RESUMEN
Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (nâ=â115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (nâ=â50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD.
Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales/fisiopatología , Cognición , Imagen por Resonancia Magnética , Neuroimagen , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Enfermedades de los Pequeños Vasos Cerebrales/diagnóstico , Imagen de Difusión Tensora , Función Ejecutiva , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Análisis de RegresiónRESUMEN
BACKGROUND AND PURPOSE: Small vessel cerebrovascular disease is an important cause of vascular cognitive impairment. It is usually sporadic but also occurs secondary to the genetic disorder cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Recurrent lacunar stroke is a characteristic feature, although symptomatic events are relatively rare, making large numbers necessary for evaluation of potential therapies. Diffusion-weighted imaging is sensitive to acute ischemic lesions and differentiates them from chronic infarcts. Detection of asymptomatic lacunar infarcts with diffusion-weighted imaging is a potential surrogate marker for treatment trials. In this study, the frequency of asymptomatic new lesions in ischemic leukoaraiosis and CADASIL was determined as a step toward assessing the potential of this technique as a surrogate marker of disease activity. METHODS: Fifty patients with sporadic small vessel disease and 19 patients with CADASIL underwent diffusion-weighted imaging. All had been asymptomatic for 3 months before imaging. Diffusion-weighted images were screened by two raters for new lesions; lesions were confirmed as recent by a visible reduction of diffusivity on the corresponding apparent diffusion coefficient maps. RESULTS: Recent ischemic lesions were identified in four patients with sporadic small vessel disease (8.0%) and two patients with CADASIL (10.5%). CONCLUSION: Asymptomatic new lesions are found in cases of sporadic small vessel disease and CADASIL. The frequency of new lesions suggests that this approach has a potential role as a surrogate marker in therapeutic trials that warrants further investigation.
Asunto(s)
Infarto Encefálico/diagnóstico , Isquemia Encefálica/diagnóstico , Enfermedades Arteriales Cerebrales/diagnóstico , Demencia Vascular/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Infarto Encefálico/epidemiología , Isquemia Encefálica/epidemiología , Enfermedades Arteriales Cerebrales/genética , Infarto Cerebral/diagnóstico , Infarto Cerebral/epidemiología , Estudios de Cohortes , Demencia por Múltiples Infartos/diagnóstico , Demencia por Múltiples Infartos/epidemiología , Demencia Vascular/epidemiología , Imagen de Difusión por Resonancia Magnética , Trastornos Distónicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Prevalencia , Reino Unido/epidemiologíaRESUMEN
BACKGROUND AND PURPOSE: Complex and syndromic craniosynostosis can be complicated by raised intracranial pressure (ICP), which in the absence of other identifiable origins, is probably caused by venous hypertension. Children with these conditions have been shown to have narrowing of the sigmoid sinus-jugular vein complex. Evidence of bony narrowing of the jugular foramina in children with complex or syndromic craniosynostosis and raised ICP compared with that in children with craniosynostosis without raised ICP would provide support for the theory that venous hypertension occurs in the former children. METHODS: Measurements of the jugular foramina were obtained from reformatted helical CT scans obtained in 12 children with complex or syndromic craniosynostosis and raised ICP (group 1) and in two control groups of children with normal ICP. The first control group comprised 10 children with simple nonsyndromic synostosis of one or two sutures (group 2), and the second control group included nine children with complex or syndromic craniosynostosis (group 3). RESULTS: Children with raised ICP had narrower jugular foramina than did the age-matched control subjects. For group 1, the mean diameter of jugular foramina was 6.5 mm; group 2, 11.5 mm (P <.01); and group 3, 10 mm (P <.05). No significant difference existed between the two control groups. CONCLUSION: Significantly narrower jugular foramina in children with raised ICP is further evidence of the role of venous outflow obstruction and intracranial venous hypertension in the development of raised ICP in complex and syndromic craniosynostosis.