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Objectives We aimed to compare brain white matter integrity in participants with post-COVID-19 conditions (PCC) and healthy controls. Methods We compared cognitive performance (NIH Toolbox®), psychiatric symptoms and diffusion tensor imaging (DTI) metrics between 23 PCC participants and 24 controls. Fractional anisotropy (FA), axial (AD), radial (RD), and mean (MD) diffusivities were measured in 9 white matter tracts and 6 subcortical regions using MRICloud. Results Compared to controls, PCC had similar cognitive performance, but greater psychiatric symptoms and perceived stress, as well as higher FA and lower diffusivities in multiple white matter tracts (ANCOVA-p-values≤0.001–0.048). Amongst women, PCC had higher left amygdala-MD than controls (sex-by-PCC p=0.006). Regardless of COVID-19 history, higher sagittal strata-FA predicted greater fatigue (r=0.48-0.52, p Conclusions Microstructural abnormalities are evident in PCC participants averaged six months after COVID-19. The restricted diffusivity (with reduced MD) and higher FA suggest enhanced myelination or increased magnetic susceptibility from iron deposition, as seen in stress conditions. The higher amygdala-MD in female PCC suggests persistent neuroinflammation, which might contribute to their fatigue, anxiety, and perceived stress.

The aim of this study was to determine the extent to which socioeconomic characteristics of the home and neighborhood are associated with racial inequalities in brain outcomes.We performed a cross-sectional analysis of the baseline dataset (v.2.0.1) from the Adolescent Brain and Cognitive Development (ABCD) Study. Cognitive performance was assessed using the National Institutes of Health Toolbox (NIH-TB) cognitive battery. Standard socioeconomic indicators of the family and neighborhood were derived from census-related statistics. Cortical morphometric measures included MRI-derived thickness, area, and volume.9638 children were included. Each NIH-TB cognitive measure was negatively associated with household and neighborhood socioeconomic characteristics. Differences in cognitive scores between Black or Hispanic children and other racial groups were mitigated by higher household income. Most children from lowest-income families or residents in impoverished neighborhoods were Black or Hispanic. These disparities were associated with racial differences in NIH-TB measures and mediated by smaller cortical brain volumes.Neighborhood socioeconomic characteristics are associated with racial differences in preadolescent brain outcomes and mitigated by greater household income. Household income mediates racial differences more strongly than neighborhood-level socioeconomic indicators in brain outcomes. Highlighting these socioeconomic risks may direct focused policy-based interventions such as allocation of community resources to ensure equitable brain outcomes in children.Neighborhood socioeconomic characteristics are associated with racial differences in preadolescent brain outcomes and mitigated by greater household income. Household income mediates racial differences more strongly than neighborhood-level socioeconomic indicators in brain outcomes. Highlighting these disparities related to socioeconomic risks may direct focused policy-based interventions such as allocation of community resources to ensure equitable brain outcomes in children.

Objectives Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection is associated with lower plasma glutathione (GSH) levels due to oxidative stress. However, plasma levels may not reflect brain GSH levels. Individuals with post-acute sequelae of COVID-19 (PASC) have a higher prevalence of cognitive fatigue, which might be related to altered brain γ-aminobutyric-acid (GABA) levels. Hence, our study aims to measure the brain GSH and GABA levels in PASC. Methods 29 PASC participants and 24 uninfected controls were recruited for this study. Each was evaluated with detailed neuropsychiatric assessments and an edited proton MRS (Hadamard Encoding and Reconstruction of Mega-Edited Spectroscopy, HERMES) method to measure GABA and GSH concentrations in predominantly grey matter (GM) and predominantly white matter (WM) brain frontal voxels. Results PASC participants were 219 ± 137 days since their COVID-19 diagnosis. Nine individuals with PASC were hospitalized. Compared to controls, individuals with PASC had similar levels of GABA in both brain regions, but lower GSH and greater age-related GSH decline in the frontal GM region. Conclusions The lower-than-normal frontal GM GSH level in participants with PASC suggest that they have ongoing oxidative stress in the brain, and that older individuals may be even more vulnerable to oxidative stress.

Objective To quantify neuropsychiatric symptoms reported by individuals with Post-Acute Sequelae of COVID-19 (PASC) using the NIH Toolbox for Assessment of Neurological and Behavioral Function (NIHTB) and Patient-Reported Outcomes Measurement Information System (PROMIS). Methods 30 PASC (20 women, 21–63 years) and 27 control (16 women, 25–68 years) participants completed three NIHTB batteries and selected PROMIS tests. Group differences on fully corrected T-scores were evaluated using analysis of covariance and Cohen’s d effect sizes. A linear regression model predicted the effects from time since diagnosis. Results PASC had poorer emotional health and motor function than controls, including poorer locomotion, endurance and dexterity, but normal cognitive function, ∼7 months post-infection. PASC participants had a steeper age-related decline on the 2-Minute Walk Endurance Test than controls. T-scores on four cognitive and three motor tests improved with longer time since diagnosis. Conclusion NIHTB and PROMIS captured the poorer emotional health and motor function in PASC, including the novel findings of deficits in locomotion and dexterity. The normal cognitive performance suggests subclinical effects that may be compensated by neural and cognitive reserves, and manifested subjectively by the negative psychological effects and fatigue. The persistent emotional and psychiatric symptoms necessitate mental health treatment be prioritized.

