Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Magn Reson Imaging ; 76: 108-115, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33220450

RESUMEN

Brain vascular damage accumulate in aging and often manifest as white matter hyperintensities (WMHs) on MRI. Despite increased interest in automated methods to segment WMHs, a gold standard has not been achieved and their longitudinal reproducibility has been poorly investigated. The aim of present work is to evaluate accuracy and reproducibility of two freely available segmentation algorithms. A harmonized MRI protocol was implemented in 3T-scanners across 13 European sites, each scanning five volunteers twice (test-retest) using 2D-FLAIR. Automated segmentation was performed using Lesion segmentation tool algorithms (LST): the Lesion growth algorithm (LGA) in SPM8 and 12 and the Lesion prediction algorithm (LPA). To assess reproducibility, we applied the LST longitudinal pipeline to the LGA and LPA outputs for both the test and retest scans. We evaluated volumetric and spatial accuracy comparing LGA and LPA with manual tracing, and for reproducibility the test versus retest. Median volume difference between automated WMH and manual segmentations (mL) was -0.22[IQR = 0.50] for LGA-SPM8, -0.12[0.57] for LGA-SPM12, -0.09[0.53] for LPA, while the spatial accuracy (Dice Coefficient) was 0.29[0.31], 0.33[0.26] and 0.41[0.23], respectively. The reproducibility analysis showed a median reproducibility error of 20%[IQR = 41] for LGA-SPM8, 14% [31] for LGA-SPM12 and 10% [27] with the LPA cross-sectional pipeline. Applying the LST longitudinal pipeline, the reproducibility errors were considerably reduced (LGA: 0%[IQR = 0], p < 0.001; LPA: 0% [3], p < 0.001) compared to those derived using the cross-sectional algorithms. The DC using the longitudinal pipeline was excellent (median = 1) for LGA [IQR = 0] and LPA [0.02]. LST algorithms showed moderate accuracy and good reproducibility. Therefore, it can be used as a reliable cross-sectional and longitudinal tool in multi-site studies.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Adulto , Envejecimiento , Algoritmos , Automatización , Estudios Transversales , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sustancia Blanca/patología
2.
Neuroimage ; 218: 116932, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32416226

RESUMEN

BACKGROUND: The amygdala and the hippocampus are two limbic structures that play a critical role in cognition and behavior, however their manual segmentation and that of their smaller nuclei/subfields in multicenter datasets is time consuming and difficult due to the low contrast of standard MRI. Here, we assessed the reliability of the automated segmentation of amygdalar nuclei and hippocampal subfields across sites and vendors using FreeSurfer in two independent cohorts of older and younger healthy adults. METHODS: Sixty-five healthy older (cohort 1) and 68 younger subjects (cohort 2), from the PharmaCog and CoRR consortia, underwent repeated 3D-T1 MRI (interval 1-90 days). Segmentation was performed using FreeSurfer v6.0. Reliability was assessed using volume reproducibility error (ε) and spatial overlapping coefficient (DICE) between test and retest session. RESULTS: Significant MRI site and vendor effects (p â€‹< â€‹.05) were found in a few subfields/nuclei for the ε, while extensive effects were found for the DICE score of most subfields/nuclei. Reliability was strongly influenced by volume, as ε correlated negatively and DICE correlated positively with volume size of structures (absolute value of Spearman's r correlations >0.43, p â€‹< â€‹1.39E-36). In particular, volumes larger than 200 â€‹mm3 (for amygdalar nuclei) and 300 â€‹mm3 (for hippocampal subfields, except for molecular layer) had the best test-retest reproducibility (ε â€‹< â€‹5% and DICE â€‹> â€‹0.80). CONCLUSION: Our results support the use of volumetric measures of larger amygdalar nuclei and hippocampal subfields in multisite MRI studies. These measures could be useful for disease tracking and assessment of efficacy in drug trials.


