Tag: epilepsy

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An Ancient Brain Area Processes Numerical Concepts

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Photo by Anna Shvets

New research in patients undergoing neurosurgery reveals the unique human ability to conceptualise numbers may be rooted deep within the brain. In good news for those who are stumped by maths, the results of the study by Oregon Health & Science University involving neurosurgery patients suggests new possibilities for tapping into those areas to improve learning.

“This work lays the foundation to deeper understanding of number, math and symbol cognition – something that is uniquely human,” said senior author Ahmed Raslan, MD, professor and chair of neurological surgery in the OHSU School of Medicine. “The implications are far-reaching.”

The study appears in the journal PLOS ONE.

Raslan and co-authors recruited 13 people with epilepsy who were undergoing a commonly used surgical intervention to map the exact location within their brains where seizures originate, a procedure known as stereotactic electroencephalography. During the procedure, researchers asked the patients a series of questions that prompted them to think about numbers as symbols (for example, 3), as words (“three”) and as concepts (a series of three dots).

As the patients responded, researchers found activity in a surprising place: the putamen.

Located deep within the basal ganglia above the brain stem, the putamen is an area of the brain primarily associated with elemental functions, such as movement, and some cognitive function, but rarely with higher-order aspects of human intelligence like solving calculus. Neuroscientists typically ascribe consciousness and abstract thought to the cerebral cortex, which evolved later in human evolution and wraps around the brain’s outer layer in folded grey matter.

“That likely means the human ability to process numbers is something that we acquired early during evolution,” Raslan said. “There is something deeper in the brain that gives us this capacity to leap to where we are today.”

Researchers also found activity as expected in regions of the brain that encode visual and auditory inputs, as well as the parietal lobe, which is known to be involved in numerical and calculation-related functions.

From a practical standpoint, the findings could prove useful in avoiding important areas during surgeries to remove tumors or epilepsy focal points, or in placing neurostimulators designed to stop seizures.

“Brain areas involved in processing numbers can be delineated and extra care taken to avoid damaging these areas during neurosurgical interventions,” said lead author Alexander Rockhill, PhD, a postdoc in Raslan’s lab.

Researchers credited the patients involved in the study.

“We are extremely grateful to our epilepsy patients for their willingness to participate in this research,” said co-author Christian Lopez Ramos, MD, neurosurgical resident at OHSU. “Their involvement in answering our questions during surgery turned out to be the key to advancing scientific understanding about how our brain evolved in the deep past and how it works today.”

Indeed, the study follows previous lines of research involving mapping of the human brain during surgery.

“I have access to the most valuable human data in nature,” Raslan said. “It would be a shame to miss an opportunity to understand how the brain and mind function. All we have to do is ask the right questions.”

In the next stage of this line of research, Raslan anticipates discerning areas of the brain capable of performing other higher-level functions.

Source: Ohio State University

Categories : NeurologyTags :

Intracranial EEG Captures Neurons Resonating as They Turn Words into Thoughts

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The lines on this diagram of the brain represent connections between various areas of the cerebral cortex involved in language processing. When we read, the neurons in these areas fire in precise synchronicity, a phenomenon known as “co-rippling.” Photo credit: UC San Diego Health Sciences

Researchers at University of California San Diego School of Medicine have brought us closer to solving how the brain processes information from specialised areas into a whole. By delving into the brain with intracranial electroencephalography, they observed how neurons synchronise across the human brain while reading. The findings are published in Nature Human Behaviour and are also the basis of a thesis by UC San Diego School of Medicine doctoral candidate Jacob Garrett.

“How the activity of the brain relates to the subjective experience of consciousness is one of the fundamental unanswered questions in modern neuroscience,” said study senior author Eric Halgren, Ph.D., professor in the Departments of Neurosciences and Radiology at UC San Diego School of Medicine. “If you think about what happens when you read text, something in the brain has to turn that series of lines into a word and then associate it with an idea or an object. Our findings support the theory that this is accomplished by many different areas of the brain activating in sync.”

