Neuroimaging of Brain Changes Associated With Cognitive Impairment in Parkinson’s Disease.
Neuroimaging of brain changes associated with cognitive impairment in Parkinson’s disease.
J Neuropsychol. 2013 Apr 1;
Christopher L, Strafella AP
Cognitive impairment occurs frequently in Parkinson’s disease (PD) and the concept of Mild Cognitive Impairment in PD (PD-MCI) has recently emerged. Patients with mild impairment are at risk of developing dementia, and thus it is a topic of growing interest. Many previous studies have investigated the neural correlates of cognitive impairment, in particular executive dysfunction, in PD patients without dementia using neuroimaging techniques including structural MRI, functional MRI and PET imaging. These studies, which have provided a foundation for understanding which brain regions and neurotransmitter systems may be involved in executive dysfunction in PD, will be reviewed. Recent neuroimaging studies that have used specific criteria to classify patients as PD-MCI, in the hopes of gaining further insight into the underlying neural mechanisms will also be discussed. In particular, this review will cover key findings involving structural MRI investigating grey and white matter changes, functional MRI to examine changes in neural activation and PET imaging to investigate metabolic and neurochemical changes that have led to an improved understanding of pathology associated with executive dysfunction in PD without dementia and PD-MCI. HubMed – addiction
‘It’s more about the heroin’: injection drug users’ response to an overdose warning campaign in a Canadian setting.
Addiction. 2013 Mar 28;
Kerr T, Small W, Hyshka E, Maher L, Shannon K
AIMS: To assess heroin injectors’ perceptions of and responses to a warning issued by public health officials regarding high-potency heroin and increases in fatal overdoses. DESIGN: Semi-structured qualitative interviews. SETTING: Vancouver, Canada. PARTICIPANTS: Eighteen active heroin injectors. MEASUREMENTS: Semi-structured interview guide focussing on heroin injectors’ perceptions of and responses to the overdose warning, including reasons for failing to adhere to risk reduction recommendations. FINDINGS: Although nearly all participants were aware of the warning, their recollections of the message and the timing of its release were obscured by on-going social interactions within the drug scene focussed on heroin quality. Many injection drug users reported seeking the high potency heroin and nearly all reported no change in overdose risk behaviours. Responses to the warning were shaped by various social, economic and structural forces that interacted with individual behaviour and undermined efforts to promote behavioural change, including sales tactics employed by dealers, poverty, the high cost and shifting quality of available heroin, and risks associated with income-generating activities. Individual-level factors, including emotional suffering, withdrawal, entrenched injecting routines, perceived invincibility and the desire for intense intoxication also undermined risk reduction messages. CONCLUSIONS: Among heroin injectors in British Columbia, a 2011 overdose warning campaign appeared to be of limited effectiveness and also produced unintended negative consequences that exacerbated overdose risk. HubMed – addiction
‘Vaping’ profiles and preferences: an online survey of electronic cigarette users.
Addiction. 2013 Mar 28;
Dawkins L, Turner J, Roberts A, Soar K
AIMS: To characterize e-cigarette use, users and effects in a sample of Electronic Cigarette Company (TECC) and Totally Wicked E-Liquid (TWEL) users. DESIGN AND SETTING: Online survey hosted at the University of East London with links from TECC/TWEL websites from September 2011 to May 2012. MEASUREMENTS: Online questionnaire. PARTICIPANTS: One thousand three hundred and forty-seven respondents from 33 countries (72% European), mean age 43 years, 70% male, 96% Causacian, 44% educated to degree level or above. FINDINGS: Seventy-four percent of participants reported not smoking for at least a few weeks since using the e-cigarette and 70% reported reduced urge to smoke. Seventy-two percent of participants used a ‘tank’ system, most commonly, the eGo-C (23%). Mean duration of use was 10 months. Only 1% reported exclusive use of non-nicotine (0?mg) containing liquid. E-cigarettes were generally considered to be satisfying to use; elicit few side effects; be healthier than smoking; improve cough/breathing; and be associated with low levels of craving. Among ex-smokers, ‘time to first vape’ was significantly longer than ‘time to first cigarette’ (t1104 ?=?11.16, P?0.001) suggesting a lower level of dependence to e-cigarettes. Ex-smokers reported significantly greater reduction in craving than current smokers (?(2) 1 ?=?133.66, P?0.0007) although few other differences emerged between these groups. Compared with males, females opted more for chocolate/sweet flavours (?(2) 1 ?=?16.16, P?0.001) and liked the e-cigarette because it resembles a cigarette (?(2) 3 ?=?42.65, P?0.001). CONCLUSIONS: E-cigarettes are used primarily for smoking cessation, but for a longer duration than nicotine replacement therapy, and users believe them to be safer than smoking. HubMed – addiction