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1.
Childs Nerv Syst ; 40(4): 1147-1157, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38092980

RESUMO

OBJECTIVE: To analyze and compare the efficacy of two selective dorsal rhizotomy (SDR) techniques with intraoperative neurophysiological monitoring, using instrumented three-dimensional gait analysis. INTRODUCTION: SDR is a common, irreversible surgical treatment increasingly used to address gait disturbances in children with chronic non-progressive encephalopathy by reducing spasticity. Various techniques have been used, which mainly differ in the percentage of rootlets selected for sectioning. A greater proportion of rootlets sectioned leads to a more effective reduction of spasticity; however, there is a potential risk of unwanted neurological effects resulting from excessive deafferentation. While there is evidence of the short- and long-term benefits and complications of SDR, no studies have compared the effectiveness of each technique regarding gait function and preservation of the force-generating capacity of the muscles. MATERIALS AND METHODS: Instrumented three-dimensional gait analysis was used to evaluate two groups of patients with spastic cerebral palsy treated by the same neurosurgeon in different time periods, initially using a classic technique (cutting 50% of the nerve rootlets) and subsequently a conservative technique (cutting no more than 33% the nerve rootlets). RESULTS: In addition to an increase in knee joint range of motion (ROM), in children who underwent SDR with the conservative technique, a statistically significant increase (p = 0.04) in the net joint power developed by the ankle was observed. Patients who underwent SDR with the conservative technique developed a maximum net ankle joint power of 1.37 ± 0.61 (unit: W/BW), whereas those who were operated with the classic technique developed a maximum net ankle joint power of 0.98 ± 0.18 (unit: W/BW). The conservative group not only showed greater improvement in net ankle joint power but also demonstrated more significant enhancements in minimum knee flexion during the stance phase and knee extension at initial contact. CONCLUSION: Our results show that both techniques led to a reduction in spasticity with a positive impact on the gait pattern. In addition, patients treated with the conservative technique were able to develop greater net ankle joint power, leading to a better scenario for rehabilitation and subsequent gait.


Assuntos
Paralisia Cerebral , Rizotomia , Criança , Humanos , Rizotomia/métodos , Resultado do Tratamento , Raízes Nervosas Espinhais/cirurgia , Marcha/fisiologia , Amplitude de Movimento Articular/fisiologia , Paralisia Cerebral/complicações , Espasticidade Muscular/cirurgia
2.
Cornea ; 43(3): 356-359, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37404122

RESUMO

PURPOSE: This study aimed to characterize cornea-centered clinical trials, completed before 2020, registered on ClinicalTrials.gov and identify discrepancies in publication. METHODS: ClinicalTrials.gov, a database from the National Institutes of Health, was queried to identify registered cornea-related clinical trials. Trials were included if they were interventional and completed before January 1, 2020. ClinicalTrials.gov, PubMed.gov, and Google Scholar were then searched to evaluate publications from the trial. Data collected for each trial included sponsor, intervention type, phase, dry eye focus, and location of the principal investigator. RESULTS: A total of 520 trials were included in the final analysis. Of all studies, 270 (51.9%) were found to have published results. Industry-sponsored studies were associated with drug intervention trials, dry eye focus, and the principal investigator's location within the United States ( P < 0.05 for all). Nonindustry sponsors were associated with device and procedure intervention trials ( P < 0.05 for both). Overall, trials that were categorized as procedure interventions were published at a significantly higher rate than other interventional categories (64.2% vs. 50.1%; P = 0.03). Subgroup analysis revealed that among nonindustry studies, late-phase trials and procedural-based trials were published at a significantly higher rate compared with other studies (67.2% vs. 51.6%; P = 0.04 and 67.8% vs. 51.6%; P = 0.03). CONCLUSIONS: Only 51.9% of registered interventional cornea-based clinical trials result in publications in the peer-reviewed literature, highlighting potential publishing discrepancies.


