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Posts tagged ‘Jean-Pierre Lagacé’

Concussion in Kids: Less-Recognized Visual Changes

Here, Christina Master, MD, a pediatric sports medicine specialist at the Children’s Hospital of Philadelphia (CHOP) talks about vision issues following concussion in children.

«In our clinical and research practice here at CHOP, we have found that a number of children have visual issues after a concussion, but they’re not typically visual acuity issues. This is something we’d like to get the message out about.

The kids we see in our offices who have had a concussion often also have oculomotor issues (eye movements), whether they are related to problems with smooth pursuits (following an object), saccadic function (going from one object to another), or the vestibulo-ocular reflex function (vision and balance).

We find that they are often very sensitive to motion and vestibular stimuli, especially from busy and active environments. We also find that they have issues in school in regard to looking back and forth between a notebook, smartboard, monitor, or tablet. We’d like you to keep an eye out for these oculomotor issues. Many of them also seem to be related to binocular visual function (how the eyes function together); in particular, we notice that a convergence insufficiency can be a problem. These kids have problems focusing on objects that are far, and then transitioning from far to near and near to far again.

Photo from: https://www.todaysparent.com/kids/kids-health/concussions-hockey-problem/

As you can imagine, much of schoolwork is very visually oriented, and these issues can present problems. What we would encourage everyone to remember when assessing a child who has had a concussion is not only to look at visual acuity but also to assess oculomotor function, including smooth pursuits, saccades, and convergence. In treating these kids as they gradually return to school, it is also often helpful to recommend accommodations to allow them to have extra time, printed notes, larger-font printed materials, and, in general, extra support from a visual standpoint while their functions recover over time.

Please remember these issues when you’re evaluating kids in your office with concussion. Remember that these issues are not just about visual acuity but also include oculomotor and binocular visual issues like convergence insufficiency.»

From: http://www.medscape.com/viewarticle/876689

 

Eye Test Screens for Traumatic Brain Injury, Concussion

 

 

Photo from: https://www.washingtonparent.com/articles/1503/1503-concussions-in-kids-dr-bills-advice-for-worried-parents.php

Of the more than 340,000 cases of traumatic brain injury clinically confirmed from 2000 to 2015, mild injury accounted for 82.5%, according to US Department of Defense statistics.

However, traumatic brain injury is often only identified when moderate or severe head injuries have occurred, leaving mild cases undiagnosed, Dr Capó-Aponte and his colleagues explain in their scientific poster.

“Since approximately 30 areas of the brain and seven of the 12 cranial nerves deal with vision, it is not unexpected that the patient with traumatic brain injury may manifest a host of visual problems, such as pupillary deficit, visual processing delays, and impaired oculomotor tracking and related oculomotor-based reading dysfunctions,” Dr Capó-Aponte pointed out.
To see whether they could identify reliable biomarkers of mild traumatic brain injury that could be detected with an easily reproducible screening test, he and his colleagues looked for subtle visual changes that could be measured in the office or in the field.

From: http://www.medscape.com/viewarticle/865691

Vision and the Brain

The visual system includes 25 neocortical areas that are predominantly or exclusively visual in function, plus an additional 7 areas that are regarded as visual-association areas on the basis of their extensive visual inputs. A total of 305 connections among these 32 visual and visual-association areas have been reported. This represents 31% of the possible number of pathways if each area were connected with all others. The actual degree of connectivity is likely to be closer to 40%. The great majority of pathways involve reciprocal connections (in both directions) between areas.

From : https://www.ncbi.nlm.nih.gov/pubmed/1822724

 

Since approximately 60% of the nerve pathways are related to the processing of visual information, it is not surprising that severe visual problems occur in one or more concussions.

 

10 things you need to know about concussions

1. A concussion is a brain injury that can cause a variety of easy-to-miss symptoms. Doctors can’t “see” concussions using imaging. You don’t need to lose consciousness and a well-fitting helmet will not necessarily prevent one.

