Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Appl Clin Inform ; 11(1): 142-152, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32074651

RESUMO

BACKGROUND: Provider orders for inappropriate advanced imaging, while rarely altering patient management, contribute enough to the strain on available health care resources, and therefore the United States Congress established the Appropriate Use Criteria Program. OBJECTIVES: To examine whether co-designing clinical decision support (CDS) with referring providers will reduce barriers to adoption and facilitate more appropriate shoulder ultrasound (US) over magnetic resonance imaging (MRI) in diagnosing Veteran shoulder pain, given similar efficacies and only 5% MRI follow-up rate after shoulder US. METHODS: We used a theory-driven, convergent parallel mixed-methods approach to prospectively (1) determine medical providers' reasons for selecting MRI over US in diagnosing shoulder pain and identify barriers to ordering US, (2) co-design CDS, informed by provider interviews, to prompt appropriate US use, and (3) assess CDS impact on shoulder imaging use. CDS effectiveness in guiding appropriate shoulder imaging was evaluated through monthly monitoring of ordering data at our quaternary care Veterans Hospital. Key outcome measures were appropriate MRI/US use rates and transition to ordering US by both musculoskeletal specialist and generalist providers. We assessed differences in ordering using a generalized estimating equations logistic regression model. We compared continuous measures using mixed effects analysis of variance with log-transformed data. RESULTS: During December 2016 to March 2018, 569 (395 MRI, 174 US) shoulder advanced imaging examinations were ordered by 111 providers. CDS "co-designed" in collaboration with providers increased US from 17% (58/335) to 50% (116/234) of all orders (p < 0.001), with concomitant decrease in MRI. Ordering appropriateness more than doubled from 31% (105/335) to 67% (157/234) following CDS (p < 0.001). Interviews confirmed that generalist providers want help in appropriately ordering advanced imaging. CONCLUSION: Partnering with medical providers to co-design CDS reduced barriers and prompted appropriate transition to US from MRI for shoulder pain diagnosis, promoting evidence-based practice. This approach can inform the development and implementation of other forms of CDS.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Processamento de Imagem Assistida por Computador , Ombro/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Appl Clin Inform ; 11(1): 79-87, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31995835

RESUMO

BACKGROUND: Despite progress in patient safety, misidentification errors in radiology such as ordering imaging on the wrong anatomic side persist. If undetected, these errors can cause patient harm for multiple reasons, in addition to producing erroneous electronic health records (EHR) data. OBJECTIVES: We describe the pilot testing of a quality improvement methodology using electronic trigger tools and preimaging checklists to detect "wrong-side" misidentification errors in radiology examination ordering, and to measure staff adherence to departmental policy in error remediation. METHODS: We retrospectively applied and compared two methods for the detection of "wrong-side" misidentification errors among a cohort of all imaging studies ordered during a 1-year period (June 1, 2015-May 31, 2016) at our tertiary care hospital. Our methods included: (1) manual review of internal quality improvement spreadsheet records arising from the prospective performance of preimaging safety checklists, and (2) automated error detection via the development and validation of an electronic trigger tool which identified discrepant side indications within EHR imaging orders. RESULTS: Our combined methods detected misidentification errors in 6.5/1,000 of study cohort imaging orders. Our trigger tool retrospectively identified substantially more misidentification errors than were detected prospectively during preimaging checklist performance, with a high positive predictive value (PPV: 88.4%, 95% confidence interval: 85.4-91.4). However, two third of errors detected during checklist performance were not detected by the trigger tool, and checklist-detected errors were more often appropriately resolved (p < 0.00001, 95% confidence interval: 2.0-6.9; odds ratio: 3.6). CONCLUSION: Our trigger tool enabled the detection of substantially more imaging ordering misidentification errors than preimaging safety checklists alone, with a high PPV. Many errors were only detected by the preimaging checklist; however, suggesting that additional trigger tools may need to be developed and used in conjunction with checklist-based methods to ensure patient safety.


