Publications by authors named "Pablo Villablanca"

Background: Validating the National Institutes of Health NIH Stroke Scale (NIHSS) as a tool to assess deficit severity and prognosis in patients with acute intracerebral hemorrhage would harmonize the assessment of intracerebral hemorrhage (ICH) and acute ischemic stroke (AIS) patients, enable clinical use of a readily implementable and non-imaging dependent prognostic tool, and improve monitoring of ICH care quality in administrative datasets.

Methods: Among randomized trial ICH patients, the relation between NIHSS scores early after Emergency Department arrival and 3-month outcomes of dependency or death (modified Rankin Scale, mRS 3-6) and case fatality was examined. NIHSS predictive performance was compared to a current standard prognostic scale, the intracerebral hemorrhage score (ICH score).

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Background And Purpose: Perfusion-based collateral indices such as the perfusion collateral index and the hypoperfusion intensity ratio have shown promise in the assessment of collaterals in patients with acute ischemic stroke. We aimed to compare the diagnostic performance of the perfusion collateral index and the hypoperfusion intensity ratio in collateral assessment compared with angiographic collaterals and outcome measures, including final infarct volume, infarct growth, and functional independence.

Materials And Methods: Consecutive patients with acute ischemic stroke with anterior circulation proximal arterial occlusion who underwent endovascular thrombectomy and had pre- and posttreatment MRI were included.

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Background: While image-derived predictors of intracranial aneurysm (IA) rupture have been well-explored, current understanding of IA growth is limited. Pulsatility index (PI) and wall shear stress pulsatility index (WSSPI) are important metrics measuring temporal hemodynamic instability. However, they have not been investigated in IA growth research.

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Collateral status has prognostic and treatment implications in acute ischemic stroke (AIS) patients. Unlike CTA, grading collaterals on MRA is not well studied. We aimed to evaluate the accuracy of assessing collaterals on pretreatment MRA in AIS patients against DSA.

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Background: To emphasize treatment speed for time-sensitive conditions, emergency medicine has developed not only the concept of the golden hour, but also the platinum half-hour. Patients with acute stroke treated within the first half-hour of onset have not been previously characterized.

Methods: In this cohort study, we analyzed patients enrolled in the FAST-MAG (Field Administration of Stroke Therapy-Magnesium) trial, testing paramedic prehospital start of neuroprotective agent ≤2 hours of onset.

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Objectives: The US Centers for Medicare and Medicaid Services (CMS) currently publicly reports hospital-quality, risk-adjusted mortality measure for ischemic stroke but not intracerebral hemorrhage (ICH). The NIHSS, which is captured in CMS administrative claims data, is a candidate metric for use in ICH risk adjustment and has been shown to predict clinical outcome with accuracy similar to the ICH Score. Correlation between early NIHSS and initial ICH volume would further support use of the NIHSS for ICH risk adjustment.

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Schizophrenia (SCZ) is a chronic cognitive and behavioral disorder associated with abnormal cortical activity during information processing. Several brain structures associated with the seven performance domains evaluated using the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB) have shown cortical volume loss in first episode schizophrenia (FES) patients. However, the relationship between morphological organization and MCCB performance remains unclear.

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Fourty-seven-year-old woman with 5-year history of progressive decreased left eye vision. Optical coherence tomography showed optic nerve atrophy (left > right) and brain MRI revealed T2 hyperintense signal along the course of left optic radiations. We present a case of a trans-synaptic degeneration of the optic radiation in a patient with confirmed optic atrophy.

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This cross-sectional study examines the differences in cortical volume and gray-to-white matter contrast (GWC) in first episode schizophrenia patients (SCZ) compared to healthy control participants (HC) and in SCZ patients as a function of exposure to second generation antipsychotic medication. We hypothesize 1) SCZ exhibit regionally lower cortical volumes relative to HCs, 2) cortical volume will be greater with longer exposure to second generation antipsychotics prior to the MRI scan, and 3) lower GWC with longer exposure to second generation antipsychotics prior to the MRI scan, suggesting more blurring from greater intracortical myelin. To accomplish this, MRI scans from 71 male SCZ patients treated with second generation oral risperidone and 42 male HCs were examined.

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Brain arteriovenous malformations (AVMs) are vascular abnormalities that typically present with spontaneous hemorrhage, seizure, or as a mass lesion. Pediatric brain AVMs are rarely diagnosed but carry a higher rate of rupture. We report a 7-week-old infant with rapid fatal intracranial hemorrhage from an undiagnosed brain.

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Background: MRI exams for patients with MR-conditional active implantable medical devices (AIMDs) are contraindicated unless specific conditions are met. This limits the maximum specific absorption rate (SAR, W/kg). Currently, there is no general framework to guide meeting a lower SAR limit.

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Purpose: To use machine learning tools and leverage big data informatics to statistically model the variation in the area of lumbar neural foramina in a large asymptomatic population.

Materials And Methods: By using an electronic health record and imaging archive, lumbar MRI studies in 645 male (mean age, 50.07 years) and 511 female (mean age, 48.