Assuntos
Síndromes do Olho Seco , Humanos , Bases de Dados Factuais , Sistema de Registros , Estados Unidos , Ensaios Clínicos como Assunto
3.
Cornea ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38950099

RESUMO

PURPOSE: To evaluate the rate of corneal swelling induced by hypoosmolar riboflavin in patients with progressive keratoconus (KCN) with corneal thickness <400 µm after the induction phase using riboflavin with 20% dextran during epithelium-off corneal crosslinking (CXL). METHODS: Prospective, nonrandomized, single-center consecutive case series. Preoperative assessments included tomography, specular microscopy, and hysteresis. After epithelial debridement, riboflavin with 20% dextran (Photrexa Viscous; Glaukos, Burlington, MA) was applied at 2-min intervals during a 30-min induction phase. Eyes that dehydrated to a minimum corneal thickness (MCT) of <400 µm after induction (postinduction pachymetry) were recruited. Hypoosmolar riboflavin 0.146% (Photrexa; Glaukos) was used every 10 s to induce stromal swelling, with pachymetry performed every 30 s until the MCT was ≥400 µm (postswelling pachymetry). Corneal swelling rate was compared with variables using regression analysis. RESULTS: In 31 eyes of 31 patients, mean postinduction pachymetry was 338.4 ± 28.7 µm. Hypoosmolar riboflavin induced a postswelling pachymetry of 413.4 ± 15.0 µm over a mean of 5.2 ± 3.2 min, and the average stromal swelling rate was 10.3 ± 8.7 µm/30 s. All eyes reached a postswelling pachymetry MCT ≥400 µm and no cases were aborted. Eyes with highly severe KCN (Kmax >70 and Belin/Ambrosio enhanced ectasia display final D score >17) experienced quicker swelling (14.4 ± 12.8 µm/30 s and 14.9 ± 12.4 µm/30 s, respectively; P < 0.05 for both). A thicker postinduction pachymetry was moderately associated with a faster rate of swelling (rs = 0.389; P = 0.030). CONCLUSIONS: Hypoosmolar riboflavin 0.146% can be safely employed in thinner corneas, allowing for swelling to ≥400 µm for epithelium-off CXL. Associations between swelling rate, KCN severity, and postinduction pachymetry were determined, allowing for a more accurate prediction of procedure time during CXL.

4.
Turk J Ophthalmol ; 53(3): 175-182, 2023 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-37345314

RESUMO

Isolated from Streptomyces caespitosus, mitomycin C (MMC) has various applications in the management of corneal and external disease due to its ability to modulate cellular proliferation. It has been employed in pterygium surgery, ocular surface neoplasia, and refractive surgery. Currently, there is no definite consensus on the treatment protocols for each of the aforementioned applications. Although its benefits in the management of corneal and external diseases are promising, MMC use has potential complications including endothelial cell loss, corneal perforation, scleral melt, secondary glaucoma, iritis, and endophthalmitis. This article will review the literature regarding the use of MMC in the field of cornea and external disease and describe protocols employed with corresponding outcomes.


Assuntos
Mitomicina , Ceratectomia Fotorrefrativa , Humanos , Mitomicina/uso terapêutico , Ceratectomia Fotorrefrativa/métodos , Lasers de Excimer , Córnea/cirurgia
5.
Funct Neurol ; 27(4): 217-24, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23597435

RESUMO

Fluctuation is a common feature of all psychogenic gait disorder (PGD) patterns. Whether this fluctuation involves only the degree of impairment or whether it affects the gait pattern itself remains an interesting question. We hypothesize that, on repeated measurements, both normal and abnormal gait may present quantitative differences while maintaining their basic underlying pattern; conversely, in psychogenic gait, the basic pattern appears not to be preserved. Using an optoelectronic system, data acquired from 19 normal subjects and 66 patients were applied to train a neural network (NN) and subsequently classify gait patterns into four different groups (normal, ataxic, spastic-paraparetic and parkinsonian). Five patients who fulfilled clinical criteria for psychogenic gait and six controls were then prospectively evaluated on two separate occasions, three months apart. Normal controls and ataxic, parkinsonian or spastic patients were correctly identified by the NN, and categorized within the corresponding groups at baseline as well as at a three-month follow-up evaluation. NN analysis showed that after three months, no PGD patient preserved the gait pattern detected at baseline, even though this finding was not clinically apparent. Modification of gait pattern detected by repeated kinematic measurement and NN analysis could suggest the presence of PGD, particularly in difficult-to-diagnose cases.


