Harvard University
ORCID: 0000-0002-8664-7707Publishes on Neurofibromatosis and Schwannoma Cases, Acute Ischemic Stroke Management, Radiomics and Machine Learning in Medical Imaging. 207 papers and 14.2k citations.
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High-functioning autistic and normal school-age boys were compared using a whole-brain morphometric profile that includes both total brain volume and volumes of all major brain regions. We performed MRI-based morphometric analysis on the brains of 17 autistic and 15 control subjects, all male with normal intelligence, aged 7-11 years. Clinical neuroradiologists judged the brains of all subjects to be clinically normal. The entire brain was segmented into cerebrum, cerebellum, brainstem and ventricles. The cerebrum was subdivided into cerebral cortex, cerebral white matter, hippocampus-amygdala, caudate nucleus, globus pallidus plus putamen, and diencephalon (thalamus plus ventral diencephalon). Volumes were derived for each region and compared between groups both before and after adjustment for variation in total brain volume. Factor analysis was then used to group brain regions based on their intercorrelations. Volumes were significantly different between groups overall; and diencephalon, cerebral white matter, cerebellum and globus pallidus-putamen were significantly larger in the autistic group. Brain volumes were not significantly different overall after adjustment for total brain size, but this analysis approached significance and effect sizes and univariate comparisons remained notable for three regions, although not all in the same direction: cerebral white matter showed a trend towards being disproportionately larger in autistic boys, while cerebral cortex and hippocampus-amygdala showed trends toward being disproportionately smaller. Factor analysis of all brain region volumes yielded three factors, with central white matter grouping alone, and with cerebral cortex and hippocampus-amygdala grouping separately from other grey matter regions. This morphometric profile of the autistic brain suggests that there is an overall increase in brain volumes compared with controls. Additionally, results suggest that there may be differential effects driving white matter to be larger and cerebral cortex and hippocampus-amygdala to be relatively smaller in the autistic than in the typically developing brain. The cause of this apparent dissociation of cerebral cortical regions from subcortical regions and of cortical white from grey matter is unknown, and merits further investigation.
PURPOSE: One third of women with advanced human epidermal growth factor receptor 2 (HER-2)-positive breast cancer develop brain metastases; a subset progress in the CNS despite standard approaches. Medical therapies for refractory brain metastases are neither well-studied nor established. We evaluated the safety and efficacy of lapatinib, an oral inhibitor of epidermal growth factor receptor (EGFR) and HER-2, in patients with HER-2-positive brain metastases. PATIENTS AND METHODS: Patients had HER-2-positive breast cancer, progressive brain metastases, prior trastuzumab treatment, and at least one measurable metastatic brain lesion. Patients received lapatinib 750 mg orally twice a day. Tumor response was assessed by magnetic resonance imaging every 8 weeks. The primary end point was objective response (complete response [CR] plus partial response [PR]) in the CNS by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included objective response in non-CNS sites, time to progression, overall survival, and toxicity. RESULTS: Thirty-nine patients were enrolled. All patients had developed brain metastases while receiving trastuzumab; 37 had progressed after prior radiation. One patient achieved a PR in the brain by RECIST (objective response rate 2.6%, 95% conditional CI, 0.21% to 26%). Seven patients (18%) were progression free in both CNS and non-CNS sites at 16 weeks. Exploratory analyses identified additional patients with some degree of volumetric reduction in brain tumor burden. The most common adverse events (AEs) were diarrhea (grade 3, 21%) and fatigue (grade 3, 15%). CONCLUSION: The study did not meet the predefined criteria for antitumor activity in highly refractory patients with HER-2-positive brain metastases. Because of the volumetric changes observed in our exploratory analysis, further studies are underway utilizing volumetric changes as a primary end point.
BACKGROUND AND PURPOSE: Despite the abundance of emerging multimodal imaging techniques in the field of stroke, there is a paucity of data demonstrating a strong correlation between imaging findings and clinical outcome. This study explored how proximal arterial occlusions alter flow in collateral vessels and whether occlusion or extent of collaterals correlates with prehospital symptoms of fluctuation and worsening since onset or predict in-hospital worsening. METHODS: Among 741 patients enrolled in a prospective cohort study involving CT angiographic imaging in acute stroke, 134 cases with proximal middle cerebral artery occlusion and 235 control subjects with no occlusions were identified. CT angiography was used to identify occlusions and grade the extent of collateral vessels in the sylvian fissure and leptomeningeal convexity. History of symptom fluctuation or progressive worsening was obtained on admission. RESULTS: Prehospital symptoms were unrelated to occlusion or collateral status. In cases, 37.5% imaged within 1 hour were found to have diminished collaterals versus 12.1% imaged at 12 to 24 hours (P=0.047). No difference in worsening was seen between cases and control subjects with adequate collaterals, but cases with diminished sylvian and leptomeningeal collaterals experienced greater risk of worsening compared with control subjects measured either by admission to discharge National Institutes of Health Stroke Scale increase > or =1 (55.6% versus 16.6%, P=0.001) or > or =4 (44.4% versus 6.4%, P<0.001). CONCLUSIONS: Most patients with proximal middle cerebral artery occlusion rapidly recruit sufficient collaterals and follow a clinical course similar to patients with no occlusions, but a subset with diminished collaterals is at high risk for worsening.