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1.
Sensors (Basel) ; 23(4)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36850430

RESUMO

Interferometric coherence from SAR data is a tool used in a variety of Earth observation applications. In the context of crop monitoring, vegetation indices are commonly used to describe crop dynamics. The most frequently used vegetation indices based on radar data are constructed using the backscattered intensity at different polarimetric channels. As coherence is sensitive to the changes in the scene caused by vegetation and its evolution, it may potentially be used as an alternative tool in this context. The objective of this work is to evaluate the potential of using Sentinel-1 interferometric coherence for this purpose. The study area is an agricultural region in Sevilla, Spain, mainly covered by 18 different crops. Time series of different backscatter-based radar vegetation indices and the coherence amplitude for both VV and VH channels from Sentinel-1 were compared to the NDVI derived from Sentinel-2 imagery for a 5-year period, from 2017 to 2021. The correlations between the series were studied both during and outside the growing season of the crops. Additionally, the use of the ratio of the two coherences measured at both polarimetric channels was explored. The results show that the coherence is generally well correlated with the NDVI across all seasons. The ratio between coherences at each channel is a potential alternative to the separate channels when the analysis is not restricted to the growing season of the crop, as its year-long temporal evolution more closely resembles that of the NDVI. Coherence and backscatter can be used as complementary sources of information, as backscatter-based indices describe the evolution of certain crops better than coherence.

2.
Epilepsia ; 63(3): 551-564, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35001365

RESUMO

OBJECTIVE: In order to more appropriately apply and understand the "epilepsy treatment gap" (ETG) concept in current health systems, revised conceptual and operational definitions of ETG are timely and necessary. This article therefore systematically reviews worldwide studies of the ETG, distinguishing high-, middle-, and low-income regions, and provides recommendations for an updated International League Against Epilepsy (ILAE) definition of ETG. METHODS: A systematic review of the ETG was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. The search was conducted from January 1990 to July 2019, in the online databases of Ovid MEDLINE and Embase. Identified abstracts were reviewed in duplicate and data independently extracted using a standard proforma. Data describing treatment gap information including both diagnostic and therapeutic aspects of access to epilepsy treatment were recorded. Descriptive statistics are presented. RESULTS: The treatment gap reported in the 45 distinctive populations represented 33 countries. Treatment gap definitions varied widely. The reported ETGs ranged broadly from 5.6% in Norway to 100% in parts of Tibet, Togo, and Uganda. The wide range of reported ETGs was multifactorial in origin including true differences in the availability and utilization of health care among study populations, variations in operational definitions of the epilepsy treatment gap, and methodological differences in sampling and identifying representative epilepsy cases in populations. Significance and recommendations For the ETG to be a useful metric to compare levels of unmet epilepsy care across different countries and regions, a standardized definition must be adapted, recognizing some of the limitations of the current definitions. Our proposed definition takes into account the lack of effective health care insurance, the diagnostic gap, the therapeutic gap, quality-of-care, and other unmet health care needs."


Assuntos
Epilepsia , Atenção à Saúde , Epilepsia/diagnóstico , Epilepsia/epidemiologia , Epilepsia/terapia , Humanos , Noruega , Relatório de Pesquisa
3.
Stat Med ; 39(23): 3195-3206, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32584425

RESUMO

We propose a multistate joint model to analyze interval-censored event-history data subject to within-unit clustering and nonignorable missing data. The model is motivated by a study of the neurocysticercosis (NC) cyst evolution at the cyst-level, taking into account the multiple cysts phases with intermittent missing data and loss to follow-up, as well as the intra-brain clustering of observations made on a predefined data collection schedule. Of particular interest in this study is the description of the process leading to cyst resolution, and whether this process varies by antiparasitic treatment. The model uses shared random effects to account for within-brain correlation and to explain the hidden heterogeneity governing the missing data mechanism. We developed a likelihood-based method using a Monte Carlo EM algorithm for the inference. The practical utility of the methods is illustrated using data from a randomized controlled trial on the effect of antiparasitic treatment with albendazole on NC cysts among patients from six hospitals in Ecuador. Simulation results demonstrate that the proposed methods perform well in the finite sample and misspecified models that ignore the data complexities could lead to substantial biases.


