Posts Tagged Brain Damage

[WEB SITE] Attention network plays key role in restoring vision after brain damage: New study highlights the role of attention as a component of vision restoration training in hemianopia

Date: September 4, 2018
Source: Institute for Medical Psychology, Otto-v.-Guericke University Magdeburg
Summary: About one-third of patients who have suffered a stroke end up with low vision, losing up to half of their visual field. This partial blindness was long considered irreversible, but recent studies have shown that vision training after optic nerve and brain damage can help restore or improve vision. A new study reports on key mechanisms of vision restoration: attention.

FULL STORY

About one third of patients who have suffered a stroke end up with low vision, losing up to half of their visual field. This partial blindness was long considered irreversible, but recent studies have shown that vision training after optic nerve and brain damage can help restore or improve vision. A new study published in the journal Clinical Neurophysiology reports on key mechanisms of vision restoration: attention.

Hemianopia is a decreased vision or blindness in half the visual field, usually as a consequence of stroke or trauma to the brain. It greatly reduces quality of life, affecting patients’ reading, driving and spatial navigation.

“Knowledge in this field is still rather fragmentary, but recent studies have shown that vision can be partially restored by vision training, which improves the deficient visual field sectors,” explains Prof. Bernhard Sabel, PhD, Director of the Institute of Medical Psychology at Magdeburg University, Germany, co-investigator of the study. “Neuroimaging evidence supports a possible role of attention in this vision restoration.”

The study confirmed this hypothesis by obtaining evidence from functional magnetic resonance imaging (fMRI) that visual training led to functional connectivity reorganization of the brain´s attentional network.

Seven chronic hemianopic patients with lesions of the visual cortex took part in vision rehabilitation training for five weeks. After the pre-tests all received training sessions lasting one and a half hours per day for six days per week for five weeks. Each training session, lasting about 60 minutes, was composed of six blocks with 120 training trials each, during which participants had to respond to specially designed visual stimuli on a computer monitor. The pre- and post-test included perimetry testing, contrast sensitivity testing and fMRI scanning one or two days before and after training, respectively. Each contrast sensitivity test consisted of 420 trials in six blocks. The visual rehabilitation training was performed with one eye open, which was randomly chosen, while the non-trained eye was covered with an opaque eye patch.

After training, the patients had significantly improved visual function at the training location, and fMRI showed that the training led to a strengthening of the cortical attentional network connections between the brain region of the right temporoparietal junction (rTPJ) and the insula and the anterior cingulate cortex (ACC).

“Our MRI results highlight the role of attention and the right TPJ activation as a component of vision restoration training in hemianopia,” notes lead investigator Yifeng Zhou, DSc, of the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, P.R. China, and State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, P.R. China. “However, it is unclear whether the rehabilitation of attentional networks is the direct result of training or the result of the rebalancing of bottom-up sensory streams, which should be investigated in future studies.”

“This discovery that the brain´s attention network is a key mechanism in partially reversing blindness is an exciting advance in the field of restoring vision in the blind, and it opens up new avenues to design new therapies that are even more effective than current methods to help people with low vision or blindness,” concludes Prof. Sabel.

Story Source:

Materials provided by Institute for Medical Psychology, Otto-v.-Guericke University MagdeburgNote: Content may be edited for style and length.


Journal Reference:

  1. Qilin Lu, Xiaoxiao Wang, Lin Li, Bensheng Qiu, Shihui Wei, Bernhard A. Sabel, Yifeng Zhou. Visual rehabilitation training alters attentional networks in hemianopia: An fMRI studyClinical Neurophysiology, 2018; 129 (9): 1832 DOI: 10.1016/j.clinph.2018.05.027

via Attention network plays key role in restoring vision after brain damage: New study highlights the role of attention as a component of vision restoration training in hemianopia — ScienceDaily

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[WEB SITE] Attention network plays key role in restoring vision after brain damage – ScienceDaily

New study highlights the role of attention as a component of vision restoration training in hemianopia

Summary:
About one-third of patients who have suffered a stroke end up with low vision, losing up to half of their visual field. This partial blindness was long considered irreversible, but recent studies have shown that vision training after optic nerve and brain damage can help restore or improve vision. A new study reports on key mechanisms of vision restoration: attention.
 
