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1.
J Geriatr Psychiatry Neurol ; 32(2): 68-73, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30630388

RESUMEN

BACKGROUND: We aimed to examine the discriminant validity of a brief self-administered cognitive screening test, the Test Your Memory (TYM) and a brief neuropsychological test, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), supplemented with executive and language tests (Color Trail Test [CTT] and modified Boston Naming Test [mBNT], respectively), in detecting cognitive impairment (CI) in a one-stop memory clinic in Singapore. METHODS: Ninety patients ≥50 years old with a diagnosis of no cognitive impairment, mild cognitive impairment, and mild Alzheimer disease were recruited from memory clinic. They received the TYM, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), RBANS, CTT, mBNT, and a gold-standard formal neuropsychological test battery. RESULTS: The TYM had a significantly larger area under the curve (AUC) than MMSE (0.96 vs 0.88, P = .03) and was equivalent to MoCA in detecting CI (0.96 vs 0.95, P = .80). At the optimal cutoff points, the TYM (<38) was significantly more sensitive than the MMSE (<24) and MoCA (<20; P < .001). The RBANS had an AUC equivalent to the RBANS supplemented with CTT and mBNT (0.92 vs 0.86, P = .22) in detecting CI. The RBANS supplemented with CTT and mBNT was more sensitive than RBANS alone in detecting CI (sensitivity: 0.98 vs 0.93, P = .016) among patients screened negative using TYM. CONCLUSION: The self-administered TYM is superior to MMSE and equivalent to MoCA in detecting CI and could be implemented routinely. The RBANS supplemented with CTT and mBNT is more sensitive in detecting CI than RBANS alone therefore could be used for diagnostic purposes.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Evaluación Geriátrica/métodos , Trastornos de la Memoria/diagnóstico , Pruebas Neuropsicológicas/normas , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/psicología , Disfunción Cognitiva/complicaciones , Disfunción Cognitiva/psicología , Femenino , Evaluación Geriátrica/estadística & datos numéricos , Humanos , Masculino , Memoria , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Proyectos Piloto , Valor Predictivo de las Pruebas , Singapur
2.
Cereb Cortex ; 27(1): 602-615, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-26503264

RESUMEN

Despite convergent evidence indicating a variety of regional abnormalities of hemispheric asymmetry in schizophrenia, patterns of wider neural network asymmetry remain to be determined. In this study, we investigated alterations in hemispheric white matter topology in schizophrenia and their association with clinical manifestations of the illness. Weighted hemispheric brain anatomical networks were constructed for each of 116 right-handed patients with schizophrenia and 66 matched healthy participants. Graph theoretical approaches were then employed to estimate the hemispheric topological properties. We found that although small-world properties were preserved in the hemispheric network, a significant hemispheric-independent deficit of global integration was found in schizophrenia. Furthermore, a significant group-by-hemisphere interaction was revealed in the characteristic path length and global efficiency, attributing to significantly reduced hemispheric asymmetry of global integration in patients compared with healthy controls. Specifically, we found reduced asymmetric nodal efficiency in several frontal regions and the hippocampus. Finally, the abnormal hemispheric asymmetry of brain anatomical network topology was associated with clinical features (duration of illness and psychotic psychopathology) in patients. Our findings provide new insights into lateralized nature of hemispheric dysconnectivity and highlight the potential for using brain network measures of hemispheric asymmetry as neural biomarkers for schizophrenia and its clinical features.


Asunto(s)
Encéfalo/diagnóstico por imagen , Lateralidad Funcional , Esquizofrenia/diagnóstico por imagen , Adolescente , Adulto , Conectoma , Imagen de Difusión Tensora , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/diagnóstico por imagen , Esquizofrenia/tratamiento farmacológico , Adulto Joven
3.
Hum Brain Mapp ; 38(4): 2008-2025, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28032370