Assuntos
Neurocisticercose , Análise por Conglomerados , Humanos , Funções Verossimilhança , Modelos Estatísticos , Método de Monte Carlo , Neurocisticercose/tratamento farmacológico
4.
Epilepsia ; 60(9): 1820-1828, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31355931

RESUMO

OBJECTIVE: To develop a causal model for the occurrence of neurocysticercosis (NC)-related seizures and test hypotheses generated from the model. METHODS: We used data from a randomized controlled trial comparing albendazole with placebo among patients newly diagnosed with NC. Based on our causal model, we explored the associations among albendazole treatment, NC cyst evolution, and seizure outcomes over 24 months of follow-up using generalized linear mixed effect models. RESULTS: We included 153 participants, of whom 51% received albendazole. The association between seizure outcomes and treatment over time demonstrated lack of linearity and heterogeneity, requiring the inclusion of time-treatment interaction terms for valid modeling. Participants in the albendazole group had fewer seizures overall and of partial onset at all time points compared with the placebo group, but the difference increased over the first few months following treatment, then decreased over time. Generalized seizures exhibited a more complex association; those in the albendazole group had fewer seizures compared with those in the placebo group for the first few months after treatment, and then the association reversed and those in the placebo arm had fewer seizures. Adjusting for the number of NC cysts in each phase resulted in an attenuation of the strength of association between albendazole and seizure outcomes, consistent with mediation. Among participants in whom all cysts had disappeared (n = 21), none continued to have seizures. SIGNIFICANCE: Albendazole treatment is associated with a possible reduction in focal seizures in the short term (3-6 months), perhaps by hastening the resolution of the cysts. However, the effect is not discernible over the long term, because most cysts either calcify or resolve completely, regardless of whether treated with albendazole. The stage of evolution of the cysticercus is an important consideration in the evaluation of albendazole effect on seizure outcome.


Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Neurocisticercose/tratamento farmacológico , Convulsões/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurocisticercose/complicações , Convulsões/etiologia , Resultado do Tratamento , Adulto Jovem
5.
BMC Neurol ; 19(1): 52, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30943908

RESUMO

BACKGROUND: Parenchymal neurocysticercosis is a frequent cause of seizures in areas endemic for Taenia solium. At present there is scarce data on the evolution of the levels of circulating metacestodal antigen before, during and after treatment with anthelmintic drugs. CASE PRESENTATION: A patient with paucisymptomatic neurocysticercosis (NCC) diagnosed by Ag-ELISA, and confirmed by MRI images, was treated with praziquantel, albendazole and dexamethasone. The level of circulating T. solium antigen was determined weekly. Circulating antigen disappeared from his blood within 14 days after the start of the treatment and correlated with the involution of the cysticerci in the brain shown by imaging. Seventeen years later, the patient has not shown any side effect nor symptoms related to the treatment or to NCC. CONCLUSIONS: If this encouraging finding is confirmed in a larger series of patients, this technique could be used to determine parasitological cure after treatment and might complement or sometimes replace sequential MRI-imaging of the brain.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Neurocisticercose/diagnóstico , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Neurocisticercose/tratamento farmacológico , Neurocisticercose/imunologia , Praziquantel/uso terapêutico , Taenia solium
6.
Epilepsia ; 59(5): 905-914, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29637551

RESUMO

Among the causes of epilepsy are several that are currently preventable. In this review, we summarize the public health burden of epilepsy arising from such causes and suggest priorities for primary epilepsy prevention. We conducted a systematic review of published epidemiologic studies of epilepsy of 4 preventable etiologic categories-perinatal insults, traumatic brain injury (TBI), central nervous system (CNS) infection, and stroke. Applying consistent criteria, we assessed the quality of each study and extracted data on measures of risk from those with adequate quality ratings, summarizing findings across studies as medians and interquartile ranges. Among higher-quality population-based studies, the median prevalence of active epilepsy across all ages was 11.1 per 1000 population in lower- and middle-income countries (LMIC) and 7.0 per 1000 in high-income countries (HIC). Perinatal brain insults were the largest attributable fraction of preventable etiologies in children, with median estimated fractions of 17% in LMIC and 15% in HIC. Stroke was the most common preventable etiology among older adults with epilepsy, both in LMIC and in HIC, accounting for half or more of all new onset cases. TBI was the attributed cause in nearly 5% of epilepsy cases in HIC and LMIC. CNS infections were a more common attributed cause in LMIC, accounting for about 5% of all epilepsy cases. Among some rural LMIC communities, the median proportion of epilepsy cases attributable to endemic neurocysticercosis was 34%. A large proportion of the overall public health burden of epilepsy is attributable to preventable causes. The attributable fraction for perinatal causes, infections, TBI, and stroke in sum reaches nearly 25% in both LMIC and HIC. Public health interventions addressing maternal and child health care, immunizations, public sanitation, brain injury prevention, and stroke prevention have the potential to significantly reduce the burden of epilepsy.


