Arturo Tamayo - Academia.edu (original) (raw)

Papers by Arturo Tamayo

Journal of Clinical Medicine

Background: We characterized clinical and imaging phenotypes and their association with clinical ... more Background: We characterized clinical and imaging phenotypes and their association with clinical outcomes in acute ischemic stroke (AIS) survivors in the understudied region of Costa Rica. Methods: We conducted a retrospective cohort study in AIS patients treated at a tertiary stroke center in Costa Rica from 2011–2015. Participants underwent detailed phenotyping for cardiovascular risk factors and stroke etiology. We assessed the association of ischemic brain lesion features and clinical outcomes using the Oxfordshire Community Stroke Project (OCSP) classification. Results: We included 684 AIS survivors (60.2% males, aged 68.1 ± 13.6 years, mean ± SD). While the cardiovascular risk profiles and mortality rates of our patients were similar to populations in European and North American countries, only 20.2% of patients with atrial fibrillation (AF) received anticoagulation. On multivariable analysis, patients with total anterior circulation infarct (TACI) displayed an increased risk ...

Principles and Practice of Clinical Research Journal

Background: Hypokinetic dysarthria-with hypophonia as its main symptom-is a common feature of Par... more Background: Hypokinetic dysarthria-with hypophonia as its main symptom-is a common feature of Parkinson's disease, affecting approximately 90% of patients. Hypophonia, characterized by reduced speech volume, leads to difficulties in communication with others due to decreased speech intelligibility. Current treatments involve intensive and cognitively demanding behavioral therapies such as the Lee Silverman Voice Treatment (LSVT). The SpeechVive is a wearable device that produces noise to elicit increased vocal intensity utilizing a natural reflex through the Lombard effect. Methods: We propose a multicenter, phase III, two-armed, parallel, open-label, randomized controlled trial comparing the effectiveness of LSVT with SpeechVive. We seek to assign 238 patients to either LSVT or SpeechVive device in a 1:1 ratio through a stratified permuted block randomization. Patients ages 50 to 80 years, diagnosed with idiopathic Parkinson's Disease based on MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) criteria, a Hoehn and Yahr stage 2 and 3, on stable dopaminergic doses for the past 3 months, with perceived communication difficulties will be included in the trial. Patients will be excluded if they present additional neurodegenerative diseases, prior stroke, laryngeal pathologies, hearing or a severe visual impairment, or who underwent speech therapy or have a deep brain stimulation electrode implanted. The primary outcome is speech intelligibility measured through the Speech Intelligibility Test (SIT) for windows. Secondary outcomes include adherence, the vocal intensity measured with Sound Pressure Level (SPL), Vocal Handicap Index (VIH), and Parkinson's Disease Questionary-39. We will measure each outcome at baseline and after eight weeks of treatment. Our principal statistical analysis is multiple linear regression analysis, with age, gender, site, and PD severity as covariates. Discussion: We present a protocol for a randomized controlled trial addressing an important issue that hampers the ability of Parkinson's Disease patients to communicate effectively. We aim at exploring SpeechVive as an alternative, more accessible treatment for hypophonia in patients with Parkinson's Disease.

Stroke, 2001

P237 Background: In the setting of acute myocardial infarction, aspirin has a significant benefit... more P237 Background: In the setting of acute myocardial infarction, aspirin has a significant benefit on mortality when combined with a thrombolytic. The NINDS guidelines recommend witholding antiplatelet agents (APA) for 24 hours after tPA administration for acute stroke. Post hoc analysis of the NINDS tPA study did not show worse outcomes in patients using APA prior to treatment, even though APA have a long platelet-inhibitory effect (the life of the platelet). Objective: To determine whether concomitant APA and tPA use was associated with worse outcomes. Method: We compared demographics, vascular risk factors, hemorrhagic complications, and 3 month outcomes of patients on APA at the time of their stroke with those patients not taking APA, in our prospective registry of tPA-treated patients. Results: Between 1 December 1998 and 24 July 2000, 64 patients were treated with tPA; 3 month follow-up data are available on 47 (73%). At the time of their stroke, 24 (38%) were taking APA, 40 (6...