Assuntos
Erros Médicos , Radiologia , Algoritmos , Lista de Checagem , Registros Eletrônicos de Saúde , Pessoal de Saúde , Humanos , Imageamento por Ressonância Magnética , Segurança do Paciente
3.
Radiology ; 284(1): 25-42, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28628411

RESUMO

Increased youth participation in sports has resulted in increased injury tolls due to shifts toward participation in competitive sports at earlier ages, increased training intensity and competition schedules, as well as specialization into one sport. The physiology of the growing musculoskeletal system makes the growing athlete particularly vulnerable to specific types of injuries. Radiologists must understand the differences between pediatric and adult athletes to recognize the particular injuries to which these young athletes are prone. Imaging and pertinent clinical details of major representative acute and overuse injuries characteristic to pediatric athletes will be discussed. © RSNA, 2017.


Assuntos
Atletas , Traumatismos em Atletas/diagnóstico por imagem , Desenvolvimento Musculoesquelético , Sistema Musculoesquelético/lesões , Esportes , Adolescente , Fatores Etários , Traumatismos em Atletas/prevenção & controle , Criança , Transtornos Traumáticos Cumulativos/diagnóstico por imagem , Transtornos Traumáticos Cumulativos/prevenção & controle , Humanos , Fatores de Risco , Equipamentos Esportivos
4.
Radiographics ; 36(6): 1606-1627, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27726738

RESUMO

Shoulder pain is one of the most common musculoskeletal conditions encountered in primary care and specialty orthopedic clinic settings. Although magnetic resonance (MR) imaging is typically the modality of choice for evaluating the soft-tissue structures of the shoulder, ultrasonography (US) is becoming an important complementary imaging tool in the evaluation of superficial soft-tissue structures such as the rotator cuff, subacromial-subdeltoid bursa, and biceps tendon. The advantages of US driving its recent increased use include low cost, accessibility, and capability for real-time high-resolution imaging that enables dynamic assessment and needle guidance. As more radiologists are considering incorporating shoulder US into their practices, the development of a standardized approach to performing shoulder US should be a priority to facilitate the delivery of high-quality patient care. Familiarity with and comfort in performing a standardized shoulder US examination, as well as knowledge of the types of anomalies that can be evaluated well with US, will enhance the expertise of those working in musculoskeletal radiology practices and add value in the form of increased patient and health care provider satisfaction. This review describes the utility and benefits of shoulder US as a tool that complements MR imaging in the assessment of shoulder pain. A standardized approach to the shoulder US examination is also described, with a review of the basic technique of this examination, normal anatomy of the shoulder, common indications for shoulder US, and characteristic US findings of common shoulder diseases-with select MR imaging and arthroscopic correlation. Online supplemental material is available for this article. ©RSNA, 2016.


Assuntos
Fraturas Ósseas/diagnóstico por imagem , Artropatias/diagnóstico por imagem , Lesões do Ombro/diagnóstico por imagem , Ombro/diagnóstico por imagem , Traumatismos dos Tendões/diagnóstico por imagem , Ultrassonografia/normas , Medicina Baseada em Evidências , Humanos , Aumento da Imagem/normas , Imagem Multimodal/normas , Traumatismo Múltiplo/diagnóstico por imagem , Posicionamento do Paciente/normas , Lesões dos Tecidos Moles/diagnóstico por imagem , Estados Unidos
5.
Radiographics ; 36(4): 1106-28, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27399238

RESUMO

Traumatic finger injuries account for a substantial number of emergency visits every year. Imaging plays an important role in diagnosis and in directing management of these injuries. Although many injuries can be managed conservatively, some require more invasive interventions to prevent complications and loss of function. Accurate diagnosis of finger injuries can often be difficult, given the complicated soft-tissue anatomy of the hand and the diverse spectrum of injuries that can occur. To best serve the patient and the treating physician, radiologists must have a working knowledge of finger anatomy, the wide array of injury patterns that can occur, the characteristic imaging findings of different finger injuries, and the most appropriate treatment options for each type of injury. This article details the intricate anatomy of the hand as it relates to common finger injuries, illustrates the imaging findings of a range of injuries, presents optimal imaging modalities and imaging parameters for the diagnosis of different injury types, and addresses which findings have important management implications for the patient and the orthopedic surgeon. With this fund of knowledge, radiologists will be able to recommend the most appropriate imaging studies, make accurate diagnoses, convey clinically relevant imaging findings to the referring physician, and suggest appropriate follow-up examinations. In this way, the radiologist will help improve patient care and outcomes. Online supplemental material is available for this article. (©)RSNA, 2016.