Assuntos
Transtornos Neurológicos da Marcha/diagnóstico , Transtornos Neurológicos da Marcha/psicologia , Transtornos Psicofisiológicos , Fenômenos Biomecânicos , Eletrônica/instrumentação , Eletrônica/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Redes Neurais de Computação , Estudos Prospectivos , Caminhada/fisiologia
6.
J Biomech ; 139: 111141, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35609492

RESUMO

Children with pathological movement patterns like crouch gait present with excessive knee and hip flexion during stance phase due to multiple factors. A good treatment requires that the primary factor is reduced or eliminated to optimise the relationship between muscle energy expenditure and muscle force production during walking. In this way, neuro-musculoskeletal simulations are reliable tools to evaluate how individual muscles contribute to gait. However, previous studies have reported that changes in energy consumed per unit time have not correlated with crouch gait severity. In this study, EMG-informed musculoskeletal simulations combined with analytical approaches (which include altered muscle composition and morphology presented in children with CP) were used to evaluate individual muscle force, energy expenditure and their relationship in five typically developing children and eleven children with different degrees of crouch gait severity. In agreement with the literature, our results show an increase in Watts required per Newton of muscle force during walking in children with crouch gait when compared to unimpaired gait. This is true for all levels of crouch but does not correlate with severity. Hamstrings required more than three times the muscle energy per Newton of muscle force during crouch gait compared with unimpaired gait. Also, a different strategy in muscle force-energy rate of quadriceps and plantarflexors muscle groups was present in crouch gait. Finally, our results showed weakness in hamstrings and gastrocnemius with an increment in their muscle energy expenditures during moderate and severe crouch gait. This could suggest that well controlled strength training (i.e. personalised and designed to improve both the muscle strength and functional mobility) focused in these muscle groups could improve knee extension of these children by providing a more efficient plantarflexor-knee extension couple during stance phase (action of the ankle plantarflexor muscles to control the progress of the tibia over the foot and the knee kinetics) and more control of the distal limb at initial contact. However, strength training of hamstrings only could be better for children with mild crouch gait.


Assuntos
Paralisia Cerebral , Transtornos Neurológicos da Marcha , Fenômenos Biomecânicos , Criança , Marcha/fisiologia , Humanos , Articulação do Joelho , Músculo Esquelético/fisiologia , Caminhada/fisiologia
7.
Am J Ophthalmol Case Rep ; 26: 101546, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35496763

RESUMO

Purpose: To report a patient with retained lens material presenting over three decades after initial cataract extraction with fluctuating corneal edema and intraocular inflammation. Observations: A 66-year-old man presented with a first episode of decreased vision and photophobia 32 years after cataract extraction without intraocular lens implantation in the right eye. Slit lamp examination revealed a tan-colored oblong mass in the inferior angle, in addition to corneal edema and an anterior chamber reaction. The patient was aphakic with traumatic mydriasis, and accordingly it was noted that the mass shifted location between anterior and posterior chambers over subsequent evaluations. The anterior chamber inflammation resolved in the latter position. The patient was requested to remain prone prior to clinical evaluation, and an in-office anterior chamber aspiration was performed. Histopathologic evaluation confirmed the presence of lens material and a phacolytic response. Conclusions And importance: Although unusual, retained lens material may manifest with ocular morbidity decades after cataract extraction. In patients with corneal edema and intraocular inflammation, retained lens material should be considered as a possible underlying cause even in patients with a remote history of cataract extraction. This case represents one of the longest reported time periods from cataract extraction to clinical presentation of retained lens material.