Xenotransplantation is the transplantation of livingcells, tissues or organs from one species to ... more Xenotransplantation is the transplantation of livingcells, tissues or organs from one species to an-other.1,2 Until recently, hyperacute rejection posed an absolute barrier to xenotransplantation, but this has been greatly diminished by advances in genetic engineer-ing. Although other immunological3 and physiological4 hurdles still exist, pig-to-human xenotransplantation may soon be feasible. While there are concerns that xenotrans-plantation could promote the transmission of animal infec-tions to humans,5 the use of specific pathogen–free donor pigs should prevent the transmission of known zoonoses. However, there is a small, but not entirely negligible, risk from other agents.6 In 1996, Health Canada began formal consideration of po-tential regulatory frameworks for xenotransplantation clinical trials. A multidisciplinary Xenotransplant Expert Working Group (XEWG) was formed to consider ethical issues (both

Jose G. Merino, Brian Silver, Edward Wong, Bart Demaerschalk, Arturo Tamayo and Plasminogen Activ... more Jose G. Merino, Brian Silver, Edward Wong, Bart Demaerschalk, Arturo Tamayo and Plasminogen Activator for Acute Ischemic Stroke Physician Knowledge of the Benefits, Risks, and Contraindications of Tissue ISSN: 1524-4628 Copyright © 2001 American Heart Association. All rights reserved. Print ISSN: 0039-2499. Online Stroke is published by the American Heart Association. 7272 Greenville Avenue, Dallas, TX 72514 2001, 32:2208-2209 Stroke http://stroke.ahajournals.org/content/32/9/2208.3 located on the World Wide Web at: The online version of this article, along with updated information and services, is

Introduction: Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer and a seriou... more Introduction: Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer and a serious disease leading to increased morbidity and high medical costs worldwide. Despite the high recurrence rate of BCCs, the current standard of care consists of regular skin check-ups, with no know therapy to prevent the recurrence. Vitamin D is a safe, affordable, and easily available supplement used for various diseases. There is evidence suggesting its potential use in preventing BCCs, with studies showing that it inhibits the Hedgehog (HH) signaling pathway, an important stimulator of carcinogenesis and the main pathway in BCC development. The objective of this study is to determine the effect of oral vitamin D supplementation on the prevention of BCC redevelopment. Methods: This study is a phase III, multicenter, randomized, placebo-controlled, triple-blinded, superiority trial with two parallel groups on 1:1 allocation of 1746 patients with a previous diagnosis of BCC. The patients wi...

Principles and Practice of Clinical Research Journal, 2021

Introduction: Postoperative delirium (POD) is an important complication of major surgery in elder... more Introduction: Postoperative delirium (POD) is an important complication of major surgery in elderly patients. It increases morbidity and mortality, hospital stay, and total healthcare costs. Since no treatment has proven effective once POD is established, prevention is key. Evidence exists that bispectral index guided anesthesia (BIS-GA) and antipsychotics may independently reduce incidence of POD, but the efficacy of combining these preventive strategies is unknown. Objective: To compare the combination of olanzapine + BIS-GA with BIS-GA alone for prevention of POD in elderly patients undergoing major elective surgery. Methods: We propose a Phase II, multi-center, randomized, double-blind, parallel, placebo-controlled trial. The study arms will be BIS-GA + two doses of olanzapine 5mg given pre and postoperatively compared with BIS-GA + placebo in patients ≥65 years hospitalized for major elective surgery. Exclusion criteria include cardiac-and neurosurgery, dementia history, concurrent antipsychotic, anticholinergic, or sedative-hypnotic use, olanzapine allergy, delirium at hospital admission, cognitive impairment and inability to be interviewed. The primary outcome is incidence of POD diagnosed by DSM-V criteria and assessed by the Confusion Assessment Method (CAM) scale. Secondary outcomes include delirium severity, rescue therapy use, length of hospital stay and incidence of adverse events. Discussion: There is an increasing need for trials that advance knowledge in prophylactic methods to prevent delirium. By combining two preventive methods, we expect to decrease the incidence of POD, which will result in decreased morbidity, mortality, and total healthcare costs.