FULL STORY

About one third of patients who have suffered a stroke end up with low vision, losing up to half of their visual field. This partial blindness was long considered irreversible, but recent studies have shown that vision training after optic nerve and brain damage can help restore or improve vision. A new study published in the journal Clinical Neurophysiology reports on key mechanisms of vision restoration: attention.

Hemianopia is a decreased vision or blindness in half the visual field, usually as a consequence of stroke or trauma to the brain. It greatly reduces quality of life, affecting patients’ reading, driving and spatial navigation.

“Knowledge in this field is still rather fragmentary, but recent studies have shown that vision can be partially restored by vision training, which improves the deficient visual field sectors,” explains Prof. Bernhard Sabel, PhD, Director of the Institute of Medical Psychology at Magdeburg University, Germany, co-investigator of the study. “Neuroimaging evidence supports a possible role of attention in this vision restoration.”

The study confirmed this hypothesis by obtaining evidence from functional magnetic resonance imaging (fMRI) that visual training led to functional connectivity reorganization of the brain´s attentional network.

Seven chronic hemianopic patients with lesions of the visual cortex took part in vision rehabilitation training for five weeks. After the pre-tests all received training sessions lasting one and a half hours per day for six days per week for five weeks. Each training session, lasting about 60 minutes, was composed of six blocks with 120 training trials each, during which participants had to respond to specially designed visual stimuli on a computer monitor. The pre- and post-test included perimetry testing, contrast sensitivity testing and fMRI scanning one or two days before and after training, respectively. Each contrast sensitivity test consisted of 420 trials in six blocks. The visual rehabilitation training was performed with one eye open, which was randomly chosen, while the non-trained eye was covered with an opaque eye patch.

After training, the patients had significantly improved visual function at the training location, and fMRI showed that the training led to a strengthening of the cortical attentional network connections between the brain region of the right temporoparietal junction (rTPJ) and the insula and the anterior cingulate cortex (ACC).

“Our MRI results highlight the role of attention and the right TPJ activation as a component of vision restoration training in hemianopia,” notes lead investigator Yifeng Zhou, DSc, of the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, P.R. China, and State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, P.R. China. “However, it is unclear whether the rehabilitation of attentional networks is the direct result of training or the result of the rebalancing of bottom-up sensory streams, which should be investigated in future studies.”

“This discovery that the brain´s attention network is a key mechanism in partially reversing blindness is an exciting advance in the field of restoring vision in the blind, and it opens up new avenues to design new therapies that are even more effective than current methods to help people with low vision or blindness,” concludes Prof. Sabel.

Story Source:

Materials provided by Institute for Medical Psychology, Otto-v.-Guericke University MagdeburgNote: Content may be edited for style and length.


Journal Reference:

  1. Qilin Lu, Xiaoxiao Wang, Lin Li, Bensheng Qiu, Shihui Wei, Bernhard A. Sabel, Yifeng Zhou. Visual rehabilitation training alters attentional networks in hemianopia: An fMRI studyClinical Neurophysiology, 2018; 129 (9): 1832 DOI: 10.1016/j.clinph.2018.05.027

Cite This Page:

Institute for Medical Psychology, Otto-v.-Guericke University Magdeburg. “Attention network plays key role in restoring vision after brain damage: New study highlights the role of attention as a component of vision restoration training in hemianopia.” ScienceDaily. ScienceDaily, 4 September 2018. <www.sciencedaily.com/releases/2018/09/180904114753.htm>.
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[WEB SITE] Can MRI Brain Scans Help Us Understand Epilepsy?

epilepsy

A massive meta-analysis of global MRI imaging data on epilepsy patients seeks to clarify a complicated and mysterious neurological disorder.

