Ketamine in Refractory Cyclic Vomiting Syndrome: A Case Report and Review of Literature.

PURPOSE: To describe the use of ketamine in an adult patient in aborting a cyclic vomiting syndrome (CVS) episode. SUMMARY: A 40-year-old man with a history of CVS was admitted after several days of nausea and vomiting. He was given parenteral doses of lorazepam and ondansetron but was unable to remain emesis-free. Ketamine was recommended by Gastroenterology as a therapeutic option after exhausting all first- and second-line agents. Ketamine is a noncompetitive N-methyl-D-aspartate receptor antagonist that is widely used for its analgesic and sedative effects. While there is some data to support its use in CVS, most of the published literature has been limited to the Emergency Department setting and no specific therapeutic dose has been established. We will review our institution's experience with low dose ketamine in an adult patient with a CVS episode that is refractory to first-line agents. CONCLUSION: In the case described, ketamine at a low sub-anesthetic dose successfully aborted a CVS episode with no appreciable side effects. As much of ketamine's full effects remain relatively unknown, additional studies are needed to determine optimal strategies for ketamine use in patients with a CVS episode.

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial.

BACKGROUND: Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention. METHODS: Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer's Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression. DISCUSSION: The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care. TRIAL REGISTRATION: ClinicalTrials.gov NCT02669394 . Registered on February 1, 2016.

Exploring the Contribution of Myelin Content in Normal Appearing White Matter to Cognitive Outcomes in Cerebral Small Vessel Disease.

BACKGROUND: Myelin damage is a salient feature in cerebral small vessel disease (cSVD). Of note, myelin damage extends into the normal appearing white matter (NAWM). Currently, the specific role of myelin content in cognition is poorly understood. OBJECTIVE: The objective of this exploratory study was to investigate the association between NAWM myelin and cognitive function in older adults with cSVD. METHODS: This exploratory study included 55 participants with cSVD. NAWM myelin was measured using myelin water imaging and was quantified as myelin water fraction (MWF). Assessment of cognitive function included processing speed (Trail Making Test Part A), set shifting (Trail Making Test Part B minus A), working memory (Verbal Digit Span Backwards Test), and inhibition (Stroop Test). Multiple linear regression analyses assessed the contribution of NAWM MWF on cognitive outcomes controlling for age, education, and total white matter hyperintensity volume. The overall alpha was set at ≤0.05. RESULTS: After accounting for age, education, and total white matter hyperintensity volume, lower NAWM MWF was significantly associated with slower processing speed (ß â€Š= -0.29, p = 0.037) and poorer working memory (ß= 0.30, p = 0.048). NAWM MWF was not significantly associated with set shifting or inhibitory control (p > 0.132). CONCLUSION: Myelin loss in NAWM may play a role in the evolution of impaired processing speed and working memory in people with cSVD. Future studies, with a longitudinal design and larger sample sizes, are needed to fully elucidate the role of myelin as a potential biomarker for cognitive function.

Functional connectivity underpinning changes in life-space mobility in older adults with mild cognitive impairment: A 12-month prospective study.

Subtle changes in mobility exist among older adults with mild cognitive impairment (MCI). Life-space mobility defines the frequency and extent of movements in the environment, and lower life-space mobility is associated with adverse health outcomes and MCI. Currently, the underlying mechanism of this association is not well understood. This study examined the functional neural correlates of life-space mobility in community-dwelling older adults with MCI. We first conducted a cross-sectional investigation of the association between resting-state default mode network (DMN) and sensori-motor network (SMN) connectivity and life-space mobility (assessed by the Life-Space Assessment (LSA)) among 60 community-dwelling older adults with MCI using aggregated data from two studies - baseline data from a randomized controlled trial (n = 20) and baseline data from a 12-month prospective study (n = 40). Using data from the 12-month prospective study (n = 35), we then examined whether baseline internetwork connectivity predicts reduced life-space mobility over 12 months. The cross-sectional analysis showed higher DMN-SMN connectivity was associated with lower LSA scores after adjusting for baseline global cognitive function and baseline age (p < 0.01). A significant reduction in LSA scores was observed in the 35 participants of the 12-month prospective study (paired sample t-test mean change = -6.53, p = 0.01). Greater baseline DMN-SMN connectivity was associated with greater reduction in life-space mobility at 12 months (p = 0.04) after adjusting for baseline age, global cognitive function, and LSA score. Our findings suggest that lower and reduced life-space mobility in older adults with MCI may be due to altered functional architecture of the brain such that normal neuro-cognitive motor behaviours may be disrupted.

Examining the Inter-relations of Depression, Physical Function, and Cognition with Subjective Sleep Parameters among Stroke Survivors: A Cross-sectional Analysis.

GOAL: Stroke survivors commonly experience depression as well as deficits in physical and cognition function. Emerging evidence also suggests sleep quality is compromised poststroke. Our primary objective was to examine the association of subjective sleep parameters (ie, total PSQI score) with depression, health related quality of life, physical function, and cognition among stroke survivors. MATERIALS AND METHODS: Cross-sectional analysis of 72 older adults with chronic stroke (≥6 months postischemic stroke) enrolled in a randomized controlled trial of exercise or cognitive enrichment. Subjective sleep parameters were assessed using the Pittsburgh Sleep Quality Index (PSQI). We report total PSQI score and specific PSQI parameter scores (ie, PSQI-subjective sleep quality, PSQI-sleep latency, PSQI-sleep duration, PSQI-habitual sleep efficiency, PSQI-sleep disturbances, PSQI-use of sleep medication, and PSQI-daytime dysfunction). Bivariate correlations and multivariate linear regression assessed associations between subjective sleep parameters and depression/health related quality of life, physical function, and cognition. FINDINGS: For bivariate correlations, depression was significantly associated with global PSQI, PSQI-subjective sleep quality, PSQI-habitual sleep efficiency, and PSQI-daytime dysfunction. Health related quality of life was significantly associated with PSQI-sleep medication. Physical function and health was significantly associated with PSQI-subjective sleep quality, PSQI-sleep latency, PSQI-sleep duration, and PSQI-daytime dysfunction. Multivariate linear regression demonstrated that PSQI-daytime dysfunction predicted depression and physical function; PSQI-subjective sleep quality predicted depression. No significant associations between global PSQI subjective sleep parameters with cognition were observed. CONCLUSION: Poor subjective sleep parameters and PSQI-subjective sleep quality among stroke survivors were associated with depression; PSQI-daytime dysfunction was associated with physical function. Thus, sleep should be considered in the management of those who have suffered a stroke to optimize poststroke rehabilitation outcomes.