Thrombosis Research, 2020

Background: Venous thromboembolism (VTE) is the second leading cause of death in cancer patients.... more Background: Venous thromboembolism (VTE) is the second leading cause of death in cancer patients. In Brazil, even though low-molecular-weight heparin (LMWH) is the gold standard of care for the management of cancerassociated thrombosis (CAT), its cost limits its use and therefore warfarin is commonly prescribed. Direct oral anticoagulants (DOACs), such as edoxaban, have been introduced as an alternative in this setting. Objective: The aim of this study was to compare the cost-effectiveness of edoxaban with LMWH (Model 1) and warfarin (Model 2) to support clinicians and hospitals when choosing an anticoagulant to manage CAT. Materials and methods: Cost-effectiveness analyses were performed using Markov state-transition models over a timeframe of 5 years, in a hypothetical, 64 years-old patients cancer population with an index VTE event. Transition probabilities, costs, quality-adjusted life years (QALYs) and risk reductions were either derived from the literature, estimated or calculated. A willingness-to-pay limit of 3 Gross Domestic Product (GDP) per head was used. Deterministic and probabilistic sensitivity analyses were performed for robustness. The main outcome of this study was the incremental cost-effectiveness ratio (ICER), expressed as cost per QALY gained. Results: Model 1 base case analysis demonstrated dominance of edoxaban compared to LMWH, with an ICER of 5204.46,representingcostsavedperQALYlost.InModel2,edoxabanwasassociatedwitha5204.46, representing cost saved per QALY lost. In Model 2, edoxaban was associated with a 5204.46,representingcostsavedperQALYlost.InModel2,edoxabanwasassociatedwitha736.90 cost increase vs. warfarin, with an ICER of $2541.03. Sensitivity analyses confirmed base-case results. Conclusion: Edoxaban represents a cost-saving alternative to LMWH for the management of CAT and is costeffective vs. warfarin.

Frontiers in Oncology, 2020

Deep penetrating nevi (DPN) are rare melanocytic nevi, which can exhibit atypical histological fe... more Deep penetrating nevi (DPN) are rare melanocytic nevi, which can exhibit atypical histological features hampering the differentiation from malignant melanoma. DPN are considered benign melanocytic lesions, but rare spread to lymph nodes and unfavorable clinical outcomes associated with borderline/atypical DPN (B-DPN) has been reported. Since no guidelines are available for DPN and B-DPN, we aimed to review the literature on DPN and B-DPN to assess the management and prognosis. We screened 3,513 references from EMBASE, Scopus and Medline databases, and included 15 studies with a total of 355 DPN patients and 48 B-DPN patients. Therapeutic interventions ranged from simple excision to wide excisions and sentinel lymph node biopsy (SLNB), with block lymph node dissection in some positive SLNB cases. Follow-up periods ranged from 3 months to 23 years during which a total of five recurrences, two in DPN and three in B-DPN group, and three metastases, in B-DPN group, were reported. While some of the included studies comprised clinical and histopathological correlation, few included genetic assessment. The present review highlights the need for prospective cohort studies applying composite measures to identify effective regimens of diagnostic workup and treatment in DPN and B-DPN.

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2001

ABSTRACT: Background: A 1995 National Institute of Neurological Disorders (NINDS) study found ben... more ABSTRACT: Background: A 1995 National Institute of Neurological Disorders (NINDS) study found benefit for intravenous tissue plasminogen activator (tPA) in acute ischemic stroke (AIS). The symptomatic intracranial hemorrhage (SICH) rate in the NINDS study was 6.4%, which may be deterring some physicians from using this medication. Methods: Starting December 1, 1998, patients with AIS in London, Ontario were treated according to NINDS criteria with one major exception; those with approximately greater than one-third involvement of the idealized middle cerebral artery (MCA) territory on neuroimaging were excluded from treatment. The method used to estimate involvement of one-third MCA territory involvement bears the acronym ICE and had a median kappa value of 0.80 among five physicians. Outcomes were compared to the NINDS study. Results: Between December 1, 1998 and February 1, 2000, 30 patients were treated. Compared to the NINDS study, more London patients were treated after 90 minu...

CMAJ - Canadian Medical Association Journal, Apr 30, 2002

Frontiers in Neurology

Background: The constantly increasing incidence of stroke in younger individuals substantiates an... more Background: The constantly increasing incidence of stroke in younger individuals substantiates an urgent need for research to elucidate underlying risk factors and etiologies. Heretofore, the vast majority of studies on stroke in the young have been carried out in European and North American regions. We aimed to characterize cerebrovascular risk profiles in a Saudi Arabic cohort of consecutive young stroke patients.Methods: We retrospectively analyzed data from consecutive ischemic stroke patients aged 15 to 49 years who underwent detailed cardiocerebrovascular evaluation at a tertiary stroke care center in Makkah, Saudi Arabia. Distributions of risk factors and stroke etiologies were assessed in the entire cohort and in two strata of very young (15–40 years) and young to middle-aged patients (41–49) to account for variability in suggested age cutoffs.Results: In the entire cohort [n = 63, ages 44 (34–47) median, interquartile range], dyslipidemia (71.4%) and small vessel occlusion ...