Assuntos
Diagnóstico por Imagem/métodos , Traumatismos dos Dedos/diagnóstico por imagem , Traumatismos dos Dedos/cirurgia , Procedimentos Ortopédicos , Humanos
6.
J Am Coll Radiol ; 13(7): 780-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27162045

RESUMO

PURPOSE: MRI is frequently overused. The aim of this study was to analyze shoulder MRI ordering practices within a capitated health care system and explore the potential effects of shoulder ultrasound substitution. METHODS: We reviewed medical records of 237 consecutive shoulder MRI examinations performed in 2013 at a Department of Veterans Affairs tertiary care hospital. Using advanced imaging guidelines, we assessed ordering appropriateness of shoulder MRI and estimated the proportion of examinations for which musculoskeletal ultrasound could have been an acceptable substitute, had it been available. We then reviewed MRI findings and assessed if ultrasound with preceding radiograph would have been adequate for diagnosis, based on literature reports of shoulder ultrasound diagnostic performance. RESULTS: Of the 237 examinations reviewed, 106 (45%) were deemed to be inappropriately ordered, most commonly because of an absent preceding radiograph (n = 98; 92%). Nonorthopedic providers had a higher frequency of inappropriate ordering (44%) relative to orthopedic specialists (17%) (P = .016; odds ratio = 3.15, 95% confidence interval = 1.24-8.01). In the 237 examinations, ultrasound could have been the indicated advanced imaging modality for 157 (66%), and most of these (133/157; 85%) could have had all relevant pathologies characterized when combined with radiographs. Regardless of indicated modality, ultrasound could have characterized 80% of all cases ordered by nonorthopedic providers and 50% of cases ordered by orthopedic specialists (P = .007). CONCLUSIONS: Advanced shoulder imaging is often not ordered according to published appropriateness criteria. While nonorthopedic provider orders were more likely to be inappropriate, inappropriateness persisted among orthopedic providers. A combined ultrasound and radiograph evaluation strategy could accurately characterize shoulder pathologies for most cases.


Assuntos
Capitação/estatística & dados numéricos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Dor de Ombro/diagnóstico por imagem , Ombro/diagnóstico por imagem , Ultrassonografia/estatística & dados numéricos , Procedimentos Desnecessários/estatística & dados numéricos , Revisão da Utilização de Recursos de Saúde , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Dor de Ombro/epidemiologia , Wisconsin/epidemiologia , Adulto Jovem
7.
Emerg Radiol ; 23(2): 175-85, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26564022

RESUMO

Distal radius fractures are the most common upper extremity fracture and account for approximately one sixth of all fractures treated in US emergency departments. These fractures are associated with significant morbidity and have a major economic impact. Radiographic evaluation of distal radius fractures is frequently performed in the emergency department setting, has a profound impact on initial management, and is essential to assessing the quality and relative success of the initial reduction. While the most appropriate definitive management of distal radius fractures remains controversial, overarching treatment principles reflect distal radius injury mechanisms and biomechanics. An intuitive understanding of the biomechanics of the distal radius and of common mechanisms of injury informs and improves the emergency radiologist's ability to identify key imaging findings with important management implications and to communicate the critical information that emergency physicians and orthopedic surgeons need to best manage distal radius fractures.


Assuntos
Fraturas do Rádio/fisiopatologia , Fenômenos Biomecânicos , Emergências , Humanos , Rádio (Anatomia)/anatomia & histologia , Fraturas do Rádio/diagnóstico por imagem , Fraturas do Rádio/terapia , Resistência ao Cisalhamento , Tomografia Computadorizada por Raios X
9.
Radiographics ; 35(5): 1563-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26186669

RESUMO

Each year, more than 250,000 hip fractures occur in the United States, resulting in considerable patient mortality and morbidity. The various types of adult proximal femoral fractures require different treatment strategies that depend on a variety of considerations, including the location, morphologic features, injury mechanism, and stability of the fracture, as well as the patient's age and baseline functional status. The authors discuss femoral head, femoral neck, intertrochanteric, and subtrochanteric fractures in terms of injury mechanisms, specific anatomic and biomechanical features, and important diagnostic and management considerations, including the diagnostic utility of imaging modalities. The authors review clinically important classification systems, such as the Pipkin, Garden, Pauwels, and Evans-Jensen classification systems, with emphasis on differentiating subchondral insufficiency fractures from avascular necrosis of the femoral head and typical subtrochanteric fractures from atypical (often bisphosphonate-related) subtrochanteric fractures. In addition, the authors describe the potential complications and management strategies for each fracture type on the basis of the patient's age and physical condition. A clear understanding of these considerations allows the radiologist to better provide appropriate and relevant diagnostic information and management guidance to the orthopedic surgeon.


