Distribución de la duración de la incapacidad temporal por contingencia común por diagnóstico médico (Cataluña, 2006-2008)

We present a simple and practical tool that allows the usual distribution of the duration of non-occupational sick leave to be determined by medical diagnosis. A total of 2,646,352 episodes of medically certified sick leave, registered by the Catalan Institute of Medical Evaluations for the period 2006-2008, were followed to closure and were entered into a spreadsheet. Given its asymmetric distribution, the median duration of sick leave was 9 days. Musculoskeletal disorders were the most frequent diagnostic group (22.5%), while neoplasms had the longest median duration (56 days). The most common specific diagnoses were diarrhea-gastroenteritis (8.2%; median: 3 days) and acute rhinopharyngitis (5.2%; median: 4 days). The distribution of the duration of sick leave in a population varies by diagnosis and is asymmetric, with most episodes being much shorter than the mean duration. This finding is important for better clinical and administrative management of sick leave episodes.     

靳三针治疗中风后痉挛性偏瘫临床研究及其对康复训练的影响

目的:观察颞三针配合挛三针治疗中风后痉挛性偏瘫的临床效果,分析其推广价值,及其与康复训练之间的相互影响。方法:将符合入组标准的116例患者随机分为靳三针组、康复组、联合组,在基础治疗上分别施加颞三针合挛三针治疗、康复训练和联合治疗,分别进行功能评定和量表评估。结果:在FCA、NDS、FMA量表评分方面,7天后,除康复组外,其他两组的量表评分与治疗前比较,差异有统计学意义(P<0.05),而14天后,3组患者的量表评分较7天前均有好转(P<0.05),与治疗前比较,差异均有显著统计学意义(P<0.01)。在CSI评分方面,治疗7天后,靳三针组、康复组评分与治疗前比较,差异有统计学意义(P<0.05),而联合组的评分差异有显著统计学意义(P<0.01),与其他两组比较,差异亦有统计学意义(P<0.05)。结论:靳三针、康复训练及其联合应用均可缓解中风后痉挛性偏瘫症状,而靳三针不仅能够降低肌张力,还能在一定程度上改善患肢功能,提高康复训练效果,而且取穴、操作简便,适宜进行推广应用。     

Racial variation in the use of do-not-resuscitate orders

OBJECTIVE: To compare the use of do-not-resuscitate (DNR) orders in African-American and white patients using a large, multisite, community-based sample. MEASUREMENTS: Our sample included 90,821 consecutive admissions to 30 hospitals in a large metropolitan region with six nonsurgical conditions from 1993 through 1995. Demographic and clinical data were abstracted from medical records. Admission severity of illness was measured using multivariate risk-adjustment models with excellent discrimination (receiver-operating characteristic curve areas, 0.82–0.88). Multiple logistic regression analysis was used to determine the independent association between race and use of DNR orders, adjusting for age, admission severity, and other covariates. MAIN RESULTS: In all patients, the rate of DNR orders was lower in African Americans than whites (9% vs 18%; p<.001). Rates of orders were also lower (p<.001) among African Americans in analyses stratified by age, gender, diagnosis, severity of illness, and in-hospital death. After adjusting for severity and other important covariates, the odds of a DNR order remained lower (p<.001) for African-Americans relative to whites for all diagnoses, ranging from 0.38 for obstructive airway disease to 0.71 for gastrointestinal hemorrhage. Results were similar in analyses limited to orders written by the first, second, or seventh hospital day. Finally, among patients with DNR orders, African Americans were less likely to have orders written on the first hospital day and more likely to have orders written on subsequent days. CONCLUSIONS: The use of DNR orders was substantially lower in African Americans than in whites, even after adjusting for severity of illness and other covariates. Identification of factors underlying such differences will improve our understanding of the degree to which expectations for care differ in African American and white patients. Dr. Rosenthal is a Research Associate, Health Services Research and Development Service, Department of Veterans Affairs, and was a recipient of a Picker/Commonwealth Scholar’s Award from the Commonwealth Fund when this work was conducted. Presented in part at the annual meeting of the Society of General Internal Medicine, Washington, DC, April 1997, and at the annual meeting of the Midwest Society of General Internal Medicine, Chicago, Ill., September 1997.     

