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Dive into the research topics where Michelle Henry is active.

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Featured researches published by Michelle Henry.


Metabolic Brain Disease | 2014

Episodic memory impairment in Addison’s disease: results from a telephonic cognitive assessment

Michelle Henry; Kevin G. F. Thomas

Patients with Addison’s disease frequently self-report memory and attention difficulties, even when on standard replacement therapy. However, few published studies examine, using objective measures and assessing across multiple domains, the cognitive functioning of Addison’s disease patients relative to healthy controls. The primary aim of this study was to investigate whether the previously reported subjective cognitive deficits in Addison’s disease are confirmed by objective measures. Conducting comprehensive neuropsychological assessments of patients with relatively rare clinical disorders, such as Addison’s disease, is challenging because access to those patients is often limited, and because their medical condition might prevent extended testing sessions. Brief telephonic cognitive assessments are a useful tool in such circumstances. Hence, we administered the Brief Test of Adult Cognition by Telephone to 27 Addison’s disease patients and 27 matched healthy controls. The instrument provides objective assessment of episodic memory, working memory, executive functioning, reasoning, and speed of processing. Statistical analyses confirmed that, as expected, patients performed significantly more poorly than controls on the episodic memory subtest. There were, however, no significant between-group differences on the attention, executive functioning, reasoning, and speed of processing subtests. Furthermore, patients with a longer duration of illness performed more poorly across all domains of cognition. We conclude that, for Addison’s disease patients, previously reported subjective cognitive deficits are matched by objective impairment, but only in the domain of episodic memory. Future research might investigate (a) whether these memory deficits are material-specific (i.e., whether non-verbal memory is also affected), and (b) the neurobiological mechanisms underlying these deficits.


Physiology & Behavior | 2015

Poor quality of life, depressed mood, and memory impairment may be mediated by sleep disruption in patients with Addison's disease

Michelle Henry; Pedro Sofio Abril Wolf; Kevin G. F. Thomas

Standard replacement therapy for Addisons disease (AD) does not restore a normal circadian rhythm. In fact, hydrocortisone replacement in AD patients likely induces disrupted sleep. Given that healthy sleep plays an important role in improving quality of life, optimizing cognition, and ensuring affect regulation, the aim of this study was to investigate whether poor quality of life, mood alterations, and memory complaints reported by AD patients are associated with their disrupted sleep patterns. Sixty patients with AD and 60 matched healthy controls completed a battery of self-report questionnaires assessing perceived physical and mental health (Short-Form 36), mood (Beck Depression Inventory-II), sleep quality (Pittsburgh Sleep Quality Index), and cognition (Cognitive Failures Questionnaire). A latent variable model revealed that although AD had a significant direct effect on quality of life, the indirect effect of sleep was significantly greater. Furthermore, although AD had no direct effect on cognitive functioning, the indirect effect of sleep was significant. The overall model showed a good fit (comparative fit index = 0.91, root mean square of approximation = 0.09, and standardized root mean square residual = 0.05). Our findings suggest that disrupted sleep, and not the disease per se, may induce poor quality of life, memory impairment, and affect dysregulation in patients with AD. We think that improving sleep architecture may improve cognitive, affective, and physical functioning.


Journal of the Association of Nurses in AIDS Care | 2017

Psychosocial Aspects of ART Counseling: A Comparison of HIV Beliefs and Knowledge in PMTCT and ART-Naïve Women

Hetta Gouse; Michelle Henry; Reuben N. Robbins; Javier Lopez-Rios; Claude A. Mellins; Robert H. Remien; John A. Joska

&NA; Antiretroviral therapy (ART)‐readiness counseling has been deemed critical to adherence, instilling knowledge, and promoting positive beliefs and attitudes. In the landscape of changing policy in South Africa, some ART initiators have had prior ART‐readiness counseling (e.g., for prevention‐of‐mother‐to‐child‐transmission [PMTCT] programs). The extent to which previous counseling resulted in retained knowledge and belief is unknown, which may be important to the promotion of womens ART adherence. We compared 320 women living with HIV and initiating ART, with and without prior PMTCT on HIV knowledge, treatment, beliefs, and attitudes. The PMTCT group held more accurate beliefs and more positive attitudes about ART. Both groups lacked understanding of basic HIV biology. Nondisclosure of HIV status was high. Thus, in individuals re‐initiating therapy, some knowledge about HIV and its treatment was not well retained. Tailored education and counseling may be critical to adherence, with a focus on biological concepts that impact ART resistance.