This synchronisation of different brain areas, called “co-rippling” is thought to be essential for binding different pieces of information together to form a coherent whole. In rodents, co-rippling has been observed in the hippocampus, the part of the brain that encodes memories. In humans, Halgren and his colleagues previously observed that co-rippling also occurs across the entire cerebral cortex.

To examine co-rippling at the mechanistic level, Ilya Verzhbinsky, an MD/PhD candidate completing his research in Halgren’s lab, led a study published in PNAS that looked at what happens to single neurons firing in different cortical areas during ripples. The present study looks at the phenomenon with a wider lens, asking how the many billions of neurons in the cortex are able to coordinate this firing to process information.

“There are 16 billion neurons in the cortex – double the number of people on Earth,” said Halgren. “In the same way a large chorus needs to be organised to sound as a single entity, our brain neurons need to be coordinated to produce a single thought or action. Co-rippling is like neurons singing on pitch and in rhythm, allowing us to integrate information and make sense of the world. Unless they’re co-rippling, these neurons have virtually no effect on the other, but once ripples are present about two thirds of neuron pairs in the cortex become synchronised. We were surprised by how powerful the effect was.”

Co-rippling in the cortex has been difficult to observe in humans due to limitations of noninvasive brain scanning. To work around this problem, the researchers used an approach called intracranial electroencephalography (EEG) scanning, which measures the electrical activity of the brain from inside the skull. The team studied a group of 13 patients with drug-resistant epilepsy who were already undergoing EEG monitoring as part of their care.

Participants were shown a series of animal names interspersed with strings of random consonants or nonsense fonts and then asked to press a button to indicate the animal whose name they saw. The researchers observed three stages of cognition during these tests: an initial hierarchical phase in visual areas of the cortex in which the participant could see the word without conscious understanding of it; a second stage in which this information was “seeded” with co-ripples into other areas of the cortex involved in more complex cognitive functions; and a final phase, again with co-ripples, where the information across the cortex is integrated into conscious knowledge and a behavioural response – pressing the button.

The researchers found that throughout the exercise, co-rippling (~100ms-long ~90Hz oscillations) occurred between the various parts of the brain engaged in these cognitive stages, but the rippling was stronger when the participants were reading real words.

The study’s findings have potential long-term implications for the treatment of neurological and psychiatric disorders, such as schizophrenia, which are characterised by disruptions in these information integration processes.

“It will be easier to find ways to reintegrate the mind in people with these disorders if we can better understand how minds are integrated in typical, healthy cases,” added Halgren.

More broadly, the study’s findings have significant implications for our understanding of the link between brain function and human experience.

“This is a fundamental question of human existence and gets at the heart of the relationship between mind and brain,” said Halgren. “By understanding how our brain’s neurons work together, we can gain new insights into the nature of consciousness itself.”

Source: University of California San Diego

Categories : NeurologyTags :

Could a New Role for Propofol be Treating Epilepsy?

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The general anaesthetic propofol may hold the keys to developing new treatment strategies for epilepsy and other neurological disorders, according to a study led by researchers at Weill Cornell Medicine and Linköping University in Sweden.

In their study, published in Nature, the researchers determined the high-resolution structural details of how propofol inhibits the activity of HCN1, an ion channel protein found on many types of neurons. Drug developers consider inhibiting HCN1 a promising strategy for treating neurologic disorders including epilepsy and chronic pain. The researchers also found, to their surprise, that when HCN1 contains either of two epilepsy-associated mutations, propofol binds to it in a way that restores its functionality.

“We might be able to exploit propofol’s unique way of binding to HCN1 for the treatment of these drug-resistant epilepsies and other HCN1-linked disorders, either by directly repurposing propofol or by designing new, more selective drugs that have the same mechanism of action,” said study co-senior author Dr Crina Nimigean, professor of physiology and biophysics in anaesthesiology at Weill Cornell Medicine.

The study’s first author was Dr Elizabeth Kim, a postdoctoral research associate in the Nimigean laboratory.  

HCN ion channels in humans come in four basic forms, HCN1 to HCN4, and are found especially on cells in the heart and nervous system. They work as switches to control the electrical voltage across the cell membrane, opening to admit an inward flow of positively charged potassium and sodium ions – thus “depolarising” the cell – when the voltage reaches a certain threshold. This function underpins much of the rhythmic activity of brain and heart muscle cells, which is why HCN channels are also called pacemaker channels.