8.
Top Spinal Cord Inj Rehabil ; 28(4): 113-120, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36457356

RESUMO

Objectives: To assess the changes in speed, stroke frequency, acceleration, and shoulder range of motion (ROM) associated with different wheelchair axle positions in people with chronic C7 tetraplegia. Methods: This repeated-measures study was conducted at the Chronic Spinal Cord Injury Unit, FLENI Escobar, Argentina. The speed, stroke frequency, acceleration, and shoulder ROM during wheelchair propulsion were measured in nine participants with C7 spinal cord injury (SCI) in four different axle positions (forward and up, forward and down, backward and down, backward and up). Two strokes performed at maximum speed were analyzed on a smooth level vinyl floor in a motion analysis laboratory. Data were analyzed for significant statistical differences using the Friedman test and the Wilcoxon signed rank test. Results: Our study showed significant differences in the speed with axle position 1 (1.57 m/s) versus 2 (1.55 m/s) and position 2 (1.55 m/s) versus 4 (1.52 m/s). The shoulder ROM showed a significant difference in the sagittal plane in position 2 (59.34 degrees) versus 3 (61.64 degrees), whereas the stroke frequency and the acceleration parameters showed no statistically significant differences with the different rear axle positions. Conclusions: Our study showed that modifying the rear axle position can improve the propulsion speed and produce changes in the shoulder ROM in the wheelchair propulsion of individuals with C7 SCI.


Assuntos
Traumatismos da Medula Espinal , Cadeiras de Rodas , Humanos , Quadriplegia , Amplitude de Movimento Articular , Cloreto de Polivinila
9.
Transl Vis Sci Technol ; 11(7): 11, 2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35822948

RESUMO

Purpose: To determine the in vivo elastic modulus of the human cornea using vibrational optical coherence tomography (VOCT). Methods: Vibrational analysis coupled with optical coherence tomography (OCT) was used to obtain the resonant frequency (RF) and elastic modulus of corneal structural components. VOCT corneal thickness values were measured using OCT images and correlated with corneal thickness determined with Pentacam (Oculus, Wetzlar, Germany). Moduli were obtained at two locations: central cornea (CC) and inferior cornea (IC). Measurements were obtained with and without anesthetic eye drops to assess their effect on the modulus measurements. Results: VOCT thickness values correlated positively (R2 = 0.97) and linearly (y = 1.039x-16.89) with those of Pentacam. Five RF peaks (1-5) were present, although their presence was variable across eyes. The RF for peaks 1 to 5 in the CC and IC ranged from 73.5 ± 4.9 to 239 ± 3 Hz and 72.1 ± 6.3 to 238 ± 4 Hz, respectively. CC and IC moduli for peaks 1 to 5 ranged from 1.023 ± 0.104 to 6.87 ± 0.33 MPa and 0.98 ± 0.15 to 6.52 ± 0.79 MPa, respectively. Topical anesthesia did not significantly alter the modulus (P > 0.05 for all), except for peak 2 in the CC (P < 0.05). Conclusions: This pilot study demonstrates the utility of VOCT as an in vivo, noninvasive technology to measure the elastic modulus in human corneas. The structural origin of these moduli is hypothesized based on previous reports, and further analyses are necessary for confirmation. Translational Relevance: This work presents VOCT as a novel approach to assess the in vivo elastic modulus of the cornea, an indicator of corneal structural integrity and health.


Assuntos
Córnea , Tomografia de Coerência Óptica , Córnea/diagnóstico por imagem , Módulo de Elasticidade , Humanos , Projetos Piloto , Tomografia de Coerência Óptica/métodos , Vibração
10.
Trauma Surg Acute Care Open ; 6(1): e000596, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34423132