Assuntos
Fraturas do Quadril , Gerenciamento Clínico , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/cirurgia , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas/métodos , Fraturas Espontâneas/diagnóstico por imagem , Fraturas Espontâneas/cirurgia , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/cirurgia , Fraturas do Quadril/classificação , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/cirurgia , Articulação do Quadril/anatomia & histologia , Articulação do Quadril/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Fixadores Internos , Ortopedia , Osteoporose/complicações , Radiografia , Cirurgia Assistida por Computador
10.
Magn Reson Imaging Clin N Am ; 22(4): 621-48, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25442026

RESUMO

This article discusses common injury mechanisms and the subsequent constellation of magnetic resonance (MR) imaging findings in the knee following trauma in the context of instability, as distinguished by the degree of knee flexion and tibial rotation at the time of initial injury, in addition to the direction and magnitude of the responsible force vectors. Using 3-dimensional imaging, common injury mechanisms are illustrated and correlated with MR imaging findings of the resulting osteochondral, ligamentous, meniscal, and musculotendinous lesions. The most common classification and grading systems for these individual lesions and their subsequent treatment implications are discussed.


Assuntos
Traumatismos do Joelho/patologia , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/patologia , Articulação do Joelho/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Índices de Gravidade do Trauma , Força Compressiva , Humanos , Traumatismos do Joelho/classificação , Modelos Anatômicos , Modelos Biológicos , Amplitude de Movimento Articular , Estresse Mecânico
11.
Radiographics ; 34(5): 1317-33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25208283

RESUMO

Treating trauma patients with displaced pelvic fractures requires a multidisciplinary approach at a designated trauma center to reduce morbidity and mortality. Immediate recognition of pelvic ring disruption and determination of pelvic stability are critical components in the evaluation of such patients. Stability is achieved by the ability of the osseoligamentous structures of the pelvis to withstand physiologic stresses without abnormal deformation. The supporting pelvic ligaments, including the posterior and anterior sacroiliac, iliolumbar, sacrospinous, and sacrotuberous ligaments, play a crucial role in pelvic stabilization. Radiologists should be familiar with the ligamentous anatomy and biomechanics relevant to understanding pelvic ring disruptions, as well as the Young and Burgess classification system, a systematic approach for interpreting pelvic ring disruptions and assessing stability on the basis of fundamental force vectors that create predictable patterns. This system provides an algorithmic approach to interpreting images and categorizes injuries as anterioposterior (AP) compression, lateral compression, vertical shear, or combined. Opening and closing of the pelvis from rotational forces result in AP compression and lateral compression injuries, respectively, whereas vertical shear injuries result from cephalad displacement of the hemipelvis. AP and lateral compression fractures are divided into types 1, 2, and 3, with increasing degrees of severity. Knowledge of these injury patterns leads to prompt identification and diagnosis of other subtle injuries and associated complications at pelvic radiography and cross-sectional imaging, allowing the orthopedic surgeon to apply corrective forces for prompt pelvic stabilization.


Assuntos
Fraturas Ósseas , Ossos Pélvicos/lesões , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Feminino , Fraturas Ósseas/classificação , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Ortopedia , Ossos Pélvicos/anatomia & histologia , Ossos Pélvicos/diagnóstico por imagem , Ossos Pélvicos/fisiologia , Tomografia Computadorizada por Raios X
12.
Radiographics ; 33(7): 2031-46, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24224597

RESUMO

The Thoracolumbar Injury Classification and Severity Score (TLICS) is a scoring and classification system developed by the Spine Trauma Study Group in response to the recognition that previous classification systems have limited prognostic value and generally do not suggest treatment pathways. The TLICS provides a spine injury severity score based on three components: injury morphology, integrity of the posterior ligamentous complex (PLC), and neurologic status of the patient. A numerical score is calculated for each category, with a lower point value assigned to a less severe or less urgent injury and a higher point value assigned to a more severe injury requiring urgent management. The total score helps guide decision making about surgical versus nonsurgical management. The TLICS also emphasizes the importance of magnetic resonance imaging in evaluating PLC injury and acknowledges that the primary driver of surgical intervention is the patient's neurologic status. Knowledge of PLC anatomy and its significance is essential in recognizing unstable injuries. Signs of PLC injury at computed tomography include interspinous distance widening, facet joint widening, spinous process fracture, and vertebral subluxation or dislocation. Familiarity with the TLICS will help radiologists who interpret spine trauma imaging studies to effectively communicate findings to spine trauma surgeons. The complete article is available online .


