People with obsessive compulsive disorder (OCD) experience persistent and distressing thoughts. In most cases, anxiety is relieved by performing repetitive acts, such as washing, checking or counting. Obsessive thoughts and compulsive behaviours can occupy so much time that people with OCD have difficulty functioning at work, taking care of themselves and relating to others. At its most extreme, OCD requires hospitalization. Carrie Cuttler is investigating whether impaired prospective memory — the type of memory required to remember an intention such as turning off the stove or taking medications — is linked to compulsive checking. Studies have shown prospective memory is impaired in patients with schizophrenia and depression, but little is known about the influence of anxiety on this type of memory. Carrie’s research could lead to more effective behavioural interventions that reduce the frequency of compulsive checking and improve quality of life for OCD patients.
Research Pillar: Clinical
Assessing the utility of novel technologies to better characterize structure and strength in growing bone: an MRI and pQCT study
Each year in Canada more than 24,000 people will fracture hips due to weakened bones caused by osteoporosis. Current ability to predict risk of hip fracture is limited. Dual-energy x-ray absorptiometry (DXA) is used to assess bone density, but it shows a two-dimensional representation of bone, which is a three-dimensional structure. DXA is also unable to assess the structural properties of bone, which are a major factor in bone strength. Sarah Manske is evaluating whether two emerging technologies can accurately measure bone structure and strength. Magnetic Resonance Imaging (MRI) can measure cross-sections of bones to evaluate strength, without radiation exposure. Quantitative computed tomography (QCT) can assess bone in three dimensions. Sarah aims to develop a model integrating different imaging technologies to provide a more comprehensive picture of fracture risk. The information could be used to target preventative health strategies to help those at greatest risk of hip fracture.
Effects of changes in joint alignment and loading on cartilage in humans
One in ten Canadians suffers from osteoarthritis, a debilitating and painful disease caused by cartilage degeneration in joints. Abnormal load on the cartilage or some part of it caused by poor joint alignment or obesity can lead to loss of cartilage, which does not usually regenerate on its own. However, it has been shown that cartilage can repair itself following surgery, although the conditions to ensure re-growth are unknown and the reasons for success or failure over the long-term are poorly understood. Using non-invasive magnetic resonance imaging (MRI) scans, Agnes d’Entremont is assessing cartilage health and knee movement in bow-legged patients before and after they have high tibial osteotomy, a surgery to correct their joint misalignment. Agnes aims to define the best conditions for protecting cartilage and promoting repair. The research could increase understanding of osteoarthritis, improve surgical outcomes, and lead to better treatments.
Clinical outcomes of cardiac surgery are influenced by genetics of inflammatory mediators
Open heart surgery usually requires a cardiopulmonary bypass (CPB) pump to manage blood circulation while the heart is stopped for repair. Use of the pump and the surgery itself can cause inflammation and, although some inflammation is needed for the wound to heal, too much can prolong organ dysfunction and recovery time in hospital. The intensity of inflammation after surgery varies substantially among individuals. Age of the patient, pre-surgery health and the amount of time on the pump are factors, but they do not fully account for the differences. There is evidence indicating that genetic factors may contribute to a greater susceptibility to infection and inflammation following cardiac surgery. David Shaw is researching whether two types of cytokines (hormone-like proteins) affect the severity of inflammation following cardiac surgery. These proteins, interleukin 18 and interleukin 10, have been implicated in complications from cardiac surgery. Identifying the genes involved in inflammation may lead to the development of new therapies to improve prognosis and treatment of inflammation.
Neuromuscular control of the head and neck in whiplash injuries
Whiplash injuries can result from the sudden backward and forward whipping movement of the neck. The injuries vary widely from temporary symptoms that resolve themselves to chronic and debilitating head, neck, shoulder, or arm pain. Women are more likely to develop symptoms after a car collision than men. Despite the high incidence and increasing costs associated with whiplash, these injuries are poorly understood. Dr. Jean-Sébastien Blouin is researching the role of neck muscle responses in whiplash injuries and the factors that make women more susceptible to whiplash symptoms. He is also investigating whether people with spinal cord injuries can maintain head stability during rear-end collisions because the lower back proprioceptors are possible triggers of the neck muscle responses, which are delayed or absent in this population. Results from this research could contribute to development of assistive devices for new cars and help reduce the risk of whiplash injuries.