Epilepsy is a neurological disorder characterized by seizures, which can vary from mild and almost undetectable to severe, featuring vigorous shaking. Almost 40 million people worldwide are affected by epilepsy. Epileptic seizures are caused by an abnormally high level of activity in nerve cells in the brain. A small number of cases have been tied to a genetic defect, and major trauma to the brain (such as an injury or stroke) can also induce seizures. However, for the majority of cases, the underlying cause of epilepsy is not known. In many instances, epilepsy can be treated with the use of anti-convulsant medication. Some people will experience an improvement in their symptoms to the point of no longer requiring medication, while others will not respond to medication at all. The variability of the disease with regards to physiology and progression makes it difficult to accurately diagnose.

How Does Epilepsy Affect the Brain?

There are multiple types of epilepsies, some more common than others, which affect different parts of the brain cortex. The disorder has been studied by using techniques such as magnetic resonance imaging (MRI), and analyses of brain tissue. The latter requires post-mortem collection of tissue, as biopsies are not routinely performed on living patients’ brains. A brain scan via MRI imaging can provide detail about pathological markers of epilepsy, but the massive amount of data collected worldwide by imaging has not yet been consolidated and analyzed in a robust manner. Gaining an understanding of distinct or shared disease markers for different forms of epilepsy could help clinicians identify targets for therapy and increase the personalization of treatment.

The ENIGMA Study

A recent study published in the journal BRAIN represents the largest neuroimaging analysis of epilepsy conducted to date.This study, called ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis)summarizes contributions from 24 research centers across 14 countries in Europe, North and South America, Asia, and Australia. Similar wide-ranging studies have revealed structural brain abnormalities in other neurological conditions such as schizophrenia, depression, and obsessive-compulsive disorder. The researchers had several goals in putting this meta-analysis together:

  1. To look at distinct types of epilepsy to see whether they share similar structural abnormalities of the brain.
  2. To analyze a well-known specific type of epilepsy, mesial temporal lobe epilepsy (MTLE) for differences between people afflicted with this disorder on different sides of the brain.
  3. To analyze idiopathic generalized epilepsies (IGE), which are thought to have a genetic component to their cause and aren’t often detectable via MRI.

The researchers compiled imaging data from 2,149 people with epilepsy and 1,727 healthy control subjects. The large sample size allowed them to perform high-powered statistical analysis of the data.

For analysis (1), the results showed that a diverse array of epilepsies showed common structural anomalies across several different regions of the brain. This suggested that distinct disease types share a common neuroanatomical signature.

For analysis (2), they found that people with mesial temporal lobe epilepsy on the right side of the hippocampus did not experience damage to the left side, and vice-versa. However, somewhat unexpectedly, they saw that damage extended to areas outside the hippocampus, suggesting that even a region-specific disorder like mesial temporal lobe epilepsy may be a network disease.

In analysis (3), the researchers found that contrary to many reports of a “normal” MRI for patients with idiopathic generalized epilepsy, several structural irregularities were observable over a large number of samples. These included reduced brain volume and thickness in several regions.

One Step Closer to Understanding Epilepsy

The authors noted some limitations to their study, such as the fact that all results were derived from cross-sectional data, meaning that it was not possible to determine whether certain features were the cause of severe brain damage at one point in time, or whether they were the product of progressive trauma. In addition, this study could not account for the possible contribution of other factors, such as medications, seizure type and frequency, and disease severity. However, this wide-scale meta-analysis represents an important step towards understanding how different types of epilepsies affect the brain, and hopefully can lead to more personalized and effective medical interventions.

Written by Adriano Vissa, PhD

Reference: Whelan CD, et al. Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study. Brain. 2018; 141(2):391-408

 

via Can MRI Brain Scans Help Us Understand Epilepsy? – Medical News Bulletin | Health News and Medical Research

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[TED] 3 Clues to undertand your Brain – TED Talks

Vilayanur Ramachandran tells us what brain damage can reveal about the connection between celebral tissue and the mind, using three startling delusions as examples.

Neurologist V.S. Ramachandran looks deep into the brain’s most basic mechanisms. By working with those who have very specific mental disabilities caused by brain injury or stroke, he can map functions of the mind to physical structures of the brain.

