Risks of Routinely Clamping External Ventricular Drains for Intrahospital Transport in Neurocritically Ill Cerebrovascular Patients

Background

Current guidelines recommend routine clamping of external ventricular drains (EVD) for intrahospital transport (IHT). The aim of this project was to describe intracranial hemodynamic complications associated with routine EVD clamping for IHT in neurocritically ill cerebrovascular patients.

Methods

We conducted a retrospective review of cerebrovascular adult patients with indwelling EVD admitted to the neurocritical care unit (NICU) during the months of September to December 2015 at a tertiary care center. All IHTs from the NICU of the included patients were examined. Main outcomes were incidence and risk factors for an alteration in intracranial pressure (ICP) and cerebral perfusion pressure after IHT.

Results

Nineteen cerebrovascular patients underwent 178 IHTs (79.8 % diagnostic and 20.2 % therapeutic) with clamped EVD. Twenty-one IHTs (11.8 %) were associated with post-IHT ICP ≥ 20 mmHg, and 33 IHTs (18.5 %) were associated with escalation of ICP category. Forty IHTs (26.7 %) in patients with open EVD status in the NICU prior to IHT were associated with IHT complications, whereas no IHT complications occurred in IHTs with clamped EVD status in the NICU. Risk factors for post-IHT ICP ≥ 20 mmHg were IHT for therapeutic procedures (adjusted relative risk [aRR] 5.82; 95 % CI, 1.76–19.19), pre-IHT ICP 15–19 mmHg (aRR 3.40; 95 % CI, 1.08–10.76), pre-IHT ICP ≥ 20 mmHg (aRR 12.94; 95 % CI, 4.08–41.01), and each 1 mL of hourly cerebrospinal fluid (CSF) drained prior to IHT (aRR 1.11; 95 % CI, 1.01–1.23).

Conclusions

Routine clamping of EVD for IHT in cerebrovascular patients is associated with post-IHT ICP complications. Pre-IHT ICP ≥ 15 mmHg, increasing hourly CSF output, and IHT for therapeutic procedures are risk factors.

     

西藏世居藏族男青年形态面指数分析

目的 探讨西藏世居藏族男青年的形态面指数特征。方法 按照国际学术界规定的方法,对西藏世居的242例藏族男青年面宽和形态面高进行活体测量,并计算形态面指数。 结果 不同年龄段藏族青年的面宽和形态面指数存在显著差异（P<0.05或P<0.01）,形态面指数与年龄呈正性相关（P<0.01）。 结论 藏族青年的形态面指数以超阔面型为主（38.4%）,阔面型（33.5%）和中面型（19.4%）次之。     

Longitudinal white matter changes associated with cognitive training

Improvements in behavior are known to be accompanied by both structural and functional changes in the brain. However, whether those changes lead to more general improvements, beyond the behavior being trained, remains a contentious issue. We investigated whether training on one of two cognitive tasks would lead to either near transfer (that is, improvements on a quantifiably similar task) or far transfer (that is, improvements on a quantifiably different task), and furthermore, if such changes did occur, what the underlying neural mechanisms might be. Healthy adults (n = 16, 15 females) trained on either a verbal inhibitory control task or a visuospatial working memory task for 4 weeks, over the course of which they received five diffusion tensor imaging scans. Two additional tasks served as measures of near and far transfer. Behaviorally, participants improved on the task that they trained on, but did not improve on cognitively similar tests (near transfer), nor cognitively dissimilar tests (far transfer). Extensive changes to white matter microstructure were observed, with verbal inhibitory control training leading to changes in a left‐lateralized network of frontotemporal and occipitofrontal tracts, and visuospatial working memory training leading to changes in right‐lateralized frontoparietal tracts. Very little overlap was observed in changes between the two training groups. On the basis of these results, we suggest that near and far transfer were not observed because the changes in white matter tracts associated with training on each task are almost entirely nonoverlapping with, and therefore afford no advantages for, the untrained tasks.     

Clinical impact of the use of the revised International Association for the Study of Lung Cancer staging system to operable non-small-cell lung cancers

Introduction

The purpose of this study, therefore, was to evaluate the impact of the use of the present classification IASLC staging system (TNM7) on the categorization of patients and survival after resection.