Aminotransferase abnormalities and Multiple Sclerosis
Multiple sclerosis (MS) is thought to be a chronic autoimmune disease of the central nervous system, which attacks myelin, a protective material that insulates nerve fibers in the brain and spinal cord. Over time, MS can cause loss of balance, impaired speech, extreme fatigue and problems with vision. Currently there is no cure, but treatment with beta-interferons (IFNBs) is available to reduce the frequency of MS attacks. After a MS patient treated with IFNBs and other medications developed liver failure, Dr. Helen Tremlett initiated research examining liver function in patients treated with beta-interferons. The research revealed that 20 to 40 per cent of MS patients treated with IFNBs developed liver enzyme abnormality.
Now Dr. Tremlett is extending her research to also investigate MS patients treated with other drugs. Since many MS patients take multiple medications, her goal is to determine whether use of other drugs increases the risk of liver injury associated with IFNBs. She is also interested in determining if MS patients taking medications other than IFNBs developed liver damage. The research could provide insights about whether people with MS are at greater risk of liver injury, and whether IFNBs are the likely cause.
The importance of sensorimotor integration in the control of normal human movement
People use sensory information from muscles, joints and skin to coordinate movement. Ability to use this information to make accurate movements declines with age. Loss of sensory information typically results in awkward, unrefined movements, which is why older people are noticeably slower and less accurate in their movements than younger individuals. Dr. Paul Kennedy’s research is directed at understanding the functional changes that occur with aging. He is studying age-related changes in the nervous system by recording electrical activity in the sensory receptors of two groups: people aged 20 to 30 and older people aged 70 to 80. His research could determine whether a decline in sensory activity reduces movement accuracy in older adults. Ultimately, the results could identify how specific changes in the nervous system related to aging contribute to functional impairments.
Clinical outcomes of acute lung injury: role of cytokine gene polymorphisms as predictors
Acute lung injury is a very common cause of respiratory dysfunction among critically ill patients in intensive care units. It is caused by excessive inflammation in response to infection or major injuries. The widespread inflammation interferes with oxygen transfer such that patients with the condition often require the support of a mechanical ventilator. Despite advances in understanding how acute lung injury develops, the mortality rate from the condition has remained at 30 to 40 per cent. Dr. Sanjay Manocha is investigating whether genetic variations predispose some patients to excessive inflammation. Understanding which genes influence the development of acute lung injury could help identify those at high risk, and lead to more targeted therapies to treat this debilitating condition.
Probing the preparation and preprogramming of voluntary movements using startle in healthy humans and clinical populations
Every day people are required to make quick, voluntary responses to environmental signals, such as sound. The higher brain (cerebral cortex) has long been thought to control these movements by receiving and analyzing sensory information and coordinating responses. But Anthony Carlsen’s research has shown reactive movements can be stimulated more quickly with a loud, startling sound at 124 decibels. The research suggests it may be possible to pre-program these quicker responses and store them in the midbrain, the area that controls auditory and visual reflexes. Anthony is using Functional Magnetic Resonance Imaging (fMRI) to determine if there is brain activity with pre-programmed responses in the midbrain. He is also testing whether the startling sound triggers a midbrain response in people with Parkinson’s disease and those who become deaf following a stroke. Results from the study could provide insights about human motor control, the source of movement deficiencies caused by Parkinson’s, and potential treatments for people with Parkinson’s and cerebral deafness.
Investigation of the effects of floor stiffness on risk of fall-related hip fractures
About 23,000 people fracture their hips in Canada each year, resulting in treatment costs of approximately $1 billion. Without improvements in prevention and given Canada’s aging population, hip fractures are expected to quadruple by 2041. Falls cause more than 90 percent of hip fractures. Fracture risk during a fall depends on the force of the impact on the femur (thigh bone). Andrew Laing is evaluating the potential of low stiffness flooring to reduce the risk of fall-related hip fractures in high-risk environments such as nursing homes and hospitals. In laboratory experiments, Andrew is testing whether reducing floor stiffness decreases force applied to a hip during a fall, and whether floor stiffness can be reduced without impairing balance. Findings could contribute to the design of flooring that reduces risk of hip fractures and provide insight into similar interventions to reduce wrist, spinal cord and head injuries.