 

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[WEB SITE] This FDA Approved Drug Could Permanently Repair Brain Damage in Victims

In Brief
  • Using a drug already approved for clinical trials, researchers were able to reduce brain damage and boost the growth of new brain cells in mice suffering from strokes.
  • The research offers new hope to those dealing with the aftermath of strokes, which are the fifth leading cause of death in the United States.

Old Drug, New Treatment

Researchers from the University of Manchester have developed a new treatment that could limit the damage caused by strokes and also promote repair in the affected area of the brain. What’s more, the drug they’re using has already been clinically approved.

The researchers’ study is published in Brain, Behavior and Immunityand it recounts how they developed their treatment using mice bred to develop ischemic strokes, the most prevalent type of stroke and one that occurs when an artery that supplies oxygen-rich blood to the brain is blocked. Soon after the mice experienced a stroke, the researchers treated them with interleukin-1 receptor antagonist (IL-1Ra), an anti-inflammatory drug that is already licensed for use in treating rheumatoid arthritis.

They noticed a reduction in the amount of brain damage typically observed after a stroke and also noted that the drug boosted neurogenesis (the birth of new cells) in the areas that did experience brain damage in the days following the treatment. The mice even regained the motor skills they lost due to the stroke.

Hope for a Cure

Stroke is the fifth leading cause of death in the United States and about 800,000 people suffer from one each year, according to the Centers for Disease Control and Prevention (CDC). They occur when the flow of blood to the brain is interrupted, usually due to a blood clot or a buildup of fat that broke off from the arteries and traveled to the brain. The condition is extremely dangerous because brain cells can die within a few minutes of the stroke, causing permanent damage or even death.

We still don’t have a treatment to adequately prevent or reverse the damage to the brain caused by strokes, but the Manchester researchers believe that their development could change that. Though they are still in early stages of clinical trials, they hope to eventually move on to larger trials and eventually human testing. Together with other research, this new study offers hope to the thousands of people whose lives are impacted by strokes worldwide.

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[WEB SITE] This FDA Approved Drug Could Permanently Repair Brain Damage in Stroke Victims

IN BRIEF
  • Using a drug already approved for clinical trials, researchers were able to reduce brain damage and boost the growth of new brain cells in mice suffering from strokes.
  • The research offers new hope to those dealing with the aftermath of strokes, which are the fifth leading cause of death in the United States.

OLD DRUG, NEW TREATMENT

Researchers from the University of Manchester have developed a new treatment that could limit the damage caused by strokes and also promote repair in the affected area of the brain. What’s more, the drug they’re using has already been clinically approved.

The researchers’ study is published in Brain, Behavior and Immunityand it recounts how they developed their treatment using mice bred to develop ischemic strokes, the most prevalent type of stroke and one that occurs when an artery that supplies oxygen-rich blood to the brain is blocked. Soon after the mice experienced a stroke, the researchers treated them with interleukin-1 receptor antagonist (IL-1Ra), an anti-inflammatory drug that is already licensed for use in treating rheumatoid arthritis.

They noticed a reduction in the amount of brain damage typically observed after a stroke and also noted that the drug boosted neurogenesis (the birth of new cells) in the areas that did experience brain damage in the days following the treatment. The mice even regained the motor skills they lost due to the stroke.

HOPE FOR A CURE

Stroke is the fifth leading cause of death in the United States and about 800,000 people suffer from one each year, according to the Centers for Disease Control and Prevention (CDC). They occur when the flow of blood to the brain is interrupted, usually due to a blood clot or a buildup of fat that broke off from the arteries and traveled to the brain. The condition is extremely dangerous because brain cells can die within a few minutes of the stroke, causing permanent damage or even death.

We still don’t have a treatment to adequately prevent or reverse the damage to the brain caused by strokes, but the Manchester researchers believe that their development could change that. Though they are still in early stages of clinical trials, they hope to eventually move on to larger trials and eventually human testing. Together with other research, this new study offers hope to the thousands of people whose lives are impacted by strokes worldwide.

Source: This FDA Approved Drug Could Permanently Repair Brain Damage in Stroke Victims

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