Longevity of a solitary mole-rat species and its implications for the assumed link between sociality and longevity in African mole-rats (Bathyergidae).

Sociality and cooperative breeding are associated with enhanced longevity in insects and birds, but whether this is also true for mammals is still subject to debate. African mole-rats (Bathyergidae) have recently been claimed to be the only mammalian family in which such an association may exist because cooperatively breeding bathyergids seem to be substantially longer lived than solitary bathyergids. However, although ample longevity data are available for several social bathyergids, almost nothing is known about mortality distribution and lifespan in solitary bathyergids. Here we present robust long-term data on the longevity of a solitary African mole-rat, the silvery mole-rat Heliophobius argenteocinereus. Our findings show that this species is much longer-lived than previously believed. Nonetheless, our comparative analysis suggests that sociality has indeed a positive effect on longevity in this family. We argue that the extreme longevity seen particularly in social bathyergids is probably caused by a combination of subterranean lifestyle and cooperative breeding.

Life expectancy, family constellation and stress in giant mole-rats (Fukomys mechowii).

Giant mole-rats (Fukomys mechowii) are remarkably long-lived subterranean rodents (maximum recorded lifespan as reported here greater than 26 years) that live in families with one reproductive pair (breeders) and their non-reproductive offspring (non-breeders). Previous studies have shown that breeders live on average approximately twice as long as non-breeders, a finding contradicting the classic trade-off between reproduction and lifespan. Because recent evidence points to the hypothalamic-pituitary-adrenal axis as playing an important role in shaping the pace of ageing in mole-rats, we analysed the influence of the social environment of giant mole-rats on intrafamilial aggression levels, indicators of long-term stress, and, ultimately, mortality. Behavioural data indicated that family constellation, especially the presence or the absence of parents, influences agonistic behaviour. As a measure of long-term stress, we established a non-invasive method of extracting and measuring cortisol from hair of giant mole-rats. Interestingly, orphaned non-breeders exhibited significantly lower levels of cortisol and lower mortality rates than did non-breeders living with both parents. Because hypercortisolism is harmful in the long-term, intrafamilial stress could help explain the earlier onset of senescence in non-breeders, resulting in a shorter lifespan. Our findings suggest that the social environment should be considered as a further factor in ageing studies involving group-living animals. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'

Health-related quality of life in patients with untreated cavernous malformations of the central nervous system.

BACKGROUND AND PURPOSE: To estimate health-related quality of life (HRQOL) in patients with untreated cavernous malformation of the CNS [cavernous cerebral malformations (CCMs)]. METHODS: We performed a cross-sectional observational study on patients with CCMs admitted to our department from 1 November 2017 to 10 January 2020 using standardized interviews [short-form-36 questionnaire, hospital anxiety and depression score (HADS-A/D), CCM perception questionnaire]. Included criteria were diagnosis of an untreated CCM and information about the diagnosis in a specialized CCM consultation. Health-related quality of life (HRQOL) data were analyzed and compared to the German normal population. Uni- and multivariate analyses were carried out to identify variables with impact on outcome. RESULTS: Two hundred nineteen (93%) of 229 eligible patients were included. Mean age was 46.3 ± 14.7 (18-86) years; 136 (62%) were female. Ninety-eight (45%) patients presented with symptomatic hemorrhage (SH), and 17 (8%) with repetitive SH. Ninety-two (42%) patients were asymptomatic. Thirty-seven patients (17%) suffered from cavernoma-related epilepsy. Twenty-eight patients (13%) suffered from familial CCMs. Patients showed significantly decreased component scores and subdomain scores compared to the normal population, with effects ranging from small to large. This accounted largely also for asymptomatic patients (except for physical component score and main physical subdomains). Multivariate regression analysis confirmed impact of functional impairment on physical component score. HADS-A was significantly increased. HADS-A/D strongly correlated with mental component score and individual perception of the CCM. CONCLUSIONS: Patients with the diagnosis of a CCM showed decreased HRQOL compared to the normal population even when not suffering functional impairment or neurological symptoms. Our data may function as benchmarks in evaluation of different (future) management strategies.