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Cerebral acidosis is a consequence of secondary injury mechanisms following traumatic brain injury (TBI), including excitotoxicity and ischemia, with potentially significant clinical implications. However, there remains an unmet clinical need for technology for non-invasive, high resolution pH imaging of human TBI for studying metabolic changes following injury. The current study examined 17 patients with TBI and 20 healthy controls using amine chemical exchange saturation transfer echoplanar imaging (CEST EPI), a novel pH-weighted molecular MR imaging technique, on a clinical 3T MR scanner.

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Article Synopsis
  • A new reliable animal model for studying ischemic stroke in rabbits is established through a technique called middle cerebral artery (MCA) embolic occlusion, allowing for better pre-clinical evaluation of stroke therapies.
  • The method involved placing a microcatheter to create MCA occlusion with real-time imaging, confirming the procedure's success in all test subjects, and tracking changes in brain tissue through MRI and histopathology for up to six hours post-occlusion.
  • Results showed consistent structural changes in the brain, such as edema and disruptions in blood-brain barrier, mirroring the conditions seen in human ischemic strokes, aiding in future stroke research.
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Objective: We aimed to investigate the geometric features of the middle cerebral artery (MCA) and their relevance to plaque distribution and ischemic stroke.

Methods: We reviewed our institutional vessel wall imaging database. Patients with symptomatic MCA atherosclerosis, asymptomatic MCA atherosclerosis, or without MCA atherosclerosis were included.

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Sterile postoperative seromas can develop after posterior spinal surgery and cause pain, weakness, and numbness. Management typically involves operative evacuation. We propose that these collections can be managed with percutaneous computed tomography (CT) guided aspiration, potentially saving the patient an additional surgery.

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We have reviewed the English literature published in the last 70 years on Diseases of the Vertebral Basilar Circulation, or Posterior Circulation Disease (PCD). We have found that errors have been made in the conduct and interpretation of these studies that have led to incorrect approaches to the management of PCD. Because of the difficulty in evaluating the PC, the management of PCD has been incorrectly applied from anterior circulation disease (ACD) experience to PCD.

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Objective: Injury severity after traumatic brain injury (TBI) is a well-established risk factor for the development of post-traumatic epilepsy (PTE). However, whether lesion location influences the susceptibility of seizures and development of PTE longitudinally has yet to be defined. We hypothesized that lesion location, specifically in the temporal lobe, would be associated with an increased incidence of both early seizures and PTE.

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Background: Postmortem and imaging studies provide converging evidence that the frontal lobe myelination trajectory is dysregulated in schizophrenia (SZ) and suggest that early in treatment, antipsychotic medications increase intracortical myelin (ICM). We used magnetic resonance imaging to examine whether the ICM trajectory in SZ is dysregulated and altered by antipsychotic treatment.

Methods: We examined 93 subjects with SZ (64 men and 29 women) taking second-generation oral antipsychotics with medication exposures of 0-333 months in conjunction with 80 healthy control subjects (52 men and 28 women).

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Background And Purpose: The impact of blood-brain barrier (BBB) disruption can be detected by intraparenchymal hyperdense lesion on the computed tomography (CT) scan after endovascular stroke therapy. The purpose of this study was to determine whether early BBB disruption predicts intracranial hemorrhage and poor outcome in patients with acute ischemic stroke treated with mechanical thrombectomy.

Methods: We analyzed patients with anterior circulation stroke treated with mechanical thrombectomy and identified BBB disruption on the noncontrast CT images immediately after endovascular treatment.

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The anatomy of the vertebral column in mammals may differ between species and between subjects of the same species, especially with regards to the composition of the thoracolumbar spine. We investigated, using several noninvasive imaging techniques, the thoracolumbar spine of a total of 44 adult rhesus macaques of both genders. Radiographic examination of the vertebral column showed a predominant spine phenotype with 12 rib-bearing thoracic vertebrae and 7 lumbar vertebrae without ribs in 82% of subjects, whereas a subset of subjects demonstrated 13 rib-bearing thoracic vertebrae and 6 lumbar vertebrae without ribs.

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Background: Advances in diagnostic imaging of stroke include multimodal techniques such as noninvasive angiography and perfusion imaging. We aimed to characterize trends in neuroimaging utilization among acute stroke patients. Utilization of multimodal imaging for acute stroke in the community has remained largely uncharacterized despite its increased adoption at academic medical centers.

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The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices.

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Background: The influence of cerebral microbleeds (CMBs) on post-thrombolytic hemorrhagic transformation (HT) in patients with acute ischemic stroke remains controversial.

Objective: To investigate the association of CMBs with HT and clinical outcomes among patients with large-vessel occlusion strokes treated with mechanical thrombectomy.

Methods: We analyzed patients with acute stroke treated with Merci Retriever, Penumbra system or stent-retriever devices.

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The electronic health record (EHR) contains a diverse set of clinical observations that are captured as part of routine care, but the incomplete, inconsistent, and sometimes incorrect nature of clinical data poses significant impediments for its secondary use in retrospective studies or comparative effectiveness research. In this work, we describe an ontology-driven approach for extracting and analyzing data from the patient record in a longitudinal and continuous manner. We demonstrate how the ontology helps enforce consistent data representation, integrates phenotypes generated through analyses of available clinical data sources, and facilitates subsequent studies to identify clinical predictors for an outcome of interest.

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