Cognitive impairment may be greater in HIV-positive (HIV+) women than in HIV+ men. Whether sex-specific differences exist in brain microstructure of HIV+ individuals is unknown and was evaluated.39 HIV+ (21 men, 18 women) and 45 seronegative (SN, 20 men, 25 women) participants were assessed with brain diffusion tensor imaging and cognitive assessments (7 neuropsychological domains). Fractional anisotropy (FA) and mean diffusivity (MD) were measured with an automated atlas in selected brain regions. Group comparisons were assessed with linear mixed effects models, with sub-regions and hemisphere (left/right) as repeated factors for each region.HIV+ women, but not HIV+ men, were slower than sex-matched SN controls on sensorimotor function (Dominant-hand: interaction-p = 0.007; Non-dominant hand: interaction-p = 0.039). Similarly, only HIV+ women had lower FA in the globus pallidus (GP, interaction-p = 0.011). Additionally, regardless of sex, the HIV+ group had poorer Fluency, Speed, and Attention than SN-controls (p = 0.006-0.008), as well as lower FA and higher MD in multiple brain regions (p = 0.001-0.044). Across all participants, performance on Attention was predicted by uncinate-FA (p 0.001, r = 0.5) and corpus callosum (CC)-FA (p = 0.038, r = 0.23), while the Speed of Information Processing was predicted by CC-FA (p = 0.009, r = 0.3). Furthermore, faster sensorimotor function correlated with higher CC-FA and uncinate-FA in men but not in women (Sex*DTI-interaction-p = 0.03-0.06).The relatively poorer sensorimotor function and abnormally lower GP_FA, suggesting lesser neuronal integrity, in HIV+ women demonstrate sex-specific effects from HIV-infection on these measures. These findings may be related to the greater immune activation and neuroinflammation in HIV+ women compared to HIV+ men. Graphical Abstract.

Tungsten is regarded as the baseline first wall material in tokamaks. This work provides a polarized method for measuring the emissivity and temperature of the tungsten using an infrared camera and a polarizer under simulating tokamak conditions. In the experiment, a polarizer with an adjustable polarization direction is set up in front of an infrared camera. A rotatable fixture is used to fix the sample and change the angle between the surface and the normal. The sample is rotated from 0° to 80°, and the polarized emissivity first increases and then decreases with increasing rotation angle. The uncertainty in emissivity resulting from this polarized method and non-polarized method is analyzed. To compare the effects of the polarized method and the non-polarized method, the rotation angle is adjusted to 0°, and a fitting model is used to describe the relationship between emissivity and temperature. Errors between the calculated temperature and measured temperature are used as a scale, and the polarized method improves the accuracy of temperature measurement. This polarized method provides a technical way to measure the emissivity and temperature in a tokamak and can be applied in other similar applications.

Tobacco smoking is highly prevalent among HIV-infected individuals. Chronic smokers with HIV showed greater cognitive deficits and impulsivity, and had more psychopathological symptoms and greater neuroinflammation than HIV non-smokers or smokers without HIV infection. However, preclinical studies that evaluated the combined effects of HIV-infection and tobacco smoking are scare. The preclinical models typically used cell cultures or animal models that involved specific HIV viral proteins or the administration of nicotine to rodents. These preclinical models consistently demonstrated that nicotine had neuroprotective and anti-inflammatory effects, leading to cognitive enhancement. Although the major addictive ingredient in tobacco smoking is nicotine, chronic smoking does not lead to improved cognitive function in humans. Therefore, preclinical studies designed to unravel the interactive effects of chronic tobacco smoking and HIV infection are needed. In this review, we summarized the preclinical studies that demonstrated the neuroprotective effects of nicotine, the neurotoxic effects of the HIV viral proteins, and the scant literature on nicotine or tobacco smoke in HIV transgenic rat models. We also reviewed the clinical studies that evaluated the neurotoxic effects of tobacco smoking, HIV infection and their combined effects on the brain, including studies that evaluated the cognitive and behavioral assessments, as well as neuroimaging measures. Lastly, we compared the different approaches between preclinical and clinical studies, identified some gaps and proposed some future directions. Graphical abstract Independent and combined effects of HIV and tobacco/nicotine. Left top and bottom panels: Both clinical studies of HIV infected persons and preclinical studies using viral proteins in vitro or in vivo in animal models showed that HIV infection could lead to neurotoxicity and neuroinflammation. Right top and bottom panels: While clinical studies of tobacco smoking consistently showed deleterious effects of smoking, clinical and preclinical studies that used nicotine show mild cognitive enhancement, neuroprotective and possibly anti-inflammatory effects. In the developing brain, however, nicotine is neurotoxic. Middle overlapping panels: Clinical studies of persons with HIV who were smokers typically showed additive deleterious effects of HIV and tobacco smoking. However, in the preclinical studies, when nicotine was administered to the HIV-1 Tg rats, the neurotoxic effects of HIV were attenuated, but tobacco smoke worsened the inflammatory cascade.

