To answer these questions, the researchers used mice genetically engineered to be deaf, unable to convert sound into nerve signals. In deaf, week-old mice, there were 25-30% more connections between subplate and cortical neurons.

“When neurons are deprived of input, such as sound, the neurons reach out to find other neurons, possibly to compensate for the lack of sound,” said Prof Kanold. “This is happening a week earlier than we thought it would, and tells us that the lack of sound likely reorganises connections in the immature cortex.”

To compare the difference extra auditory stimuli made, the researchers put 2-day old pups in a quiet enclosure or an enclosure with a constant beeping sound. There were differences between the subplate neuron connections for beeping and quiet enclosure mice, but not as great as between the deaf and hearing mice. The quiet enclosure mice had stronger connections between the subplate and cortical neurons, similar to the deaf mice. The mice in the beeping enclosure also had a greater diversity in neural circuitry.

“In these mice we see that the difference in early sound experience leaves a trace in the brain, and this exposure to sound may be important for neurodevelopment,” explained Prof Kanold.

The researchers are planning to examine how sound in early development impacts the brain in later life, as well as how sounds in the womb influences neural wiring. This has application for cochlear implants for children born deaf. They also plan to study premature infants neural wiring problems and develop biomarkers for abnormal subplate neuron development. 

Source: Medical Xpress

Journal information: Early peripheral activity alters nascent subplate circuits in the auditory cortex, Science Advances (2021). DOI: 10.1126/sciadv.abc9155

Categories : Gender Mental Health NeurologyTags :

Women are Better ‘Mind Readers’ Than Men, Study Finds

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Women are better at ‘reading minds’ than men, finds a new study aimed at better understanding social interaction and the challenges faced by people with autism. 

Sometimes known in the field of psychology as ‘mentalising‘, the process is when people try to ascertain what others are really thinking, for example when they are sarcastic or even lying. Mind-reading has some basis in neuroscience: for example, some research indicates that sensitivity to social interactions is associated with the posterior superior temporal sulcus, an area of the brain which is also known to process biological motion. Everybody has some proficiency with mind reading, and some are inherently better than others. However, some lack the ability to a point where it becomes difficult to function in society, for example in autism.

The study made use of a self-report questionnaire asking participants to rate how well, for example, they could relate to others. It used four questions, each with ratings from one to four, giving a maximum total score of 16. The researchers determined that women scored higher than men on the questionnaire, and also confirmed the challenges reported by those with autism. 

Senior author Dr Punit Shah, at the University of Bath’s Department of Psychology explained: “We will all undoubtedly have had experiences where we have felt we have not connected with other people we are talking to, where we’ve perceived that they have failed to understand us, or where things we’ve said have been taken the wrong way. Much of how we communicate relies on our understanding of what others are thinking, yet this is a surprisingly complex process that not everyone can do.”

Dr Shah emphasised that there is a different between mind-reading and empathy, saying: “Mind-reading refers to understanding what other people are thinking, whereas empathy is all about understanding what others are feeling. The difference might seem subtle but is critically important and involves very different brain networks. By focussing carefully on measuring mind-reading, without confusing it with empathy, we are confident that we have just measured mind-reading. And, when doing this, we consistently find that females reported greater mind-reading abilities than their male counterparts.”

Lead researcher, Rachel Clutterbuck, emphasised the clinical importance of the questionnaire. She said: “This new test, which takes under a minute to complete, has important utility in clinical settings. It is not always obvious if someone is experiencing difficulties understanding and responding to others—and many people have learnt techniques which can reduce the appearance of social difficulties, even though these remain.

“This work has great potential to better understand the lived experience of people with mind-reading difficulties, such as those with autism, whilst producing a precise quantitative score that may be used by clinicians to identify individuals who may benefit from interventions.”

Dr Shah added that this study was about helping to understand mind-reading capabilities, and had created a freely available questionnaire for other efforts in this regard.

Source: Medical Xpress

Journal information: Rachel A. Clutterbuck et al, Development and validation of the Four-Item Mentalising Index., Psychological Assessment (2021). DOI: 10.1037/pas0001004

Categories : NeurologyTags :

Geometric Model of Sherlock Episode Reveals How We Recall Events

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Using a TV episode and a geometrical model, researchers at Dartmouth have come up with a new way to understand how the brain evaluates which experiences to store as memories and which to discard.

The researchers based their study around participants’ recall of a BBC episode of Sherlock against a geometric model of the events that happened in it. Their results allowed new insights into how memories are stored and then related to others.

Senior author Jeremy R Manning, an assistant professor of psychological and brain sciences, and director of the Contextual Dynamics Lab at Dartmouth, explained: “When we represent experiences and memories as shapes, we can use the tools provided by the field of geometry to explore how we remember our experiences, and to test theories of how we think, learn, remember, and communicate.

“When you experience something, its shape is like a fingerprint that reflects its unique meaning, and how you remember or conceptualise that experience can be turned into another shape. We can think of our memories like distorted versions of our original experiences. Through our research, we wanted to find out when and where those distortions happen (i.e. what do people get right and what do people get wrong), and examine how accurate our memories of experiences are.”