2. Symptoms can include headache, nausea, vomiting, light sensitivity, dizziness, confusion, slurred speech, poor balance, irritability, memory problems, blurred vision, sleepiness, sadness, anxiety or feeling in a fog. If you suspect a concussion, call the doctor.

3. If his head hurts, he’s off the ice, no questions asked. It doesn’t matter if he’s in the third period of a tied championship game.

4. Do not give Advil or Aspirin. Administered in large amounts, Advil and Aspirin can cause further bruising or internal bleeding. Tylenol is a safer bet; ask your doctor about proper dosages.

5. For the first 48 hours, be vigilant for signs of deterioration. Severe headache or persistent vomiting means you should go to the ER.

6. Concussion risk increases with each one. The brain is more likely to get reinjured if it hasn’t properly healed the first time. A child’s brain needs both physical and mental rest to heal (no jumping, no math problems).

7. Screens exacerbate a concussion headache. That means you have to limit the three things kids are most addicted to: TV, computer and phone.

8. If he says his head hurts, and the pain won’t go away, believe him—even if, ordinarily, your kid will do anything to skip school. The boredom of staying home and off screens will drive him—and you—so batty, there’s no way he’s faking.

9. His brain needs to rest in a dim room. This means no screens, pulling the curtains and keeping sunglasses handy. Contact teachers about making up homework in stages and catching up gradually.

10. Don’t send him back to school or sports until he’s symptom-free. Even with a mild concussion, this means no school or sports for at least a week—sometimes two.

From: https://www.todaysparent.com/kids/kids-health/concussions-hockey-problem/

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Concussions and Vision – 2

Photo JPL-blogueA concussion is a traumatic brain injury that alters the way your brain functions. Effects are usually temporary but can include headaches and problems with concentration, memory, balance and coordination. Although concussions usually are caused by a blow to the head, they can also occur when the head and upper body are violently shaken. These injuries can cause a loss of consciousness, but most concussions do not. Because of this, some people have concussions and don’t realize it. Concussions are common, particularly if you play a contact sport, such as football. But every concussion injures your brain to some extent. This injury needs time and rest to heal properly. Most concussive traumatic brain injuries are mild, and people usually recover fully. The signs and symptoms of a concussion can be subtle and may not be immediately apparent. Symptoms can last for days, weeks or even longer. Concussion01Common symptoms after a concussive traumatic brain injury are headaches, loss of memory (amnesia) and confusion. The amnesia, which may or may not follow a loss of consciousness, usually involves the loss of memory of the event that caused the concussion. The post-concussion syndrome is a complex disorder in which various symptoms such as headaches and dizziness pain can last for weeks and sometimes months after the injury that caused the concussion. A concussion is a mild traumatic brain injury, usually following a blow to the head.

Loss of consciousness is not necessary for a diagnosis of concussion or post-concussion syndrome. In fact, the risk of post-concussion syndrome brain does not appear to be associated with the severity of the initial injury. In most people, symptoms of post-concussion syndrome occur in seven to ten days after the blow and may disappear within three months, but may also persist for a year or more.

Reduced cognitive abilities with visual activities

Visual perceptual deficits can be caused by concussions and have dramatic effects on school and even athletic success. Speed of visual processing and visual reaction time can be reduced. Processing speed may slow in an athlete both on and off the field. The speed with which an athlete processes visual information affects many aspects of competitive sport, including reading of the playing field, the judgment of the speed of a moving ball or puck, and judgment the speed of the other players in the field.