RESUMEN

Convergent evidences have revealed that schizophrenia is associated with brain dysconnectivity, which leads to abnormal network organization. However, discrepancies were apparent between the structural connectivity (SC) and functional connectivity (FC) studies, and the relationship between structural and functional deficits in schizophrenia remains largely unknown. In this study, resting-state functional magnetic resonance imaging and structural diffusion tensor imaging were performed in 20 patients with schizophrenia and 20 matched healthy volunteers (patients/controls = 19/17 after head motion rejection). Functional and structural brain networks were obtained for each participant. Graph theoretical approaches were employed to parcellate the FC networks into functional modules. The relationships between the entries of SC and FC were estimated within each module to identify group differences and their correlations with clinical symptoms. Although five common functional modules (including the default mode, occipital, subcortical, frontoparietal, and central modules) were identified in both groups, the patients showed a significantly reduced modularity in comparison with healthy participants. Furthermore, we found that schizophrenia-related aberrations of SC-FC coupling exhibited complex patterns among modules. Compared with controls, patients showed an increased SC-FC coupling in the default mode and the central modules. Moreover, significant SC-FC decoupling was demonstrated in the occipital and the subcortical modules, which was associated with longer duration of illness and more severe clinical manifestations of schizophrenia. Taken together, these findings demonstrated that altered module-dependent SC-FC coupling may underlie abnormal brain function and clinical symptoms observed in schizophrenia and highlighted the potential for using new multimodal neuroimaging biomarkers for diagnosis and severity evaluation of schizophrenia. Hum Brain Mapp 38:2008-2025, 2017. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Conectoma , Vías Nerviosas/fisiopatología , Esquizofrenia/patología , Esquizofrenia/fisiopatología , Adulto , Imagen de Difusión Tensora , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/diagnóstico por imagen , Oxígeno/sangre , Escalas de Valoración Psiquiátrica , Esquizofrenia/diagnóstico por imagen , Adulto Joven
4.
Stroke ; 46(10): 2808-14, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26330446

RESUMEN

BACKGROUND AND PURPOSE: The present study sought to examine the association between the burden of cerebrovascular disease (CeVD) as assessed by multimodal magnetic resonance imaging and neurocognitive function. METHODS: Cognitively impaired patients and controls were tested on an extensive neuropsychological battery and underwent multimodal brain magnetic resonance imaging. CeVD markers determined from magnetic resonance imaging included the presence of multiple lacunes, multiple cerebral microbleeds, and moderate or severe white matter hyperintensities as markers for small-vessel disease and cortical stroke and intracranial stenosis as markers for large-vessel disease. A weighted CeVD burden score was constructed, and its association with global and domain-specific cognitive performance was investigated. RESULTS: A total of 305 cases and 94 controls were included in the analysis. A graded association of CeVD burden with neurocognitive function was found. Moreover, a clear threshold of CeVD burden was associated with severe impairment. White matter hyperintensities was associated with global neurocognitive deficits, whereas microbleeds were associated with domain-specific impairments. CONCLUSIONS: The weighted CeVD burden score comprising markers of both small- and large-vessel diseases were associated with deficits in both global and domain-specific neurocognitive function. Additional studies are needed to validate the use of this CeVD burden score for the prediction of dementia.


Asunto(s)
Trastornos Cerebrovasculares/complicaciones , Trastornos Cerebrovasculares/patología , Trastornos del Conocimiento/etiología , Neuroimagen/métodos , Anciano , Estudios de Casos y Controles , Trastornos del Conocimiento/patología , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas
5.
Dement Geriatr Cogn Disord ; 39(3-4): 176-85, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25572449

RESUMEN

BACKGROUND: The Montreal Cognitive Assessment (MoCA) was developed as a screening instrument for mild cognitive impairment (MCI). We evaluated the MoCA's test performance by educational groups among older Singaporean Chinese adults. METHOD: The MoCA and Mini-Mental State Examination (MMSE) were evaluated in two independent studies (clinic-based sample and community-based sample) of MCI and normal cognition (NC) controls, using receiver operating characteristic curve analyses: area under the curve (AUC), sensitivity (Sn), and specificity (Sp). RESULTS: The MoCA modestly discriminated MCI from NC in both study samples (AUC = 0.63 and 0.65): Sn = 0.64 and Sp = 0.36 at a cut-off of 28/29 in the clinic-based sample, and Sn = 0.65 and Sp = 0.55 at a cut-off of 22/23 in the community-based sample. The MoCA's test performance was least satisfactory in the highest (>6 years) education group: AUC = 0.50 (p = 0.98), Sn = 0.54, and Sp = 0.51 at a cut-off of 27/28. Overall, the MoCA's test performance was not better than that of the MMSE. In multivariate analyses controlling for age and gender, MCI diagnosis was associated with a <1-point decrement in MoCA score (η(2) = 0.010), but lower (1-6 years) and no education was associated with a 3- to 5-point decrement (η(2) = 0.115 and η(2) = 0.162, respectively). CONCLUSION: The MoCA's ability to discriminate MCI from NC was modest in this Chinese population, because it was far more sensitive to the effect of education than MCI diagnosis.


