The Wohl Institute for Advanced Imaging

Tel Aviv, Israel

The Wohl Institute for Advanced Imaging

Tel Aviv, Israel

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PubMed | Tel Aviv Sourasky Medical Center, Bar - Ilan University, Oxford Brookes University, Child Development & Pediatric Neurology Service and 4 more.
Type: | Journal: Neural plasticity | Year: 2015

Neuroplasticity studies examining children with hemiparesis (CH) have focused predominantly on unilateral interventions. CH also have bimanual coordination impairments with bimanual interventions showing benefits. We explored neuroplasticity following hand-arm bimanual intensive therapy (HABIT) of 60 hours in twelve CH (6 females, mean age 11 3.6y). Serial behavioral evaluations and MR imaging including diffusion tensor (DTI) and functional (fMRI) imaging were performed before, immediately after, and at 6-week follow-up. Manual skills were assessed repeatedly with the Assisting Hand Assessment, Childrens Hand Experience Questionnaire, and Jebsen-Taylor Test of Hand Function. Beta values, indicating the level of activation, and lateralization index (LI), indicating the pattern of brain activation, were computed from fMRI. White matter integrity of major fibers was assessed using DTI. 11/12 children showed improvement after intervention in at least one measure, with 8/12 improving on two or more tests. Changes were retained in 6/8 children at follow-up. Beta activation in the affected hemisphere increased at follow-up, and LI increased both after intervention and at follow-up. Correlations between LI and motor function emerged after intervention. Increased white matter integrity was detected in the corpus callosum and corticospinal tract after intervention in about half of the participants. Results provide first evidence for neuroplasticity changes following bimanual intervention in CH.

Green D.,Tel Aviv University | Green D.,Evelina Childrens Hospital Guys and St Thomas NHS Foundation Trust | Green D.,Oxford Brookes University | Schertz M.,Paediatric Neurology Unit | And 8 more authors.
Developmental Medicine and Child Neurology | Year: 2013

Aim: This study investigated the effects of a theme-based ('magic') variation of the hand-arm bimanual intensive therapy programme, in two different countries, in improving activity performance for children with hemiplegia, including those with severe movement restrictions. Method: Twenty-three children with spastic hemiplegia (13 males, 10 females; mean age 10y 7mo, range 7-15y; Manual Ability Classification System level I, two; level II, 13; level III, eight), participated in one of three, 2-week, summer camps. A within-participant experimental design was used with the Assisting Hand Assessment and Children's Hand Experience Questionnaire as primary outcome measures. Evaluations occurred immediately before the first day, on the last day, and 3 months after intervention. Two groups underwent additional assessments 2 weeks before the camp. Results: Significant intervention effects were seen on the Assisting Hand Assessment (p=0.002) and on the Children's Hand Experience Questionnaire (p<0.001), the latter maintained at follow-up. The affected hand was reported to be used in 25% of bimanual activities before the camp, progressing to 93% after camp, and decreasing to 86% at follow-up. Severity of impairment did not influence progress. Interpretation: This themed approach to intensive intervention showed positive results in bimanual use, with improvements in independence sustained at follow-up. Although children across camps and motor severity made progress, some questions remain about intensity and duration of intervention to optimize longer-term outcomes. © 2013 Mac Keith Press.

PubMed | The Wohl Institute for Advanced Imaging, Hebrew University of Jerusalem, Tel Aviv University, The Gilbert Israeli Neurofibromatosis Center and Sheba Medical Center
Type: Journal Article | Journal: Pediatric blood & cancer | Year: 2015

Optic pathway gliomas (OPG) represent 5% of pediatric brain tumors and compose a major therapeutic dilemma to the treating physicians. While chemotherapy is widely used for these tumors, our ability to predict radiological response is still lacking. In this study, we use volumetric imaging to examine in detail the long-term effect of chemotherapy on the tumor as well as its various sub-components.The tumors of 15 patients with OPG, treated with chemotherapy, were longitudinally measured using our novel, previously described volumetric method. Patients were treated with up to five lines of chemotherapy. Sufficient follow-up imaging data, and patients numbers, allowed for analysis of two treatment lines. Volumetric measurements of the tumors were segmented into solid-non-enhancing, solid-enhancing, and cystic components. Outcome analysis was done per specific treatment line and for the overall follow-up period.An average reduction of 9.7% (23%) in the gross-total-solid volume (GTSV) was noted following treatment with vincristine and carboplatin. The cystic component grew under therapy by an average of 12.6% (39%). When measured over the course of the whole study period, the cystic component grew by an average of 35% (100%) and the GTSV increased by 12% (35%).Initial treatment with vincristine and carboplatin seems to have a minimal initial effect, mostly on the solid components. The cystic component in itself seems to be unaffected by chemotherapy, and contributes to the subsequent growth of the total volume. During the overall treatment period, both solid and cystic components grew regardless of combined treatment methods.

PubMed | Tel Aviv Sourasky Medical Center, Bar - Ilan University, Childrens Hospital of Eastern Ontario, Tel Aviv University and 3 more.
Type: | Journal: Neural plasticity | Year: 2016

The brain has a remarkable capacity for reorganization following injury, especially during the first years of life. Knowledge of structural reorganization and its consequences following perinatal injury is sparse. Here we studied changes in brain tissue volume, morphology, perfusion, and integrity in children with hemiplegia compared to typically developing children, using MRI. Children with hemiplegia demonstrated reduced total cerebral volume, with increased cerebrospinal fluid (CSF) and reduced total white matter volumes, with no differences in total gray matter volume, compared to typically developing children. An increase in cortical thickness at the hemisphere contralateral to the lesion (CLH) was detected in motor and language areas, which may reflect compensation for the gray matter loss in the lesion area or retention of ipsilateral pathways. In addition, reduced cortical thickness, perfusion, and surface area were detected in limbic areas. Increased CSF volume and precentral cortical thickness and reduced white matter volume were correlated with worse motor performance. Brain reorganization of the gray matter within the CLH, while not necessarily indicating better outcome, is suggested as a response to neuronal deficits following injury early in life.