Frontiers in Human Neuroscience | 2018

Elevated Cortisol Leaves Working Memory Unaffected in Both Men and Women

Robyn Human; Michelle Henry; W. Jake Jacobs; Kevin G. F. Thomas

Activation of the hypothalamic-pituitary-adrenal (HPA) axis (as might occur, for example, when the organism encounters a threat to allostatic balance) leads to the release of cortisol into the bloodstream and, ultimately, to altered neural functioning in particular brain regions (e.g., the prefrontal cortex (PFC)). Although previous studies suggest that exposure to acute psychosocial stress (and hence, presumably, elevation of circulating cortisol levels) enhances male performance on PFC-based working memory (WM) tasks, few studies have adequately investigated female performance on WM tasks under conditions of elevated cortisol. Hence, we compared associations between elevated (relative to baseline) levels of circulating cortisol and n-back performance in a South African sample (38 women in the late luteal phase of their menstrual cycle, 38 men). On Day 1, participants completed practice n-back tasks. On Day 2, some completed the Trier Social Stress Test (TSST), whereas others experienced a relaxation period, before completing 1-back and 3-back tasks. We measured self-reported anxiety and salivary cortisol at baseline, post-manipulation and end of session. We reconstituted group assignment so that all women with elevated cortisol were in one group (EC-Women; n = 17), all men with elevated cortisol were in another (EC-Men; n = 19), all women without elevated cortisol were in a third (NoEC-Women; n = 21), and all men without elevated cortisol were in a fourth (NoEC-Men; n = 19) group. Analyses suggested this reconstitution was effective: in EC, but not NoEC, groups cortisol levels rose significantly from baseline to post-manipulation. Analyses of n-back data detected significant relations to task load (i.e., better performance on 1-back than on 3-back tasks), but no significant relations to sex, performance accuracy/speed, or cortisol variation. The data patterns are inconsistent with reports describing sex differences in effects of stress on WM performance. We speculate that cross-study methodological differences account for these inconsistencies, and, particularly, that between-study variation in the magnitude of baseline cortisol levels might affect outcomes. For instance, diurnal cortisol rhythms of South African samples might have flatter curves, and lower baseline values, than predominantly Caucasian samples from the United States and western Europe due to greater prenatal and lifetime stress, more socioeconomic disadvantage and faster ancestral life history (LH) strategies. We describe ways to disconfirm this hypothesis, and urge further cross-national research exploring these possibilities.


Applied Neuropsychology | 2018

Home-versus acquired-language test performance on the Hopkins Verbal Learning Test-Revised among multilingual South Africans

Travis M. Scott; Hetta Gouse; John A. Joska; Kevin G. F. Thomas; Michelle Henry; Anna Dreyer; Reuben N. Robbins

Abstract The Hopkins Verbal Learning Test-Revised (HVLT-R) has been adapted for use in many different languages and in low- and middle-income countries. However, few adaptations have evaluated performance differences between home- and acquired-language administrations. The present study examined performance on an adapted HVLT-R between multilingual South Africans who chose to be tested in a home or acquired language. The HVLT-R was administered to 112 multilingual, isiXhosa as home language, Black South African adults (49% men) with no major medical, neurological, or psychiatric problems. Sixty-one preferred to take the test in isiXhosa and 51 preferred English. We examined between-language differences in word equivalency, primary scores, learning indices, and serial position effects. We also examined language, age, education, and gender on test performance. English-examinees were significantly younger and more educated than isiXhosa-examinees (p’s < .05). Although isiXhosa words had more letters and syllables than English words (p’s <.001), there were no significant differences between groups on HVLT-R performance or serial recall (p’s > .05). More education and being a woman predicted better Total and Delayed Recall (p’s<.05). Performance on this modified HVLT-R appears similar between English and isiXhosa administrations among South African isiXhosa first language speakers, which makes comparisons between preferred language administrations appropriate.