Frontiers in Neurology

Posterior circulation involves the vertebrobasilar arteries, which supply oxygen and glucose to v... more Posterior circulation involves the vertebrobasilar arteries, which supply oxygen and glucose to vital human brainstem structures and other areas. This complex circulatory- perfusion system is not homogenous throughout the day; rather, its hemodynamic changes rely on physiological demands, ensuring brainstem perfusion. This dynamic autoregulatory pattern maintains cerebral perfusion during blood pressure changes. Accumulative evidence suggests that activity within the autonomic nervous system is involved in the regulation of cerebral blood flow. Neither the sympathetic nor parasympathetic nervous systems work independently. Functional studies have shown a tight and complicated cross talk between these systems. In pathological processes where sympathetic stimulation is present, systemic vasoconstriction is followed, representing the most important CNS parasympathetic trigger that will promote local vasodilation. Stroke is a clear example of this process. The posterior circulation is a...

Principles and Practice of Clinical Research Journal

Current sports medicine reports, 2018

Temporal lobe epilepsy (TLE) is a common form of epilepsy that presents with complex partial seiz... more Temporal lobe epilepsy (TLE) is a common form of epilepsy that presents with complex partial seizures and in some cases with generalization to tonic-clonic activity that are often well controlled with antiepileptic medication in up to two thirds of patients. The remaining one third with “medically i

Abstracts of the International Stroke Conference, 2001

50 Objectives: To develop a reliable method of estimation of >1/3 involvement of the middle ce... more 50 Objectives: To develop a reliable method of estimation of >1/3 involvement of the middle cerebral artery territory (MCAT) on early CT scan. Background: The European Cooperative Acute Stroke Study (ECASS) suggested that > 1/3 involvement of the MCAT on early CT scan was a risk factor for symptomatic intracerebral hemorrhage (SICH) following treatment with tissue plasminogen activator (tPA) for acute ischemic stroke (AIS). There are no published guidelines on how to perform such an evaluation. The ICE method was developed for the purpose of standardizing the approach of infarct size estimation. This method requires the observer of the CT scan to mentally: 1) Idealize the MCAT into an area approximating a trapezoid, 2) Close a geometric figure around the area(s) of hypodensity(ies), and 3) Estimate the ratio of the two geometric figures (C/I). Methods: Five stroke fellows (observers) were tested with 40 CT scans which had been performed within the first few hours of an acute neurological event. Observers were blinded to patient history. They were asked whether to treat the patient on the basis of the CT scan. The decision not to treat was predicated on the presence of hemorrhage or > 1/3 MCAT involvement. Results: Five scans showed evidence of hemorrhage. All observers detected the hemorrhages. The remaining scans were of patients with presumed ischemia. Six scans were thought to show > 1/3 MCAT involvement by all observers. For all scans, median interobserver agreement among 10 paired comparisons was 86% (range 73–93%). Median kappa was 0.72 (range 0.44–0.85, p Conclusion: The ICE method has very good interobserver reliability. The method merits further investigation among non-stroke physicians.

Cmaj Canadian Medical Association Journal, Apr 30, 2002

Canadian Journal of Cardiology, 2015

In patients with patent foramen ovale (PFO), strategies are needed to identify patients at higher... more In patients with patent foramen ovale (PFO), strategies are needed to identify patients at higher risk, who might benefit from PFO closure. We studied the frequency of detection of a right-to-left shunt (RLS) using transesophageal echocardiography (TEE) among patients with cryptogenic stroke and transcranial Doppler (TCD) to detect RLS, and analyzed the prediction of recurrent stroke according to TCD shunt grade, by detection of RLS on TEE, and by atrial septal aneurysm or mobility. Among 334 patients with TCD, 69.8% were female, with a mean (SD) age of 53 (14) years, with a median follow-up of 420 days. There were 284 cases with TCD and TEE; 54 (19%) had atrial septal aneurysm or mobility. Echocardiography failed to show a RLS in 43 (15.1%) of the patients who had TCD and TEE, even in some patients with high-grade shunts on TCD: 18 (42%) were grade 3 or higher on TCD. Survival free of stroke or transient ischemic attack was predicted significantly by TCD shunt grade < 2 (P = 0.028), shunt grade < 3 (P = 0.03), and shunt grade < 4 (P < 0.0001); this was attenuated by adjustment for risk factors in Cox regression (P = 0.08). Neither RLS on TEE (P = 0.47), or atrial septal aneurysm or mobility (P = 0.08), predicted events. Our findings suggest that TCD might be more sensitive than TEE for detection of RLS, which misses some cases with substantial RLS, and might be valuable for prediction of recurrent stroke or transient ischemic attack in patients with PFO. TCD complements TEE for management of suspected paradoxical embolism.

