Connect with us
  • Elysium

News

A malformation illustrates the incredible plasticity of the brain

Published

on

People born without a corpus callosum do not have a bridge between the two cerebral hemispheres. Neuroscientists from UNIGE have shown how the brain manages to adapt.

One in 4,000 people is born without a corpus callosum, a brain structure consisting of neural fibres that are used to transfer information from one hemisphere to the other. A quarter of these individuals do not have any symptoms, while the remainder either have low intelligence quotients or suffer from severe cognitive disorders.

In a study published in the journal Cerebral Cortex, neuroscientists from the University of Geneva (UNIGE) discovered that when the neuronal fibres that act as a bridge between the hemispheres are missing, the brain reorganises itself and creates an impressive number of connections inside each hemisphere.

These create more intra-hemispheric connections than in a healthy brain, indicating that plasticity mechanisms are involved. It is thought that these mechanisms enable the brain to compensate for the losses by recreating connections to other brain regions using alternative neural pathways.

The corpus callosum develops in utero between the tenth and twentieth week of gestation. Agenesis of the corpus callosum is a congenital brain malformation in which this brain structure fails to develop, resulting in one out of 4,000 babies born without a corpus callosum. When it is missing, nothing replaces this structure measuring about ten centimetres, with the exception of cerebrospinal fluid. This means that the information transmitted from one hemisphere to the other can no longer be conveyed by the neuronal projections from the corpus callosum.

Vanessa Siffredi, a researcher in UNIGE’s Faculty of Medicine says: “Their role in a healthy brain is to ensure the functioning of various cognitive and sensorimotor functions.”

Surprisingly, 25% of people with this malformation have no visible signs; 50% have average intelligence quotients and learning difficulties; and the remaining 25% suffer from severe cognitive disorders.

The scientific literature shows that, in the absence of the corpus callosum, certain fibres designed to serve as a bridge between the hemispheres, known as Probst bundles, bypass the absent brain area and curl up inside each hemisphere.

“The back-up zones vary from one individual to another. And we don’t understand their functions,” explains the neuroscientist. The UNIGE scientists – working in collaboration with their colleagues at the University of Melbourne – set out to understand this variability and to examine the role of the fibres. Using MRI brain imaging, they studied the anatomical and functional links between different brain regions of approximately 20 Australian children aged 8 to 17 suffering from agenesis of the corpus callosum.

This approach first made it possible to observe the physical relationships between the different regions of the brain, i.e. their structural links. In children with corpus callosum agenesis, the neural fibres inside each hemisphere are greater in number and of higher quality than in healthy brains.

Furthermore, the UNIGE scientists succeeded in determining the correlations between the activity of different brain regions and their functional links.

“If two regions are active together, it means they are communicating with each other,” explains Dr Siffredi.

The data shows that intra and inter-hemispheric functional connectivity of brains without the corpus callosum are comparable to those of healthy brains.

“Remarkably, communication between the two hemispheres is maintained. We think that plasticity mechanisms, such as the strengthening of structural bonds within each hemisphere, compensated for the lack of neuronal fibres between hemispheres. New connections are created and the signals can be re-routed so that communication is preserved between the two hemispheres.”

The Geneva neuroscientists likewise observed a correlation between the increase in intra-hemispheric connections and cognitive skills.

This information is very interesting for clinical work since, as agenesis is currently detected by means of ultrasound during pregnancy, it is often proposed that a pregnancy be terminated.

“In the not-too-distant future, we could imagine using MRI imaging to predict whether the malformation observed by ultrasound runs the risk of being associated with cognitive impairment or not, and so better inform future parents,” concludes Dr Siffredi.

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

News

Smoking linked to stroke in new study 

Published

on

Guido Falcone, assistant professor of neurology at Yale School of Medicine, was the senior author of the study

Adults who smoke, or are genetically predisposed to smoking behaviours, are more likely to experience a subarachnoid haemorrhage (SAH), new research has revealed.

