Rationale and design for the detection and neurological impact of cerebrovascular events in non-cardiac surgery patients cohort evaluation (NeuroVISION) study: a prospective international cohort study.

OBJECTIVES: Covert stroke after non-cardiac surgery may have substantial impact on duration and quality of life. In non-surgical patients, covert stroke is more common than overt stroke and is associated with an increased risk of cognitive decline and dementia. Little is known about covert stroke after non-cardiac surgery.NeuroVISION is a multicentre, international, prospective cohort study that will characterise the association between perioperative acute covert stroke and postoperative cognitive function. SETTING AND PARTICIPANTS: We are recruiting study participants from 12 tertiary care hospitals in 10 countries on 5 continents. PARTICIPANTS: We are enrolling patients ≥65 years of age, requiring hospital admission after non-cardiac surgery, who have an anticipated length of hospital stay of at least 2 days after elective non-cardiac surgery that occurs under general or neuraxial anaesthesia. PRIMARY AND SECONDARY OUTCOME MEASURES: Patients are recruited before elective non-cardiac surgery, and their cognitive function is measured using the Montreal Cognitive Assessment (MoCA) instrument. After surgery, a brain MRI study is performed between postoperative days 2 and 9 to determine the presence of acute brain infarction. One year after surgery, the MoCA is used to assess postoperative cognitive function. Physicians and patients are blinded to the MRI study results until after the last patient follow-up visit to reduce outcome ascertainment bias.We will undertake a multivariable logistic regression analysis in which the dependent variable is the change in cognitive function 1 year after surgery, and the independent variables are acute perioperative covert stroke as well as other clinical variables that are associated with cognitive dysfunction. CONCLUSIONS: The NeuroVISION study will characterise the epidemiology of covert stroke and its clinical consequences. This will be the largest and the most comprehensive study of perioperative stroke after non-cardiac surgery. TRIAL REGISTRATION NUMBER: NCT01980511; Pre-results.

Engaging Patients and Clinicians in Establishing Research Priorities for Gestational Diabetes Mellitus.

OBJECTIVES: We involved patients and clinicians in Alberta, Canada, to establish research priorities in gestational diabetes mellitus (GDM), using an approach based on a model proposed by the James Lind Alliance (JLA). METHODS: We adapted the 4-step JLA process to engage women with GDM and clinicians to identify uncertainties about the management of GDM. Uncertainties were identified through a survey and a review of the clinical practice guidelines (CPG). Uncertainties were short-listed by a steering committee, followed by a 1-day facilitated workshop using a nominal group format and involving a similar number of patients and clinicians, who identified the top 10 research priorities. RESULTS: Across the various survey formats, 75 individuals submitted 389 uncertainties, the majority (44; 59%) coming from patients. We removed 9 questions as being out of scope or unclear, and 41 were identified on a review of CPG, resulting in a total of 421 uncertainties. After the priority setting process, the final top 10 research priorities included questions about a simpler, more accurate and convenient screening test; risk factors for GDM; improving postpartum diabetes screening; the impact of GDM on the future health of the children; lifestyle challenges and mental health issues; safety, effectiveness and/or impact of diet and/or medication treatments; appropriate timing for delivery; and how care is provided, organized or communicated. CONCLUSIONS: These top 10 research priorities were informed through a comprehensive and transparent process involving women who have experienced GDM as well as clinicians, and they may be regarded as research priorities for GDM.

Direct Invasion of the Optic Nerves, Chiasm, and Tracts by Cryptococcus neoformans in an Immunocompetent Host.

Cryptococcus spp is a common fungal infection and frequent cause of meningitis in immunocompromised patients; however, immunocompetent patients are also at risk of infection. Visual loss often occurs via elevated intracranial hypertension but can rarely occur through direct optic nerve, chiasm, or tract invasion. We report a case of a 38-year-old woman who presented with decreased acuity in both eyes. She had generalized visual field constriction in the right eye and temporal hemianopsia in the left eye. Magnetic resonance imaging of the brain and orbits showed multiple areas of ill-defined enhancement in the optic chiasm and tracts as well as in the diaphragmatic sella, prepontine and interpeduncular cisterns, and along cranial nerves VI, VII, and VIII bilaterally. Initial cerebrospinal fluid (CSF) showed 34 white blood cells, hypoglycorrhachia, and negative cryptococcal antigen and bacterial and fungal cultures. A transphenoidal biopsy of the dura and pituitary gland was unremarkable. Empiric steroids resulted in marked improvement in visual acuity in both eyes, but while tapering steroids, she developed rapid visual loss bilaterally. Repeat CSF performed 6 weeks later demonstrated a cryptococcal antigen titer of 1:512. Retroactive staining of the pituitary biopsy was positive for mucicarmine, a component of the polysaccharide capsule of Cryptococcus spp. After induction therapy with amphotericin B and flucytosine and 1 year of fluconazole, her visual acuity was 20/20 in both eyes. In summary, Cryptococcus can affect immunocompetent patients and often presents with insidious, chronic meningitis. Visual loss is common in cryptococcal meningitis but usually results from fulminant papilledema related to elevated intracranial pressure. In rare cases, direct nerve or chiasm infiltration by the fungus results in vision loss.

Rapid adaptation of visual search in simulated hemianopia.

Patients with homonymous hemianopia have altered visual search patterns, but it is unclear how rapidly this develops and whether it reflects a strategic adaptation to altered perception or plastic changes to tissue damage. To study the temporal dynamics of adaptation alone, we used a gaze-contingent display to simulate left or right hemianopia in 10 healthy individuals as they performed 25 visual search trials. Visual search was slower and less accurate in hemianopic than in full-field viewing. With full-field viewing, there were improvements in search speed, fixation density, and number of fixations over the first 9 trials, then stable performance. With hemianopic viewing, there was a rapid shift of fixation into the blind field over the first 5-7 trials, followed by continuing gradual improvements in completion time, number of fixations, and fixation density over all 25 trials. We conclude that in the first minutes after onset of hemianopia, there is a biphasic pattern of adaptation to altered perception: an early rapid qualitative change that shifts visual search into the blind side, followed by more gradual gains in the efficiency of using this new strategy, a pattern that has parallels in other studies of motor learning.