Journal of Clinical Medicine

Background: We characterized clinical and imaging phenotypes and their association with clinical ... more Background: We characterized clinical and imaging phenotypes and their association with clinical outcomes in acute ischemic stroke (AIS) survivors in the understudied region of Costa Rica. Methods: We conducted a retrospective cohort study in AIS patients treated at a tertiary stroke center in Costa Rica from 2011–2015. Participants underwent detailed phenotyping for cardiovascular risk factors and stroke etiology. We assessed the association of ischemic brain lesion features and clinical outcomes using the Oxfordshire Community Stroke Project (OCSP) classification. Results: We included 684 AIS survivors (60.2% males, aged 68.1 ± 13.6 years, mean ± SD). While the cardiovascular risk profiles and mortality rates of our patients were similar to populations in European and North American countries, only 20.2% of patients with atrial fibrillation (AF) received anticoagulation. On multivariable analysis, patients with total anterior circulation infarct (TACI) displayed an increased risk ...

Principles and Practice of Clinical Research Journal

Background: Hypokinetic dysarthria-with hypophonia as its main symptom-is a common feature of Par... more Background: Hypokinetic dysarthria-with hypophonia as its main symptom-is a common feature of Parkinson's disease, affecting approximately 90% of patients. Hypophonia, characterized by reduced speech volume, leads to difficulties in communication with others due to decreased speech intelligibility. Current treatments involve intensive and cognitively demanding behavioral therapies such as the Lee Silverman Voice Treatment (LSVT). The SpeechVive is a wearable device that produces noise to elicit increased vocal intensity utilizing a natural reflex through the Lombard effect. Methods: We propose a multicenter, phase III, two-armed, parallel, open-label, randomized controlled trial comparing the effectiveness of LSVT with SpeechVive. We seek to assign 238 patients to either LSVT or SpeechVive device in a 1:1 ratio through a stratified permuted block randomization. Patients ages 50 to 80 years, diagnosed with idiopathic Parkinson's Disease based on MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) criteria, a Hoehn and Yahr stage 2 and 3, on stable dopaminergic doses for the past 3 months, with perceived communication difficulties will be included in the trial. Patients will be excluded if they present additional neurodegenerative diseases, prior stroke, laryngeal pathologies, hearing or a severe visual impairment, or who underwent speech therapy or have a deep brain stimulation electrode implanted. The primary outcome is speech intelligibility measured through the Speech Intelligibility Test (SIT) for windows. Secondary outcomes include adherence, the vocal intensity measured with Sound Pressure Level (SPL), Vocal Handicap Index (VIH), and Parkinson's Disease Questionary-39. We will measure each outcome at baseline and after eight weeks of treatment. Our principal statistical analysis is multiple linear regression analysis, with age, gender, site, and PD severity as covariates. Discussion: We present a protocol for a randomized controlled trial addressing an important issue that hampers the ability of Parkinson's Disease patients to communicate effectively. We aim at exploring SpeechVive as an alternative, more accessible treatment for hypophonia in patients with Parkinson's Disease.

Stroke, 2001

P237 Background: In the setting of acute myocardial infarction, aspirin has a significant benefit... more P237 Background: In the setting of acute myocardial infarction, aspirin has a significant benefit on mortality when combined with a thrombolytic. The NINDS guidelines recommend witholding antiplatelet agents (APA) for 24 hours after tPA administration for acute stroke. Post hoc analysis of the NINDS tPA study did not show worse outcomes in patients using APA prior to treatment, even though APA have a long platelet-inhibitory effect (the life of the platelet). Objective: To determine whether concomitant APA and tPA use was associated with worse outcomes. Method: We compared demographics, vascular risk factors, hemorrhagic complications, and 3 month outcomes of patients on APA at the time of their stroke with those patients not taking APA, in our prospective registry of tPA-treated patients. Results: Between 1 December 1998 and 24 July 2000, 64 patients were treated with tPA; 3 month follow-up data are available on 47 (73%). At the time of their stroke, 24 (38%) were taking APA, 40 (6...