In the study, the researchers used cryo-electron microscopy and other methods to determine, at near-atomic scale, how propofol reduces HCN1 activity – which it does with selectivity for HCN1 over other HCNs. They found that the drug inhibits HCN1 by binding within a groove between two elements of the channel protein’s central pore structure, making it harder for the pore to open.

As they investigated propofol’s action on HCN1, the researchers examined how the drug affects different known mutants of the channel, including mutants that leave it excessively open and are associated with hard-to-treat epilepsy syndromes such as early infantile epileptic encephalopathy (EIEE). The researchers were surprised to find that for two different HCN1 mutations that cause EIEE, propofol restores the mutant channels to normal or near-normal function.

From their experiments, the researchers derived a model in which the mutations decouple HCN1’s voltage-sensing and pore mechanisms, while propofol effectively recouples them, allowing membrane voltage to control ion flow again.

The results suggest at least two possibilities for translation to therapies. One is simply to use propofol, an existing, approved drug, to treat these HCN1-mutation epilepsies and potentially other HCN1-linked disorders. Propofol is a potent anesthetic that requires careful monitoring by anaesthesiologists, but it might be able to restore HCN1 function at doses below those used for general anaesthesia.

The other possibility, the researchers said, is to use the new structural data on propofol’s binding to design modified, non-anesthetic versions of propofol, or even completely different compounds, that bind to HCN1 with a similar effect but much more selectively—in other words, without binding to other channels, including other HCNs, in the body and thereby potentially causing unwanted side effects.

“For that we will need a better understanding of how propofol inhibits HCN1 better than other HCN channels,” Dr Kim said.

Source: Weill Cornell Medicine

Categories : Implants and Prostheses NeurologyTags :

New Neural Prosthetic Device Can Help Restore Memory in Humans

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Scientists have demonstrated the first successful use of a neural prosthetic device to recall specific memories. The findings appear online in Frontiers in Computational Neuroscience.

This groundbreaking research was derived from a 2018 study led by Robert Hampson, PhD, professor of regenerative medicine, translational neuroscience and neurology at Wake Forest University School of Medicine. That study demonstrated the successful implementation of a prosthetic system that uses a person’s own memory patterns to facilitate the brain’s ability to encode and recall memory, improving recall by as much as 37%.

In the previous study, the team’s electronic prosthetic system was based on a multi-input multi-output (MIMO) nonlinear mathematical model, and the researchers influenced the firing patterns of multiple neurons in the hippocampus, a part of the brain involved in making new memories.

In this study, researchers from Wake Forest and University of Southern California (USC) built a new model of processes that assists the hippocampus in helping people remember specific information.

When the brain tries to store or recall information such as, “I turned off the stove” or “Where did I put my car keys?” groups of cells work together in neural ensembles that activate so that the information is stored or recalled.

Using recordings of the activity of these brain cells, the researchers created a memory decoding model (MDM) which let them decode what neural activity is used to store different pieces of specific information.

The neural activity decoded by the MDM was then used to create a pattern, or code, which was used to apply neurostimulation to the hippocampus when the brain was trying to store that information.

“Here, we not only highlight an innovative technique for neurostimulation to enhance memory, but we also demonstrate that stimulating memory isn’t just limited to a general approach but can also be applied to specific information that is critical to a person,” said Brent Roeder, Ph.D., a research fellow in the department of translational neuroscience at Wake Forest University School of Medicine and the study’s corresponding author.

The team enrolled 14 adults with epilepsy who were participating in a diagnostic brain-mapping procedure that used surgically implanted electrodes placed in various parts of the brain to pinpoint the origin of their seizures.

Participants underwent all surgical procedures, post-operative monitoring and neurocognitive testing at one of the three sites participating in this study including Atrium Health Wake Forest Baptist Medical Center, Keck Hospital of USC in Los Angeles and Rancho Los Amigo National Rehabilitation Center in Downey, California.

The team delivered MDM electrical stimulation during visual recognition memory tasks to see if the stimulation could help people remember images better.