Assuntos
Epilepsia/prevenção & controle , Prevenção Primária/métodos , Traumatismos do Nascimento/complicações , Traumatismos do Nascimento/prevenção & controle , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/prevenção & controle , Infecções do Sistema Nervoso Central/complicações , Infecções do Sistema Nervoso Central/prevenção & controle , Epilepsia/etiologia , Humanos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/prevenção & controle
7.
Ann Neurol ; 80(3): 434-42, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27438337

RESUMO

OBJECTIVE: The diagnosis of neurocysticercosis (NCC) remains problematic because of the heterogeneity of its clinical, immunological, and imaging characteristics. Our aim was to develop and assess a new set of diagnostic criteria for NCC, which might allow for the accurate detection of, and differentiation between, parenchymal and extraparenchymal disease. METHODS: A group of Latin American NCC experts developed by consensus a new set of diagnostic criteria for NCC. A multicenter, retrospective study was then conducted to validate it. The reference standard for diagnosis of active NCC was the disappearance or reduction of cysts after anthelmintic treatment. In total, three pairs of independent neurologists blinded to the diagnosis evaluated 93 cases (with NCC) and 93 controls (without NCC) using the new diagnostic criteria. Mixed-effects logistic regression models were used to estimate sensitivity and specificity. RESULTS: Inter-rater reliability (kappa) of diagnosis among evaluators was 0.60. For diagnosis of NCC versus no NCC, the new criteria had a sensitivity of 93.2% and specificity of 81.4%. For parenchymal NCC, the new criteria had a sensitivity of 89.8% and specificity of 80.7% and for extraparenchymal NCC, the new criteria had a sensitivity of 65.9% and specificity of 94.9%. INTERPRETATION: These criteria have acceptable reliability and validity and could be a new tool for clinicians and researchers. An advantage of the new criteria is that they consider parasite location (ie, parenchymal or extraparenchymal), which is an important factor determining the clinical, immunological, and radiological presentation of the disease, and importantly, its treatment and prognosis. Ann Neurol 2016;80:434-442.


Assuntos
Consenso , Neurocisticercose/diagnóstico , Guias de Prática Clínica como Assunto/normas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
Epilepsia Open ; 9(2): 776-784, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38366910

RESUMO

There are limited data on first seizure (FS) among adults in low and middle-income countries. We describe findings from a prospective cohort study involving 180 adults presenting with seizures in emergency departments in five Latin American countries. Overall, 102 participants (56.7%) had acute symptomatic seizures (ASyS) while 78 (43.3%) had unprovoked seizures (UPS). Among patients with ASyS, 55 (53.9%) had structural causes, with stroke (n = 24, 23.5%), tumor (n = 10, 9.8%), and trauma (n = 3, 3%) being the most frequent. Nineteen patients (18.6%) had infectious causes, including four (4%) with meningoencephalitis, three (3%) neurocysticercosis, and two (2%) bacterial meningoencephalitis. Twenty patients (19.6%) had metabolic/toxic evidence, including four (4%) with uremic encephalopathy, two (2%) hyponatremia, and three (3%) acute alcohol intoxication. Immune dysfunction was present in seven (7%) patients and neurodegenerative in two (2%). Among participants with UPS, 45 (57.7%) had unknown etiology, 24 (30.7%) had evidence of structural disorders (remote symptomatic), four (5%) were related to infectious etiology (>7 days before the seizure), and five (6.4%) had genetic causes. During the 3- and 6-month follow-up, 29.8% and 14% of patients with UPS, respectively, experienced seizure recurrence, while 23.9% and 24.5% of patients with ASyS had seizure recurrence. Longer follow-up is necessary to assess seizure recurrence for patients with ASyS after the acute cause is resolved and to determine the 10-year risk of recurrence, which is part of the definition of epilepsy. PLAIN LANGUAGE SUMMARY: We monitored 180 adults who presented with their first seizure in emergency departments across five Latin American countries. Among these patients, 57% had acute symptomatic seizures, with structural causes such as stroke (23%), infection (17%), or tumor (10%) being more prevalent. Among the 43% with unprovoked seizures, 58% showed no identifiable acute cause, while 6.4% were due to genetics. Within 3 months after their initial seizure, 26.6% of individuals experienced a second seizure, with 11.9% continuing to have seizures in Months 3-6. Between Months 3 and 6, an additional 20% of patients encountered a second seizure. Research is needed to better understand the cause and prognosis of these patients to improve outcomes.