Asunto(s)
Amígdala del Cerebelo/anatomía & histología , Hipocampo/anatomía & histología , Procesamiento de Imagen Asistido por Computador/normas , Neuroimagen/normas , Programas Informáticos , Adulto , Anciano , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Neuroimagen/métodos , Reproducibilidad de los Resultados
3.
Neurol Sci ; 41(9): 2503-2509, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32215850

RESUMEN

INTRODUCTION: Hematoma expansion (HE) after intracerebral hemorrhage (ICH) is associated with short-term mortality, but its impact on long-term prognosis is still unclear. The aim of this study was to evaluate the impact of HE on long-term survival and functional status after spontaneous ICH. METHODS: Consecutive patients admitted with spontaneous ICH were prospectively enrolled and followed up for a minimum of 2 years. We compared short-term (< 30 days) and long-term survival and functional status between ICH patients with HE (HE+) and those without (HE-). Main outcomes were mortality and poor outcome, defined as modified Rankin Scale ≥ 3. Secondary outcomes included recurrent ICH, admission to institutionalized care, and ischemic events (stroke, myocardial infarction, and systemic embolism). RESULTS: Overall, 140 patients were included (mean age 74.9 years, male 59.3%) and followed up for a mean of 2.25 years. HE+ patients (25.7%) had larger hematoma volume at admission (23.8 ml vs 15.3 ml, p < 0.05), higher NIHSS score (14.6 vs 10.5, p < 0.05) and higher cumulative mortality (59.3% vs 39.2%, p < 0.05) compared to HE- patients. Survival analysis showed that HE+ confers higher mortality and worse functional status at all time points. HE did not associate with secondary outcomes. DISCUSSION: HE translates into higher mortality and functional dependence over long-term follow-up. Strategies limiting HE might benefit long-term functional status.


Asunto(s)
Hemorragia Cerebral , Accidente Cerebrovascular , Anciano , Hemorragia Cerebral/complicaciones , Hematoma/etiología , Humanos , Masculino , Pronóstico , Factores de Riesgo
4.
J Headache Pain ; 21(1): 6, 2020 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-31948389

RESUMEN

BACKGROUND: Dural arteriovenous fistulas are intracranial vascular malformations, fed by dural arteries and draining venous sinuses or meningeal veins. Clinical course varies widely and ranges from benign with spontaneous remission to fatal, due to cerebral hemorrhage. In a 10-year single institution experience, clinical presentation of dural arteriovenous fistulas, and in particular headache and angiographic features, as well as long-term outcome were analyzed. METHODS: Data of 42 intracranial dural arteriovenous fistulas of 40 patients concerning demographic characteristics, medical history and risk factors, clinical presentation and headache features, location and neuroimaging findings, as well as treatment and outcome, were collected. Furthermore, we used the modified-Rankin Scale to assess the long-term outcome, by telephone contact with patients and/or their relatives. RESULTS: Patients aged between 25 and 89 years (mean age 55.8 ± 15.5). According to different clinical presentation and evolution, related to their unique drainage pattern into the cavernous sinus, we examined the carotid-cavernous fistulas separately from other dural arteriovenous fistulas. Interestingly, we found that the migraine-like headache was the major onset symptom of dural arteriovenous fistulas different from carotid-cavernous fistulas (p = 0.036). On the other hand, non-migraine-like headache was a typical characteristic of carotid-cavernous fistulas (p = 0.003). Moreover, ocular symptoms were more frequently observed in carotid-cavernous fistulas (92.9% p < 0.001). Seventy percent of patients did not report any impact on quality of life (mRS 0 or 1) at follow-up. CONCLUSIONS: These findings suggest a link between the site of lesion and clinical features of the headache, a symptom that usually leads to hospitalization. In particular, ocular symptoms accompanying non-migraine-like headache should be promptly recognized and raise the suspicion of a carotid-cavernous fistula, while migraine-like headache may suggests other dural arteriovenous fistulas. This study provides new significant insights on headache and its characteristics as a presentation symptom in dural arteriovenous fistulas.