They found that when they used this electrical stimulation, there were significant changes in how well people remembered things. In about 22% of cases, there was a noticeable difference in performance.

When they looked specifically at participants with impaired memory function, who were given the stimulation on both sides of their brain, almost 40% of them showed significant changes in memory performance.

“Our goal is to create an intervention that can restore memory function that’s lost because of Alzheimer’s disease, stroke or head injury,” Roeder said.

“We found the most pronounced change occurred in people who had impaired memory.”

Roeder said he hopes the technology can be refined to help people live independently by helping them recall critical information such as whether medication has been taken or whether a door is locked.

“While much more research is needed, we know that MDM-based stimulation has the potential to be used to significantly modify memory,” Roeder said.

Source: Atrium Health Wake Forest Baptist

Categories : Ageing Diseases, Syndromes and ConditionsTags :

Promising Results for Epilepsy Drug in Slowing Osteoarthritis

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Yale researchers report in the journal Nature that they have identified a drug target that may alleviate joint degeneration associated with osteoarthritis.

The most common therapies for the degenerative disease have been pain relievers and lifestyle changes, to reduce pain and stiffness, but there is a pressing need for therapies that can prevent joint breakdown that occurs in osteoarthritis, which occurs as a result of the breakdown of cartilage in the joints.

Sodium channels found in cell membranes produce electrical impulses in “excitable” cells within muscles, the nervous system, and the heart. And in previous research, Yale’s Stephen G. Waxman identified the key role of one particular sodium channel, called Nav1.7, in the transmission of pain signals.

Now, the labs of Chuan-Ju Liu, professor of orthopaedics, and Waxman, professor neurology, neuroscience and pharmacology, have found that the same Nav1.7 channels are also present in non-excitable cells that produce collagen and help maintain the joints in the body. These channels can be targeted by existing drugs to block them.

In the new study, the researchers deleted Nav1.7 genes from these collagen-producing cells and significantly reduced joint damage in two osteoarthritis models in mice.

They also demonstrated that drugs used to block Nav1.7 – including carbamazepine, a sodium channel blocker currently used to treat epilepsy and trigeminal neuralgia – also provided substantial protection from joint damage in the mice.

“The function of sodium channels in non-excitable cells has been a mystery,” Waxman said.

“This new study provides a window on how small numbers of sodium channels can powerfully regulate the behaviour of non-excitable cells.”

“The findings open new avenues for disease-modifying treatments,” added Wenyu Fu, a research scientist in the Liu laboratory and first author of the study.

Source: Yale University

Categories : NeurologyTags :

What Happens When the Brain Loses a Hub?

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A University of Iowa-led team of international neuroscientists have obtained the first direct recordings of the human brain in the minutes before and after a brain hub crucial for language meaning was surgically disconnected. The results reveal the importance of brain hubs in neural networks and the remarkable way in which the human brain attempts to compensate when a hub is lost, with immediacy not previously observed. The findings were reported recently in the journal Nature Communications.

Hubs are critical for connectivity

The human brain has hubs – the intersection of many neuronal pathways that help coordinate brain activity required for complex functions like understanding and responding to speech. But debate has reigned as to whether highly interconnected brain hubs are irreplaceable for certain brain functions. By some accounts the brain, as an already highly interconnected neural network, can in principle immediately compensate for the loss of a hub, in the same way that traffic can be redirected around a blocked-off city centre.

With a rare experimental opportunity, the UI neurosurgical and research teams led by Matthew Howard III, MD, professor and DEO of neurosurgery, and Christopher Petkov, PhD, professor and vice chair for research in neurosurgery, have achieved a breakthrough in understanding the necessity of a single hub. By obtaining evidence for what happens when a hub required for language meaning is lost, the researchers showed both the intrinsic importance of the hub as well as the remarkable and rapid ability of the brain to adapt and at least partially attempt to immediately compensate for its loss.

Evaluating the impact of losing a brain hub

The study was conducted during surgical treatment of two patients with epilepsy. Both patients were undergoing procedures that required surgical removal of the anterior temporal lobe – a brain hub for language meaning – to allow the neurosurgeons access to a deeper brain area causing the patients’ debilitating epileptic seizures. Before this type of surgery, neurosurgery teams often ask the patients to conduct speech and language tasks in the operating room as the team uses implanted electrodes to record activity from parts of the brain close to and distant from the planned surgery area. These recordings help the clinical team effectively treat the seizures while limiting the impact of the surgery on the patient’s speech and language abilities.

Typically, the recording electrodes are not needed after the surgical resection procedure and are removed. The innovation in this study was that the neurosurgery team was able to safely complete the procedure with the recording electrodes left in place or replaced to the same location after the procedure. This made it possible to obtain rare pre- and post-operative recordings allowing the researchers to evaluate signals from brain areas far away from the hub, including speech and language areas distant from the surgery site. Analysis of the change in responses to speech sounds before and after the loss of the hub revealed a rapid disruption of signaling and subsequent partial compensation of the broader brain network.

“The rapid impact on the speech and language processing regions well removed from the surgical treatment site was surprising, but what was even more surprising was how the brain was working to compensate, albeit incompletely within this short timeframe,” says Petkov, who also holds an appointment at Newcastle University Medical School in the UK.

The findings disprove theories challenging the necessity of specific brain hubs by showing that the hub was important to maintain normal brain processing in language.

“Neurosurgical treatment and new technologies continue to improve the treatment options provided to patients,” says Howard, who also is a member of the Iowa Neuroscience Institute.

“Research such as this underscores the importance of safely obtaining and comparing electrical recordings pre and post operatively, particularly when a brain hub might be affected.”

According to the researchers, the observation on the nature of the immediate impact on a neural network and its rapid attempt to compensate provides evidence in support of a brain theory proposed by Professor Karl Friston at University College London, which posits that any self-organising system at equilibrium works towards orderliness by minimising its free energy, a resistance of the universal tendency towards disorder.

These neurobiological results following human brain hub disconnection were consistent with several predictions of this and related neurobiological theories, showing how the brain works to try to regain order after the loss of one of its hubs.

Source: University of Iowa Health Care

Categories : Neurology New Compounds and TreatmentsTags :

A New Drug Could Provide Hope in Treatment-resistant Epilepsy

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In cases where standard therapies fail, an in-development drug called XEN1101 reduces seizure frequency by more than 50% in some patients and in some cases eliminates them, according to a new study published in JAMA Neurology. Unlike several treatments that must be started at low doses and slowly ramped up, the new drug can safety be taken at its most effective dose from the start, the authors say.

Focal seizures, the most common type seen in epilepsy, occur when nerve cells in a particular brain region send out a sudden, excessive burst of electrical signals. Along with seizures, this uncontrolled activity can lead to abnormal behaviour, periods of lost awareness, and mood changes. While many available therapies control or reduce seizures, they fail to stop seizures in about one-third of patients and may cause harsh side effects, experts say.

Led by researchers at NYU Grossman School of Medicine, a new clinical trial found that patients who added XEN1101 to their current antiseizure treatments saw a 33% to 53% drop in monthly seizures, depending on their dose. By contrast, those given a placebo had on average 18% fewer seizures during the treatment phase of the trial, which lasted eight weeks. Most patients then volunteered to extend the trial, with about 18% of those treated with the new drug remaining entirely seizure free after six months, and about 11% having no seizures after a year or longer.

“Our findings show that XEN1101 may offer a swift, safe, and effective way to treat focal epilepsy,” said study lead author, neurologist Jacqueline French, MD. “These promising results offer hope for those who have struggled for decades to get their symptoms under control.”

French, a professor in the Department of Neurology at NYU Langone Health, notes that XEN1101 was well tolerated by the study participants, who reported side effects similar to other antiseizure treatments, including dizziness, nausea, and fatigue, and the majority felt well enough to continue the regimen. Another benefit of the drug, she adds, is that it takes more than a week to break down, so levels in the brain remain consistent over time. This steadiness allows the treatment to be started at full strength and helps to avoid dramatic spikes that worsen side effects, and dips that allow seizures to return. This lengthy breakdown time also allows for a “grace period” if a dose is accidently skipped or taken late.

XEN1101 is part of a class of chemicals called potassium-channel openers, which avert seizures by boosting the flow of potassium out of nerves, stopping them from firing. French notes that while other drugs of this kind have been explored for epilepsy patients in the past, such treatments were taken out of use because the compounds were later found to gradually build up in the skin and eyes, prompting safety concerns, the researchers say.

Meanwhile, XEN1101 combines the effectiveness of potassium-channel openers with the safety of more traditional drugs, says French, who is also a member of NYU Langone’s Comprehensive Epilepsy Center.

For the study, which included 285 men and women with epilepsy and ran from January 2019 to September 2021, the research team recruited adults with epilepsy who had already tried and stopped taking an average of six drugs that failed to treat their focal seizures. Patients in the trial had to have experienced at least four episodes a month despite ongoing treatment to qualify. The patients were randomly provided either a daily oral capsule of XEN1101 (in 10mg, 20mg, or 25mg doses) or placebo.

Among the results, the trial revealed no signs of dangerous side effects such as heart problems, allergic reactions, or concerning skin discolourations. However, French says that the research team plans to expand the number of patients exposed to the drug and monitor for potential issues that could arise in the long term, or include specific groups of people, such as pregnant women. In addition, the team also intends to explore XEN1101 for other types of seizures, including those that broadly affect the brain at the same time (generalised seizures).

“Our study highlights the importance of finding as many therapeutic options as possible for those who suffer from seizures,” says French. “Since everyone responds differently, treating epilepsy cannot be a one-size-fits-all approach.”

Source: NYU Langone Health / NYU Grossman School of Medicine

Categories : General Interest NeurologyTags :

Inspiring, but not Therapeutic: Study Finally Silences The ‘Mozart Effect’

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Over the past fifty years, there have been remarkable claims about the effects of Wolfgang Amadeus Mozart’s music. Reports about alleged symptom-alleviating effects of listening to Mozart’s Sonata KV448 in epilepsy attracted a lot of public attention. However, the empirical validity of the underlying scientific evidence has remained unclear. Now, University of Vienna psychologists Sandra Oberleiter and Jakob Pietschnig show in a new study published in the journal Nature Scientific Reports that there is no evidence for a positive effect of Mozart’s melody on epilepsy.

In the past, Mozart’s music has been associated with numerous ostensibly positive effects on humans, animals, and even microorganisms. For instance, listening to his sonata has been said to increase the intelligence of adults, children, or foetuses in the womb. Even cows were said to produce more milk, and bacteria in sewage treatment plants were said to work better when they heard Mozart’s composition.

However, most of these alleged effects have no scientific basis. The origin of these ideas can be traced back to the long-disproven observation of a temporary increase in spatial reasoning test performance among students after listening to the first movement allegro con spirito of Mozart’s sonata KV448 in D major.

More recently, the Mozart effect experienced a further variation: Some studies reported symptom relief in epilepsy patients after they had listened to KV448. However, a new comprehensive research synthesis by Sandra Oberleiter and Jakob Pietschnig from the University of Vienna, based on all available scientific literature on this topic, showed that there is no reliable evidence for such a beneficial effect of Mozart’s music on epilepsy. They found that this alleged Mozart effect can be mainly attributed to selective reporting, small sample sizes, and inadequate research practices in this corpus of literature. “Mozart’s music is beautiful, but unfortunately, we cannot expect relief from epilepsy symptoms from it” conclude the researchers.

Source: University of Vienna

Categories : Obstetrics & GynaecologyTags :

No Added Seizure Risk from Antidepressant Use in Pregnancy

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A large Swedish study in the journal Neurology found that pregnant women taking selective serotonin reuptake inhibitors (SSRIs) or selective norepinephrine reuptake inhibitors (SNRIs) during the first trimester of was not linked to an increased risk for neonatal seizures and epilepsy in childhood.

Any increase in seizures or epilepsy is likely due to other factors, the researchers said.

“It’s not likely the medications themselves that are causing the seizures and epilepsy in children, but rather the reasons why these women are taking the medication,” according to Kelsey Kathleen Wiggs, a PhD candidate at Indiana University in Bloomington. There are also the other background factors that differ between women who do and do not use SSRI/SNRIs.