Xenotransplantation is the transplantation of livingcells, tissues or organs from one species to ... more Xenotransplantation is the transplantation of livingcells, tissues or organs from one species to an-other.1,2 Until recently, hyperacute rejection posed an absolute barrier to xenotransplantation, but this has been greatly diminished by advances in genetic engineer-ing. Although other immunological3 and physiological4 hurdles still exist, pig-to-human xenotransplantation may soon be feasible. While there are concerns that xenotrans-plantation could promote the transmission of animal infec-tions to humans,5 the use of specific pathogen–free donor pigs should prevent the transmission of known zoonoses. However, there is a small, but not entirely negligible, risk from other agents.6 In 1996, Health Canada began formal consideration of po-tential regulatory frameworks for xenotransplantation clinical trials. A multidisciplinary Xenotransplant Expert Working Group (XEWG) was formed to consider ethical issues (both

Jose G. Merino, Brian Silver, Edward Wong, Bart Demaerschalk, Arturo Tamayo and Plasminogen Activ... more Jose G. Merino, Brian Silver, Edward Wong, Bart Demaerschalk, Arturo Tamayo and Plasminogen Activator for Acute Ischemic Stroke Physician Knowledge of the Benefits, Risks, and Contraindications of Tissue ISSN: 1524-4628 Copyright © 2001 American Heart Association. All rights reserved. Print ISSN: 0039-2499. Online Stroke is published by the American Heart Association. 7272 Greenville Avenue, Dallas, TX 72514 2001, 32:2208-2209 Stroke http://stroke.ahajournals.org/content/32/9/2208.3 located on the World Wide Web at: The online version of this article, along with updated information and services, is

Introduction: Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer and a seriou... more Introduction: Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer and a serious disease leading to increased morbidity and high medical costs worldwide. Despite the high recurrence rate of BCCs, the current standard of care consists of regular skin check-ups, with no know therapy to prevent the recurrence. Vitamin D is a safe, affordable, and easily available supplement used for various diseases. There is evidence suggesting its potential use in preventing BCCs, with studies showing that it inhibits the Hedgehog (HH) signaling pathway, an important stimulator of carcinogenesis and the main pathway in BCC development. The objective of this study is to determine the effect of oral vitamin D supplementation on the prevention of BCC redevelopment. Methods: This study is a phase III, multicenter, randomized, placebo-controlled, triple-blinded, superiority trial with two parallel groups on 1:1 allocation of 1746 patients with a previous diagnosis of BCC. The patients wi...

Principles and Practice of Clinical Research Journal, 2021

Introduction: Postoperative delirium (POD) is an important complication of major surgery in elder... more Introduction: Postoperative delirium (POD) is an important complication of major surgery in elderly patients. It increases morbidity and mortality, hospital stay, and total healthcare costs. Since no treatment has proven effective once POD is established, prevention is key. Evidence exists that bispectral index guided anesthesia (BIS-GA) and antipsychotics may independently reduce incidence of POD, but the efficacy of combining these preventive strategies is unknown. Objective: To compare the combination of olanzapine + BIS-GA with BIS-GA alone for prevention of POD in elderly patients undergoing major elective surgery. Methods: We propose a Phase II, multi-center, randomized, double-blind, parallel, placebo-controlled trial. The study arms will be BIS-GA + two doses of olanzapine 5mg given pre and postoperatively compared with BIS-GA + placebo in patients ≥65 years hospitalized for major elective surgery. Exclusion criteria include cardiac-and neurosurgery, dementia history, concurrent antipsychotic, anticholinergic, or sedative-hypnotic use, olanzapine allergy, delirium at hospital admission, cognitive impairment and inability to be interviewed. The primary outcome is incidence of POD diagnosed by DSM-V criteria and assessed by the Confusion Assessment Method (CAM) scale. Secondary outcomes include delirium severity, rescue therapy use, length of hospital stay and incidence of adverse events. Discussion: There is an increasing need for trials that advance knowledge in prophylactic methods to prevent delirium. By combining two preventive methods, we expect to decrease the incidence of POD, which will result in decreased morbidity, mortality, and total healthcare costs.

