RESUMEN
Although it is currently not known whether early assessment and treatment of hemispatial neglect improves rehabilitation outcome, identification in the acute phase of post stroke is important for nursing, counseling families, and planning intervention strategies. Previous tests of neglect either fail to detect mild forms of neglect or are too lengthy for use at the bedside. We tested and selected an efficient, small battery of tests to address this gap. Two hundred and twenty-four stroke patients completed the Sunnybrook Neglect Assessment Procedure (SNAP). Normal performance was determined from a population of 100 normal elderly volunteers. The SNAP was shown to be a highly reliable and valid instrument. Factor analysis showed good internal consistency, suggesting that performance on each subtest is positively correlated with the others. The SNAP is a useful and reliable tool to assess neglect at the bedside in acute stroke patients.
Asunto(s)
Trastornos de la Percepción/diagnóstico , Accidente Cerebrovascular/complicaciones , Anciano , Anciano de 80 o más Años , Atención , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Trastornos de la Percepción/etiología , Reproducibilidad de los Resultados , Percepción VisualRESUMEN
PURPOSE: Quantification methods for white matter hyperintensities (WMH) on Magnetic Resonance Imaging are heterogeneous, deterring their application. This study compared three WMH rating scales, varying in complexity, and a volumetric method, to evaluate trade-offs between complexity and clinical utility in differentiating dementia subgroups and in correlating with cognition. METHODS: WMH were rated using the Fazekas, Age-Related White Matter Changes (ARWMC) and Scheltens scales, and segmented by computational volumetry in 108 patients with Alzheimer's Disease (AD), 23 with Mild Cognitive Impairment (MCI) and 34 normal controls (NC). Global and hippocampal atrophy, age and education, were accounted for in correlations of WMH with cognitive domains. RESULTS: Intra- and inter-rater reliability were high (intraclass correlation coefficients = 0.88-0.97) across rating scales. WMH scores of all scales were highly correlated with volumes (Spearman r = 0.78-0.90, Ps < 0.001), as well as with each other (Spearman r = 0.86-0.91, Ps < 0.001). The Fazekas scale showed significant separation between AD, MCI and NC using non-parametric analysis, while the ARWMC and Scheltens' scales, and WMH volumes demonstrated significant correlations (standardized ß = -0.19 to -0.24, Ps < 0.05) with cognitive domain scores using multivariate regression analysis, controlling for age, education, global and hippocampal atrophy in patients with AD. CONCLUSIONS: This study suggests that the degree of complexity of WMH rating scales did not affect validation against WMH volumes, but did vary in validation against cognition. The simplest scale performed best in separating cognitive subgroups, but the more complex scales and quantification correlated better with cognitive measures, especially executive function. Hence the best choice of scale depends on the particular application.
Asunto(s)
Enfermedad de Alzheimer/patología , Encéfalo/patología , Disfunción Cognitiva/patología , Imagen por Resonancia Magnética , Fibras Nerviosas Mielínicas/patología , Anciano , Anciano de 80 o más Años , Envejecimiento , Análisis de Varianza , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadísticas no ParamétricasRESUMEN
Patients with Alzheimer's disease (AD) display a multiplicity of cognitive deficits in domains such as memory, language, and attention, all of which can be clearly linked to the underlying neuropathological alterations. The typical degenerative changes occur early on in the disease in the temporal-parietal lobes, with other brain regions, such as the frontal cortex, becoming more affected as the disease progresses. In light of the importance of the parietal cortex in mediating visuospatial attentional processing, in the present study, we investigated a deficit in covert orienting of visual attention and its relationship to cortical hypoperfusion in AD. We characterized the visual attentional profile of 21 AD patients, relative to that of 26 matched normal individuals, and then assessed the correspondence between behavior and hypoperfusion, as measured by regional cerebral blood flow using SPECT. Relative to controls, the AD group demonstrated a unilateral attentional deficit, with disproportionate slowing in reorienting attention to targets in the left compared to the right hemispace, especially following an invalid peripheral cue. Furthermore, even in the presence of bilateral pathology typical of AD, there was a positive correlation between this unilateral attentional disorder and the magnitude of the right superior parietal lobe hypoperfusion. The association of the altered attentional processing profile (i.e., greater difficulty disengaging attention from right-sided stimuli) with right-hemisphere-predominant hypoperfusion not only confirms the critical role of the right parietal lobe in covert attentional orienting but, more importantly, identifies a potential locus of the behavioral alterations in visuospatial processing in AD.
Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/psicología , Atención/fisiología , Corteza Cerebral/fisiología , Percepción Visual/fisiología , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Corteza Cerebral/irrigación sanguínea , Circulación Cerebrovascular/fisiología , Señales (Psicología) , Escolaridad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Lóbulo Parietal/diagnóstico por imagen , Estimulación Luminosa , Desempeño Psicomotor/fisiología , Radiofármacos , Tiempo de Reacción/fisiología , Exametazima de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
BACKGROUND: Alzheimer's Disease (AD) is frequently associated with changes in appetite. This study investigated the relationship between regional cerebral perfusion and appetite loss in AD. METHODS: 64 patients with possible or probable AD were characterized as being with (n=22) or without (n=44) appetite loss based on the Neuropsychiatric Inventory (NPI) Appetite subscale. 99mTc-ECD SPECT scans were coregistered to a standardized template in Talairach space generating mean ratios of uptake referenced to the cerebellum. Regions of interest (ROIs) included anterior cingulate cortex (ACC), middle mesial temporal cortex (MTC-m), inferior mesial temporal cortex (MTC-i), insula (INS), orbitofrontal cortex (OFC) and thalamus-hypothalamus (THAL). RESULTS: Backward stepwise logistic regression analysis of these ROIs showed hypoperfusion in the L-ACC (p=0.015) and L-OFC (p=0.015), relative sparing of perfusion in the R-ACC (p=0.010), R-OFC (p=0.010) and L-MTC-m (p=0.006), and greater anxiety (p=0.005) independently predicted loss of appetite (chi(2)=22.24, p=0.001, Nagelkerke R(2)=0.41). CONCLUSIONS: Hypoperfusion in the left anterior cingulate and left orbitofrontal cortices, and relative sparing of perfusion in the right anterior cingulate, right orbitofrontal and left middle mesial temporal cortices emerged as predictors of appetite loss in this sample of patients. These findings are consistent with impairments in the extrinsic motivational pathways of eating and impaired reward value of food as components of appetite loss in AD.
Asunto(s)
Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/diagnóstico por imagen , Anorexia/diagnóstico por imagen , Anorexia/etiología , Anciano , Anciano de 80 o más Años , Mapeo Encefálico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Análisis Multivariante , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
BACKGROUND/AIMS: To assess the association between regional cerebral blood flow (rCBF) and apathy in Alzheimer's Disease (AD). METHODS: SPECT and MRI scans were obtained from 51 nondepressed outpatients meeting criteria for probable AD (age 77.6 +/- 6.6 years; MMSE 22.3 +/- 5.1; 23 apathetic, 28 nonapathetic) and 23 healthy elderly (75.6 +/- 3.8 years) controls. The following regions of interest (ROIs) were compared between apathetic and nonapathetic AD patients and then referenced against aged controls: anterior cingulate, orbitofrontal cortex, middle medial temporal cortex, hippocampus, medial superior temporal cortex, thalamus/hypothalamus and pons. RESULTS: Apathetic and nonapathetic patients had significant differences in rCBF. Relative to nonapathetic AD patients, apathetic AD patients had lower perfusion in 2 ROIs (right orbitofrontal cortex and left anterior cingulate) and higher perfusion in 5 ROIs (right and left hippocampi, left medial superior temporal gyrus, and right and left middle medial temporal cortex). Comparison of rCBF in these 7 ROIs to healthy elderly controls confirmed hypoperfusion in the left anterior cingulate and right orbitofrontal cortex and suggested a relative sparing of perfusion among apathetic AD patients in the remaining 5 ROIs. CONCLUSIONS: In this group of nondepressed patients with AD, apathetic subjects displayed significant perfusion differences compared to nonapathetic subjects.
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Enfermedad de Alzheimer/epidemiología , Enfermedad de Alzheimer/fisiopatología , Encéfalo/irrigación sanguínea , Encéfalo/fisiopatología , Depresión/epidemiología , Depresión/psicología , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Encéfalo/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: It is not understood why some patients with Alzheimer disease (AD) display aggression and others do not. OBJECTIVE: To examine the relation between regional brain perfusion and aggression in AD. DESIGN: Single-photon emission computed tomographic scans were coregistered to a standardized template in Talairach space, generating mean ratios of uptake referenced to the cerebellum. PARTICIPANTS: Forty-nine outpatients (25 men and 24 women; mean +/- SD age, 74 +/- 11 years) with probable AD (Mini-Mental State Examination score, 17.7 +/- 5.0; 30 aggressive and 19 nonaggressive), comparable in age, sex, and severity of cognitive impairment. MAIN OUTCOME MEASURES: Regional perfusion ratios were determined for 5 bilateral regions of interest: orbitofrontal, middle medial temporal, inferior medial temporal, hypothalamus/thalamus, and anterior cingulate. RESULTS: Compared with nonaggressive patients, aggressive ones displayed hypoperfusion in the right and left middle medial temporal regions of interest (P = .02 for both), but not the others (all (t tests, unpaired, 2-tailed). On regression analyses, right middle temporal hypoperfusion (P = .001), younger age (P = .002), greater activity disturbances (P = .004), and higher Mini-Mental State Examination scores (P = .04) independently predicted aggression, accounting for 44% of the total variance (F = 8.7; P<.001). Statistical parametric mapping analyses supported right middle medial temporal hypoperfusion in the aggressive group (P = .008). CONCLUSION: In this sample of patients with AD, the right middle medial temporal region emerged as an important neural correlate of aggression.