Using a public dataset of brain recordings from 17 participants who had viewed the same Sherlock episode and described what had happened. This dataset also contained detailed notes on what took place in that episode. They took these notes to create a list of 32 topics, which were then represented as a 32-dimensional model. Visualised in 2 dimensions, a dot-to-dot shape emerges, to which the shapes made by the participants’ recall of events can be compared.

Using the episode’s shape as a structure, they were able to see at what points the participants’ memories matched the episode, and what points they forgot or had distorted recollections. The shape also featured extraneous elements of fine detail, like architectural embellishments such as carvings, which reflected low-conceptual details. Some participants accurately recounted these low-conceptual details while others could only recall high-level plot points.

“One of our most intriguing findings was that, as people were watching the episode, we could use their brain activity patterns to predict the distorted shapes that their memories would take on when they recounted it later,” explained Manning. “This suggests that some of the details about our ongoing experiences get distorted in our brains from the moment they are stored as new memories. Even when two people experience the same physical event, their subjective experiences of that event start to diverge from the moment their brains start to make sense of what happened and distill that event into memories.”

These findings could be used as the basis for research into improving educational delivery, as well as patients’ understanding of matters explained to them by their doctors.

Source: Medical Xpress

Journal information: Geometric models reveal behavioural and neural signatures of transforming experiences into memories, Nature Human Behavior (2021). DOI: 10.1038/s41562-021-01051-6

Categories : Neurology PaediatricsTags :

No Evidence for Strep Exacerbating Chronic Tics in Kids

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A new study has found that children with chronic tic disorders, mainly Tourette syndrome, do not have tic exacerbations when exposed to group A Streptococcus.

No significant association with tic exacerbations emerged across four definitions of pharyngeal strep exposure with a mean follow-up of 16 months, though a weak link was observed in trend, reported Davide Martino, MD, PhD, of the University of Calgary, and co-authors.

Strep was however significantly associated with longitudinal changes in hyperactivity-impulsivity symptom severity of 17% to 21%.
“The link between Streptococcus and tics in children is still a matter of intense debate,” Martino stated. “We wanted to look at that question, as well as a possible link between strep and behavioral symptoms like obsessive-compulsive disorder and attention deficit hyperactivity disorder.

“While our findings suggest that strep is not likely to be one of the main triggers for making tics worse, more research is needed into other possible explanations. For example, the social stress of having this disorder could be implicated in making tics worse more than infections. It’s also possible another pathogen might be triggering an immune response associated with tic worsening.”

In an invited editorial, Andrea Cavanna, MD, PhD, of the University of Birmingham, and Keith Coffman, MD, of Children’s Mercy Hospital in Kansas City, observed that group A Streptococcus had been posited as a potential environmental factor in tic disorders for the past two decades.

The editorialists noted that, on the basis of isolated clinical observations, tic disorders should be included as a collateral feature in conditions which are known as pediatric autoimmune neuropsychiatric disorders associated with Streptococcus (PANDAS) infections. However, the results of longitudinal clinical studies were inconclusive, with a case control study even arguing against the association.

Drawing data from the EMTICS study, recruiting children with chronic tic disorders from 2013 to 2016, one arm of the study prospectively examined associations between new group A Streptococcus throat exposures and tic exacerbations, obsessive-compulsive disorder (OCD), and attention deficit hyperactivity disorder (ADHD) symptoms.

Four definitions of strep exposure were used: new definite (newly positive throat swab regardless of serological results), new possible (elevated anti-streptolysin O [ASOT] or anti-DNAseB [ADB] titers with negative or no throat swab), ongoing definite, and ongoing possible.

Initially, 59 children had a positive throat swab; as the study progressed, 103 children had new definite strep exposure. During follow-up, 308 children (43%) had tic exacerbations. The proportion of exacerbations temporally associated with strep exposure ranged from 5.5% to 12.9%, depending on exposure definition. No association between OCD symptoms and strep exposure was seen.

“Our study of the largest prospective cohort of youth with chronic tic disorders ever documented to date provides evidence against a temporal association between group A Streptococcus exposure and clinically relevant tic exacerbations,” the researchers wrote.

“This result indicates that specific diagnostic work-up or active management of group A Streptococcus infections in the context of worsening of tic severity in patients with chronic tic disorders is not warranted,” the researchers added.

The researchers noted that limitations included the data being collected from specialist centres in different countries, and that some cases of strep may have been missed.

Source: MedPage Today

Journal information (article): Martino D, et al “Association of Group A Streptococcus Exposure and Exacerbations of Chronic Tic Disorders: A Multinational Prospective Cohort Study” Neurology 2021; DOI: 10.1212/WNL.0000000000011610.

Journal information (editorial): Cavanna A, Coffman K “Streptococcus and Tics: Another Brick in the Wall?” Neurology 2021. DOI: 10.1212/WNL.0000000000011608.