RESUMO

BACKGROUND: Uncompensated care (UC) is healthcare provided with no payment from the patient or an insurance provider. UC directly contributes to escalating healthcare costs in the USA and potentially impacts patient care. In Texas, there has been a steady increase in the number of trauma centers and UC volumes without an increase in trauma funding of UC. The method of calculating UC trauma funds in Texas is imprecise as it is driven by Medicaid volumes and not actual trauma care costs. METHODS: Five years of annual trauma UC disbursement reports from the Texas Department of State Health Services were used to determine changes in UC economic considerations for level I, II, and III trauma centers in the largest urban trauma service areas (TSAs). Data for UC costs, compensation, and TSA demographics were used to assess variations. Statistical significance was determined using a Kruskal-Wallis test with Dunn's pairwise comparison post-hoc analysis and logistic regression. RESULTS: TSA-E (Dallas-Fort Worth area) has 33% of the level I trauma centers in Texas (n=6) and yet serves only 27% of the total state population across 14 metropolitan and 5 non-metropolitan counties. Since 2015, TSA-E has shown higher UC costs (p<0.02) and lower reimbursement (p<0.01) than the second largest urban hub, TSA-Q (Houston area). TSA-E level I trauma centers trended towards decreased UC reimbursements. DISCUSSION: The unregulated expansion of trauma centers in Texas has led to an unprecedented increase in hospitals participating in trauma care. The unbalanced allocation of UC funding could lead to further economic instability, compromise resource allocation, and negatively impact patient care in an already fragile healthcare environment. LEVEL OF EVIDENCE: Level IV; Retrospective economic analysis and evaluation.

11.
Case Rep Oncol ; 14(3): 1483-1489, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899240

RESUMO

The purpose of this publication is to report a child with choroidal metastasis from a primary lung carcinoid tumor treated with 125-iodine plaque brachytherapy while achieving complete tumor regression. A 15-year-old girl with a history of stage IV lung carcinoid tumor developed painless progressive visual loss in her right eye. Ophthalmological exam documented a unilateral solitary large choroidal mass with complete exudative retinal detachment. Planned palliative treatment with plaque brachytherapy was performed utilizing a total dose of 45 Gy to the tumor apex. No tumor regression was noted after 6 months of follow-up. Ten months after primary therapy, re-treatment with a total dose of 90 Gy to the tumor apex was performed due to tumor progression. Complete regression was achieved after secondary treatment without evidence of recurrence after 18 months of follow-up. In conclusion, high-dose plaque brachytherapy may induce complete tumor regression in select adolescent patients with choroidal metastasis from lung carcinoid tumor.

12.
J Neurol Neurosurg Psychiatry ; 81(4): 423-7, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19965856

RESUMO

Background Focal spasticity is a significant motor disorder following stroke, and Botulinum Toxin Type-A (BoNT-A) is a useful treatment for this. The authors evaluated kinematic modifications induced by spasticity, and whether or not there is any improvement following injection of BoNT-A. Methods Eight patients with stroke with upper-limb spasticity, showing a flexor pattern, were evaluated using kinematics before and after focal treatment with BoNT-A. A group of sex- and age-matched normal volunteers acted as a control group. Results Repeated-measures ANOVA showed that patients with stroke performed more slowly than the control group. Following treatment with BoNT-A, there was a significant improvement in kinematics in patients with stroke, while in the control group, performance remained unchanged. Conclusions Focal treatment of spasticity with BoNT-A leads to an adaptive change in the upper limb of patients with spastic stroke.


Assuntos
Fenômenos Biomecânicos/efeitos dos fármacos , Fenômenos Biomecânicos/fisiologia , Toxinas Botulínicas Tipo A/farmacocinética , Toxinas Botulínicas Tipo A/uso terapêutico , Fármacos Neuromusculares/farmacocinética , Fármacos Neuromusculares/uso terapêutico , Espasmo , Acidente Vascular Cerebral/complicações , Extremidade Superior/fisiopatologia , Toxinas Botulínicas Tipo A/administração & dosagem , Feminino , Humanos , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Fármacos Neuromusculares/administração & dosagem , Espasmo/tratamento farmacológico , Espasmo/etiologia , Espasmo/fisiopatologia
13.
An Pediatr (Engl Ed) ; 92(2): 109.e1-109.e7, 2020 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-31676246