Aids and Behavior | 2018

Empowering Lay-Counsellors with Technology: Masivukeni, a Standardized Multimedia Counselling Support Tool to Deliver ART Counselling

Hetta Gouse; R. N. Robbins; Claude A. Mellins; A. Kingon; Jessica C. Rowe; Michelle Henry; R. H. Remien; A. Pearson; F. Victor; John A. Joska

Lay-counsellors in resource-limited settings convey critical HIV- and ART-information, and face challenges including limited training and variable application of counselling. This study explored lay-counsellors and Department of Health (DoH) perspectives on the utility of a multimedia adherence counselling program. Masivukeni, an mHealth application that provides scaffolding for delivering standardized ART counselling was used in a 3-year randomized control trail at two primary health care clinics in Cape Town, South Africa. In this programmatic and descriptive narrative report, we describe the application; lay-counsellors’ response to open-ended questions regarding their experience with using Masivukeni; and perspectives of the City of Cape Town and Western Cape Government DoH, obtained through ongoing engagements and feedback sessions. Counsellors reported Masivukeni empowered them to provide high quality counselling. DoH indicated strong support for a future implementation study assessing feasibility for larger scale roll-out. Masivukeni has potential as a counselling tool in resource-limited settings.


Metabolic Brain Disease | 2014

Erratum to: Episodic memory impairment in Addison's disease: results from a telephonic cognitive assessment

Michelle Henry; Kevin G. F. Thomas

Patients with Addison’s disease frequently selfreport memory and attention difficulties, even when on standard replacement therapy. However, few published studies examine, using objective measures and assessing across multiple domains, the cognitive functioning of Addison’s disease patients relative to healthy controls. The primary aim of this study was to investigate whether the previously reported subjective cognitive deficits in Addison’s disease are confirmed by objective measures. Conducting comprehensive neuropsychological assessments of patients with relatively rare clinical disorders, such as Addison’s disease, is challenging because access to those patients is often limited, and because their medical condition might prevent extended testing sessions. Brief telephonic cognitive assessments are a useful tool in such circumstances. Hence, we administered the Brief Test of Adult Cognition by Telephone to 27 Addison’s disease patients and 27 matched healthy controls. The instrument provides objective assessment of episodic memory, working memory, executive functioning, reasoning, and speed of processing. Statistical analyses confirmed that, as expected, patients performed significantly more poorly than controls on the episodic memory subtest. There were, however, no significant between-group differences on the attention, executive functioning, reasoning, and speed of processing subtests. Furthermore, patients with a longer duration of illness performed more poorly across all domains of cognition. We conclude that, for Addison’s disease patients, previously reported subjective cognitive deficits are matched by objective impairment, but only in the domain of episodic memory. Future research might investigate (a) whether these memory deficits are material-specific (i.e., whether non-verbal memory is also affected), and (b) the neurobiological mechanisms underlying these deficits.


European Journal of Endocrinology | 2018

Reduced slow-wave sleep and altered diurnal cortisol rhythms in patients with Addison’s disease

Michelle Henry; Kevin Garth Flusk Thomas


Psychoneuroendocrinology | 2017

Impaired quality and efficiency of sleep impairs cognitive functioning in Addison’s disease

Michelle Henry; Pedro Sofio Abril Wolf; Kevin Garth Flusk Thomas


Physiology & Behavior | 2016

Corrigendum to “Poor quality of life, depressed mood, and memory impairment may be mediated by sleep disruption in patients with Addison's disease” [Physiol. Behav. 151 (2015) 379–385]

Michelle Henry; Pedro Sofio Abril Wolf; Kevin G. F. Thomas

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Hetta Gouse

University of Cape Town

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Anna Dreyer

University of Cape Town

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Robyn Human

University of Cape Town

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