Asunto(s)
Malformaciones Vasculares del Sistema Nervioso Central/complicaciones , Cefalea/etiología , Adulto , Anciano , Anciano de 80 o más Años , Seno Cavernoso , Angiografía Cerebral , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/etiología , Calidad de Vida , Adulto Joven
5.
Neurobiol Aging ; 80: 91-98, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31103636

RESUMEN

Brain iron load is one of the main neuropathologic hallmarks of Parkinson's disease (PD). Previous studies indicated that iron in the substantia nigra (SN) is related to disease duration and motor impairment. We explore, through a cross-sectional study, the association between brain iron distribution, evaluated by T2*-weighted magnetic resonance imaging (T2*), and clinical features in a cohort of patients with PD. Thirty-two patients with PD, compared with 10 control subjects, were evaluated for motor and cognitive features (attention and working memory, executive functions, language, memory, and visuospatial function). They underwent a magnetic resonance imaging protocol including T2* analysis of specific brain regions of interest to measure iron load compared with healthy control subjects. We found that iron content of the SN correlated positively with both disease duration and Unified Parkinson's Disease Rating Scale III off score. Montreal Cognitive Assessment, Spatial Span, and Graded Naming Test scores were inversely associated with iron load of the SN, whereas Wechsler Adult Intelligence Scale-IV Similarities score showed an inverse relationship with iron content in all the regions of interest examined. Our findings suggest a relationship between topographic brain iron distribution and cognitive domain impairment.


Asunto(s)
Encéfalo/diagnóstico por imagen , Cognición , Disfunción Cognitiva/etiología , Imagen de Difusión por Resonancia Magnética , Actividad Motora , Trastornos Motores/etiología , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/psicología , Encéfalo/metabolismo , Disfunción Cognitiva/patología , Femenino , Humanos , Hierro/metabolismo , Masculino , Persona de Mediana Edad , Trastornos Motores/patología , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/fisiopatología
6.
J Neurol ; 265(3): 522-529, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29327284

RESUMEN

INTRODUCTION: The MRI evidence of persistent black holes (pBHs) on T1-weighted images reflects brain tissue loss in multiple sclerosis (MS). The evolution of contrast-enhancing lesions (CELs) into pBHs probably depends on the degree and persistence of focal brain inflammation. The aim of our retrospective study was to evaluate the effect of a single cycle of intravenous methylprednisolone (IVMP), as for MS relapse treatment, on the risk of CELs' evolution into pBHs. PATIENTS AND METHODS: We selected 57 patients with CELs on the baseline MRI scan. We evaluated the evolution of CELs into pBHs on a follow-up MRI scan performed after ≥ 6 months in patients exposed and not exposed to IVMP for the treatment of relapse after the baseline MRI. RESULTS: In our cohort, 182 CELs were identified in the baseline MRI and 57 of them (31.3%) evolved into pBHs. In the multivariate analysis, the exposure of CELs to IVMP resulted to be a significant independent protective factor against pBHs' formation (OR 0.28, 95% CI 0.11-0.766, p = 0.005), while ring enhancement pattern and the fact of being symptomatic were significant risk factors for CELs' conversion into pBHs (OR 6.42, 95% CI 2.55-17.27, p < 0.001 and OR 13.19, 95% CI 1.56-288.87, p = 0.037). CONCLUSIONS: The exposure of CELs to a cycle of IVMP as for relapse treatment is associated with a lower risk of CELs' evolution into pBHs. Future studies are required to confirm the potential independent protective effect of IVMP on CELs' evolution into pBHs.


Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/diagnóstico por imagen , Metilprednisolona/administración & dosificación , Esclerosis Múltiple Recurrente-Remitente/diagnóstico por imagen , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Fármacos Neuroprotectores/administración & dosificación , Adolescente , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Glucocorticoides/administración & dosificación , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
7.
Front Aging Neurosci ; 10: 439, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30705627

RESUMEN

Background/Aims: We aimed to assess the association between in volumetric measures of hippocampal sub-regions - in healthy older controls (HC), subjects with mild cognitive impairment (MCI) and AD- with circulating levels of IL-4. Methods: From AddNeuroMed Project 113 HC, 101 stable MCI (sMCI), 22 converter MCI (cMCI) and 119 AD were included. Hippocampal subfield volumes were analyzed using Freesurfer 6.0.0 on high-resolution sagittal 3D-T1W MP-RAGE acquisitions. Plasmatic IL-4 was measured using ELISA assay. Results: IL-4 was found to be (a) positively associate with left subiculum volume (ß = 0.226, p = 0.037) in sMCI and (b) negatively associate with left subiculum volume (ß = -0.253, p = 0.011) and left presubiculum volume (ß = -0.257, p = 0.011) in AD. Conclusion: Our results indicate a potential neuroprotective effect of IL-4 on the areas of the hippocampus more vulnerable to aging and neurodegeneration.

8.
Hum Brain Mapp ; 38(1): 12-26, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27519630

RESUMEN

Free water elimination (FWE) in brain diffusion MRI has been shown to improve tissue specificity in human white matter characterization both in health and in disease. Relative to the classical diffusion tensor imaging (DTI) model, FWE is also expected to increase sensitivity to microstructural changes in longitudinal studies. However, it is not clear if these two models differ in their test-retest reproducibility. This study compares a bi-tensor model for FWE with DTI by extending a previous longitudinal-reproducibility 3T multisite study (10 sites, 7 different scanner models) of 50 healthy elderly participants (55-80 years old) scanned in two sessions at least 1 week apart. We computed the reproducibility of commonly used DTI metrics (FA: fractional anisotropy, MD: mean diffusivity, RD: radial diffusivity, and AXD: axial diffusivity), derived either using a DTI model or a FWE model. The DTI metrics were evaluated over 48 white-matter regions of the JHU-ICBM-DTI-81 white-matter labels atlas, and reproducibility errors were assessed. We found that relative to the DTI model, FWE significantly reduced reproducibility errors in most areas tested. In particular, for the FA and MD metrics, there was an average reduction of approximately 1% in the reproducibility error. The reproducibility scores did not significantly differ across sites. This study shows that FWE improves sensitivity and is thus promising for clinical applications, with the potential to identify more subtle changes. The increased reproducibility allows for smaller sample size or shorter trials in studies evaluating biomarkers of disease progression or treatment effects. Hum Brain Mapp 38:12-26, 2017. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Envejecimiento , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora , Agua/metabolismo , Anciano , Anciano de 80 o más Años , Anisotropía , Femenino , Voluntarios Sanos , Humanos , Imagenología Tridimensional , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sustancia Blanca/diagnóstico por imagen
10.
J Neurooncol ; 129(2): 355-61, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27324494

RESUMEN

In the present study we assessed the activity of the next-generation anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor (-TKI) alectinib, in patients with ALK-postive, advanced non-small cell lung cancer (NSCLC) and central nervous system (CNS) metastases. NSCLCs with ALK-positive disease, as assessed by fluorescence in situ hybridization, and CNS metastases were treated with alectinib 600 mg BID. Included patients were followed prospectively in order to evaluate the efficacy of the drug, with particular emphasis on activity in the CNS. Eleven consecutive patients were enrolled. The majority of them were pretreated with crizotinib (n = 10, 90.9 %), and cranial radiotherapy (n = 8, 72.7 %). Six of the seven patients with measurable CNS disease experienced a CNS response, including three patients who were naïve for cranial radiation. Median duration of response was 8 months. For the whole population, median CNS-progression-free survival (-PFS), systemic-PFS, overall-PFS, overall survival, and 1-year survival were 8, 11, 8, 13 months, and 31.1 %, respectively. Two patients experiencing a CNS response were assessed for alectinib's concentrations in serum and cerebro-spinal fluid (CSF), and showed a CSF-to-serum ratio ranging from 0.001 to 0.003 ng/mL. Alectinib is highly active against CNS metastases from ALK-positive NSCLCs, irrespective of prior treatment(s) with ALK-TKI(s) and/or cranial radiotherapy. The low CSF-to-serum ratio of alectinib suggests that measuring the concentrations of the drug in the CSF may not be a reliable surrogate of its distribution into the CNS.