Asunto(s)
Disfunción Cognitiva/diagnóstico , Pruebas Neuropsicológicas , Anciano , China/etnología , Cognición , Disfunción Cognitiva/etnología , Diagnóstico Diferencial , Escolaridad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Reproducibilidad de los Resultados , Singapur/epidemiología
6.
Br J Psychiatry ; 204(1): 55-60, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24202961

RESUMEN

BACKGROUND: Abnormalities in the corpus callosum have been reported in patients with schizophrenia for over 30 years but the influence of inter-individual differences and illness characteristics remains to be fully elucidated. AIMS: To examine the influence of individual and illness characteristics on the corpus callosum in Chinese Singaporean patients with schizophrenia. METHOD: Using magnetic resonance and diffusion tensor imaging, mean corpus callosum area, volume and fractional anisotropy were investigated in 120 Chinese Singaporean patients (52 with chronic and 68 with first-episode schizophrenia) and compared with data from 75 matched healthy controls. RESULTS: Both area and volume were significantly reduced in patients relative to controls but no significant differences in corpus callosum existed between genders in either patients or controls. Differences in area and volume of the corpus callosum were greatest in patients whose condition was chronic relative to patients with a first episode and controls. Anterior callosum in patients, regardless of chronicity, was no different to that of controls. CONCLUSIONS: Morphological abnormalities in the corpus callosum may increase with illness progression.


Asunto(s)
Pueblo Asiatico/psicología , Cuerpo Calloso/patología , Esquizofrenia/patología , Adulto , Análisis de Varianza , Anisotropía , Estudios de Casos y Controles , China , Enfermedad Crónica , Imagen de Difusión Tensora , Progresión de la Enfermedad , Femenino , Lateralidad Funcional/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Tamaño de los Órganos , Escalas de Valoración Psiquiátrica , Singapur , Factores de Tiempo
7.
Int Psychogeriatr ; 26(8): 1305-16, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24787730

RESUMEN

BACKGROUND: An association between metabolic syndrome (MetS) and disturbances in neurocognitive function has been identified in Caucasians but the nature and extent of impaired cognition in Asian MetS patients, who may be at greater risk of degenerative cognitive decline, remains unspecified. METHODS: A cross-sectional study was conducted at the National University Hospital of Singapore. Participants were recruited from a diabetes clinic at the National University Hospital. Fifty-three patients who met MetS criteria and 44 clinical controls were recruited. All participants were 55 years and above and community ambulant. Neurocognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). CANTAB performances between MetS and control groups were examined with analysis of variance (ANOVA) and the relative contributions of vascular risk, and intrademographic factors on CANTAB scores were dilineated with stepwise regression analyses. RESULTS: Participants with MetS consistently performed significantly worse than controls across all CANTAB subtests. Education and Chinese race were found to be potential protective factors. CONCLUSIONS: Executive and memory impairment is present in Asian patients with midlife MetS who may be particularly vulnerable to the detrimental impact of MetS in midlife.


Asunto(s)
Trastornos del Conocimiento , Función Ejecutiva/fisiología , Trastornos de la Memoria , Síndrome Metabólico , Análisis de Varianza , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etnología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Trastornos del Conocimiento/psicología , Estudios Transversales , Escolaridad , Etnicidad , Femenino , Humanos , Masculino , Trastornos de la Memoria/diagnóstico , Trastornos de la Memoria/etnología , Trastornos de la Memoria/etiología , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/psicología , Síndrome Metabólico/complicaciones , Síndrome Metabólico/epidemiología , Síndrome Metabólico/psicología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Medición de Riesgo , Factores de Riesgo , Singapur/epidemiología , Estadística como Asunto
8.
Int Psychogeriatr ; 26(5): 787-93, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24423626

RESUMEN

BACKGROUND: The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were compared with and without the addition of a brief processing speed test, the symbol digit modalities test (SDMT), for vascular cognitive impairment (VCI) screening at three to six months after stroke. METHODS: Patients with ischemic stroke and transient ischemic attack were assessed with MoCA and MMSE, as well as a formal neuropsychological battery three to six months after stroke. VCI was defined by impairment in any cognitive domain on neuropsychological testing. The area under the receiver operating characteristic curve (AUC) was used to compare test discriminatory ability. RESULTS: One hundred and eighty-nine patients out of 327 (58%) had VCI, of whom 180 (95%) had vascular mild cognitive impairment (VaMCI), and nine (5%) had dementia. The overall AUCs of the MoCA and MMSE scores and performance at their respective cut-off points were equivalent in detecting VCI (AUCs: 0.87 (95% CI 0.83-0.91) vs. 0.84 (95% CI 0.80-0.88), p = 0.13; cut-offs: MoCA (≤23) vs. MMSE (≤26), sensitivity: 0.78 vs. 0.71; specificity: 0.80 vs. 0.82; positive predictive value: 0.84 vs. 0.84; negative predictive value: 0.72 vs. 0.67; and correctly classified 78.6% vs. 75.5%; p = 0.42). The AUCs of MMSE and MoCA were improved significantly by the SDMT (AUCs: MMSE+SDMT 0.90 (95% CI 0.87-0.93), p <0.001; MoCA+SDMT 0.91 (95% CI 0.88-0.94), p < 0.02). CONCLUSIONS: The MoCA and MMSE are equivalent and moderately sensitive, and can be supplemented with the SDMT to improve their accuracy in VCI screening.