Objective Cognitive deficits and microstructural brain abnormalities are well documented in HIV-positive individuals (HIV+). This study evaluated whether chronic marijuana (MJ) use contributes to additional cognitive deficits or brain microstructural abnormalities that may reflect neuroinflammation or neuronal injury in HIV+. Method Using a 2 × 2 design, 44 HIV+ participants [23 minimal/no MJ users (HIV+), 21 chronic active MJ users (HIV + MJ)] were compared to 46 seronegative participants [24 minimal/no MJ users (SN) and 22 chronic MJ users (SN + MJ)] on neuropsychological performance (7 cognitive domains) and diffusion tensor imaging metrics, using an automated atlas to assess fractional anisotropy (FA), axial (AD), radial (RD), and mean (MD) diffusivities, in 18 cortical and 4 subcortical brain regions. Results Compared to SN and regardless of MJ use, the HIV+ group had lower FA and higher diffusivities in multiple white matter and subcortical structures (p < 0.001–0.050), as well as poorer cognition in Fluency (p = 0.039), Attention/Working Memory (p = 0.009), Learning (p = 0.014), and Memory (p = 0.028). Regardless of HIV serostatus, MJ users had lower AD in uncinate fasciculus (p = 0.024) but similar cognition as nonusers. HIV serostatus and MJ use showed an interactive effect on mean diffusivity in the right globus pallidus but not on cognitive function. Furthermore, lower FA in left anterior internal capsule predicted poorer Fluency across all participants and worse Attention/Working Memory in all except SN subjects, while higher diffusivities in several white matter tracts also predicted lower cognitive domain Z-scores. Lastly, MJ users with or without HIV infection showed greater than normal age-dependent FA declines in superior longitudinal fasciculus, external capsule, and globus pallidus. Conclusions Our findings suggest that, except in the globus pallidus, chronic MJ use had no additional negative influence on brain microstructure or neurocognitive deficits in HIV+ individuals. However, lower AD in the uncinate fasciculus of MJ users suggests axonal loss in this white matter tract that connects to cannabinoid receptor rich brain regions that are involved in verbal memory and emotion. Furthermore, the greater than normal age-dependent FA declines in the white matter tracts and globus pallidus in MJ users suggest that older chronic MJ users may eventually have lesser neuronal integrity in these brain regions.

The existing methods of contact respiration rate (RR) measurement can bring discomfort to the person being measured. However, RR is a human index that has to be monitored in clinical medicine. To overcome the limitations of contact measurement methods, a non-contact RR measurement method based on an infrared thermal camera is proposed. This is based on the phenomenon that human breathing causes periodic temperature changes around the nostrils. First, an infrared thermal camera is used to collect image sequences of the human face. And then, to track a region-of-interest (ROI) in moving image sequences, the You Only Look Once V3 deep learning method is used to track the nostril ROI from the recorded facial image sequences. The performance of the deep learning model is analyzed through experiments. The average temperature of the nostril ROI of the tracked image is calculated, and the temperature change value of the continuous image series can be obtained. The temperature change curve reflects the respiratory process. A Butterworth low-pass filter is used to filter the continuous temperature value to obtain robust respiratory signals, to improve the signal-noise ratio. Last, the respiratory rate is calculated by time-domain and frequency-domain methods. RR is calculated in different conditions, such as normal respiration, fast respiration, and slow respiration. Through the training, the training accuracy of the model reaches 97.9%. Experimental results show that the method can achieve high precision, and the maximum error is not more than 2%. Those indicate the proposed method can effectively measure the RR. Therefore, the proposed non-contact RR measurement method can be a useful reference for clinical RR measurement and other applications.

Tungsten is considered as the potential plasma facing material in future fusion reactors due to its high melting point, low sputtering, and low fuel retention, and is already used as the baseline material for divertors in some Tokamak devices. The emissivity of tungsten is low and varies with the target temperature, surface state, and wavelength, etc. Therefore, it is indispensable to obtain the emissivity characteristics of tungsten for accurate temperature measurement in the Tokamak devices. In this work, the emissivity measurement system using a single-wavelength infrared thermometer with the same operating conditions as Tokamak devices is constructed and the normal spectral emissivity of tungsten between 170 and 500 °C is measured. The measurement results indicate that the normal spectral emissivity of tungsten ranges from 0.0880 to 0.1291 between 170 and 500 °C with the wavelength of 10.2 μm, and the emissivity increases with the increase of temperature. Meanwhile, the uncertainty of emissivity measurement results is estimated, which ranges from 0.0064 to 0.0125. Besides tungsten, the proposed emissivity method can also be applied to measure the emissivity of other first wall materials such as molybdenum, etc. This work provides a useful reference for accurate temperature measurement of the first wall in nuclear fusion devices.

Objective To examine the relation between neuroticism and fatigue in Chinese patients with stroke. Design Cross-sectional study. Setting Acute stroke unit. Participants Survivors of ischemic stroke (N=191) recruited from the acute stroke unit between May 1, 2010, and September 1, 2011. Interventions Not applicable. Main Outcome Measures The personality trait of neuroticism was measured with the neuroticism subscale of the Chinese version of the NEO Five-Factor Inventory. The level of fatigue was measured with the Fatigue Assessment Scale. The National Institutes of Health Stroke Scale, Geriatric Depression Scale, Barthel Index, and Mini-Mental State Examination were administered to obtain demographic and clinical information. Results Fatigue severity 3 months after stroke positively correlated with Geriatric Depression Scale and NEO Five-Factor Inventory neuroticism scores and negatively correlated with the Barthel Index score. Conclusions Neuroticism, independent of depressive symptoms, is a predictor of fatigue severity 3 months after stroke. Interventions such as psychological screening programs are warranted for early detection of patients at high risk of poststroke depression.

BACKGROUND: Previous studies found enlarged striatum and white matter in those with stimulants use disorders. Whether primarily ketamine users (Primarily-K) and ketamine users who co-used stimulants and other substances (K+PolyS) have abnormal brain volumes is unknown. This study aims to evaluate possible brain structural abnormalities, cognitive function and depressive symptoms, between Primarily-K and K+PolyS users. METHODS: Striatal and white matter volumes were automatically segmented in 39 Primarily-K users, 41 K+PolyS users and 46 non-drug users (ND). Cognitive performance in 7 neurocognitive domains and depressive symptoms were also evaluated. RESULTS: Ketamine users had larger caudates than ND-controls (Right: 1-way-ANCOVA-p=0.035; K+PolyS vs. ND, p =0.030; Linear trend for K+PolyS>Primarily-K>ND, p=0.011; Left: 1-way-ANCOVA-p=0.047, Primarily-K vs. ND p=0.051) and larger total white matter (1-way ANCOVA-p=0.009, Poly+K vs. Primarily-K, p=0.05; Poly+K vs. ND p=0.011; Linear trend for K+PolyS>Primarily-K >ND, p=0.004). Across all ketamine users, they performed poorer on Arithmetic, learning and memory tasks, and were more depressed than Non-users (p