Wall Contrast Enhancement of Thrombosed Intracranial Aneurysms at 7T MRI.

BACKGROUND AND PURPOSE: The pathophysiology of wall contrast enhancement in thrombosed intracranial aneurysms is incompletely understood. This in vivo study aimed to investigate wall microstructures with gadolinium-enhanced 7T MR imaging. MATERIALS AND METHODS: Thirteen patients with 14 thrombosed intracranial aneurysms were evaluated using a 7T whole-body MR imaging system with nonenhanced and gadolinium-enhanced high-resolution MPRAGE. Tissue samples were available in 5 cases, and histopathologic findings were correlated with 7T MR imaging to identify the gadolinium-enhancing microstructures. RESULTS: Partial or complete inner wall enhancement correlated with neovascularization of the inner wall layer and the adjacent thrombus. Additional partial or complete outer wall enhancement can be explained by formation of vasa vasorum in the outer aneurysm wall layer. The double-rim enhancement correlated with perifocal edema and wall histologic findings suggestive of instability. CONCLUSIONS: Two distinct aneurysm wall microstructures responsible for gadolinium enhancement not depictable at lower spatial resolutions can be visualized in vivo using high-resolution gadolinium-enhanced 7T MR imaging.

Automatic and efficient MRI-US segmentations for improving intraoperative image fusion in image-guided neurosurgery.

Knowledge of the exact tumor location and structures at risk in its vicinity are crucial for neurosurgical interventions. Neuronavigation systems support navigation within the patient's brain, based on preoperative MRI (preMRI). However, increasing tissue deformation during the course of tumor resection reduces navigation accuracy based on preMRI. Intraoperative ultrasound (iUS) is therefore used as real-time intraoperative imaging. Registration of preMRI and iUS remains a challenge due to different or varying contrasts in iUS and preMRI. Here, we present an automatic and efficient segmentation of B-mode US images to support the registration process. The falx cerebri and the tentorium cerebelli were identified as examples for central cerebral structures and their segmentations can serve as guiding frame for multi-modal image registration. Segmentations of the falx and tentorium were performed with an average Dice coefficient of 0.74 and an average Hausdorff distance of 12.2 mm. The subsequent registration incorporates these segmentations and increases accuracy, robustness and speed of the overall registration process compared to purely intensity-based registration. For validation an expert manually located corresponding landmarks. Our approach reduces the initial mean Target Registration Error from 16.9 mm to 3.8 mm using our intensity-based registration and to 2.2 mm with our combined segmentation and registration approach. The intensity-based registration reduced the maximum initial TRE from 19.4 mm to 5.6 mm, with the approach incorporating segmentations this is reduced to 3.0 mm. Mean volumetric intensity-based registration of preMRI and iUS took 40.5 s, including segmentations 12.0 s.

Should we resect peri-lesional hemosiderin deposits when performing lesionectomy in patients with cavernoma-related epilepsy (CRE)?

In this review, the authors perform a database search and summarize and discuss all eligible studies that provide (subgroup) analysis of the postoperative seizure outcome of patients with cavernoma-related epilepsy undergoing sole lesionectomy or lesionectomy including the hemosiderin rim. Based on the currently available data, the authors conclude that if surgical treatment of cavernoma-related epilepsy is performed, the peri-lesional hemosiderin should be resected. However, cases of eloquent or multiple localization or widespread hemosiderin deposit in which a complete resection is challenging should undergo a specific preoperative work-up.