Asunto(s)
Carbazoles/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Neoplasias del Sistema Nervioso Central/secundario , Neoplasias Pulmonares/patología , Piperidinas/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Adulto , Anciano , Quinasa de Linfoma Anaplásico , Encéfalo/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Neoplasias del Sistema Nervioso Central/diagnóstico por imagen , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Neoplasias Pulmonares/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Proteínas Tirosina Quinasas Receptoras/sangre , Proteínas Tirosina Quinasas Receptoras/líquido cefalorraquídeo , Estudios Retrospectivos
11.
Hum Brain Mapp ; 37(6): 2114-32, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26990928

RESUMEN

Understanding how to reduce the influence of physiological noise in resting state fMRI data is important for the interpretation of functional brain connectivity. Limited data is currently available to assess the performance of physiological noise correction techniques, in particular when evaluating longitudinal changes in the default mode network (DMN) of healthy elderly participants. In this 3T harmonized multisite fMRI study, we investigated how different retrospective physiological noise correction (rPNC) methods influence the within-site test-retest reliability and the across-site reproducibility consistency of DMN-derived measurements across 13 MRI sites. Elderly participants were scanned twice at least a week apart (five participants per site). The rPNC methods were: none (NPC), Tissue-based regression, PESTICA and FSL-FIX. The DMN at the single subject level was robustly identified using ICA methods in all rPNC conditions. The methods significantly affected the mean z-scores and, albeit less markedly, the cluster-size in the DMN; in particular, FSL-FIX tended to increase the DMN z-scores compared to others. Within-site test-retest reliability was consistent across sites, with no differences across rPNC methods. The absolute percent errors were in the range of 5-11% for DMN z-scores and cluster-size reliability. DMN pattern overlap was in the range 60-65%. In particular, no rPNC method showed a significant reliability improvement relative to NPC. However, FSL-FIX and Tissue-based physiological correction methods showed both similar and significant improvements of reproducibility consistency across the consortium (ICC = 0.67) for the DMN z-scores relative to NPC. Overall these findings support the use of rPNC methods like tissue-based or FSL-FIX to characterize multisite longitudinal changes of intrinsic functional connectivity. Hum Brain Mapp 37:2114-2132, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Imagen por Resonancia Magnética , Anciano , Mapeo Encefálico/métodos , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiología , Análisis de Regresión , Reproducibilidad de los Resultados , Descanso , Estudios Retrospectivos
12.
Neuroimage ; 124(Pt A): 442-454, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26163799