Assuntos
Imageamento por Ressonância Magnética/métodos , Traumatismos da Coluna Vertebral/diagnóstico , Vértebras Torácicas/lesões , Tomografia Computadorizada por Raios X/métodos , Índices de Gravidade do Trauma , Diagnóstico Diferencial , Humanos , Cuidados Pré-Operatórios , Traumatismos da Coluna Vertebral/cirurgia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/patologia
13.
AJR Am J Roentgenol ; 201(3): W409-24, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23971472

RESUMO

OBJECTIVE: Acute shoulder trauma can result in complex injuries to the bone and soft-tissue structures of the shoulder girdle with the associated risk of development of shoulder girdle instability. Destabilizing injuries to the shoulder girdle and fractures of the proximal humerus can occur in predictable patterns based on the injury mechanism. The objectives of this article are to illustrate the relevant anatomy of the shoulder, use 3D modeling and animation to aid in a mechanistic understanding of some of the most common injury patterns, discuss the most relevant radiologic findings that determine the ultimate treatment approach, and discuss an approach to imaging diagnosis with attention to the common treatment strategies. CONCLUSION: Understanding the force mechanisms responsible for the most common patterns of traumatic shoulder girdle injuries and proximal humeral fractures can improve detection of associated clinically significant secondary injuries, increase the effectiveness of injury classification, and ultimately direct appropriate and timely intervention.


Assuntos
Diagnóstico por Imagem , Fraturas do Úmero/diagnóstico , Úmero/lesões , Instabilidade Articular/diagnóstico , Luxação do Ombro/diagnóstico , Lesões do Ombro , Lesões dos Tecidos Moles/diagnóstico , Fenômenos Biomecânicos , Humanos , Fraturas do Úmero/fisiopatologia , Úmero/fisiopatologia , Imageamento Tridimensional , Instabilidade Articular/fisiopatologia , Luxação do Ombro/fisiopatologia , Articulação do Ombro/anatomia & histologia , Lesões dos Tecidos Moles/fisiopatologia
14.
AJR Am J Roentgenol ; 201(2): 378-93, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23883219

RESUMO

OBJECTIVE: Acute traumatic glenohumeral dislocation is one of the most commonly encountered shoulder injuries and can produce a complex combination of associated bony and soft-tissue injuries, the full extent of which is often initially underappreciated. The objectives of this article are to illustrate the relevant anatomy of the shoulder and provide a more intuitive understanding of the complex biomechanics of traumatic glenohumeral instability through the use of 3D modeling and animation to improve the radiologist's awareness of some of the most common injury patterns, and potentially improve the detection of associated injuries. Emphasis is placed on the most critical injuries to determine the ultimate treatment modality, and imaging recommendations are provided. CONCLUSION: Understanding the force mechanisms responsible for traumatic glenohumeral dislocation can potentially improve detection of associated secondary injuries, which can guide more effective injury classification and ultimately direct more appropriate and timely intervention.


Assuntos
Diagnóstico por Imagem , Instabilidade Articular/diagnóstico , Luxação do Ombro/diagnóstico , Lesões do Ombro , Lesões dos Tecidos Moles/diagnóstico , Humanos , Articulação do Ombro/anatomia & histologia
15.
Radiographics ; 33(3): 869-88, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23674780