Thrombosis Research, 2020

Background: Venous thromboembolism (VTE) is the second leading cause of death in cancer patients.... more Background: Venous thromboembolism (VTE) is the second leading cause of death in cancer patients. In Brazil, even though low-molecular-weight heparin (LMWH) is the gold standard of care for the management of cancerassociated thrombosis (CAT), its cost limits its use and therefore warfarin is commonly prescribed. Direct oral anticoagulants (DOACs), such as edoxaban, have been introduced as an alternative in this setting. Objective: The aim of this study was to compare the cost-effectiveness of edoxaban with LMWH (Model 1) and warfarin (Model 2) to support clinicians and hospitals when choosing an anticoagulant to manage CAT. Materials and methods: Cost-effectiveness analyses were performed using Markov state-transition models over a timeframe of 5 years, in a hypothetical, 64 years-old patients cancer population with an index VTE event. Transition probabilities, costs, quality-adjusted life years (QALYs) and risk reductions were either derived from the literature, estimated or calculated. A willingness-to-pay limit of 3 Gross Domestic Product (GDP) per head was used. Deterministic and probabilistic sensitivity analyses were performed for robustness. The main outcome of this study was the incremental cost-effectiveness ratio (ICER), expressed as cost per QALY gained. Results: Model 1 base case analysis demonstrated dominance of edoxaban compared to LMWH, with an ICER of 5204.46,representingcostsavedperQALYlost.InModel2,edoxabanwasassociatedwitha5204.46, representing cost saved per QALY lost. In Model 2, edoxaban was associated with a 5204.46,representingcostsavedperQALYlost.InModel2,edoxabanwasassociatedwitha736.90 cost increase vs. warfarin, with an ICER of $2541.03. Sensitivity analyses confirmed base-case results. Conclusion: Edoxaban represents a cost-saving alternative to LMWH for the management of CAT and is costeffective vs. warfarin.

Frontiers in Oncology, 2020

Deep penetrating nevi (DPN) are rare melanocytic nevi, which can exhibit atypical histological fe... more Deep penetrating nevi (DPN) are rare melanocytic nevi, which can exhibit atypical histological features hampering the differentiation from malignant melanoma. DPN are considered benign melanocytic lesions, but rare spread to lymph nodes and unfavorable clinical outcomes associated with borderline/atypical DPN (B-DPN) has been reported. Since no guidelines are available for DPN and B-DPN, we aimed to review the literature on DPN and B-DPN to assess the management and prognosis. We screened 3,513 references from EMBASE, Scopus and Medline databases, and included 15 studies with a total of 355 DPN patients and 48 B-DPN patients. Therapeutic interventions ranged from simple excision to wide excisions and sentinel lymph node biopsy (SLNB), with block lymph node dissection in some positive SLNB cases. Follow-up periods ranged from 3 months to 23 years during which a total of five recurrences, two in DPN and three in B-DPN group, and three metastases, in B-DPN group, were reported. While some of the included studies comprised clinical and histopathological correlation, few included genetic assessment. The present review highlights the need for prospective cohort studies applying composite measures to identify effective regimens of diagnostic workup and treatment in DPN and B-DPN.

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2001

ABSTRACT: Background: A 1995 National Institute of Neurological Disorders (NINDS) study found ben... more ABSTRACT: Background: A 1995 National Institute of Neurological Disorders (NINDS) study found benefit for intravenous tissue plasminogen activator (tPA) in acute ischemic stroke (AIS). The symptomatic intracranial hemorrhage (SICH) rate in the NINDS study was 6.4%, which may be deterring some physicians from using this medication. Methods: Starting December 1, 1998, patients with AIS in London, Ontario were treated according to NINDS criteria with one major exception; those with approximately greater than one-third involvement of the idealized middle cerebral artery (MCA) territory on neuroimaging were excluded from treatment. The method used to estimate involvement of one-third MCA territory involvement bears the acronym ICE and had a median kappa value of 0.80 among five physicians. Outcomes were compared to the NINDS study. Results: Between December 1, 1998 and February 1, 2000, 30 patients were treated. Compared to the NINDS study, more London patients were treated after 90 minu...

CMAJ - Canadian Medical Association Journal, Apr 30, 2002

Frontiers in Neurology

Background: The constantly increasing incidence of stroke in younger individuals substantiates an... more Background: The constantly increasing incidence of stroke in younger individuals substantiates an urgent need for research to elucidate underlying risk factors and etiologies. Heretofore, the vast majority of studies on stroke in the young have been carried out in European and North American regions. We aimed to characterize cerebrovascular risk profiles in a Saudi Arabic cohort of consecutive young stroke patients.Methods: We retrospectively analyzed data from consecutive ischemic stroke patients aged 15 to 49 years who underwent detailed cardiocerebrovascular evaluation at a tertiary stroke care center in Makkah, Saudi Arabia. Distributions of risk factors and stroke etiologies were assessed in the entire cohort and in two strata of very young (15–40 years) and young to middle-aged patients (41–49) to account for variability in suggested age cutoffs.Results: In the entire cohort [n = 63, ages 44 (34–47) median, interquartile range], dyslipidemia (71.4%) and small vessel occlusion ...

Frontiers in Neurology

Posterior circulation involves the vertebrobasilar arteries, which supply oxygen and glucose to v... more Posterior circulation involves the vertebrobasilar arteries, which supply oxygen and glucose to vital human brainstem structures and other areas. This complex circulatory- perfusion system is not homogenous throughout the day; rather, its hemodynamic changes rely on physiological demands, ensuring brainstem perfusion. This dynamic autoregulatory pattern maintains cerebral perfusion during blood pressure changes. Accumulative evidence suggests that activity within the autonomic nervous system is involved in the regulation of cerebral blood flow. Neither the sympathetic nor parasympathetic nervous systems work independently. Functional studies have shown a tight and complicated cross talk between these systems. In pathological processes where sympathetic stimulation is present, systemic vasoconstriction is followed, representing the most important CNS parasympathetic trigger that will promote local vasodilation. Stroke is a clear example of this process. The posterior circulation is a...

Principles and Practice of Clinical Research Journal

Current sports medicine reports, 2018

Temporal lobe epilepsy (TLE) is a common form of epilepsy that presents with complex partial seiz... more Temporal lobe epilepsy (TLE) is a common form of epilepsy that presents with complex partial seizures and in some cases with generalization to tonic-clonic activity that are often well controlled with antiepileptic medication in up to two thirds of patients. The remaining one third with “medically i

Abstracts of the International Stroke Conference, 2001

50 Objectives: To develop a reliable method of estimation of >1/3 involvement of the middle ce... more 50 Objectives: To develop a reliable method of estimation of >1/3 involvement of the middle cerebral artery territory (MCAT) on early CT scan. Background: The European Cooperative Acute Stroke Study (ECASS) suggested that > 1/3 involvement of the MCAT on early CT scan was a risk factor for symptomatic intracerebral hemorrhage (SICH) following treatment with tissue plasminogen activator (tPA) for acute ischemic stroke (AIS). There are no published guidelines on how to perform such an evaluation. The ICE method was developed for the purpose of standardizing the approach of infarct size estimation. This method requires the observer of the CT scan to mentally: 1) Idealize the MCAT into an area approximating a trapezoid, 2) Close a geometric figure around the area(s) of hypodensity(ies), and 3) Estimate the ratio of the two geometric figures (C/I). Methods: Five stroke fellows (observers) were tested with 40 CT scans which had been performed within the first few hours of an acute neurological event. Observers were blinded to patient history. They were asked whether to treat the patient on the basis of the CT scan. The decision not to treat was predicated on the presence of hemorrhage or > 1/3 MCAT involvement. Results: Five scans showed evidence of hemorrhage. All observers detected the hemorrhages. The remaining scans were of patients with presumed ischemia. Six scans were thought to show > 1/3 MCAT involvement by all observers. For all scans, median interobserver agreement among 10 paired comparisons was 86% (range 73–93%). Median kappa was 0.72 (range 0.44–0.85, p Conclusion: The ICE method has very good interobserver reliability. The method merits further investigation among non-stroke physicians.

Cmaj Canadian Medical Association Journal, Apr 30, 2002

Canadian Journal of Cardiology, 2015

In patients with patent foramen ovale (PFO), strategies are needed to identify patients at higher... more In patients with patent foramen ovale (PFO), strategies are needed to identify patients at higher risk, who might benefit from PFO closure. We studied the frequency of detection of a right-to-left shunt (RLS) using transesophageal echocardiography (TEE) among patients with cryptogenic stroke and transcranial Doppler (TCD) to detect RLS, and analyzed the prediction of recurrent stroke according to TCD shunt grade, by detection of RLS on TEE, and by atrial septal aneurysm or mobility. Among 334 patients with TCD, 69.8% were female, with a mean (SD) age of 53 (14) years, with a median follow-up of 420 days. There were 284 cases with TCD and TEE; 54 (19%) had atrial septal aneurysm or mobility. Echocardiography failed to show a RLS in 43 (15.1%) of the patients who had TCD and TEE, even in some patients with high-grade shunts on TCD: 18 (42%) were grade 3 or higher on TCD. Survival free of stroke or transient ischemic attack was predicted significantly by TCD shunt grade < 2 (P = 0.028), shunt grade < 3 (P = 0.03), and shunt grade < 4 (P < 0.0001); this was attenuated by adjustment for risk factors in Cox regression (P = 0.08). Neither RLS on TEE (P = 0.47), or atrial septal aneurysm or mobility (P = 0.08), predicted events. Our findings suggest that TCD might be more sensitive than TEE for detection of RLS, which misses some cases with substantial RLS, and might be valuable for prediction of recurrent stroke or transient ischemic attack in patients with PFO. TCD complements TEE for management of suspected paradoxical embolism.