RESUMEN

To date, limited data are available regarding the inter-site consistency of test-retest reproducibility of functional connectivity measurements, in particular with regard to integrity of the Default Mode Network (DMN) in elderly participants. We implemented a harmonized resting-state fMRI protocol on 13 clinical scanners at 3.0T using vendor-provided sequences. Each site scanned a group of 5 healthy elderly participants twice, at least a week apart. We evaluated inter-site differences and test-retest reproducibility of both temporal signal-to-noise ratio (tSNR) and functional connectivity measurements derived from: i) seed-based analysis (SBA) with seed in the posterior cingulate cortex (PCC), ii) group independent component analysis (ICA) separately for each site (site ICA), and iii) consortium ICA, with group ICA across the whole consortium. Despite protocol harmonization, significant and quantitatively important inter-site differences remained in the tSNR of resting-state fMRI data; these were plausibly driven by hardware and pulse sequence differences across scanners which could not be harmonized. Nevertheless, the tSNR test-retest reproducibility in the consortium was high (ICC=0.81). The DMN was consistently extracted across all sites and analysis methods. While significant inter-site differences in connectivity scores were found, there were no differences in the associated test-retest error. Overall, ICA measurements were more reliable than PCC-SBA, with site ICA showing higher reproducibility than consortium ICA. Across the DMN nodes, the PCC yielded the most reliable measurements (≈4% test-retest error, ICC=0.85), the medial frontal cortex the least reliable (≈12%, ICC=0.82) and the lateral parietal cortices were in between (site ICA). Altogether these findings support usage of harmonized multisite studies of resting-state functional connectivity to characterize longitudinal effects in studies that assess disease progression and treatment response.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/fisiología , Giro del Cíngulo/fisiología , Imagen por Resonancia Magnética/métodos , Anciano , Anciano de 80 o más Años , Artefactos , Interpretación Estadística de Datos , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Vías Nerviosas/fisiología , Reproducibilidad de los Resultados , Relación Señal-Ruido
13.
Expert Opin Pharmacother ; 16(17): 2601-13, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26439599

RESUMEN

INTRODUCTION: Central nervous system (CNS) metastases represent an important cause of morbidity and mortality in non-small cell lung cancer (NSCLC) patients. Local approaches of neurosurgery (usually for single brain lesions), whole brain radiotherapy, and stereotactic radiosurgery are often withheld for the treatment of NSCLC-derived brain metastases (BMs). However, systemic treatment is consistently emerging as an option for patients with asymptomatic BMs, which could allow for delaying cranial radiotherapy at symptomatic/radiological progression. AREAS COVERED: Chemotherapy, monoclonal antibodies, tyrosine-kinase inhibitors (TKIs) for molecularly selected NSCLCs, such as epidermal growth factor receptor (EGFR)-mutant and anaplastic lymphoma kinase (ALK)-rearranged diseases, and immune checkpoint inhibitors are all systemic treatments that have shown activity against NSCLC-derived CNS metastases. Among these, EGFR- and ALK-TKIs will be discussed more in detail owing to their superior efficacy in this context. EXPERT OPINION: Up-front systemic treatment should be considered for patients with asymptomatic, multiple BMs, as recently acknowledged by the European Society of Medical Oncology guidelines. Nevertheless, it must be emphasized that the best treatment strategy for NSCLC-derived BMs has to be defined within a multidisciplinary team.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Quinasa de Linfoma Anaplásico , Anticuerpos Monoclonales/uso terapéutico , Neoplasias Encefálicas/inmunología , Neoplasias Encefálicas/secundario , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/secundario , Terapia Combinada , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Mutación , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/genética , Insuficiencia del Tratamiento
14.
Hum Brain Mapp ; 36(9): 3516-27, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26043939

RESUMEN

Recently, there has been an increased interest in the use of automatically segmented subfields of the human hippocampal formation derived from magnetic resonance imaging (MRI). However, little is known about the test-retest reproducibility of such measures, particularly in the context of multisite studies. Here, we report the reproducibility of automated Freesurfer hippocampal subfields segmentations in 65 healthy elderly enrolled in a consortium of 13 3T MRI sites (five subjects per site). Participants were scanned in two sessions (test and retest) at least one week apart. Each session included two anatomical 3D T1 MRI acquisitions harmonized in the consortium. We evaluated the test-retest reproducibility of subfields segmentation (i) to assess the effects of averaging two within-session T1 images and (ii) to compare subfields with whole hippocampus volume and spatial reliability. We found that within-session averaging of two T1 images significantly improved the reproducibility of all hippocampal subfields but not that of the whole hippocampus. Volumetric and spatial reproducibility across MRI sites were very good for the whole hippocampus, CA2-3, CA4-dentate gyrus (DG), subiculum (reproducibility error∼2% and DICE > 0.90), good for CA1 and presubiculum (reproducibility error ∼ 5% and DICE ∼ 0.90), and poorer for fimbria and hippocampal fissure (reproducibility error ∼ 15% and DICE < 0.80). Spearman's correlations confirmed that test-retest reproducibility improved with volume size. Despite considerable differences of MRI scanner configurations, we found consistent hippocampal subfields volumes estimation. CA2-3, CA4-DG, and sub-CA1 (subiculum, presubiculum, and CA1 pooled together) gave test-retest reproducibility similar to the whole hippocampus. Our findings suggest that the larger hippocampal subfields volume may be reliable longitudinal markers in multisite studies.