RESUMO

INTRODUCTION: Approved drugs for attention deficit hyperactivity disorder (ADHD) in Spain are methylphenidate, lisdexamphetamine, atomoxetine and guanfacine. Due to adverse cardiovascular effects, mainly increased blood pressure and heart rate, its use in patients with known or undiagnosed heart disease may be controversial. OBJECTIVE: To obtain a consensus document from the Spanish Society of Paediatric Cardiology and Congenital Heart Diseases (SECPCC) and experts from other Agencies and Societies as a guide for the paediatric cardiologist and physicians who treat children and adolescents with ADHD. METHODOLOGY: An analysis was performed on the bibliography and Clinical Practice Guidelines, technical data sheets approved by the Spanish Agency of Medicines and Health Devices, and the Spanish Ministry of Health Guidelines. A Working Group was formed, with a Coordinator, as well as members of the Clinical Cardiology Working Group and Arrhythmia Group of the SECPCC. This Group produced a preliminary document that was reviewed by a group of external experts and a group of internal experts of the SECPCC with a consensus being reached on the final document. RESULTS: The recommendations of the SECPCC and the group of experts are presented on cardiovascular evaluation prior to treatment in children and adolescents with no known cardiovascular disease and with known cardiovascular disease. The recommendations of the SECPCC and the group of experts are also presented on the use of medications for ADHD in children and adolescents with cardiological symptoms with no evidence of heart disease, congenital heart disease, cardiomyopathy, Marfan syndrome and other aortic diseases, hypertension, and arrhythmias.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Cardiopatias Congênitas/fisiopatologia , Adolescente , Criança , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Humanos , Espanha
14.
Cardiol Young ; 19(5): 527-9, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19674501

RESUMO

We report the occurrence of non-obstructive totally anomalous pulmonary venous connection to the superior caval vein in a child conceived by intracytoplasmic injection of sperm, a type of assisted reproductive technology. Totally anomalous pulmonary venous connection is an uncommon congenital anomaly, in which all the pulmonary veins connect to the morphologically right atrium, or one of its tributaries. To our knowledge, this malformation has not been previously described in a child conceived on the basis of assisted reproductive technology.


Assuntos
Anormalidades Múltiplas/etiologia , Veias Pulmonares/anormalidades , Injeções de Esperma Intracitoplásmicas/efeitos adversos , Veia Cava Superior/anormalidades , Humanos , Lactente , Masculino
15.
An Pediatr (Barc) ; 71(3): 240-3, 2009 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-19625225

RESUMO

INTRODUCTION: A high prevalence of parietal cell antibodies (PCA) has been reported in children with autoimmune thyroid disease (AITD). The aim of this study was to determine the prevalence of autoimmune gastritis markers among children diagnosed as AITD. PATIENTS AND METHODS: We studied 26 patients with AITD. Basal samples were taken to determine: hemogram, vitamin B12 and folic acid plasmatic levels, gastrin plasmatic levels, and PCA's determination. Other autoimmune disease comorbidity were also studied. RESULTS: Free T4 and TSH values were normal, with hormonal substitutive treatment. Hb, MCV, HCM, vitamin B12, folic acid and gastrin were in normal range for all 26 patients. We reported 6 cases diabetes mellitus type 1 and 2 of celiac disease. A single patient was PCA positive. It was a 14-year-old hyperthyroid girl without any other autoimmune disease. CONCLUSIONS: AITD in childhood and adolescence is associated with other autoimmune diseases, specially DM1 and CD. PCA becomes an early and sensitive marker to detect autoimmune gastritis.


Assuntos
Doenças Autoimunes/complicações , Gastrite/complicações , Gastrite/imunologia , Doenças da Glândula Tireoide/complicações , Doenças da Glândula Tireoide/imunologia , Adolescente , Doenças Autoimunes/epidemiologia , Criança , Estudos Transversais , Feminino , Gastrite/epidemiologia , Humanos , Masculino , Prevalência , Estudos Prospectivos , Adulto Jovem
16.
Biomech Model Mechanobiol ; 18(6): 1837-1846, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31165376

RESUMO

Cost funtions are needed for calculation of muscle forces in musculoskeletal models. The behavior of the energy-related cost function, proposed by Praagman et al. (J Biomech 39(4):758-765, 2006. https://doi.org/10.1016/j.jbiomech.2004.11.034 ) (CFP), can be used as an optimization criteria in musculoskeletal models for studying gait. In particular, in this work, its performance is compared against two empirical phenomenological models at different walking speed conditions. Also, the sensitivity of the CFP function to model parameters, such as muscle mass, maximal isometric muscle force, optimal muscle fiber length and maximum muscle velocity of the contractile element, was analyzed. The obtained results showed that CFP presents different behavior (in terms of the normalized root-mean-squared deviation (NRMSD) and the coefficient of multiple correlation (CMC)) for different muscles. Also, it provided estimates with median of NRMSD between 0.176 and 0.299 and median of CMC between 0.703 and 0.865 both metrics for slow, free and fast walking speed, which could be considered as acceptable results. Furthermore, the results indicated that CFP is insensitive to changes in muscle mass and relatively sensitive to maximal isometric muscle force. However, CFP presented a noisy behavior on estimations of muscle energy rate for some muscle as compared to phenomenological models. Finally, estimations by CFP during gait are within the values obtained by the empirical phenomenological models.


Assuntos
Velocidade de Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Simulação por Computador , Eletromiografia , Feminino , Humanos , Masculino
17.
Proc Inst Mech Eng H ; 232(11): 1083-1097, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30280643

RESUMO

Analysis of the human locomotor system using rigid-body musculoskeletal models has increased in the biomechanical community with the objective of studying muscle activations of different movements. Simultaneously, the finite element method has emerged as a complementary approach for analyzing the mechanical behavior of tissues. This study presents an integrative biomechanical framework for gait analysis by linking a musculoskeletal model and a subject-specific finite element model of the pelvis. To investigate its performance, a convergence study was performed and its sensitivity to the use of non-subject-specific material properties was studied. The total hip joint force estimated by the rigid musculoskeletal model and by the finite element model showed good agreement, suggesting that the integrative approach estimates adequately (in shape and magnitude) the hip total contact force. Previous studies found movements of up to 1.4 mm in the anterior-posterior direction, for single leg stance. These results are comparable with the displacement values found in this study: 0-0.5 mm in the sagittal axis. Maximum von Mises stress values of approximately 17 MPa were found in the pelvic bone. Comparing this results with a previous study of our group, the new findings show that the introduction of muscular boundary conditions and the flexion-extension movement of the hip reduce the regions of high stress and distributes more uniformly the stress across the pelvic bone. Thus, it is thought that muscle force has a relevant impact in reducing stresses in pelvic bone during walking of the finite element model proposed in this study. Future work will focus on including other deformable structures, such as the femur and the tibia, and subject-specific material properties.


Assuntos
Marcha , Fenômenos Mecânicos , Modelagem Computacional Específica para o Paciente , Pelve/fisiologia , Adulto , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Masculino , Estresse Mecânico
18.
An Pediatr (Engl Ed) ; 88(5): 273-279, 2018 May.
Artigo em Espanhol | MEDLINE | ID: mdl-28711428

RESUMO

INTRODUCTION AND OBJECTIVES: Congenital heart disease is a major cause of infant mortality in developed countries. In Spain, there are no publications at national level on mortality due to congenital heart disease. The aim of this study is to analyse mortality in infants with congenital heart disease, lethality of different types of congenital heart disease, and their variation over a ten-year period. METHODS: A retrospective observational study was performed to evaluate mortality rate of children under one year old with congenital heart disease, using the minimum basic data set, from 2003 to 2012. Mortality rate and relative risk of mortality were estimated by Poisson regression. RESULTS: There were 2,970 (4.58%) infant deaths in a population of 64,831 patients with congenital heart disease, with 73.8% of deaths occurring during first week of life. Infant mortality rate in patients with congenital heart disease was 6.23 per 10,000 live births, and remained constant during the ten-year period of the study, representing 18% of total infant mortality rate in Spain. The congenital heart diseases with highest mortality rates were hypoplastic left heart syndrome (41.4%), interruption of aortic arch (20%), and total anomalous pulmonary drainage (16.8%). Atrial septal defect (1%) and pulmonary stenosis (1.1%) showed the lowest mortality rate. CONCLUSIONS: Congenital heart disease was a major cause of infant mortality with no variations during the study period. The proportion of infants who died in our study was similar to other similar countries. In spite of current medical advances, some forms of congenital heart disease show very high mortality rates.


Assuntos
Cardiopatias Congênitas/mortalidade , Feminino , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Masculino , Estudos Retrospectivos , Espanha/epidemiologia , Fatores de Tempo
19.
An Pediatr (Engl Ed) ; 89(5): 294-301, 2018 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-29605620

RESUMO

INTRODUCTION AND OBJECTIVES: Congenital heart disease (CHD) represents the most common congenital malformation. The objective of this study was to analyse the incidence of CHD in Spain, and it is the first nationwide study so far. METHODS: A retrospective observational study was performed in order to evaluate the incidence of CHD in Spain. The administrative database (minimum basic data set) from 2003 to 2012 was analysed in children less than one year old admitted to hospital with codes of CHD (International Classification of Diseases, 9th Revision, clinical modification). Cumulative incidence, Incidence relative risk, and standardised incidence ratio were calculated to study geographic variations. RESULTS: There were 64,831 infants with CHD among the 4,766,325 births analysed during the period studied, with an incidence of 13.6‰. The incidence excluding atrial septal defect was 7.29 ‰.The most frequent CHD were atrial septal defect (6.31‰), ventricular septal defect (3.48‰), patent ductus arteriosus (2.71‰), coarctation of the aorta (0.55‰), pulmonary stenosis (0.50‰), transposition of the great arteries (0.49‰), atrioventricular septal defect (0.45‰), and tetralogy of Fallot (0.41‰). Castilla and Leon, together with Extremadura, showed the highest risks for severe and very severe CHD, while Madrid and Cantabria showed the lowest. CONCLUSIONS: An increase of mild CHD was observed during the period analysed. This could have been influenced by improvements in diagnostic techniques, extended use of echocardiography, and the International Classification of Diseases, 9th Revision, clinical modification coding system, and to a decrease in very severe CHD, which is less influenced by external factors. Significant geographical differences were found in the incidence of severe and very severe CHD.


Assuntos
Cardiopatias Congênitas/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Espanha/epidemiologia , Fatores de Tempo
20.
Top Spinal Cord Inj Rehabil ; 23(2): 168-173, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29339893

RESUMO

Background: Subjects with spinal cord injury (SCI) propel their wheelchairs by generating a different level of muscle activity given their multiple deficits in muscle strength. Exercise training programs seem to be effective in improving wheelchair propulsion capacity. Functional electrical stimulation (FES) therapy is a complementary tool for rehabilitation programs. Objectives: To determine the accuracy of the synchronization between the FES activation and the push phase of the propulsion cycle by using hand pressure sensors that allow anterior deltoids activation when the hand is in contact with the pushrim. Methods: We analyzed 2 subjects, with injuries at C6 American Spinal Injury Association Impairment Scale (AIS) A and T12 AIS A. The stimulation parameters were set for a 30 Hz frequency symmetrical biphasic wave, 300 µs pulse width. Data were collected as participants propelled the wheelchair over a 10-m section of smooth, level vinyl floor. Subjects were evaluated in a motion analysis laboratory (ELITE; BTS, Milan, Italy). Results: Subject 1 showed synchronization between the FES activation and the push phase of 87.5% in the left hand and of 80% in the right hand. Subject 2 showed synchronization of 95.1% in the left and of hand 94.9% in the right hand. Conclusion: Our study determined a high accuracy of a novel FES therapeutic option, showing the synchronization between the electrical stimulation and the push phase of the propulsion cycle.


Assuntos
Terapia por Estimulação Elétrica/métodos , Exercício Físico/fisiologia , Ombro/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Cadeiras de Rodas , Adulto , Humanos , Masculino , Traumatismos da Medula Espinal/fisiopatologia , Resultado do Tratamento
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