A theory of direction selectivity for macaque primary visual cortex

This paper offers a theory for the origin of direction selectivity (DS) in the macaque primary visual cortex, V1. DS is essential for the perception of motion and control of pursuit eye movements. In the macaque visual pathway, neurons with DS first appear in V1, in the Simple cell population of the Magnocellular input layer 4Cα. The lateral geniculate nucleus (LGN) cells that project to these cortical neurons, however, are not direction selective. We hypothesize that DS is initiated in feed-forward LGN input, in the summed responses of LGN cells afferent to a cortical cell, and it is achieved through the interplay of 1) different visual response dynamics of ON and OFF LGN cells and 2) the wiring of ON and OFF LGN neurons to cortex. We identify specific temporal differences in the ON/OFF pathways that, together with item 2, produce distinct response time courses in separated subregions; analysis and simulations confirm the efficacy of the mechanisms proposed. To constrain the theory, we present data on Simple cells in layer 4Cα in response to drifting gratings. About half of the cells were found to have high DS, and the DS was broadband in spatial and temporal frequency (SF and TF). The proposed theory includes a complete analysis of how stimulus features such as SF and TF interact with ON/OFF dynamics and LGN-to-cortex wiring to determine the preferred direction and magnitude of DS.

This paper proposes a solution to a longstanding question in visual neuroscience, namely, the origin of direction selectivity (DS) in the visual cortex of macaque monkeys. Motion perception is a vital visual capability well developed in primates. As perceiving motion requires perceiving the direction in which a target moves, DS, the ability of visual neurons to sense the direction of movement, is essential for motion perception (1) and for the control of pursuit eye movements (2). For these reasons, understanding DS is an important first step toward understanding how the cortex processes motion signals.DS in cortical neurons was first documented in the cat (3). Since then, it has been found in neurons all along the visual dorsal stream (an area associated with motion processing) in primates like macaque monkeys (4–7), whose vision is like that of humans. Neurons with DS are, in fact, present across species; they are widespread among visual mammals, an experimental fact that testifies to their biological significance.In the visual pathway of macaques, DS appears first in the primary visual cortex (V1), in the Simple cell population of the input layer 4Cα (8). These neurons provide feed-forward direction-selective signals to subsequent cortical layers and brain regions in the dorsal pathway. Thus, to discover the origin of DS, one is led to examining how neurons in layer 4Cα acquire their DS—and that is where it gets interesting: The neurons that provide visual signals to layer 4Cα, the Magnocellular cells in the lateral geniculate nucleus (LGN), are not direction selective (9–12). Yet many of the cells in the input layer of V1 to which they project are direction selective. A fundamental scientific question, therefore, is how 4Cα neurons acquire their DS. That is the question we would like to answer in this paper.Although many papers have been written on DS since its discovery over half a century ago, and there is continued interest in the subject (13–16), no satisfactory mechanistic explanation for the origin of DS in primate cortex has been proposed before now: Early conceptual models of how DS may arise, such as the Reichardt multiplier (17) or the motion energy model (18), were not concerned with biological mechanisms. Later work proposed neural mechanisms for the motion energy model (19), but they are not sufficient for explaining DS in primate cortex. See Discussion for comparisons of different model mechanisms.It is widely accepted that the DS computation requires spatiotemporal inseparability (STI); that is, different subregions of the receptive field have different time courses of response (18, 20, 21). What were lacking were biological mechanisms that could produce STI, and a clear understanding of how DS depends on the interaction between STI and the spatial and temporal character of the visual stimulus. These are the issues we address in this paper.We hypothesize that a plausible biological mechanism is the interplay between 1) the different dynamics of ON and OFF LGN cells and 2) the specific wiring that connects ON and OFF cells to V1. Item 2 refers here to the well-known fact that OFF and ON LGN cells are wired to segregated V1 receptive field subregions (3, 22, 23). Our main contribution is item 1: We identify, in Results, dynamic differences in the ON/OFF pathways that, together with item 2, produce distinct response time courses in separated receptive-field subregions. The mechanisms we propose are biologically grounded, and, as we show, they are sufficient for initiating DS in the feed-forward LGN input to cortical cells.To constrain our theory, we present experimental results on the responses of macaque 4Cα Simple cells to drifting gratings. Most Simple cells we recorded in 4Cα were unambiguously direction selective, preferring, consistently, the same direction over their entire visible ranges of spatial frequency (SF) and temporal frequency (TF); about half of the cells had high DS. Our data reveal also an important characteristic of neurons with DS, namely, the approximate invariance of DS with SF and TF. Explaining the broadband character of DS (in TF and SF) is a challenge for all previous theories. Our theory includes a complete analysis of how stimulus features like SF and TF interact with ON/OFF dynamics and LGN-to-cortex wiring to explain the broadband character of DS. The theoretical predictions are in good agreement with data.With regard to broader implications, although the theory as described in this paper is specifically about DS, an important message is that, when combining information from multiple channels, slight biases in their temporal filters can greatly enhance the capability of a system. Thus, it may be possible to exploit the temporal axis further in the processing of biological and nonbiological signals, especially in the neural processing of sensory inputs and, possibly, in computer vision.     