The study found that while smokers are at a higher risk of SAH, that rises to over 60 per cent among those with genetic variants that predispose them to smoking.

The research, published in Stroke, a journal of the American Stroke Association, establishes a link between smoking and the risk of SAH for the first time.

While it has been proven in other types of stroke, this is pioneering research in its link with SAH – a type of stroke that occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull.

Results of the study show:

  • the relationship between smoking and SAH risk appeared to be linear, with those who smoked half a pack to 20 packs of cigarettes a year having a 27% increased risk;
  • heavier smokers, those who smoked more than 40 packs of cigarettes a year, were nearly three times more at risk for SAH than those who did not smoke; and,
  • people who were genetically predisposed to smoking behaviours were at a 63% greater risk for SAH.

Researchers also stated that while their findings suggest a more pronounced and harmful effect of smoking in women and adults with high blood pressure, they believe larger studies are needed to confirm these results.

“Previous studies have shown that smoking is associated with higher risks of SAH, yet it has been unclear if smoking or another confounding condition such as high blood pressure was a cause of the stroke,” says senior study author Guido Falcone, assistant professor of neurology at Yale School of Medicine.

“A definitive, causal relationship between smoking and the risk of SAH has not been previously established as it has been with other types of stroke.”

During the study, researchers analysed the genetic data of 408,609 people from the UK Biobank, aged 40 to 69 at time of recruitment (2006-2010).

Incidence of SAH was collected throughout the study, with a total of 904 SAHs occurring by the end of the study.

Researchers developed a genetic risk scoring system that included genetic markers associated with risk of smoking and tracked smoking behaviour data, which was collected at the time each participant was recruited.

“Our results provide justification for future studies to focus on evaluating whether information on genetic variants leading to smoking can be used to better identify people at high risk of having one of these types of brain haemorrhages,” said lead study author Julian N. Acosta, neurologist, postdoctoral research fellow at the Yale School of Medicine.

“These targeted populations might benefit from aggressive diagnostic interventions that could lead to early identification of the aneurysms that cause this serious type of bleeding stroke.”

Continue Reading

News

New campaign to reduce stroke risk launched on Stroke Prevention Day 

Published

on

Almost nine out of ten strokes are associated with modifiable risk factors

A 12-week campaign is being launched today – Stroke Prevention Day – to help raise awareness of how the risk of stroke can be reduced. 

The campaign encourages people to make one small positive change to their lifestyle to reduce the possibility of stroke, which is the fourth highest cause of death in the UK. 

According to the Stroke Association UK, 89 per cent – almost 9 in 10 – strokes are associated with modifiable risk factors in the Western countries, including lifestyle elements that can be changed to reduce risk, such as weight, diet and blood pressure. 

New research commissioned by the charity, which is leading the campaign, has also revealed: 

  •  Only 1 in 20 (6%) UK adults think they’re at high risk of a stroke, despite the fact that the global lifetime risk of stroke from the age of 25 years onward was approximately 25% among both men and women
  • Almost half (47%) of the country don’t know that high blood pressure is a top risk factor for stroke 
  • 3 in 4 people (73%) said that they have had no information about stroke reduction recently, which rises to over 4 in 5 (85%) of over-65s, who are most at risk of having a stroke.

Blood pressure is the biggest cause of stroke, with 55 per cent of stroke patients having hypertension when they experience their stroke. Further, around 1 in 4 adults from 55 years of age will develop AFib. 

“While these numbers are concerning, they also demonstrate that with increased awareness, we can all take simple steps to reduce our risk,” says Charlie Fox, sales director of OMRON Healthcare, who are supporting the Stroke Association campaign alongside Patients Know Best. 

“As an incredibly important risk factor for stroke, having a healthy heart should be a top priority and remain front of mind.”

AFib can be asymptomatic and may not be present during a medical appointment as episodes can be occasional, which means it is often left undiagnosed. 

But given its seriousness, those who may be at risk should routinely record electrocardiogram (ECG) measurements, according to current medical guidelines. 

Through doing so at home will enable patients to become more in control of their health, with OMRON being one of the companies developing the technology to support them in doing so. 

“The public wants and needs to be more in control of its health, which is why we create products and services that are suitable for use at home as part of our Going for Zero strokes pledge,” adds Fox. 

“OMRON Complete, for example, is an upcoming, clinically validated home blood pressure monitor with a built-in ECG which can help detect AFib which we’re excited to launch in the coming months. 

“It is our hope that through this awareness programme and by equipping the public with the tools it needs, we can make having an empowered and informed lifestyle the new normal.”

People with a Patients Know Best (PKB) Personal Health Record can also log readings to get a more complete picture of their health journey. This allows them to look back with ease and share readings with clinical teams and caregivers in a safe, secure and meaningful way.

Fox concludes: “Your blood pressure provides important health insights. Monitoring it regularly alongside your ECG readings empowers you with knowledge, helps you act sooner, and can even save your life”.

More information about the campaign and how you can make your one small change can be found here: www.stroke.org.uk/PreventionDay

Continue Reading

News

What are the IDDSI Levels and why do they matter?

Published

on

Wiltshire Farm Foods takes you through the importance of the IDDSI Levels

Sponsored feature

Dysphagia, more commonly known as swallowing difficulties, can be prevalent amongst those in neuro rehabilitation. For those in recovery, understanding how their swallowing has been affected, what solutions are available and which nutritional, delicious and above all, safe, meals they should be eating, is of paramount importance.   

When someone starts to experience dysphagia, they are most commonly seen by a speech and language therapist (SLT) and a dietitian. Together, they will create a plan for the management of dysphagia. A speech and language therapist will explain in detail the importance of texture modified food and drinks and will work with you to carefully understand the right texture modification for you. 

What is IDDSI?

This is where IDDSI can help you understand your recommended texture modified diet in more detail.  IDDSI stands for International Dysphagia Diet Standardisation Initiative. This is a committee that have developed a framework of 8 levels which provide common terminology to describe food textures and the thickness of liquids for those living with dysphagia.

The purpose of IDDSI is to create standardised terminology and descriptors for texture modified foods and liquids that can be applied and understood globally – across all cultures and age spans.

Before the introduction of IDDSI, there were national descriptors in the UK which were formed by opinion rather than international standards. Having different terminology, categories and definitions in different countries caused some instances of food being of incorrect consistency. The IDDSI framework was fully adopted by food manufacturers and healthcare settings in the UK in March 2019.

The framework consists of levels for both drinks (liquids) and foods, some of which overlap as you can see in the image above. Here is a breakdown of each category in the IDDSI FOODS framework. 

Level 3 – Liquidised/Moderately Thick

  • Can be drunk from a cup
  • Does not retain its shape
  • Can be eaten with a spoon, not a fork
  • Smooth texture with no ‘bits’

Level 4 – Pureed/Extremely Thick

  • Usually eaten with a spoon (a fork is possible)
  • Does not flow easily
  • Does not require chewing
  • Retains its shape
  • No lumps
  • Not a sticky consistency

Level 5 – Minced

  • Can be eaten with either a fork or a spoon
  • Can be scooped and shaped
  • Small lumps are visible, but are easy to squash with tongue
  • Biting is not required
  • Minimal chewing required

Level 6 – Soft & Bite-Sized

  • Can be eaten with fork or spoon
  • Can be mashed/broken down with pressure
  • Chewing is required before swallowing

How can I check my meals are made to IDDSI standards?

You can check to see whether your food is compliant with the IDDSI Framework by watching these IDDSI Food Test videos.

To discover a Softer Foods range which is IDDSI compliant and created with your patients’ needs in mind, register here for the opportunity to try some complimentary meals from Wiltshire Farm Foods.

Continue Reading
Softer Foods

Trending