Asunto(s)
Disfunción Cognitiva/diagnóstico , Demencia Vascular/diagnóstico , Ataque Isquémico Transitorio/complicaciones , Tamizaje Masivo , Accidente Cerebrovascular/complicaciones , Área Bajo la Curva , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/psicología , Demencia Vascular/etiología , Demencia Vascular/fisiopatología , Demencia Vascular/psicología , Femenino , Humanos , Pruebas de Inteligencia/normas , Ataque Isquémico Transitorio/fisiopatología , Ataque Isquémico Transitorio/psicología , Masculino , Tamizaje Masivo/métodos , Tamizaje Masivo/normas , Escala del Estado Mental , Persona de Mediana Edad , Pruebas Neuropsicológicas/normas , Valor Predictivo de las Pruebas , Mejoramiento de la Calidad , Curva ROC , Índice de Severidad de la Enfermedad , Singapur , Accidente Cerebrovascular/fisiopatología , Accidente Cerebrovascular/psicología , Factores de Tiempo
9.
J Neurol Neurosurg Psychiatry ; 84(11): 1219-25, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23933740

RESUMEN

OBJECTIVE: Silent lacunar infarct (SLI) is associated with cognitive decline and linked to an increased risk of stroke and dementia. We examined the association of SLI with MRI measures of cortical thickness, subcortical and lateral ventricular shapes and cognition in 285 ethnic Chinese elderly. METHODS: SLI, cortical thickness, shapes of subcortical and ventricular structures were quantified using MRI. The cognitive performance was assessed using comprehensive neuropsychological tests. Linear regression was used to examine associations among SLI, brain measures and cognition. RESULTS: SLI was associated with atrophy in multiple subcortical structures, ventricular enlargement and widespread cortical thinning. Both SLI and atrophy were independently related to poorer performance in attention, memory and language domains. Only SLI was associated with visuomotor speed and executive function, while atrophy mediated the association between SLI and visuoconstruction. CONCLUSIONS: Our findings support a vascular contribution to neurodegeneration and cognitive impairment.


Asunto(s)
Encéfalo/patología , Disfunción Cognitiva/diagnóstico , Demencia por Múltiples Infartos/diagnóstico , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Imagen por Resonancia Magnética , Accidente Vascular Cerebral Lacunar/diagnóstico , Anciano , Anciano de 80 o más Años , Atrofia , Ganglios Basales/patología , Tronco Encefálico/patología , Corteza Cerebral/patología , Dominancia Cerebral/fisiología , Femenino , Humanos , Cápsula Interna/patología , Ventrículos Laterales/patología , Masculino , Escala del Estado Mental , Pruebas Neuropsicológicas , Singapur
10.
Environ Technol ; 44(19): 2900-2912, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35220916

RESUMEN

With a worldwide ever increasing demand for metals, particularly for the manufacture of electronics and batteries, there is not only a concurrent need to recover these materials from their subsequent waste streams but also a need to make advancements to do this via development of more efficient and eco-friendly processes for metal recovery; solid-phase extraction can be considered a promising alternative to conventional processes. This work studied the production of novel nanofibers modified with Cyanex 272 and their application in the recovery of cobalt present in aqueous solution The nanofibers produced by forcespinning were characterized by SEM, FT-IR and TGA and the extraction of cobalt was evaluated by variation of the pH, solid:liquid (S:L) ratio, extraction time and Cyanex 272 content in the nanofibers. The best extraction efficiency was 99.96%, achieved under the following conditions: pH 8; (S:L) ratio of 1:200; 25% of Cyanex 272; Extraction time of 60 min. The maximum extraction capacity obtained was 15.46 mg Co/g of nanofiber and 70.15 mg Co/g of extractor. In successive reuse cycles, the results demonstrated that the extraction efficiency was maintained at over 85%. The findings showed that Nylon 6/Cyanex 272 nanofibers are a new robust and promising material for the recovery of heavy metals from aqueous solution, confirming that nanofibers have an efficiency similar to conventional liquid-liquid extraction, without the disadvantage of volatile organic compounds emissions generated by the use of organic diluents.