Both ketamine and methamphetamine (MA) have become very popular and have been abused worldwide over the past two decades. However, the relationship between dependence on ketamine or MA and psychiatric comorbidities is still unclear. This study aimed to examine the frequency of co-morbid psychiatric disorders in patients dependent on ketamine or methamphetamine who were receiving treatment at three substance abuse treatment clinics (SACs) in Hong Kong. This was a retrospective chart review. The medical records of 183 patients (103 with ketamine and 80 with MA dependence) treated between January 2008 and August 2012 were retrieved. Patients’ demographic data, patterns of substance abuse and comorbid psychiatric diagnoses were recorded. The mean age of onset and duration of substance abuse were 18.1 ± 4.7 and 9.2 ± 6.2 years for ketamine and 19.9 ± 8.8 and 10.5 ± 9.8 years for MA users, respectively. Psychotic disorders were more common in MA dependent users (76.2 % vs. 28.2 %, p < 0.001), whereas mood disorders were more common in ketamine dependent users (27.2 % vs. 11.2 %, p = 0.008). Ketamine and MA dependence have a notably different profile of psychiatric co-morbidity. Compared with MA dependence, ketamine dependence is more likely to be associated with mood disorders and less likely with psychotic disorders.

Zolpidem/zopiclone (Z-drugs) and benzodiazepines (BDZs) have different profiles of comorbidity, but studies have seldom explored these differences. This study examined psychiatric comorbidity in patients dependent on Z-drugs or BDZs attending substance abuse clinics in Hong Kong. In this retrospective chart review, the medical records of 207 patients (117 on Z-drugs and 90 on BDZs) treated between January 2008 and August 2012 were analysed. Demographic data, patterns of substance misuse and comorbid psychiatric diagnoses were recorded. Patients dependent on Z-drugs were younger (40.5 ± 10.4 vs. 46.8 ± 11.6; p

Aggression and agitation are common after a stroke. The association between agitation/aggression following stroke and Health-Related Quality of Life (HRQoL) in stroke survivors is unknown. This study aimed to examine the association between agitation/aggression and HRQoL in Chinese stroke survivors.Three hundred and twenty-four stroke patients entered this cross-sectional study. Agitation/aggression was assessed using the Chinese version of Neuropsychiatric Inventory (CNPI). HRQoL was measured with the Stroke Specific Quality of Life (SSQoL).Three months after the index stroke, agitation/aggression was found in 60 (18.5%) patients. In the agitation/aggression group, 44 patients (73.3%) showed passive agitation/aggression, whereas 16 (26.7%) displayed passive and active agitation/aggression. No patients showed only active agitation/aggression. Patients with agitation/aggression were more likely to have history of diabetes and greater severity of depression, as well as lower SSQoL total score and Personality Changes and Social Role scores. Controlling for diabetes and depression severity did not alter the above results. The Energy and Thinking scores of the SSQoL were significantly lower in the passive/active agitation/aggression group relative to the passive agitation/aggression group (adjusted for CNPI aggression/agitation score).In this study sample, agitation/aggression was preponderantly of the passive type and was associated with poorer HRQoL independently from depression or medical conditions. Patients with both passive and active agitation/aggression had lower Quality of Life (QoL) than patients with only passive agitation/aggression. The causality of the association between low QoL and agitation/aggression needs to be explored in future studies.

HIV-infected individuals (HIV+) have 2-3 times higher prevalence of tobacco smoking than the general U.S. population. This study aims to evaluate the independent and combined effects of tobacco-smoking and HIV-infection on brain microstructure and cognition using a 2 × 2 design. 21 HIV + Smokers, 25 HIV + Nonsmokers, 25 Seronegative (SN)-Smokers and 23 SN-Nonsmokers were evaluated using diffusion tensor imaging. Fractional anisotropy (FA), mean (MD), radial (RD) and axial (AD) diffusivity were assessed in 8 major cerebral fiber tracts and 5 subcortical regions. Cognitive performance in 7 neurocognitive domains was also assessed. Compared to SN, HIV+ had higher AD in genu of corpus callosum (GCC, p = 0.002). Smokers also had higher diffusivities in GCC, splenium of corpus callosum (SCC), anterior corona radiata (ACR), sagittal stratum (SS) and superior fronto-occipital fasciculus (SFO), than Nonsmokers (p-values0.001-0.003). Tobacco-Smoking and HIV-infection showed synergistic effects on AD_SS (p = 0.002) and RD_SFO (p = 0.02), but opposite effects in FA_putamen (p = 0.024). Additive effects from HIV+ and Tobacco-Smoking were observed in 9 other white matter tracts, with highest diffusivities and lowest FA in HIV + Smokers. Higher diffusivities in the GCC, SCC, ACR and SS predicted poorer cognitive performance across all participants (p ≤ 0.001). Higher AD_GCC also predicted slower Speed of information processing and poorer Fluency and Attention only in HIV + Smokers (p = 0.001-0.003). Chronic tobacco smoking and HIV-infection appear to have additive and synergistic adverse effects on brain diffusivities, suggesting greater neuroinflammation, which may contribute to poorer cognition. Therefore, chronic tobacco-smoking may be a risk factor for HIV-associated neurocognitive disorders. Graphical Abstract ᅟ.

Background No study has examined ketamine users’ psychiatric morbidity using structured diagnostic instruments. The aim of this study was thus to determine the psychiatric comorbidity of community-based ketamine users using the Structured Clinical Interview for DSM-IV ( Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), Axis I Disorders (SCID). Methods A convenience sample of 200 frequent ketamine users was recruited from community organizations in Hong Kong. Participants were screened with the Severity of Dependence Scale (SDS), Beck Depression Inventory (BDI), Anxiety subscale of the Hospital Anxiety Depression Scale (HADSA), and SCID psychotic symptoms. Those who scored above the threshold (cutoff point of 8/9 on the BDI and 4/5 on HADSA) or displayed evidence of psychotic symptoms were referred for a structured clinical interview conducted by a psychiatrist. Results One hundred and seventy participants scored above the cutoff point on 1 or more of the scales, and 115 participants attended the SCID interview. Fifty-one of these 115 participants received a psychiatric diagnosis of 1 or more comorbidities for the month preceding the interview. Mood disorders accounted for 80.4% of the diagnoses, anxiety disorders for 33.3%, and psychotic disorders for 7.8%. Conclusions Female gender and history of psychiatric/psychological clinic attendance were significantly associated with comorbid psychiatric disorders, whereas ketamine dependence had a borderline association.

Background Ketamine abuse causes cognitive impairments, which negatively impact on users’ abstinence, prognosis, and quality of life. Results of cognitive impairments in chronic ketamine users have been inconsistent across studies, possibly due to the small sample sizes and the confounding effects of concomitant use of other illicit drugs. This study investigated the cognitive impairment and its related factors in chronic ketamine users with a large sample size and explored the impact of another drug use on cognitive functions. Methods Cognitive functions, including working, verbal and visual memory and executive functions were assessed in ketamine users: 286 non-heavy other drug users and 279 heavy other drug users, and 261 healthy controls. Correlations between cognitive impairment and patterns of ketamine use were analysed. Results Verbal and visual memory were impaired, but working memory and executive functions were intact for all ketamine users. No significant cognitive differences were found between the two ketamine groups. Greater number of days of ketamine use in the past month was associated with worse visual memory performance in non-heavy other drug users. Higher dose of ketamine use was associated with worse short-term verbal memory in heavy other drug users. Conclusion Verbal and visual memory are impaired in chronic ketamine users. Other drug use appears to have no impact on ketamine users’ cognitive performance.

Background and Purpose— Cerebral microbleeds (CMBs) are common in stroke survivors and community-dwelling elderly. The clinical significance of CMBs in the outcome of poststroke depression (PSD) is unknown. This study examined the association between the 1-year outcome of PSD and CMBs. Methods— The study population comprised 774 Chinese patients with acute ischemic stroke who were admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong. Three and 15 months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a Geriatric Depression Scale score of ≥7. Of the 213 patients with PSD at the 3-month follow-up, 135 (63.4%) attended the 15-month follow-up, at which time 89 (65.9%) patients remained depressed (nonremitters), and 46 (34.1%) had recovered (remitters). The presence and location of CMBs were evaluated with magnetic resonance imaging. Results— In comparison with the remitters, nonremitters were more likely to have lobar CMBs (18.4% versus 4.3%; P =0.024). Lobar CMBs remained an independent predictor of PSD in the multivariate analysis, with an odds ratio of 4.96 ( P =0.039). Conclusions— The results suggest that lobar CMBs may influence the outcome of PSD. The importance of CMBs in the clinical course of depression in stroke survivors warrants further investigation.

Cognitive impairment has been found to be reversible in people with substance abuse, particularly those using ketamine. Ketamine users are often poly-substance users. This study compared the cognitive functions of current and former ketamine users who were also abusing other psychoactive substances with those of non-users of illicit drugs as controls.One hundred ketamine poly-drug users and 100 controls were recruited. Drug users were divided into current (n = 32) and ex-users (n = 64) according to the duration of abstinence from ketamine (30 days). The Beck Depression Inventory (BDI), the Hospital Anxiety Depression Scale (HADSA) and the Severity of Dependence Scale (SDS) were used to evaluate depression and anxiety symptoms and the severity of drug use, respectively. The cognitive test battery comprised verbal memory (Wechsler Memory Scale III: Logic Memory and Word List), visual memory (Rey-Osterrieth Complex Figure, ROCF), executive function (Stroop, Wisconsin Card Sorting Test, and Modified Verbal Fluency Test), working memory (Digit Span Backward), and general intelligence (Information, Arithmetic and Digit-Symbol Coding) tests.Current users had higher BDI and HADSA scores than ex-users (p0.001 for BDI and p = 0.022 for HADSA) and controls (p0.001 for BDI and p = 0.002 for HADSA). Ex-users had higher BDI (p = 0.006) but equal HADSA scores (p = 1.000) compared to controls. Both current and ex-users had lower scores on Logical Memory delayed recall (p = 0.038 for current users and p = 0.032 for ex-users) and ROCF delayed recall (p = 0.033 for current users and p = 0.014 for ex-users) than controls. Current users also performed worse on ROCF recognition than controls (p = 0.002). No difference was found between the cognitive functions of current and ex-users.Ketamine poly-drug users displayed predominantly verbal and visual memory impairments, which persisted in ex-users. The interactive effect of ketamine and poly-drug use on memory needs further investigation.

Both cognitive impairment and depressive symptoms have been reported in ketamine users. However, no previous study has examined the relationship between them. This study aimed to examine cognitive functions and depressive symptoms and their relationship in young ketamine users in Hong Kong.Fifty-one current ketamine users, 49 ex-ketamine users, and 100 healthy controls were recruited from counseling and youth centers in Hong Kong in this cross-sectional study. Cognitive assessment included mental and motor speed; working, verbal, and visual memory; and executive functions. Depressive symptoms were measured using the Beck Depression Inventory. One-way analyses of covariance (ANCOVA) and chi-square tests were used to analyze participants' demographic data, patterns of drug use, Beck Depression Inventory score, and performance in a cognitive battery. Cognitive functions were adjusted for age, gender, and education using ANCOVA. Correlations between the Beck Depression Inventory score and cognitive functions were examined using Pearson's correlation coefficient.Cognitive impairment was found only in current ketamine users in the domains of mental and motor speed (p.001), visual and verbal memory (p.001), and executive functions (p.001). Depressive symptoms were also more frequently found in current ketamine users (p.001). Correlations between depressive symptoms and certain cognitive scores were statistically significant but modest.Current ketamine use is associated with cognitive impairment. Illicit substance treatment and rehabilitation services should pay attention to ketamine's cognitive effects and motivate their clients to quit using ketamine and stay abstinent.

Aim High serum bilirubin predicts depression in non-stroke subjects, but it is unknown whether it also predicts post-stroke depression (PSD). This study examined the association between the risk of PSD and bilirubin level. Methods Six hundred and thirty-five patients with acute ischemic stroke in Hong Kong were recruited. Serum total bilirubin, alanine transaminase and alkaline phosphatase levels were measured in all patients during their hospital stay. A psychiatrist gave the Structured Clinical Interview for DSM-IV to all patients 3 months after the index stroke, with 61 patients diagnosed with PSD: 27 with major depression, 24 with minor depression and 10 with dysthymia. Results In the full sample, the 25%, 50% and 75% percentile bilirubin levels were 7.0, 10.0 and 14.0 μmol/L, respectively. Significant differences were found between the PSD and non-PSD groups in terms of bilirubin level (P = 0.006). In post-hoc comparisons, the proportion of patients with bilirubin ≥14.1 μmol/L was significantly higher in the PSD group (37.7% vs 19.7%, P = 0.001). In the final regression model, bilirubin level (≥14.1 μmol/L) remained a significant independent predictor of PSD, with an odds ratio of 2.4. Conclusions High bilirubin level is associated with PSD. Further investigations are needed to clarify the underlying pathophysiological link between bilirubin level and PSD.

Objective The caudate nucleus may be involved in the pathogenesis of the fatigue observed in neurological disorders. However, the significance of caudate lesions in poststroke fatigue (PSF) is unknown. This study examined the association between caudate infarcts and PSF. Methods Five hundred Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. All participants were assessed for PSF with the Fatigue Severity Scale (FSS) three months after their index stroke. PSF was defined as a mean FSS score of 4.0 or more. Physical functioning and depressive symptoms were measured by the Barthel Index (BI) and the Geriatric Depression Scale (GDS). Results One hundred and twenty-five (25.0%) of the patients had PSF. Compared to the non-fatigue group, the PSF patients were more likely to be women and had hyperlipidemia, lower BI and higher GDS scores. Caudate (8.0% versus 1.3%, p = 0.001) and putamen (19.2% versus 12.0%, p = 0.043) acute infarcts were more common in the PSF group, whereas pons infarcts (13.6% versus 22.2%, p = 0.038) were less common. Acute caudate infarcts remained an independent predictor of PSF in the multivariate analysis, with an odds ratio of 6.4. Conclusions The results suggest that patients with PSF are more likely to have caudate infarcts.

The serotonin receptor 2C (HTR2C) gene has been shown to play a pivotal role in major depression. We examined the association between post-stroke depression (PSD) and polymorphism in HTR2C. A cohort of 223 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a geriatric depression scale score of 7 or above. Possible confounding factors, including previous history of stroke, severity of stroke, level of social support, and recent life events, were investigated. All patients were genotyped for polymorphisms of HTR2C. Separate analyses were performed for males and females. Sixty-one patients were found to have PSD. There were significant associations between the HTR2C gene and PSD status in the male patients, but not in the female ones. After adjusting for possible confounders, the rs12837651 T allele (odds ratio = 4.020) and the rs2192371 G allele (odds ratio = 2.866) were found to be significantly associated with PSD in males. Genetic variation in HTR2C receptors appears to be involved in the pathogenesis of PSD in Chinese males.

Stroke is the leading cause of chronic disability. Many people who survive a cerebrovascular accident live with the chronic and disabling consequences. Stroke survivors commonly report a low sense of well-being caused by restricted physical functions and the general psychological sequelae of disability coupled with a variety of specific neuropsychiatric complications.

© 2015 Tang et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated, Background: Both apathy and suicide are common in poststroke patients. However, the association between poststroke apathy and suicide-related ideation (SI) in Chinese stroke patients is not clear and poorly understood. The aim of this study was to examine the association between apathy and SI in stroke. Methods: A cross-sectional study was conducted to investigate the association in 518 stroke survivors from Acute Stroke Unit of the Prince of Wales Hospital in Hong Kong. Geriatric Mental State Examination-Version A (GMS) and Neuropsychiatric Inventory-apathy subscale (NPI-apathy) were employed to assess poststroke SI and apathy, respectively. Patients' clinical characteristics were obtained with the following scales: the National Institutes of Health Stroke Scale (NIHSS), the Mini-Mental State Examination (MMSE), and the Geriatric Depression Scale (GDS). Results: Thirty-two (6.2%) stroke survivors reported SI. The SI group had a significantly higher frequency of NPI-apathy than the non-SI group (31.2% vs 5.3%, p < 0.001). The SI group also had higher GDS scores (10.47 ± 3.17 vs 4.24 ± 3.71, p < 0.001). Regression analysis revealed that NPI-apathy (OR 2.955, 95% CI 1.142-7.647, p = 0.025) was a significant predictor of SI. The GDS score also predicted SI (OR 1.436, 95% CI 1.284-1.606, p < 0.001). Conclusions: The current findings show that poststroke apathy is an independent predictor of SI 3 months after stroke. Early screening for and intervention targeting apathy through medication and psychological treatments may be necessary to improve stroke patients' apathy and reduce SI., This project is supported by the Health and Medical Research Fund, grant reference number is 01120376.

Tang W-K, Lu J-Y, Liang H, Chan T-T, Mok V, Ungvari GS, Wong K-S. Is insomnia associated with suicidality in stroke? Objective To evaluate the relationship between insomnia and suicidality (SI) in Chinese patients with first or recurrent stroke. Design Cross-sectional survey. Setting Acute stroke unit of a general hospital. Participants Patients (N=787) with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong. Interventions Not applicable. Main Outcome Measures Suicidality (SI) was assessed with the Geriatric Mental State Examination at 3 months after subjects' index stroke. Insomnia symptoms were evaluated with a standard insomnia questionnaire. The association between insomnia symptoms and SI was examined and adjusted for potential confounders, including age, sex, marital status, previous stroke, depression, fatigue, Mini-Mental State Examination score, and neurologic deficits measured with the National Institutes of Health Stroke Scale. Results Eighty-seven patients (11.1%) were found to have SI (SI group). Frequent awakening was significantly more common in the SI group than in the non-SI group and remained a significant predictor of SI in forward logistic regression analysis (odds ratio, 1.7) after adjusting for possible confounders. Conclusions These findings should alert clinicians to the potential danger of insomnia and the importance of its early identification and treatment in stroke patients.

The present study aimed to explore the possible difference in plasma neuropeptide Y (NPY) level between patients with primary insomnia and healthy normal sleepers. The sample comprised 42 patients with primary insomnia and 38 age- and sex-matched healthy controls. Clinical measures, including the Pittsburgh Sleep Quality Index (PSQI), State-Trait Anxiety Inventory (STAI), and Beck Depression Inventory (revised edition, BDI-R), were recorded, respectively. Morning fasting plasma NPY levels of all participants were determined by using enzyme-linked immunosorbent assay (ELISA). Student’s t-test or chi-square test was used to compare the differences in demographic and clinical factors and scores of psychometric assessments between groups. Bivariate correlation test was used to analyze the relationship between NPY level and factors, such as age, body mass index (BMI), PSQI, STAI, and BDI-R score. Analysis of covariance (ANCOVA) was used to study the difference of plasma NPY level between two groups with adjustment for age, sex, BMI, STAI, and BDI-R total score. We found that morning plasma NPY levels in patients with primary insomnia were significantly lower than those in the normal controls (5.11 ± 2.87 vs. 7.01 ± 3.44 ng/ml, p = 0.009). The difference in plasma NPY level persisted even after adjustment for age, sex, BMI, STAI, and BDI-R total score (p = 0.026). For all subjects, plasma NPY level was found decreasing significantly with age (r = −0.232, p = 0.038). In addition, there was a trend that plasma NPY level was negatively associated with PSQI total score (r = −0.209, p = 0.063). Our findings suggest that NPY system may involve in the pathophysiological process of primary insomnia. Further studies are warranted to determine the causal relationship between low plasma NPY level and primary insomnia disorder.

Background: Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance in which patients enact their dreams while in REM sleep. The behavior is typically violent in association with violent dream content, so serious harm can be done to the patient or the bed partner. The prevalence of RBD is well-known in Parkinson's disease, Lewy body dementia, and multiple systems atrophy. However, its prevalence and causes in stroke remained unclear. The aim of this study was to determine factors influencing the appearance of RBD in a prospective cohort of patients with acute ischemic stroke. Methods: A total of 2,024 patients with first-ever or recurrent acute ischemic stroke were admitted to the Acute Stroke Unit at the Prince of Wales Hospital between January 2010 and November 2011; 775 of them received an MRI scan. Within 2~days of admission, a research nurse collected demographic and clinical data and assessed the severity of each stroke using the National Institute of Health Stroke Scale (NIHSS). One hundred and nineteen of the 775 patients meeting study entry criteria formed the study sample. All eligible participants were invited to attend a research clinic 3~months after the onset of the index stroke. In the attendance, a research assistant administered the MMSE and the 13-item RBD questionnaire (RBDQ). Results: Among 119 stroke patients, 10.9\% were exhibited RBD, defined as an REM sleep behavior disorder questionnaire score of 19 or above. The proportion of patients with acute brainstem infarct was significantly higher in RBD patients than those without RBD. Compared with patients without RBD, RBD patients were more likely to have brainstem infarcts and had smaller infarct volumes. In a multivariate analysis, in which stroke location and infarct volume were inserted, brainstem infarcts were an independent predictor of RBD (odds ratio = 3.686; P = 0.032). Conclusions: The results support the notion of a predominant role of brainstem injury in the development of RBD and suggest that patients with brainstem infarcts RBD should be evaluated by a clinical neurologist. \copyright 2014 Tang et al.; licensee BioMed Central Ltd.

One hundred primary ketamine users and 100 controls were recruited in Hong Kong between December 2009 and December 2011. Cognitive assessment included general intelligence, working, verbal, and visual memory, and executive functions. A Univariate General Linear Model was used to compare cognitive performance between the male and female ketamine users and controls. The female users appeared to have a higher risk of visual memory impairment than their male counterparts. Further studies are warranted to clarify the mechanism of the sex-specific effect of ketamine on cognitive functions.

Background: Apathy is common in stroke survivors. Unlike poststroke depression, apathy after stroke has not been extensively investigated and the significance of the location of infarcts in the development of apathy following a stroke is unknown. This study examined the association between poststroke apathy (PSA) and the location of infarcts. Methods: A cohort of 185 patients with acute ischemic stroke admitted to the Stroke Unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a psychiatrist administered the Apathy Evaluation Scale (AES). PSA was defined as an AES score of 37 or above. The presence and location of infarcts were evaluated with magnetic resonance imaging. Results: Altogether 185 patients met the entry criteria and formed the study sample; 20 (10.8%) had PSA. PSA patients were older and had higher stroke severity and more depressive symptoms. The PSA group also had lower levels of physical and cognitive functioning. Compared with the non-PSA group, PSA patients were more likely to have acute pontine infarcts (35.0% vs. 11.5%; p = 0.011). They had a higher mean number (0.5 ± 0.7 vs. 0.1 ± 0.3; p = 0.003) and larger volume (0.6 ± 1.4 vs. 0.1 ± 0.3 ml; p = 0.002) of acute pontine infarcts. Six variables were entered into the predictive regression model: age, the presence, number and volume of acute pontine infarcts, the number of old infarcts and periventricular white matter hyperintensities scores. The volume of infarcts remained an independent predictor of PSA in the multivariate analysis, with an odds ratio of 3.9 (p = 0.007). The Geriatric Depression Scale, National Institutes of Health Stroke Scale, Barthel Index and Mini-Mental State Examination scores were also entered into the subsequent associative regression model; the volume of acute pontine infarcts remained a significant predictor (odds ratio = 3.8). Conclusions: This is the first report of an association between pontine infarcts and the risk of PSA. The results suggest that pontine infarcts may play a role in the development of PSA. The importance of acute pontine infarcts in the pathogenesis of PSA warrants further investigation.

White matter hyperintensities (WMH) are common in stroke. The influence of WMH on health-related quality of life (HRQoL) following a lacunar stroke is unknown. This study evaluated the impact of WMH on HRQoL in acute lacunar stroke. A cohort of 160 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a research assistant administered the Short Form-36 (SF-36) to assess HRQoL. The severity of WMH was evaluated with magnetic resonance imaging (MRI). In univariate analysis, the severity of deep WMH (DWMH) negatively correlated with patients' vitality (VT; p < 0.05), social function (SF; p < 0.001), role-emotional (RE; p < 0.01), mental health (MH; p < 0.01), and mental component summary (MCS; p < 0.001) scores of HRQoL. DWMH was independently associated with all of the above five SF-36 scores (p < 0.05) in linear regression analysis. These findings suggest that DWMH has a significant impact on the HRQoL of stroke survivors. The importance of DWMH in the long-term HRQoL in lacunar stroke warrants further investigation.

Objective To evaluate the relation between poststroke pain and suicidality (SI) in Chinese patients with first or recurrent stroke. Design Cross-sectional survey. Setting Acute stroke unit of a university-affiliated general hospital. Participants Patients (N=496) with acute ischemic stroke admitted to the Acute Stroke Unit. Interventions Not applicable. Main Outcome Measures Patients were interviewed 3 months after the index stroke. SI was assessed with the Geriatric Mental State Examination. Pain was evaluated with the Faces Pain Rating Scale-Revised (FPS-R). The association between FPS-R scores and SI was examined and adjusted for potential confounders, including marital status, depression, neurologic deficits assessed by the National Institute of Health Stroke Scale, and functioning measured by the Barthel Index. Results Thirty-seven (7.5%) of the patients had SI (the SI group). Compared with the non-SI group, patients in the SI group were more likely to experience pain (59.5% vs 37.7%), had a higher mean FPS-R score (6.0±2.5 vs 4.5±2.3), and had an FPS-R score of >4 (43.2% vs 15.9%). After adjustment for possible confounders, the FPS-R score of >4 (odds ratio=2.9) remained a significant predictor of SI in the subsequent forward logistic regression models. Conclusions These findings should alert clinicians that the early identification and treatment of pain may reduce suicide risk in patients with stroke.

Objective Cerebral microbleeds (CMBs) are common in stroke survivors. The clinical significance of CMBs in the development of suicidality (SI) following stroke is unknown. This study examined the association between SI and CMBs. The aim of the study reported here was to determine the relationship between CMBs and SI in ischemic stroke survivors. Methods: A cohort of 367 patients with acute ischemic stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. SI was assessed with the Geriatric Mental State Examination at three months following the subjects' index stroke. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS). A qualified psychiatrist administered the Chinese version of the Structured Clinical Interview for DSM-IV to diagnose depressive disorders. The presence and location of CMBs were evaluated with magnetic resonance imaging (MRI). Results Compared with the non-SI patients, SI patients were more likely to have CMBs in any brain region (36.6% vs. 20.2%, p=0.017), specifically more lobar (29.3% vs. 13.5%, p=0.008) and thalamic CMBs (19.5% vs. 7.5%, p=0.018). Presence of CMBs (odds ratio was 2.5, p=0.026) and lobar CMBs (odds ratio 2.6, p=0.034) were independent predictors of SI in the multivariate analysis. Conclusions The results suggest that lobar CMBs may play roles in the development of SI. The importance of CMBs in the pathogenesis of SI in stroke survivors warrants further investigation.

Background and Purpose— This study examined the association between poststroke anxiety symptoms (PSA) and frontal lobe infarcts. Methods— A cohort of 693 patients was recruited. PSA was defined as an anxiety subscale of the Hospital Anxiety and Depression Scale score of 8 or above. The presence and location of infarcts were evaluated with MRI. Results— Compared with the non-PSA group, PSA patients were more likely to have right frontal acute infarcts. Right frontal infarcts remained independent predictors of PSA in the multivariate analysis, with an odds ratio of 4.44 ( P =0.002). Conclusions— The results suggest that right frontal acute infarcts may play a role in the development of PSA.