Publications by authors named "Lesley J Ritchie"

Alzheimer's disease (AD) is a neurodegenerative disorder with a clinical presentation characterized by memory impairment and executive dysfunction. Our group previously demonstrated significant alterations in white matter microstructural metrics in AD compared to healthy older adults. We aimed to further investigate the relationship between white matter microstructure in AD and cognitive function, including memory and executive function.

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Alzheimer's disease (AD) is a neurodegenerative disorder that may benefit from early diagnosis and intervention. Therefore, there is a need to identify early biomarkers of AD using non-invasive techniques such as functional magnetic resonance imaging (fMRI). Recently, novel approaches to the analysis of resting-state fMRI data have been developed that focus on the moment-to-moment variability in the blood oxygen level dependent (BOLD) signal.

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Objective: Superficial siderosis (SS) is a neurodegenerative condition due to the long-term effects of hemosiderin deposition on the surface of the brain, cerebellum, brainstem, and spinal cord. SS symptoms include sensorineural hearing loss, ataxia and upper motor neuron signs. SS was diagnostically evasive until magnetic resonance imaging (MRI) became available.

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Objectives: To summarize the clinical characteristics and outcomes of pediatric sports-related concussion (SRC) patients who were evaluated and managed at a multidisciplinary pediatric concussion program and examine the healthcare resources and personnel required to meet the needs of this patient population.

Methods: We conducted a retrospective review of all pediatric SRC patients referred to the Pan Am Concussion Program from September 1st, 2013 to May 25th, 2015. Initial assessments and diagnoses were carried out by a single neurosurgeon.

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Object: The objectives of this study were twofold: (1) to examine the prevalence of emotional symptoms among children and adolescents with a sports-related concussion (SRC) who were referred to a multidisciplinary pediatric concussion program and (2) to examine the prevalence, clinical features, risk factors, and management of postinjury psychiatric outcomes among those in this clinical population.

Methods: The authors conducted a retrospective chart review of all patients with SRC referred to a multidisciplinary pediatric concussion program between September 2013 and October 2014. Clinical assessments carried out by a single neurosurgeon included clinical history, physical examination, and Post-Concussion Symptom Scale (PCSS) scoring.

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The lack of gold standard diagnostic criteria for cognitive impairment in the absence of dementia has resulted in variable nomenclature, case definitions, outcomes, risk factors, and prognostic utilities. Our objective was to elucidate the clinical correlates of conversion to dementia in a longitudinal population-based sample. Using data from the Canadian Study of Health and Aging, a machine learning algorithm was used to identify symptoms that best differentiated converting from nonconverting cognitively impaired not demented participants.

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Our objective was to compare the predictive ability of different models of mild cognitive impairment (MCI) as a marker of incipient dementia in a longitudinal population-based Canadian sample. We examined the use of existing, well-documented MCI criteria using data from persons who underwent a clinical examination in the second wave of the Canadian Study of Health and Aging (CSHA). Demographic characteristics, average neuropsychological test performance, and sample frequencies and conversion rates were calculated for each classification.

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In this study, the relations between cognitive status and neuropsychiatric impairments in nondemented older adults in cross section and over time is examined. Using data from the Canadian Study of Health and Aging (CSHA), a longitudinal, nation-wide study in which data were collected 3 times (ie, CSHA-1, CSHA-2, CSHA-3) at 5-year intervals, individuals were classified with (n = 240) and without (n = 386) cognitive impairment at CSHA-2. Loss of interest, changes in personality and mood, and depression were reported by a knowledgeable informant (ie, family or friends) more frequently for those with cognitive impairment than for those without cognitive impairment.

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The effect of chronic mild stress (CMStress) was examined in an animal model of chronic cerebral hypoperfusion. Eight-month-old male Sprague-Dawley rats underwent permanent bilateral occlusion of the carotid arteries (2VO) or sham surgery. At 7 days postsurgery, animals from these groups were randomly assigned to undergo CMStress consisting of relatively mild stressor exposure 6 days a week for 6 weeks or a no-stress regimen.

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