The CHESS score: a simple tool for early prediction of shunt dependency after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Acute hydrocephalus is an early and common complication of aneurysmal subarachnoid hemorrhage (SAH). However, considerably fewer patients develop chronic hydrocephalus requiring shunt placement. Our aim was to develop a risk score for early identification of patients with shunt dependency after SAH. METHODS: Two hundred and forty-two SAH individuals who were treated in our institution between January 2008 and December 2013 and survived the initial impact were retrospectively analyzed. Clinical parameters within 72 h after the ictus were correlated with shunt dependency. Independent predictors were summarized into a new risk score which was validated in a subsequent SAH cohort treated between January and December 2014. RESULTS: Seventy-five patients (31%) underwent shunt placement. Of 23 evaluated variables, only the following five showed independent associations with shunt dependency and were subsequently used to establish the Chronic Hydrocephalus Ensuing from SAH Score (CHESS, 0-8 points): Hunt and Hess grade ≥IV (1 point), location of the ruptured aneurysm in the posterior circulation (1 point), acute hydrocephalus (4 points), the presence of intraventricular hemorrhage (1 point) and early cerebral infarction on follow-up computed tomography scan (1 point). The CHESS showed strong correlation with shunt dependency (P = 0.0007) and could be successfully validated in both internal SAH cohorts tested. Patients scoring ≥6 CHESS points had significantly higher risk of shunt dependency (P < 0.0001) than other patients. CONCLUSION: The CHESS may become a valuable diagnostic tool for early estimation of shunt dependency after SAH. Further evaluation and external validation will be required in prospective studies.

The role of decompressive craniectomy in children with severe traumatic brain injury.

OBJECTIVE: Severe traumatic brain injury (TBI) remains the leading cause of death in children. The present study analyses the outcome of children after severe TBI treated by decompressive craniectomy (DC) due to elevated intracranial pressure (ICP) in a single centre. METHODS: Fifty-six consecutive children (age < 16 years) were treated for severe TBI at our institution between 2001 and 2011. For study purposes, children with severe generalized traumatic brain swelling without concomitant mass lesion were further analysed. Descriptive statistics were used to report clinical conditions as well as outcome measurements after conservative treatment only in comparison to secondary decompressive craniectomy. RESULTS: Of 56 children, a total of eight children presented with generalized and progressive traumatic brain swelling and impending brain herniation. Four children were treated conservatively following standardized local protocol for anti-oedematous management, with ICP amenable to intensified therapy. Four children required decompressive surgery due to progressive oedema refractory to intensified conservative management. Children receiving secondary DC had a longer stay in the intensive care unit as well as a longer average time of assisted ventilation compared to children treated conservatively. Concomitant injuries were more severe in the DC subgroup. Yet, Glasgow Outcome Scale was equally distributed in both groups. CONCLUSION: In children with refractory ICP conditions due to severe TBI, decompressive surgery might lead to a similar favourable outcome compared to children in whom ICP can be controlled only by conservative management. Timing of surgery depends on the neurological deterioration of the patients and a continuous ICP monitoring.

Infectious microorganisms in mice (Mus musculus) purchased from commercial pet shops in Germany.

In this study, we investigated the prevalence of infectious microorganisms (viruses, bacteria, fungi and eukaryotic parasites) in mice from different pet shops in Germany; such animals may compromise the hygienic integrity of laboratory animal vivaria if private pet holders act as unintended vectors of infections carried by them. House mice sold as pets or feed specimens were purchased from different pet shops and tested for a comprehensive panel of unwanted microorganisms. We found a number of microorganisms in these pet shop mice, the most prevalent of which were Helicobacter species (92.9%), mouse parvovirus (89.3%), mouse hepatitis virus (82.7%), Pasteurella pneumotropica (71.4%) and Syphacia species (57.1%). Several microorganisms (e.g. mouse parvovirus, Theiler's murine encephalomyelitis virus, pneumonia virus of mice, Encephalitozoon cuniculi, Clostridium piliforme) had considerably higher prevalences than those reported in similar studies on wild mice from North America, Europe or Australia. Our study shows that direct contact with pet shop mice may constitute a risk for laboratory animal vivaria if hygienic precautions are not taken. However, even relatively simple precautions seem effective enough to hold the risk at bay.