Asunto(s)
Cobalto , Nanofibras , Cobalto/química , Espectroscopía Infrarroja por Transformada de Fourier , Metales , Agua
11.
PLoS One ; 18(6): e0287005, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37379281

RESUMEN

BACKGROUND: Innovation ecosystems are an important driver of regional economic growth and development. STEM assets connected to universities may play an important role in such ecosystems. OBJECTIVE: To systematically review the literature relating to the effect of university STEM assets on regional economies and innovation ecosystems, providing a better understanding of how the impact is generated and constrained, as well as identifying any gaps in knowledge. METHODS: Keyword and text word searches using the Web of Science Core Collection (Clarivate), Econlit (EBSCO) and ERIC (EBSCO) were performed in July 2021 and February 2023. Papers were double screened on abstract and title, and were included if there was consensus that they fulfilled the inclusion criteria of: (i) relating to an OECD country; (ii) having been published between 1 January 2010 and 28 February 2023; and (iii) concerning the impact of STEM assets. Data extraction was undertaken for each article by a single reviewer and checked by a second reviewer. Due to the heterogeneity of the study designs and outcome measures used, it was not possible to perform a quantitative synthesis of results. A narrative synthesis was subsequently undertaken. RESULTS: Of the 162 articles identified for detailed review, 34 were accepted as being sufficiently relevant to the study to be included for final analysis. Three important features identified were that the literature: i) is predominately concerned with supporting new businesses; ii) describes a high level of involvement with a university in providing that support; and iii studies economic impacts at local, regional and national levels. DISCUSSION: The evidence points to a gap in the literature relating to looking at the broader impact of STEM assets and any corresponding transformational, system-level effects that go beyond narrowly defined, short to medium-term outcomes. The main limitation of this review is that information on STEM assets in the non-academic literature is not captured.


Asunto(s)
Ecosistema , Humanos , Universidades
12.
J Neurol Neurosurg Psychiatry ; 83(6): 580-5, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22496580

RESUMEN

OBJECTIVES: To determine the prognostic value of brief cognitive screening tests administered in the subacute stroke phase (initial 2 weeks) for the detection of significant cognitive impairment 3-6 months after stroke, the authors compared the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). METHODS: Patients with ischaemic stroke and transient ischaemic attack were assessed with both MoCA and MMSE within 14 days after index stroke, followed by a formal neuropsychological evaluation of seven cognitive domains 3-6 months later. Cognitive outcomes were dichotomised as either no-mild (impairment in ≤2 cognitive domains) or moderate-severe (impairment in ≥ 3 cognitive domains) vascular cognitive impairment. Area under the receiver operating characteristic (ROC) curve analysis was used to compare discriminatory ability. RESULTS: 300 patients were recruited, of whom 239 received formal neuropsychological assessment 3-6 months after the stroke. 60 (25%) patients had moderate-severe VCI. The overall discriminant validity for detection of moderate-severe cognitive impairment was similar for MoCA (ROC 0.85 (95% CI 0.79 to 0.90) and MMSE (ROC 0.83 (95% CI 0.77 to 0.89)), p=0.96). Both MoCA (21/22) and MMSE (25/26) had similar discriminant indices at their optimal cutoff points; sensitivity 0.88 versus 0.88; specificity 0.64 versus 0.67; 70% versus 72% correctly classified. Moreover, both tests had similar discriminant indices in detecting impaired cognitive domains. CONCLUSIONS: Brief screening tests during acute admission in patients with mild stroke are predictive of significant vascular cognitive impairment 3-6 months after stroke.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Ataque Isquémico Transitorio/diagnóstico , Accidente Cerebrovascular/diagnóstico , Adulto , Trastornos del Conocimiento/complicaciones , Femenino , Humanos , Ataque Isquémico Transitorio/complicaciones , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Admisión del Paciente , Valor Predictivo de las Pruebas , Curva ROC , Sensibilidad y Especificidad , Singapur , Accidente Cerebrovascular/complicaciones
13.
Int Psychogeriatr ; 24(11): 1749-55, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22687278