PubMed | the Wohl Institute for Advanced Imaging, Tel Aviv University, Tel Aviv Sourasky Medical Center and Carmel Medical Center
Type: Journal Article | Journal: Hippocampus | Year: 2016

The hippocampus is known to play a vital role in learning and memory and was demonstrated as an early imaging marker for Alzheimers disease (AD). However, its role as a predictor for mild cognitive impairment and dementia following stroke is unclear. The main purpose of this study was to examine the associations between hippocampal volume, mean diffusivity (MD) and connectivity and cognitive state following stroke. Eighty three consecutive first ever mild to moderate stroke or transient ischemic attack (TIA) survivors from our ongoing prospective TABASCO (Tel Aviv Brain Acute Stroke Cohort) study underwent magnetic resonance imaging scans within 7 days of stroke onset. Hippocampal volume was measured from T1 weighted images, hippocampal mean diffusivity was calculated from diffusion tensor imaging and connectivity was calculated from resting state fMRI. Global cognitive assessments were evaluated during hospitalization and 6 and 12 months later using a computerized neuropsychological battery. Multiple linear regression analysis was used to test which of the hippocampi measurements best predict cognitive state. All three imaging parameters were significantly correlated to each other (|rs| >0.3, Ps<0.005), and with cognitive state 6 and 12 months after the event. Multiple regression analyses demonstrated the predictive role of hippocampal mean diffusivity (=-0.382, P=0.026) on cognitive state, above and beyond that of volume and connectivity of this structure. To our knowledge, the combination of hippocampal volume, mean diffusivity and connectivity in first ever post stroke or TIA patients has not yet been considered in relation to cognitive state. The results demonstrate the predictive role of hippocampal mean diffusivity, suggesting that these changes may precede and contribute to volumetric and connectivity changes in the hippocampi, potentially serving as a marker for early identification of patients at risk of developing cognitive impairment or dementia.

PubMed | The Wohl Institute for Advanced Imaging and Tel Aviv Sourasky Medical Center
Type: Comparative Study | Journal: Journal of neuro-oncology | Year: 2016

Differentiation between treatment-related changes and progressive disease (PD) remains a major clinical challenge in the follow-up of patients with high grade brain tumors. The aim of this study was to differentiate between treatment-related changes and PD using dynamic contrast enhanced (DCE) MRI. Twenty patients were scanned using conventional, DCE-MRI and MR spectroscopy (total of 44 MR scans). The enhanced lesion area was extracted using independent components analysis of the DCE data. Pharmacokinetic parameters were estimated from the DCE data based on the Extended-Tofts-Model. Voxel based classification for treatment-related changes versus PD was performed in a patient-wise leave-one-out manner, using a support vector machine classifier. DCE parameters, K (trans), v e, k ep and v p, significantly differentiated between the tissue types. Classification results were validated using spectroscopy data showing significantly higher choline/creatine values in the extracted PD component compared to areas with treatment-related changes and normal appearing white matter, and high correlation between choline/creatine values and the percentage of the identified PD component within the lesion area (r=0.77, p<0.001). On the training data the sensitivity and specificity were 98 and 97%, respectively, for the treatment-related changes component and 97 and 98% for the PD component. This study proposes a methodology based on DCE-MRI to differentiate lesion areas into treatment-related changes versus PD, prospectively in each scan. Results may have major clinical importance for pre-operative planning, guidance for targeting biopsy, and early prediction of radiological outcomes in patients with high grade brain tumors.

PubMed | The Wohl Institute for Advanced Imaging and Tel Aviv Sourasky Medical Center
Type: | Journal: Journal of neuro-oncology | Year: 2017

Normal brain cells depend on glucose metabolism, yet they have the flexibility to switch to the usage of ketone bodies during caloric restriction. In contrast, tumor cells lack genomic and metabolic flexibility and are largely dependent on glucose. Ketogenic-diet (KD) was suggested as a therapeutic option for malignant brain cancer. This study aimed to detect metabolic brain changes in patients with malignant brain gliomas on KD using proton magnetic-resonance-spectroscopy (

PubMed | the Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center and Tel Aviv University
Type: Journal Article | Journal: Human brain mapping | Year: 2016

We present a novel method for fiber-based comparison of diffusion tensor imaging (DTI) scans of groups of subjects. The method entails initial preprocessing and fiber reconstruction by tractography of each brain in its native coordinate system. Several diffusion parameters are sampled along each fiber and used in subsequent comparisons. A spatial correspondence between subjects is established based on geometric similarity between fibers in a template set (several choices for template are explored), and fibers in all other subjects. Diffusion parameters between groups are compared statistically for each template fiber. Results are presented at single fiber resolution. As an initial exploratory step in neurological population studies this method points to the locations affected by the pathology of interest, without requiring a hypothesis. It does not make any grouping assumptions on the fibers and no manual intervention is needed. The framework was applied here to 18 healthy subjects and 23 amyotrophic lateral sclerosis (ALS) patients. The results are compatible with previous findings and with the tract based spatial statistics (TBSS) method. Hum Brain Mapp 37:477-490, 2016. 2015 Wiley Periodicals, Inc.

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