“When it rains, it pours,” Wiggs said. “Women who are taking antidepressants in pregnancy are doing that for lots of different reasons, and they might be at risk for different things than women who aren’t taking those medications in pregnancy.”

The study found an elevated risk for neonatal seizures (risk ratio [RR] 1.41) and epilepsy in early childhood (HR 1.21) among offspring of mothers who used antidepressants in pregnancy.

Adjustment for maternal indications for SSRI/SNRI use and background factors like smoking during pregnancy revealed that they were drivers for both associations: neonatal seizures (RR 1.10); epilepsy diagnosis at 5 years (HR 0.96). Parental history of epilepsy was not found to affect the association.

The findings provide a “conclusive answer” to these concerns with using SSRI/SNRIs during pregnancy, according to Anne Berg, PhD, and Torin Glass, BM, Bch, BAO.

“[SSRI/SNRIs] have been demonstrated to have serotonergic central nervous system effects and are associated with an observable withdrawal syndrome which may be seen in the neonate following in utero exposure,” noted Drs Berg and Glass, in an accompanying editorial.

“The authors understood that with a population-based data registry and huge sample size, they had more than sufficient statistical power to detect even a modest increase in risk,” the editorialists wrote. “They tested this hypothesis and were able to reject it, definitively!”

In order to determine whether antidepressants had a causal association with infant seizures and childhood epilepsy, the researchers analysed data from national Swedish healthcare registries on a total of 1 721 274 children in Sweden born between 1996 and 2011.

Participants were divided into two groups: one group of mothers who reported use of an SSRI (fluoxetine, citalopram, paroxetine, sertraline, fluvoxamine, escitalopram) or SNRI (venlafaxine, duloxetine) during the first trimester of pregnancy (n = 24 308), and another group with no reported antidepressant use (n = 1 696 966).

Source: MedPage Today

Categories : NeurologyTags :

People with Epilepsy Live Significantly Shorter Lives

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A Danish cohort study published in Brain shows that people with epilepsy live 10-12 years fewer than those without the condition, with a slightly greater reduction for men than women. The study researchers also found that excess mortality is particularly pronounced among people with epilepsy and mental disorders.

One of the most frequently occurring neurological diseases, epilepsy affects 50 million people worldwide, and is known to increase the risk of early death by three times.

“The significantly reduced life expectancy is found both in people who develop epilepsy as a result of an underlying condition, such as brain cancer or stroke, and in those who develop epilepsy without an obvious underlying cause,” explained Julie Werenberg Dreier, one of the researchers behind the study.

The average reduction in life expectancy was 12 years for men with epilepsy and 11 years for women. Among people with epilepsy and mental disorders life expectancy was on average reduced by up to 16 years.

“We discovered that the reduced life expectancy for people with epilepsy was related to a wide range of causes of death which don’t just include the neurological, but also cardiovascular diseases, psychiatric disorders, alcohol related conditions, accidents and suicide,” said Jakob Christensen, one of the researchers behind the study.

Researchers used Danish healthcare register to follow almost six million Danes, including more than 130 000 people with epilepsy.

“The large study has enabled detailed analyses of a range of different causes of death and, for the first time, we’ve been able to estimate the number of years lost due to individual causes of death in people with epilepsy. This is important information as it can be used to target preventive efforts in order to reduce the mortality gap that we currently see in people with epilepsy,” said Julie Werenberg Dreier.

The mortality rate among people with epilepsy is due to a wide range of different conditions that cut across virtually all medical specialities, the researchers said. There is therefore a need for a collective effort to reduce mortality.

“The alarming results provide important knowledge for all healthcare professionals who, in one way or another, come into contact with people with epilepsy — also when prioritising and allocating resources in the healthcare system. The results clearly show how serious a disease epilepsy can be, and the findings of the study should be used in the prioritisation and planning of preventive measures,” said Jakob Christensen, emphasising that the results confirm the tendencies that have been shown in a few smaller studies which have estimated reduction in life expectancy in people with epilepsy.

“The study should be followed up by additional research, for example into the questions of how medical treatment and recurring seizures affect life expectancy.”

Source: Aarhus University