Assuntos
Meningoencefalite , Neoplasias , Acidente Vascular Cerebral , Adulto , Humanos , América Latina , Estudos Prospectivos , Projetos Piloto , Recidiva , Convulsões/etiologia , Estudos de Coortes , Prognóstico , Acidente Vascular Cerebral/complicações , Neoplasias/complicações , Meningoencefalite/complicações
11.
Ann Neurol ; 81(3): 474-475, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28120395
12.
Ann Neurol ; 80(6): 954, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27730673
14.
Epileptic Disord ; 24(6): 994-1019, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36219093

RESUMO

This educational review article aims to provide information on the central nervous system (CNS) infectious and parasitic diseases that frequently cause seizures and acquired epilepsy in the developing world. We explain the difficulties in defining acute symptomatic seizures, which are common in patients with meningitis, viral encephalitis, malaria, and neurocysticercosis, most of which are associated with increased mortality and morbidity, including subsequent epilepsy. Geographic location determines the common causes of infectious and parasitic diseases in a particular region. Management issues encompass prompt treatment of acute symptomatic seizures and the underlying CNS infection, correction of associated predisposing factors, and decisions regarding the appropriate choice and duration of antiseizure therapy. Although healthcare provider education, to recognize and diagnose seizures and epilepsy related to these diseases, is a feasible objective to save lives, prevention of CNS infections and infestations is the only definitive way forward to reduce the burden of epilepsy in developing countries.


Assuntos
Doenças Transmissíveis , Encefalite Viral , Epilepsia , Neurocisticercose , Doenças Transmissíveis/complicações , Encefalite Viral/complicações , Epilepsia/complicações , Epilepsia/etiologia , Humanos , Neurocisticercose/complicações , Neurocisticercose/epidemiologia , Convulsões/complicações , Convulsões/etiologia
15.
PLoS Negl Trop Dis ; 16(8): e0010652, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36037251

RESUMO

BACKGROUND: Neurocysticercosis (NC) is one of the major parasitic diseases affecting the central nervous system and is endemic in much of Asia, sub-Saharan Africa, and Latin America. Its epidemiology is difficult to assess, although official registries are available in Brazil, Colombia, Ecuador, and Mexico. METHODOLOGY/PRINCIPAL FINDINGS: Using official statistics, we assessed trends in NC hospitalization rates during 1998-2019 in Brazil and Ecuador, during 2004-2019 in Mexico, and during 2009-2019 in Colombia. We also assessed the trend in NC mortality in Brazil (1998-2019), the trend in hospitalizations for NC in a Mexican tertiary-level hospital (Instituto Nacional de Neurología y Neurocirugía [INNN]; 1995-2019), and in Mexican primary care ambulatory clinics (1995-2019). Associations between NC hospitalization rates and the human development index (HDI) were also examined. In Brazil, Ecuador, and Mexico, statistically significant decreases in NC hospitalization rates were observed. In Mexico, a significant increase in the age of patients at INNN was observed, suggesting a decreasing incidence of recent infection. Conversely, a significant increase in NC hospitalization rate was observed in Colombia. HDI was not significantly associated with NC hospitalization rates when adjusting for time. CONCLUSIONS: The downward trends in NC cases in Brazil, Ecuador, and Mexico are encouraging, especially in the context of the PAHO/WHO plan of action to eliminate neglected tropical diseases from the region. On the other hand, in Colombia, the increased NC hospitalization rate is concerning and needs further evaluation so that the authorities can take specific measures. These results should encourage health authorities in other endemic countries to establish a system of official registries to identify where the need for a control program is most urgent. However, it is also important to remember that NC persists, although less frequently in some Latin American countries, and efforts to achieve its control must continue.