Asunto(s)
Envejecimiento/patología , Hipocampo/anatomía & histología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Anciano , Europa (Continente) , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Reproducibilidad de los Resultados , Programas Informáticos
17.
Neuroimage ; 101: 390-403, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25026156

RESUMEN

Large-scale longitudinal neuroimaging studies with diffusion imaging techniques are necessary to test and validate models of white matter neurophysiological processes that change in time, both in healthy and diseased brains. The predictive power of such longitudinal models will always be limited by the reproducibility of repeated measures acquired during different sessions. At present, there is limited quantitative knowledge about the across-session reproducibility of standard diffusion metrics in 3T multi-centric studies on subjects in stable conditions, in particular when using tract based spatial statistics and with elderly people. In this study we implemented a multi-site brain diffusion protocol in 10 clinical 3T MRI sites distributed across 4 countries in Europe (Italy, Germany, France and Greece) using vendor provided sequences from Siemens (Allegra, Trio Tim, Verio, Skyra, Biograph mMR), Philips (Achieva) and GE (HDxt) scanners. We acquired DTI data (2 × 2 × 2 mm(3), b = 700 s/mm(2), 5 b0 and 30 diffusion weighted volumes) of a group of healthy stable elderly subjects (5 subjects per site) in two separate sessions at least a week apart. For each subject and session four scalar diffusion metrics were considered: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial (AD) diffusivity. The diffusion metrics from multiple subjects and sessions at each site were aligned to their common white matter skeleton using tract-based spatial statistics. The reproducibility at each MRI site was examined by looking at group averages of absolute changes relative to the mean (%) on various parameters: i) reproducibility of the signal-to-noise ratio (SNR) of the b0 images in centrum semiovale, ii) full brain test-retest differences of the diffusion metric maps on the white matter skeleton, iii) reproducibility of the diffusion metrics on atlas-based white matter ROIs on the white matter skeleton. Despite the differences of MRI scanner configurations across sites (vendors, models, RF coils and acquisition sequences) we found good and consistent test-retest reproducibility. White matter b0 SNR reproducibility was on average 7 ± 1% with no significant MRI site effects. Whole brain analysis resulted in no significant test-retest differences at any of the sites with any of the DTI metrics. The atlas-based ROI analysis showed that the mean reproducibility errors largely remained in the 2-4% range for FA and AD and 2-6% for MD and RD, averaged across ROIs. Our results show reproducibility values comparable to those reported in studies using a smaller number of MRI scanners, slightly different DTI protocols and mostly younger populations. We therefore show that the acquisition and analysis protocols used are appropriate for multi-site experimental scenarios.