Biologic Therapy for the Treatment of Giant Cell Arteritis

Abstract

Giant cell arteritis (GCA), a vasculitis of the medium and large arteries, is traditionally managed with glucocorticoids. However, the side effects of chronic glucocorticoid use and the occurrence of refractory cases warrant the consideration of steroid-sparing agents, including biologic agents. Interleukin-6 (IL-6) inhibition shows the most promise as biologic therapy for refractory cases of GCA, but data to support the use of other existing biologic agents are currently lacking. A better understanding of the pathogenesis of GCA as well as clinical trials investigating both existing and emerging biologic agents is needed to expand therapeutic options for the treatment of GCA.     

Step manifestations and sensitivity changes in Gilles de la Tourette syndrome

Nasal and temporal step-like visual field defects are seen in people exhibiting Tourette syndrome (TS). These field defects are found to be associated with change in the sensitivity level of the local visual field area when compared to identical areas in the second eye. The sensitivity level of the visual field area is found to change for step manifestations in the majority of visual fields. In particular, the majority of steps situated outside 30° eccentricity from fixation are found to have more sensitivity compared to normal identical areas in the fellow eye. Similarly, steps located within 10° eccentricity from fixation are found to be associated with reduced sensitivity compared to more normal identical areas in the fellow eye.

In view of these findings, knowledge about plasma dopamine level in TS and the different effects of dopamine on rod and cone systems, a possible dopaminergic mechanism is suggested as the pathogenesis of step-like field defects.     

Surgically induced astigmatism after 3.0 mm temporal and nasal clear corneal incisions in bilateral cataract surgery

Aims:

To compare the corneal refractive changes induced after 3.0 mm temporal and nasal corneal incisions in bilateral cataract surgery.

Materials and Methods:

This prospective study comprised a consecutive case series of 60 eyes from 30 patients with bilateral phacoemulsification that were implanted with a 6.0 mm foldable intraocular lens through a 3.0 mm horizontal clear corneal incision (temporal in the right eyes, nasal in the left eyes). The outcome measures were surgically induced astigmatism (SIA) and uncorrected visual acuity (UCVA) 1 and 3 months, post-operatively.

Results:

At 1 month, the mean SIA was 0.81 diopter (D) for the temporal incisions and 0.92 D for nasal incisions (P = 0.139). At 3 months, the mean SIA were 0.53 D for temporal incisions and 0.62 D for nasal incisions (P = 0.309). The UCVA was similar in the 2 incision groups before surgery, and at 1 and 3 months post-operatively.

Conclusion:

After bilateral cataract surgery using 3.0 mm temporal and nasal horizontal corneal incisions, the induced corneal astigmatic change was similar in both incision groups. Especially in Asian eyes, both temporal and nasal incisions (3.0 mm or less) would be favorable for astigmatism-neutral cataract surgery.     

Central Serous Chorioretinopathy in Giant Cell Arteritis

A 66-year-old woman started oral prednisone for temporal artery biopsy (TAB) proven GCA and developed central haziness OD > OS. Visual acuity worsened to 20/100 OD and 20/25 OS. Clinical exam, optical coherence tomography (OCT) and fluorescein angiography (FA) revealed central serous chorioretinopathy (CSCR). The patient was treated with focal laser therapy for CSCR and steroid taper. Patients with giant cell arteritis on high dose steroids may present with significant loss of visual acuity and field. CSCR (precipitated by steroids) should be considered in the differential diagnosis as increasing the steroid dose for presumed visual loss secondary to GCA might worsen rather than improve the visual outcome.