RESUMO

Traumatic elbow injuries are commonly encountered in the emergency department setting, but their complexity and clinical significance often go unrecognized at the initial evaluation. Initial imaging in patients with elbow trauma should not only help identify major injuries that require immediate intervention but also allow detection of other, often more subtle injuries that may lead to instability or poor functional outcomes if appropriate treatment is delayed. Awareness and detection of these injuries may be improved by a better-developed and more intuitive understanding of the mechanisms that underlie the most common injury patterns. Ideally, such understanding should prompt appropriate early use of advanced imaging techniques. Traumatic elbow injuries should be described in the radiology report within the context of their clinical significance and their implications for management, information that is often best captured by the injury grading and classification systems used by the orthopedic surgery community. This article reviews the relevant anatomy and functional stability of the elbow and discusses common traumatic elbow injury patterns, including elbow dislocations as well as fractures of the distal humerus, radial head and neck, coronoid process, and olecranon. Less commonly encountered injury constellations that are clinically significant are also described. Injury patterns are explained in the context of the responsible force mechanism by using three-dimensional modeling and animation, with emphasis on the functional impact of associated secondary bone and soft-tissue injuries. The utility of cross-sectional imaging modalities such as computed tomography and magnetic resonance imaging in the acute care setting is discussed, and specific imaging guidelines are provided. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.333125176/-/DC1.


Assuntos
Diagnóstico por Imagem/métodos , Lesões no Cotovelo , Articulação do Cotovelo/cirurgia , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/cirurgia , Lesões dos Tecidos Moles/diagnóstico , Lesões dos Tecidos Moles/cirurgia , Humanos
18.
J Vestib Res ; 21(4): 209-17, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21846953

RESUMO

Motion sickness has been defined as a set of physiological signs and symptoms produced as a result of prolonged sensory conflict in central nervous system vestibular centers. It has long been noted that the particular pattern of motion sickness signs and symptoms does not fit the conventional "fight or flight vs. rest and digest" autonomic synergy. We argue that most of the progression of symptoms is consistent with a new etiologic hypothesis: that an as-yet-unidentified ganglionic cholinomimetic agent is slowly released in proportion to sensory conflict. The agent accumulates systemically and stimulates the peripheral sympathetic and parasympathetic ganglia, the adrenal medulla, and potentiates the response of central cholinergic emetic pathways to the same conflict stimulus. The predominant effects of ganglionic stimulation on each autonomic organ, determined by resting tone, are selectively enhanced or inhibited by adrenal catecholamine release, producing the atypical pattern of autonomic changes seen in motion sickness. The adrenergic response may eventually also counter the central emetic drive. The hypothesis could be experimentally pursued via human and animal experiments employing a nicotinic antagonist that has both central and peripheral ganglionic actions such as mecamylamine.


Assuntos
Colinérgicos/farmacologia , Enjoo devido ao Movimento/fisiopatologia , Animais , Catecolaminas/metabolismo , Gânglios Autônomos/efeitos dos fármacos , Humanos , Modelos Neurológicos , Receptores Nicotínicos/fisiologia
19.
J Vestib Res ; 18(1): 1-14, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18776594

RESUMO

Short-radius centrifugation (SRC) provides a practical means of producing artificial gravity for long duration space flights, though perceptual side-effects could limit its operational feasibility. Head turns (HT) during SRC, other than those about the centrifugation axis, produce Cross-Coupled Stimulation (CCS), perceived as a tumbling sensation. CCS can be nauseagenic, though adaptation can minimize this detrimental effect over time. The force environment of CCS suggests that the head turn velocity plays a role in determining the stimulus magnitude, though its degree has not been characterized. Twenty-three subjects performed right quadrant head turns of 8 different velocities while spinning at 19 and 23 RPMs on the SRC over two consecutive days. The perceptual effects were characterized by subjective metrics, investigating the acute differences between velocities as well as the chronic effects on adaptation. It was found that the perceived CCS magnitude can be regulated by modulating HT velocity. Further, a threshold of HT velocity exists above which an asymptotic perceptual response is observed, and below which the perceptual response diminishes at an exponential rate relative to head turn velocity. Finally, the effects of HT velocity are independent of HT direction, though the differing head turn directions likely produce contextually specific stimuli. These results suggest that HT velocity modulation could provide a practical means of incremental adaptation to CCS during SRC.


Assuntos
Movimentos da Cabeça/fisiologia , Cinestesia/fisiologia , Percepção de Movimento/fisiologia , Enjoo devido ao Movimento/prevenção & controle , Limiar Sensorial/fisiologia , Adaptação Fisiológica , Adolescente , Adulto , Análise de Variância , Centrifugação , Feminino , Gravidade Alterada , Humanos , Modelos Lineares , Masculino , Valores de Referência , Rotação , Simulação de Ausência de Peso
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA