Research Location: BC Children's Hospital

Approximately eight per cent of babies in British Columbia are born prematurely (less than 37 weeks after conception), and survival rates have improved dramatically for these infants. Motor and cognitive impairments are common among children born prematurely: five to 10 per cent will exhibit motor deficits such as cerebral palsy, and up to half will experience problems with brain functions (such as learning to speak). At school age, these delays in development can become greater concerns as they may interfere with learning and social interaction. Recent studies suggest that the developmental impairment observed may be associated with abnormal development of the brain regions responsible for motor and brain functioning. Early brain abnormalities, such as white matter injury (WMI), may underlie maturational impairments of these regions. A key brain pathway of interest is the corticospinal tract, which carries voluntary motor information from the control centre of the brain (the cortex) to muscles of the body. Elysia Adams is determining whether brain abnormalities, such as WMI, in premature newborns in their early life will affect their motor and brain function. Using advanced imaging techniques with magnetic resonance imaging (MRI), she is comparing corticospinal tract development among premature babies with and without these brain abnormalities,. This will allow her to determine whether WMI affects the development of the corticospinal tract and to establish whether later motor function can be predicted by assessing the tract’s development. Ultimately, this research could lead to ways to predict brain outcome among babies born prematurely. This would allow doctors to identify motor problems earlier and provide appropriate treatments, such as physiotherapy, to improve outcomes or prevent the long-term consequences of these developmental delays.

Developmental dyslexia is defined as the difficulty in learning to read, and affects between 5 and 17.5 per cent of school-age children. The cause of dyslexia is unknown, but there may be a neurobiological basis. Current diagnostic tests for dyslexia are typically conducted by grade two or three, however by this time, the child already displays significant reading difficulties and may never catch up to their peers. Developing diagnostic tests to assess or predict reading difficulties at an earlier age could allow for earlier intervention and prevention of academic and social difficulties associated with dyslexia. For many children, the main problem in dyslexia involves sound (phonological) processing. For instance, the child may not be able to link sounds to letters, or break words up into their individual sounds. Also, people with dyslexia may show deficits in visual and auditory temporal processing, which is the perception and integration of rapidly presented stimuli. For example, the child may have difficulty with determining the direction of motion or sound. It is unknown whether there is a link between reading and temporal processing skills. Marita Partanen is examining whether reading and temporal processing use overlapping brain networks, and whether these brain areas are affected in children with dyslexia. She is using functional magnetic resonance imaging (fMRI) to track brain activation in children as they complete simple tasks. If a link between reading ability and temporal processing can be established, there is potential for simpler and earlier diagnostic tests for dyslexia that assess temporal processing. Ultimately, the ability to diagnose dyslexia at a younger age may lead to new programs that can improve academic and social outcomes for people with dyslexia.

Amblyopia – commonly known as “”lazy eye”” – is a developmental disorder that causes poor vision in one eye compared to the other eye. Amblyopia can arise from an inward or outward turn of the weaker eye. This prevents both eyes from working together to form one image and results in double vision. It can also arise when one eye has much better focus than the other eye. In both cases, as the brain matures it will begin to ignore the image coming from the weaker eye, eventually causing vision in that eye to deteriorate. Regardless of how amblyopia arises, the most common treatment is to place an eye patch over the good eye. This forces the maturing brain to start using the weaker eye, so that vision in this eye will “”catch up”” to the vision of the good eye. This form of treatment has been very effective in treating some cases of amblyopia, but not other cases. Currently, eye care professionals primarily use letter charts to assess how the ability to process form is affected in amblyopia. Research over the years has found that in addition to abnormalities in processing form, there are also abnormalities in motion processing. Typically, eye care professionals do not assessmotion perception, so any abnormalities in motion processing that may develop currently do not get treated. Using functional magnetic resonance imaging (fMRI), John Secen is looking at differences in brain activity between children with and without amblyopia as they perform a motion processing task. This research will improve upon the current understanding of the neural basis behind motion-processing deficits in amblyopia, and hopefully, this knowledge could lead to the development of new screening techniques so that these abnormalities in motion processing can be detected and treated.

The brain perceives pain through the nociception system, which prompts increased activity in the autonomic nervous system (ANS). In turn, the ANS activates the sympathetic nervous system (SNS), creating a stress response in the body that includes increased respiration, blood pressure and heart rate. In sick patients, a strong stress response can cause serious injury. Anesthesiologists try to minimize the stress response during surgery by giving patients drugs that block nociception. Finding the appropriate balance can be challenging — too much anesthesia can make the patient very ill, while too little anesthesia increases the stress response. Anesthesiologists currently rely on a patient’s vital signs — pulse rate, blood pressure, temperature, and respiratory rate — to estimate the level of ANS activation and determine appropriate drug dosage. Unfortunately, these vital signs alone are not enough to estimate ANS activity, because they are often affected by other factors. Christopher Brouse is developing a nociception monitor that automatically determines the level of activation of a patient’s ANS. It will use computer algorithms that analyze very small, fast changes in the patient’s heart rate, called heart rate variability (HRV). Previous research has shown that HRV responds to ANS activation much more predictably than other vital signs do; therefore, HRV can provide a better estimate. With the data gathered from his first pilot pain study, Brouse is now developing and fine tuning a pain index that correlates with ANS activity. By accurately monitoring subtle vital signs, the nociception monitor has the potential to increase patient safety during and after surgery and reduce recovery times. It could also be used for patients recovering from surgery to gauge their pain and respond with the appropriate amount of drugs.

Psychotropic medications like benzodiazepines (tranquilizers used to control anxiety) and serotonin reuptake inhibitors (antidepressants used to treat depression) are frequently prescribed during pregnancy to manage depression and anxiety, even though these drugs have not been approved for this purpose, and the impact on infant development is unclear. These drugs increase the activity of certain chemicals in the brain that inhibit nerve cell activity. Whitney Weikum is expanding on her earlier MSFHR-funded research on language development in infants. Now Weikum is studying the effects of prenatal exposure to psychotropic drugs on critical periods of infant language development. During the first years of life, infants rapidly and almost effortlessly acquire language. There appear to be a number of discrete periods critical for acquiring language information. At birth, infants have the ability to discriminate almost all the distinctive sounds from the world’s languages. Weikum is testing infants’ responses to different language sounds at 36 weeks gestation, as newborns, and during the first year to learn whether psychotropic drugs affect cognitive and language development. The results will be compared to women who experienced depression, but did not take medication, to determine the impact of depression alone on infants’ language development. The goal is to help women and physicians make informed decisions about whether to use psychotropic medications during pregnancy.