Post-traumatic visual syndrome and midline shift syndrome

Following a neurological event such as a traumatic brain injury, cerebrovascular accident, multiple sclerosis, cerebral palsy, etc., it has been noted by clinicians that persons frequently will report visual problems such as seeing objects appearing to move that are known to be stationary; seeing words in print run together; and experiencing intermittent blurring. More interesting symptoms are sometimes reported, such as attempting to walk on a floor that appears tilted and having significant difficulties with balance and spatial orientation when in crowded moving environments. These types of symptoms are not uncommon. Frequently, persons reporting these symptoms to eye care professionals (optometrists and ophthalmologists) have been told that their problems are not in their eyes and that their eyes appear to be healthy. What is often overlooked is dysfunction of the visual process causing one of two syndromes: Post Trauma Vision Syndrome (PTVS) and/or Visual Midline Shift Syndrome (VMSS). Recent research has documented PTVS utilizing Visual Evoked Potentials (VEP). This documentation concludes that the ambient visual process frequently becomes dysfunctional after a neurological event such as a TBI or CVA. Persons can often have visual symptoms that are related to dysfunction between one of two visual processes: ambient process and focal process. These two systems are responsible for the ability to organize ourselves in space for balance and movement, as well as to focalize on detail such as looking at a traffic light.

Post Trauma Vision Syndrome results when there is dysfunction between the ambient and focal process causing the person to over emphasize the details. Essentially individuals with PTVS begin to look at paragraphs of print almost as isolated letters on a page and have great difficulty organizing their reading ability. It has been found that the use of prisms and binasal occlusion can effectively demonstrate functional improvement, while also being documented on brain wave studies by increasing the amplitude (this is like turning up the volume on your radio). Concussion02 Visual Midline Shift Syndrome also results from dysfunction of the ambient visual process. It is caused by distortions of the spatial system causing the individual to misperceive their position in their spatial environment. This causes a shift in their concept of their perceived visual midline. This will frequently cause the person to lean to one side, forward and/or backward. It frequently can occur in conjunction with individuals that have had a hemiparesis (paralysis to one side following a TBI or CVA). The shifting concept of visual midline actually reinforces the paralysis, by using specially designed yoked prisms that can be prescribed, the midline is shifted to a more centered position thereby enabling individuals to frequently begin weight bearing on their affected side. This works very effectively in conjunction with physical and occupational therapy attempting to rehabilitate weight bearing for ambulation.

The symptoms of the syndrome shift of midline visual may include:

  • dizziness or nausea
  • spatial disorientation
  • always heading towards the right or left along a corridor
  • locomotion or posture problems as to lean back on your heels, forward or to one side when walking, either standing or sitting in a chair
  • perception of uneven pavement (or having a sloping side or the other)
  • neuromotor difficulties associated with balance, coordination and posture

Fortunately, many vision problems after a concussion can be resolved with rest and by allowing the brain to heal. But there are still many problems that can linger even after years, especially regarding spatial localization. Vision therapy, also called neuro-optometric rehabilitation, can be very effective in cases where visual symptoms persist, even when other symptoms such as dizziness or balance problems are solved.

Reading problems and concussion Reading deficits can come from various problems after stroke or injury or a blow to the head. It is crucial that the type of reading problem is diagnosed. Problems can occur individually or as part of a constellation of related problems PTVS. The treatment of PTVS by various neuro-optometric rehabilitation interventions can solve many of the problems. In the next article, we will continue discussing visual problems and concussions.

Source : Lagacé JP. Les commotions cérébrales et la vision – généralités. Revue L’Optométriste – Volume 37 No 2, Mars-avril 2015.

British study examines mobile phone effects on children

Photo JPL-blogueBritish scientists launched a major government-commissioned study on Tuesday into the effects of mobile phone usage on the developing brains of children.

About 2,500 children from London will be tested at the age of 11 and 12 and then again two years later, to assess how their cognitive abilities develop in relation to their changing use of phones and other wireless technologies.

blogue - fillette-iPhone

 Source : http://cypressinternalmedicine.com/wp-content/uploads/2011/11/photo-1.jpg

Professor Patrick Haggard, deputy director of the Institute of Cognitive Neuroscience at University College London, said it was the “largest follow-up study of its kind in adolescents worldwide”.

The World Health Organisation says there is no convincing evidence that mobile phones affect health, but existing data only goes back about 15 years.

In the study, the children will undertake classroom-based computerised tasks to measure cognitive abilities such as memory and attention.

“Cognition is essentially how we think, how we make decisions and how we process and recall information,” said Dr Mireille Toledano of Imperial College London, the principal investigator on the study.

Participants and their parents will also be asked questions about how they use mobile phones and other devices, and other aspects of their lifestyle.

An estimated 70 percent of all 11- to 12-year-olds in Britain now own a mobile phone, rising to 90 percent by the age of 14, according to the researchers.

The Study of Cognition, Adolescents and Mobile Phones (SCAMP) is being carried out by Imperial College London at the commission of the British Department of Health.

Letters were sent out to 160 different schools inviting them to enrol pupils, and tests will begin at the start of the new school year in September.

Imperial College is already involved in a separate international study, called Cosmos, into the possible long-term health effects of mobile phones on 290,000 adults in five European countries.

Video Displays and Dry Eye in Children

Photo JPL-blogueSource: http://www.practiceupdate.com/journalscan/9378

In a population of Korean children in grades 5 and 6 (ages 9–11), the authors compared symptoms and use of video display terminals in those with dry eye disease (9.7%, as determined by ophthalmic exam) with children without clinically determined dry eye. The risk factors for dry eyes in this population were related more to smartphone use (including mean duration of use, as reported by questionnaire) than to either computer or television viewing.

Blogue - Apple Addict

Photograph from Thomas PLESSIS (T.P Photographie)
                               With permission
                     http://www.thomas-plessis.com

 

The authors remind to keep the possibility of dry eye, which seems to be related to increased smartphone use, in mind in this population.

It is not uncommon for children between the ages of 9 and 11 — the population studied here — to exhibit potential signs of dry eye, which might include frequent blinking. Parents of children in this age range might also notice frequent or deep blinking behaviors that can be associated with tics or spasmodic blinking due to stress or anxiety.

The authors provide evidence that some of the signs and symptoms of ocular or visual discomfort can be associated with dry eyes. However, the jury is out on correlation or causation because the rate of dry eye signs was significantly greater in children with more smartphone use. The authors note that other visual factors have been reported as potentially associated with sustained smartphone use, such as accommodative issues and transient myopia. Because dry eye disease is not widely recognized as a potential problem in this age range, it adds to considerations in differential diagnosis of visual and ocular problems in childhood.

Two-hundred eighty-eight children were classified in either a dry eye disease group or control group according to the diagnostic criteria of dry eye disease. The results of ocular examinations, including best-corrected visual acuity, slit-lamp examination, and tear break-up time, were compared between groups. The results of questionnaires concerning video display terminal use and ocular symptoms were also compared.

Twenty-eight children were included in the dry eye disease group and 260 children were included in the control group. Gender and best-corrected visual acuity were not significantly different between the two groups. Smartphone use was more common in the dry eye disease group (71%) than the control group (50%) (P = .036). The daily duration of smartphone use and total daily duration of video display terminal use were associated with increased risk of dry eye disease (P = .027 and .001, respectively), but the daily duration of computer and television use did not increase the risk of dry eye disease (P = .677 and .052, respectively).

The results showed that smartphone use is an important dry eye disease risk factor in children. Close observation and caution regarding video display terminal use, especially smartphones, are needed for children.

Study source: JH Moon, MY  Lee, NJ Moon. Association Between Video Display Terminal Use and Dry Eye Disease in School Children. J Pediatr Ophthalmol Strabismus 2014 Mar 01;51(2)87-92.

Smartphones do affect vision in children

How to hold your phone so it doesn’t (completely) wreck your vision

Photo JPL-blogueSource:  http://www.marketwatch.com/story/dont-give-up-your-eyes-for-an-iphone-2013-08-23

Spending half the day staring into a 10 cm (four-inch) screen may also wreck one’s eyesight, new research suggests — and the devices may not be to blame so much as how we hold them.

David Allamby, an eye surgeon and the founder of Focus Clinics in London, recently coined the term “screen sightedness” and pointed out that according to his research, there has been a 35% increase in the number of people with advancing myopia since smartphones launched in 1997.

Allamby is concerned that use of portable devices could increase cases of myopia in children of another 50% in ten years!

Nearsightedness affects more than 30 % of the population of the U.S and more than 80% in Asia. The environmental factors that contribute include “close work,” or stress on the eye caused by reading or otherwise focusing on near visual tasks.

Using a smartphone strains the eyes in much the same way reading a book or staring at a computer monitor does, with one exception — the distance between the eye and the object. When a phone or other device is held close to one’s face, it forces the eye to work harder than usual to focus on text, says Mark Rosenfield, an optometrist. The discomfort can eventually result in fatigue.

enfant-iphone

Source: http://www.loupiote.com/photos/5391333755.shtml

People tend to hold smartphones considerably closer to their faces than they would a book or newspaper, even as close as seven or eight inches, Rosenfield says. And since smartphones have such a small screen, the importance of visual stress tends to be higher than for other devices.

Holding a smartphone farther away (but still using it the same amount) won’t necessarily prevent myopia entirely, Schaal said. But holding the phone at least 16 inches away from the face during use can be beneficial, Rosenfield says.

He also suggests taking breaks from using the phone. During those breaks, it is helpful to look into the distance, which relaxes the eye as it focuses on faraway detail instead of what is close.

Young children’s eyes may be spared early damage by limiting smartphone and tablet use, doctors say. Spending hours playing games or otherwise intently viewing a screen causes children’s eyes to exert effort for long periods. In the past, children focused on larger objects like blocks or toys, rather than such fine detail. They should be encouraged to engage in a variety of activities with different focusing targets of both near and far away objects.

Mayo Clinic Study: In-School Eye Movement Training Improves Early Reading Fluency

Photo JPL-blogueIn a new Mayo Clinic study, researchers examined the physical act of reading to see if practicing eye movements in school could lead to better early reading fluency.

Reading fluency is defined as the ability to read easily, quickly, without errors and with good intonation.

Saccades or rapid eye movements are required for the physical act of reading. Previous studies have shown that the ability to perform complex tasks such as saccadic eye movements are not fully developed at the age when children begin to learn to read. Eye movements in younger children are imprecise, resulting in the need for the eyes to go back to re-read text, leading to slower performance. When translated into the task of reading, it slows the reading rate and leads to poor reading fluency and may affect reading comprehension and academic performance.

“There are studies that show that 34 percent of third graders are not proficient in reading, and if you are not proficient in reading by third or fourth grade there is a four times higher likelihood that you will drop out of high school,” says Amaal Starling, M.D., Mayo Clinic neurologist and co-author of the study published in Clinical Pediatrics.

Dr. Starling says that the purpose of the new study was to determine the effect of six weeks of in-school training using the King-Devick remediation software on reading fluency. This software allows people to practice rapid number naming which requires eye movements in a left to right orientation. It teaches the physical act of reading.

In this study, standardized instructions were used, and participants in the treatment group were asked to read randomized numbers from left to right at variable speeds without making any errors. The treatment protocol consisted of 20-minute individual training sessions administered by laypersons, three days each week for six weeks, for a total of six hours of training.

Randomized numbers are presented at variable speeds from left to right; the participants read the numbers as quickly as possible.


Examples of pages taken from the King-Devick Test

(Images deleted following a call from the company)

 

Students in the treatment group had significantly higher reading fluency scores after treatment and post-treatment scores were significantly higher compared with the control group. At the one-year follow-up, reading fluency scores were significantly higher than post-treatment scores for students in first grade. Additionally, these one-year follow-up scores were higher than pretreatment scores across all grades, with an average improvement of 17 percentile rank points in the treatment group.

“The results of this pilot study suggest that the King-Devick remediation software may be effective in significantly improving reading fluency through rigorous practice of eye movements,” says Dr. Starling. “What our study also found was that there was an even greater improvement between first and third grade versus third and fourth graders, which means there may be a critical learning period that will determine reading proficiency.”

“The outcome of this study suggests that early childhood intervention with a simple methodology of eye movement training via the remediation software, which is inexpensive and can be implemented in developed or developing cultures easily, might allow a lasting improvement in ability to read, with clear sociologic ramifications,” says Craig H. Smith, M.D., neuro-ophthalmologist, Chief Medical Officer, Aegis Creative, and Senior Advisor, Bill and Melinda Gates Foundation, and a co-author of the study.

The authors hypothesize that this improvement in reading fluency is a result of rigorous practice of eye movements and shifting visuospatial attention, which are vital to the act of reading.

Commentary:

Training activities by computer undoubtedly bring improvements, at least in regard to eye movements, but vision therapy performed in real space would probably be much more effective.

In addition, the recognition by the medicine (or at least the group of physicians who participated in this study) the effectiveness of vision therapy is a big step for optometry.

Those who dispute the link between vision and academics must critically review and change these misguided beliefs. We cannot afford to let unfounded, dogmatic opinions, professional animosities and political agendas stop our children from achieving single, clear, comfortable and binocular vision while attaining their highest academic level possible.

Yes, there is a link between vision and learning. And yes, vision therapy improves academic performance.

Source: http://www.ncbi.nlm.nih.gov/pubmed/24790022

Researchers recommend increasing time spent outdoors during school

Photo JPL-blogueDecidedly, studies on myopia and vitamin D or activities spent outside keep coming!

Results of a study involving 2,000 first-grade students prompted the researchers to suggest mandatory targets for the amount of time children spend outside during school hours.

Ian G. Morgan, PhD, of the Research School of Biology, Australian National University, Canberra, and the Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China, reported results of the Guangzhou Outdoor Activity Longitudinal Study here at the Association for Research in Vision and Ophthalmology meeting.

“The prevalence of myopia in East Asia has increased dramatically in the last 50 years, and a slower increase has been seen in Europe and North America,” Morgan said in his presentation.

The prevalence of high myopia, considered to be at least -6 D, is 20% in East Asia, he said, and prevention becomes essential.

The researchers recruited more than 2,000 first-grade students in 12 primary schools in Guangzhou. The school had been involved in previous studies, so records on visual acuity assessment dating back 20 years were available for children from this school, Morgan said.

One 45-minute class of outdoor activity was added at the end of the day, and children in the control group went home at the normal time, he said. The two groups of children were matched for prevalence of myopia, mean spherical equivalent and axial length.

Over the 3-year period, cumulative incident myopia was 39.5% in the control group and 30.4% in the intervention arm, a reduction of 23%, according to the study abstract.

“Differences in axial length did not quite reach statistical significance,” Morgan said. “It seemed to indicate that by increasing the amount of time outdoors, we were able to lower the level of incident myopia and prevalence of myopia. This is apparently a dose-response relationship.”

“We, therefore, recommend that myopia control programs based on increased time outdoors be developed in primary schools, at least in countries with currently high prevalence rates for myopia, with evidence-based mandatory targets for the amount of time children spend outdoors,” the authors concluded in their abstract.

 ?

Morgan asked: “Is the mechanism brighter light and increased dopamine release outdoors, or is it increased UV exposure outdoors? Evidence from animal studies favor the light-dopamine hypothesis, but a clinical trial of vitamin D needs to be done.”

From:

http://www.healio.com/optometry/optics/news/online/%7B5f21032e-c14c-4e33-96c2-345d7beaa63a%7D/researchers-recommend-increasing-time-spent-outdoors-during-school