Assuntos
Neurocisticercose , Hospitalização , Humanos , Incidência , América Latina/epidemiologia , México/epidemiologia , Neurocisticercose/epidemiologia
16.
Seizure ; 90: 123-129, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33632613

RESUMO

Epilepsy and neurocysticercosis are common neurological disorders and are major public health issues that contribute to the world's burden of disease. Acute symptomatic seizures, the main clinical manifestation of parenchymal neurocysticercosis, are caused by the host brain immune-inflammatory process in response to the death or degenerative phase of the parasite. Seizures may recur over the course of several months while the local inflammatory activity lasts. If the seizures recur once the acute process resolves, the patient can be diagnosed as having epilepsy. However, most acute symptomatic seizures secondary to neurocysticercosis do not evolve to epilepsy. Recent prospective studies suggest that the development of epilepsy, while more common than in the general population, is not as common in neurocysticercosis patients as originally suggested by cross-sectional studies. Antiparasitic treatment has been found to hasten the transition of cysts from the active phase to the degenerative phase and is associated with a short-term reduction in focal seizures after treatment. However, antiparasitic treatment has not been found to affect the transition from the degenerative phase to calcification, which is an epileptogenic substrate associated with subsequent epilepsy. In this narrative review, we critically appraise the relationship among neurocysticercosis, seizures, and epilepsy in the context of new developments in the literature.


Assuntos
Epilepsia , Neurocisticercose , Encéfalo/diagnóstico por imagem , Estudos Transversais , Epilepsia/epidemiologia , Epilepsia/etiologia , Humanos , Neurocisticercose/complicações , Neurocisticercose/diagnóstico , Neurocisticercose/epidemiologia , Convulsões/diagnóstico , Convulsões/epidemiologia , Convulsões/etiologia
18.
Epilepsia ; 51(4): 671-5, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19732133

RESUMO

PURPOSE: To consider the definition of acute symptomatic seizures for epidemiological studies, and to refine the criteria used to distinguish these seizures from unprovoked seizures for specific etiologies. METHODS: Systematic review of the literature and of epidemiologic studies. RESULTS: An acute symptomatic seizure is defined as a clinical seizure occurring at the time of a systemic insult or in close temporal association with a documented brain insult. Suggestions are made to define acute symptomatic seizures as those events occurring within 1 week of stroke, traumatic brain injury, anoxic encephalopathy, or intracranial surgery; at first identification of subdural hematoma; at the presence of an active central nervous system (CNS) infection; or during an active phase of multiple sclerosis or other autoimmune diseases. In addition, a diagnosis of acute symptomatic seizure should be made in the presence of severe metabolic derangements (documented within 24 h by specific biochemical or hematologic abnormalities), drug or alcohol intoxication and withdrawal, or exposure to well-defined epileptogenic drugs. DISCUSSION: Acute symptomatic seizures must be distinguished from unprovoked seizures and separately categorized for epidemiologic purposes. These recommendations are based upon the best available data at the time of this report. Systematic studies should be undertaken to better define the associations in question, with special reference to metabolic and toxic insults, for which the time window for the occurrence of an acute symptomatic seizure and the absolute values for toxic and metabolic dysfunction still require a clear identification.


Assuntos
Convulsões/diagnóstico , Doença Aguda , Estudos Transversais , Diagnóstico Diferencial , Humanos , Convulsões/epidemiologia , Convulsões/etiologia
20.
Trends Parasitol ; 36(10): 826-834, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32819826

RESUMO

The presentation of cysticercosis is very heterogeneous both between and within countries. Several host and parasite factors are involved in this heterogeneity. Differences in the intensity of infection pressure have not been studied thus far. We have compiled data that could demonstrate that differences in infection pressure are involved in the still high prevalence of parenchymal neurocysticercosis and ocular cysticercosis in some countries (which have a stable infection pressure) and in the high proportion of extraparenchymal neurocysticercosis in others (which have had a progressive decrease in infection pressure). Therefore, the distribution of clinicoradiological forms of cysticercosis could be a marker of the intensity of infection pressure and could help to determine in which countries control programs should be a priority.


Assuntos
Cisticercose/epidemiologia , Animais , Cisticercose/parasitologia , Cisticercose/prevenção & controle , Transmissão de Doença Infecciosa , Humanos , Prevalência , Serviços Preventivos de Saúde/normas
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