Asunto(s)
Imagen de Difusión Tensora/normas , Sustancia Blanca/anatomía & histología , Anciano , Anciano de 80 o más Años , Imagen de Difusión Tensora/instrumentación , Imagen de Difusión Tensora/métodos , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
18.
PLoS One ; 8(6): e66834, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23825570

RESUMEN

Motor impairment is the most relevant clinical feature in Parkinson's disease (PD). Functional imaging studies on motor impairment in PD have revealed changes in the cortical motor circuits, with particular involvement of the fronto-striatal network. The aim of this study was to assess brain activations during the performance of three different motor exercises, characterized by progressive complexity, using a functional fMRI multiple block paradigm, in PD patients and matched control subjects. Unlike from single-task comparisons, multi-task comparisons between similar exercises allowed to analyse brain areas involved in motor complexity planning and execution. Our results showed that in the single-task comparisons the involvement of primary and secondary motor areas was observed, consistent with previous findings based on similar paradigms. Most notably, in the multi-task comparisons a greater activation of supplementary motor area and posterior parietal cortex in PD patients, compared with controls, was observed. Furthermore, PD patients, compared with controls, had a lower activation of the basal ganglia and limbic structures, presumably leading to the impairment in the higher levels of motor control, including complexity planning and execution. The findings suggest that in PD patients occur both compensatory mechanisms and loss of efficiency and provide further insight into the pathophysiological role of distinct cortical and subcortical areas in motor dysfunction.


Asunto(s)
Corteza Cerebral/fisiopatología , Imagen por Resonancia Magnética , Actividad Motora , Enfermedad de Parkinson/fisiopatología , Anciano , Conducta/fisiología , Estudios de Casos y Controles , Corteza Cerebral/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad
19.
New Microbiol ; 36(2): 193-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23686126

RESUMEN

Stroke due to brain vascular disease is a serious complication of tuberculous meningitis (TBM). This study evaluated the frequency, clinical characteristics, risk factors and outcomes of patients with TBM complicated by stroke admitted to the Infectious Disease Clinic, University of Perugia Hospital, Italy from 1971 to 2010. Over four decades, 419 patients were admitted with tuberculosis, of these 30 (7.1%) were diagnosed with TBM: 20 definite, one probable and nine possible. Twenty-six were evaluable for stroke and six (23%) had stroke. The latter six had advanced stages of meningitis, two tested HIV positive, three HIV negative and in one HIV was not performed. Of seven patients without stroke tested for HIV, only one resulted positive. No differences were found regarding CSF cell count, sugar, protein, microscopy or growth of Mycobacterium tuberculosis among patients with or without stroke. The overall survival rate at discharge was 83% in patients with stroke and 95% in those without stroke. It was found that stroke can be frequent among patients with TBM and the presence of HIV infection might be associated with a higher rate of stroke. Further research is needed on these findings, especially in low TB endemic countries.


Asunto(s)
Accidente Cerebrovascular/epidemiología , Tuberculosis Meníngea/complicaciones , Adolescente , Adulto , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Humanos , Italia/epidemiología , Masculino , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/aislamiento & purificación , Mycobacterium tuberculosis/fisiología , Factores de Riesgo , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/mortalidad , Tasa de Supervivencia , Tuberculosis/epidemiología , Tuberculosis/microbiología , Tuberculosis Meníngea/microbiología , Adulto Joven
20.
Mediterr J Hematol Infect Dis ; 5(1): e2013017, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23505605

RESUMEN

Tuberculous meningitis (TBM) is a devastating disease. TBM occurs more commonly in HIV infected patients. The influence of HIV co-infection on clinical manifestations and outcome of TBM is not well defined. Yet, some differences have been observed and stroke has been recorded to occur more frequently. This study reports on an HIV infected Caucasian female with lung, meningeal tuberculosis and stroke due to a cortical sub-cortical ischemic lesion. TBM was documented in the absence of neurologic symptoms. At the same time, miliary lung TB caused by multi-susceptible Mycobacterium tuberculosis was diagnosed. Anti-TB therapy consisting of a combination of four drugs was administered. The patient improved and was discharged five weeks later. In conclusion, TBM and multiple underling pathologies including HIV infection, as well as other risk factors can lead to a greater risk of stroke. Moreover, drug interactions and their side effects add levels of complexity. TBM must be included in the differential diagnosis of HIV infected patients with stroke and TBM treatment needs be started as soon as possible before the onset of vasculopathy.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...