Methods

Between August 1985 and January 2007, 414 consecutive patients underwent pulmonary resection with a curative intention for NSCLC at the British Hospital in Buenos Aires were included in this study only if they were pathologically staged as N0-M0. Preoperative staging was performed according to the TNM classification system of the International Union Against Cancer (173 men, 58 women).

Results

231 tumours were identified as pathological N0. Mean age was 61.4 years. 173 patients (74.9%) were men. When the TNM7 was applied, 28 patients (12.1%) changed their T factor staging (14 were moved towards a higher T and 14 were moved to a lower T) and 41 patients (17.7%) changed their pathological staging by applying the TNM7: 14 patients were downstaged (6.1%) and 27 (11.7%) were upstaged. With the present T definition among 103 patients in stage IB 27 were upstaged (18 to IIA and 9 to IIB) and in the group of stage IIIB (n = 14) all of them were downstaged (5 to IIB and 9 to IIA). The current T definition showed a statistically significant difference between the two T1 subgroups (93% versus 70% 5 year survival between T1a and T1b, p = 0.027).

Conclusion

This study shows that the clinical impact of the using the IASLC proposed staging system would be modest but relevant, identifying a subgroup with a better prognosis (T1a).     

The anti-nausea effects of CB1 agonists are mediated by an action at the visceral insular cortex

BACKGROUND AND PURPOSE

Conditioned gaping reactions reflect nausea-induced behaviour in rats. Cannabinoid 1 receptor (CB₁) agonists interfere with the establishment of nausea-induced conditioned gaping; however, it is not known if their effects are mediated by an action at peripheral or central CB₁ receptors.

EXPERIMENTAL APPROACH

We utilized the conditioned gaping model of nausea to evaluate the effect of peripheral and central administration of the peripherally restricted CB₁ agonist, CB13, on the establishment of LiCl-induced gaping in rats. We further evaluated the ability of HU-210 administered to the gustatory insular cortex (GIC) or visceral insular cortex (VIC) to interfere with LiCl-induced conditioned gaping and determined if this effect was mediated by CB₁ receptors.

KEY RESULTS

Central, but not peripheral, CB13 suppressed LiCl-induced conditioned gaping. Central administration of the potent CB₁ agonist, HU-210, delivered to the VIC, but not the GIC, suppressed the establishment of LiCl-induced gaping reactions, but not LiCl-induced suppression of hedonic reactions or conditioned taste avoidance. This pattern of results suggests that HU-210 delivered to the VIC prevented LiCl-induced nausea, but not learning per se. The suppression of LiCl-induced conditioned gaping by HU-210 was mediated by CB₁ receptors because it was prevented by co-administration of CB₁ antagonist/inverse agonist, AM-251, into the VIC. A high dose of AM-251 (20 µg) administered alone into the VIC did not produce conditioned gaping reactions.

CONCLUSIONS AND IMPLICATIONS

The nausea-relieving effects of CB₁ agonists, but not the nausea-inducing effects of CB₁ inverse agonists, are mediated, at least in part, by their action at the VIC in rats.     

Twin studies of posttraumatic stress disorder: differentiating vulnerability factors from sequelae

Posttraumatic stress disorder (PTSD) is defined by one's response to an environmental event. However, genetic factors are important in determining people's response to that event, and even their likelihood of being exposed to particular traumatic events in the first place. Classical twin designs can decompose genetic and environmental sources of variance. Such studies are reviewed extensively elsewhere, and we cover them only briefly in this review. Instead, we focus primarily on the identical co-twin control design. This design makes it possible to resolve the "chicken-egg" dilemma inherent in standard case-control designs, namely, distinguishing risk from sequelae. Abnormalities that are present in both the twin with PTSD and the unaffected co-twin suggest pre-existing vulnerability indicators. These include smaller hippocampal volume, large cavum septum pellucidum, more neurological soft signs, lower general intellectual ability, and poorer performance in the specific cognitive abilities of executive function, attention, declarative memory, and processing of contextual cues. In contrast, abnormalities in a twin with PTSD that are not present in the identical co-twin suggest consequences of PTSD or trauma exposure. These include psychophysiological responding, higher resting anterior cingulate metabolism, event-related potential abnormalities associated with attentional processes, recall intrusions, and possibly some types of chronic pain. Most co-twin control studies of PTSD have been small and come from the same twin registry of middle-aged male veterans. Consequently, there is a great need for replication and extension of the findings, particularly in women and younger individuals. The creation of new twin registries would do much toward accomplishing this goal. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.