RESUMEN

BACKGROUND: To examine the discriminant validity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) in detecting patients with cognitive impairment at higher risk for dementia at a memory clinic setting. METHODS: Memory clinic patients were administered the MoCA, MMSE, and a comprehensive formal neuropsychological battery. Mild cognitive impairment (MCI) subtypes were dichotomized into two groups: single domain-MCI (sd-MCI) and multiple domain-MCI (md-MCI). Area under the receiver operating characteristic curve (ROC) analysis was used to compare the discriminatory ability of the MoCA and the MMSE. RESULTS: Two hundred thirty patients were recruited, of which 136 (59.1%) were diagnosed with dementia, 61 (26.5%) with MCI, and 33 (14.3%) with no cognitive impairment (NCI). The majority of MCI patients had md-MCI (n = 36, 59%). The MoCA had significantly larger AUCs than the MMSE in discriminating md-MCI from the lower risk group for incident dementia (NCI and sd-MCI) [MoCA 0.92 (95% CI, 0.86-0.98) vs. MMSE 0.84 (95% CI, 0.75-0.92), p = 0.02). At their optimal cut-off points, the MoCA (19/20) remained superior to the MMSE (23/24) in detecting md-MCI [sensitivity: 0.83 vs. 0.72; specificity: 0.86 vs. 0.83; PPV: 0.79 vs. 0.72; NPV: 0.89 vs. 0.83; correctly classified: 85.1% vs. 78.7%]. CONCLUSION: The MoCA is superior to the MMSE in the detection of patients with cognitive impairment at higher risk for incident dementia at a memory clinic setting.


Asunto(s)
Disfunción Cognitiva/diagnóstico , Demencia/diagnóstico , Evaluación Geriátrica , Pruebas de Inteligencia/normas , Competencia Mental , Escala del Estado Mental/normas , Anciano , Anciano de 80 o más Años , Disfunción Cognitiva/complicaciones , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/psicología , Demencia/epidemiología , Demencia/etiología , Demencia/psicología , Femenino , Evaluación Geriátrica/métodos , Evaluación Geriátrica/estadística & datos numéricos , Humanos , Masculino , Tamizaje Masivo , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Medición de Riesgo , Singapur/epidemiología
14.
Bioelectromagnetics ; 33(2): 176-85, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25929484

RESUMEN

Research on long-term exposure to electromagnetic fields on cognition is lacking. We investigated the associations between frequent digital mobile phone use and global and domain-specific cognitive changes in older persons, a vulnerable group experiencing age-associated cognitive decline. We assessed 871 non-demented Chinese participants in the Singapore Longitudinal Ageing Studies cohort on the frequency of digital mobile phone use, neurocognitive performance and confounding variables at baseline, and neurocognitive performance at the 4-year follow-up. Findings showed that digital mobile phone users were typically self-selected to possess characteristics favoring better cognitive functioning and concomitantly demonstrate better performance on cognitive tasks. There was evidently no significant deleterious effect of digital mobile phone use on cognitive functioning in older people. Findings suggest, however, that digital mobile phone use may have an independent facilitating effect on global and executive functioning.


Asunto(s)
Envejecimiento/fisiología , Cognición/fisiología , Cognición/efectos de la radiación , Exposición a Riesgos Ambientales/estadística & datos numéricos , Función Ejecutiva/fisiología , Función Ejecutiva/efectos de la radiación , Anciano , Anciano de 80 o más Años , Teléfono Celular , Femenino , Humanos , Estudios Longitudinales , Masculino , Microondas , Persona de Mediana Edad , Dosis de Radiación , Singapur/epidemiología
15.
Cogn Neuropsychiatry ; 17(2): 115-32, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21722047

RESUMEN

INTRODUCTION: Impaired depth perception, a fundamental aspect of early visual processing, has been shown in patients with schizophrenia suggesting a disturbance to magnocellular and possibly parvocellular pathways. Despite some evidence showing visual-perceptive deficits in people with schizotypal personality traits (SPT), depth perception has not been evaluated in these subjects. METHODS: 12 clinically healthy schizotypy and 17 control participants were examined using a novel stereoscopic depth perception task. A mixed ANOVA design considered the Group (SPT/control) as independent factor, and trial Block (BD/BD+/BD-) and target Condition (SDSS/SDDS/DDSS/DDDS) were considered as repeated measures. RESULTS: Schizotypal participants were not significantly different to controls on simple judgements of depth but demonstrated a subtle impairment in perceiving binocular depth when performing high difficulty judgements. CONCLUSIONS: The presence of subtle depth perception problems in schizotypal subjects, similar but less marked than those of schizophrenia patients, may suggest a less pervasive disturbance of early information processing. If so, such deficits could be considered as innate neurological changes that may occur in people vulnerable for schizophrenia, thus with the potential to be a novel intermediate phenotype.


Asunto(s)
Percepción de Profundidad/fisiología , Juicio , Psicología del Esquizofrénico , Trastorno de la Personalidad Esquizotípica/psicología , Adolescente , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica , Adulto Joven
16.
COPD ; 9(5): 555-62, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22909131

RESUMEN

INTRODUCTION: Various cognitive deficits associated with reduced pulmonary function are reported in different studies, but the pattern of cognitive deficits across multiple domains and its associated everyday functional disability remain unclear. METHODS: We analyzed neuropsychological functioning, cognitive impairment and accompanying disability in instrumental activities of daily living (IADL) associated with reduced pulmonary function in community-living middle-aged and older adults in Singapore. Performance on a comprehensive battery of neuropsychological tests, spirometry and cognitively demanding IADLs were assessed in the population-based Singapore Longitudinal Ageing Studies. RESULTS: Consecutive 10% increase in forced expiratory volume in 1 s (FEV1) as percent of predicted was positively associated with 0.18 points increase in Mini-mental state examination (MMSE) and 0.04 points increase in executive function, independent of age, education and other variables. Subjects with moderate-to-severe airway obstruction showed significantly poorer MMSE score (p for linear trend = 0.001), and information processing speed (p for linear trend < 0.001). FEV1 (per 10% of predicted) was significantly associated with lower risk of cognitive impairment (OR = 0.92, 95% CI: 0.87-0.98, P = 0.005) and cognitive IADL disability (OR = 0.86,95% CI:0.79-0.93, P < 0.001). Pulmonary restriction was associated with greater risk of cognitive impairment (OR = 1.98, 95% CI: 1.26-3.11, P = 0.003) and cognitive IADL disability (OR = 2.43, 95% CI: 1.31-4.53, P = 0.005). Moderate-to-severe airway obstruction (OR = 2.04, 95% CI: 1.11-3.74, P = 0.022) was positively associated with cognitive IADL disability. CONCLUSION: The findings suggest a measurable but modest cognitive effect of low pulmonary function that was accompanied by corresponding disability in living activities. The effect on executive functioning should be further investigated in longitudinal studies.


Asunto(s)
Trastornos del Conocimiento/epidemiología , Enfermedades Pulmonares/epidemiología , Actividades Cotidianas , Anciano , Envejecimiento , China/etnología , Trastornos del Conocimiento/etnología , Femenino , Humanos , Enfermedades Pulmonares/etnología , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Análisis de Regresión , Singapur/epidemiología , Espirometría
17.
Psychiatry Res ; 176(1): 8-12, 2010 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-20083312

RESUMEN

Sex differences in the onset, epidemiology, clinical presentation and neuropathology of schizophrenia suggest that sexual dimorphism in brain development may be relevant to pathogenesis. Sex hormones, in particular testosterone, are considered to be crucial in brain development, but few investigations have examined the potential role of prenatal testosterone in schizophrenia. In this study, we examined a retrospective marker of prenatal testosterone release - 2D:4D finger length ratio (2D:4D), the relative length of 2nd to 4th digit, in 64 Asian patients with schizophrenia and 64 sex-matched controls. No significant difference in mean finger lengths was present, however 2D:4D ratio was significantly different between patients and controls. The effect was primarily seen in males consistent with a 'less masculinised' pattern and hypotheses suggesting that schizophrenia may be associated with an abnormality in prenatal circulating testosterone.


Asunto(s)
Tamaño Corporal/fisiología , Dedos/anatomía & histología , Esquizofrenia/patología , Adulto , Pueblo Asiatico , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores Sexuales , Testosterona/fisiología , Adulto Joven
18.
Psychiatry Res ; 184(1): 10-5, 2010 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-20832252

RESUMEN

The left paracingulate sulcus (PCS) is longer than the right and the adjacent cortex is activated by the generation of words. In adult patients with chronic schizophrenia the anatomical asymmetry is reduced. In 35 controls and 38 adolescents with schizophrenia or schizoaffective disorder (mean age = 16 years) we found that semantic verbal fluency correlated with leftward PCS asymmetry in controls but not in patients. At intake, PCS length did not differ between patients and controls, but at follow-up (13 controls, 10 patients, mean age = 18 years) PCS asymmetry (comprising both increasing left and decreasing right length) increased significantly, the increase was greater in males than in females, and there was a trend for a diagnosis * sex * side * time interaction such that in controls leftward PCS asymmetry increased, while in patients of both sexes there was convergence toward symmetry. Thus sulcal anatomy develops differentially in the two sexes during adolescence, and the pattern of asymmetric sex-dependent change over time may distinguish patients with psychosis from controls. Greater change in asymmetry during adolescence may explain earlier age of onset in males and greater deficits in verbal fluency.


Asunto(s)
Lateralidad Funcional/fisiología , Giro del Cíngulo/patología , Trastornos Psicóticos/patología , Esquizofrenia/patología , Semántica , Caracteres Sexuales , Adolescente , Femenino , Giro del Cíngulo/fisiopatología , Humanos , Procesamiento de Imagen Asistido por Computador , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Análisis Multivariante , Trastornos Psicóticos/fisiopatología , Esquizofrenia/fisiopatología , Estadística como Asunto , Conducta Verbal/fisiología , Adulto Joven
19.
Appl Neuropsychol Adult ; 27(6): 497-503, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-30793954

RESUMEN

Previous research on older adults with superior cognitive abilities (super-cognition) has typically examined cognition using a single domain approach, which may not adequately capture the multidimensional nature of successful cognitive aging. Furthermore, the lifestyle factors associated with super-cognition have not been studied adequately. The current study examined the cognitive profiles and lifestyle factors associated with super-cognition. Community-dwelling older adults (N = 693) were administered neuropsychological tests and self-reported measures of lifestyle factors at midlife (retrospectively recalled). Then, using an a priori set of criteria, we classified them as super-cognition or normal. A latent class analysis was conducted to examine the different cognitive profiles of super-cognition, and both groups were compared on their lifestyle-related outcomes. A total of 64 and 263 participants met the criteria for super-cognition and normal participants respectively. A three-class solution best described super-cognition among our participants. Approximately half of them had superior immediate memory; two other smaller groups of participants with super-cognition had superior attention, language, and visuospatial abilities. Participants with super-cognition reported less participation in social activities and, frequently, working more than 9 hours/day and feeling stressed, at midlife. Super-cognition among the elderly is associated with having a busier, more socially-isolated and stressful midlife.


Asunto(s)
Envejecimiento/psicología , Cognición , Envejecimiento Cognitivo/psicología , Estilo de Vida , Admisión y Programación de Personal , Participación Social , Estrés Psicológico , Anciano , Atención , Escolaridad , Ejercicio Físico , Femenino , Humanos , Vida Independiente , Lenguaje , Análisis de Clases Latentes , Masculino , Memoria , Persona de Mediana Edad , Pruebas Neuropsicológicas , Sueño , Procesamiento Espacial
20.
Psychiatry Res ; 172(2): 121-7, 2009 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-19297135

RESUMEN

The passivity phenomenon is a distressing Schneiderian first rank symptom in patients with schizophrenia. Based on extant data of functional and structural cerebral changes underlying passivity, we sought to examine cerebral white matter integrity in our subjects. We hypothesised that the passivity phenomenon would be associated with white matter changes in specific cortical (frontal, parietal cortices, and cingulate gyrus) and subcortical regions (thalamus and basal ganglia) and correlated with relevant neurocognitive deficits, compared with characteristics in those without the passivity phenomenon. Thirty-six subjects (11 with passivity and 25 without passivity) with schizophrenia were compared with 32 age-, gender- and handedness-matched healthy controls using diffusion tensor imaging. Neuropsychological testing was administered. Patients with passivity were associated with increased fractional anisotropy within the frontal cortex, cingulate gyrus, and basal ganglia and decreased fractional anisotropy within the thalamus when compared with patients without passivity. Within patients with passivity, fractional anisotropy in the frontal cortex correlated with the age of onset of illness and neurocognitive deficits related to attention and executive functioning. The findings suggest distributed involvement of cortical and subcortical regions underlying passivity and support the notion of neural network models underlying specific psychiatric symptoms such as passivity.


Asunto(s)
Encéfalo/patología , Trastornos del Conocimiento/diagnóstico , Imagen de Difusión por Resonancia Magnética , Esquizofrenia/diagnóstico , Esquizofrenia/patología , Psicología del Esquizofrénico , Adulto , Anisotropía , Atención/fisiología , Encéfalo/fisiopatología , Mapeo Encefálico , Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Trastornos del Conocimiento/patología , Trastornos del Conocimiento/fisiopatología , Femenino , Lateralidad Funcional , Humanos , Masculino , Vías Nerviosas/fisiopatología , Pruebas Neuropsicológicas , Esquizofrenia/fisiopatología
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