Three‐dimensional analysis of shape variations and symmetry of the fibula,tibia, calcaneus and talus

The bones forming the talocrural joint (TCJ) and subtalar joint (STJ) are often assumed to be bilaterally symmetric. Therefore, the contralateral limb (i.e. the fibula, tibia, calcaneus and talus) is used as a template or an intra‐subject control in clinical and research practice. However, the validity of the symmetry assumption is controversial, because insufficient information is available on the shape variations and bilateral (a)symmetry of the fibula, tibia, calcaneus and talus. Using three‐dimensional spatially dense sampled representations of bone shapes extracted from bilateral computed tomography scans of 66 individuals (55 male, mean age: 61 ± 10 years; 11 female, mean age: 53 ± 15 years), we analyzed whether: (i) similar shape patterns exist in the left and right bones of the same type; (ii) gender has an effect on bone shape variations; (iii) intra‐subject shape variation is smaller than that of inter‐subject for a given shape variance direction. For the first set of analyses, all left and right instances of the same type of bone were considered as two separate groups, and statistically compared with each other on multiple aspects including group location (central tendency), variance‐covariance scale (dispersion) and orientation (covariance structure) using distance‐based permutational tests. For the second and third sets of analyses, all left and right bones of the same type were pooled into one group, and shape variations in the TCJ and STJ bones were extracted using principal component analysis. The effects of gender on age‐adjusted bone shape differences were assessed using an analysis of covariance. Moreover, intra‐class correlation was employed to evaluate intra‐ and inter‐subject bone shape variations. For each bone type, both sides had similar shape patterns (P_{permutational}‐values > 0.05). After Bonferroni adjustment, gender led to shape differences, which were mainly in the lateral and medial condyles of the tibia (P = 0.003), the length and height of the calcaneus (P < 0.001), the posterior and anterior talar articular surfaces of the calcaneus (P = 0.001), and in the posterior aspect of the talus (P = 0.001). Intra‐subject shape variations in the tibial tuberosity together with the diameter of the tibia, and the curvature of the fibula shaft and the diameter of the fibula were as high as those of inter‐subject. This result suggests that the shape symmetry assumption could be violated for some specific shape variations in the fibula and tibia.     

A Symbol Digit Modalities Test version suitable for functional MRI studies

The Symbol Digit Modalities Test is an easy test used to assess cognitive impairment in a wide range of neurological diseases, like multiple sclerosis. We adapted the oral version of this cognitive task making it suitable for functional Magnetic Resonance Imaging studies. Symbol Digit Modalities Test performance was associated with increased brain activity in frontal and parietal areas involved in selective attention and working memory functions. These may provide the basis for future studies assessing potential abnormal cortical activations in multiple sclerosis patients and other clinical populations.     

Factors associated with severe maternal outcomes in patients with eclampsia in an obstetric intensive care unit: A cohort study

To describe the clinical profile, management, maternal outcomes and factors associated with severe maternal outcome (SMO) in patients admitted for eclampsia.A retrospective cohort study was carried out. All women admitted to the Obstetric Intensive Care Unit (ICU) at Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Recife, Northeast of Brazil, from April 2012 to December 2019 were considered for inclusion and patients with the diagnosis of eclampsia were selected. Patients who, after reviewing their medical records, did not present a diagnosis of eclampsia were excluded from the study. Severe maternal outcome (SMO) was defined as all cases of near miss maternal mortality (MNM) plus all maternal deaths during the study period. The Risk Ratio (RR) and its 95% confidence interval (95% CI) were calculated as a measure of the relative risk. Multiple logistic regression analysis was performed to control confounding variables. The institute''s internal review board and the board waived the need of the informed consent.Among 284 patients with eclampsia admitted during the study period, 67 were classified as SMO (23.6%), 63 of whom had MNM (22.2%) and 5 died (1.8%). In the bivariate analysis, the following factors were associated with SMO: age 19 years or less (RR = 0.57 95% CI 0.37–0.89, P = .012), age 35 years or more (RR = 199 95% CI 1.18–3.34, P = .019), the presence of associated complications such as acute kidney injury (RR = 3.85 95% CI 2.69–5.51, P < .001), HELLP syndrome (RR = 1.81 95% CI 1.20–2.75, P = .005), puerperal hemorrhage (PPH) (RR = 2.15 95% CI 1.36–3.40, P = .003) and acute pulmonary edema (RR = 2.78 95% CI 1.55–4.96, P = .008). After hierarchical multiple logistic regression analysis, the factors that persisted associated with SMO were age less than or equal to 19 years (ORa = 0.46) and having had PPH (ORa = 3.33).Younger age was a protective factor for developing SMO, while those with PPH are more likely to have SMO.     

Genetic screening for autosomal recessive nonsyndromic mental retardation in an isolated population in Israel

Nonsyndromic mental retardation (NSMR) is the diagnosis of exclusion in mentally retarded individuals without additional abnormalities. We have recently identified a protein-truncating mutation, G408fsX437, in the gene CC2D1A on chromosome 19p13.12 in nine consanguineous Israeli Arab families with severe autosomal recessive NSMR, and have developed a comprehensive prevention program among the at-risk population in the village. The subjects tested were healthy women who were invited to undergo the genetic screening test as a part of their routine pregnancy monitoring. One hundred and seventeen subjects reported a family history positive for mental retardation. We tested 524 pregnant or preconceptional women and found 47 carriers (approximately 1/11), whose spouses were then recommended to undergo testing. We identified eight carrier couples, who were given genetic counseling and offered prenatal diagnosis. Of all the marriages, 28.6% were consanguineous; 16.5% of the total were between first cousins. The high prevalence of the mutation can be explained both by the founder effect owing to the generally high consanguinity rate among the inhabitants of the village, and also because two families with excessive numbers of mentally retarded offspring were unacceptable as marriage partners by the rest of the families. This is the first example of the establishment of a large-scale genetic screening program for autosomal recessive NSMR, which was made possible owing to the high frequency of the specific causative mutation in this isolated population.     

Age-related changes in cardiac autonomic control during sleep

Aging is commonly associated with decreased sleep quality and increased periodic breathing (PB) that can influence heart rate variability (HRV). Cardiac autonomic control, as inferred from HRV analysis, was determined, taking into account the sleep quality and breathing patterns. Two groups of 12 young (21.1 +/- 0.8 years) and 12 older (64.9 +/- 1.9 years) volunteers underwent electroencephalographic, cardiac, and respiratory recordings during one experimental night. Time and frequency domain indices of HRV were calculated in 5-min segments, together with electroencephalographic and respiratory power spectra. In the elderly, large R-R oscillations in the very-low frequency (VLF) range emerged, that reflected the frequency of PB observed in 18% of the sleep time. PB occurred more frequently during rapid eye movement sleep (REM) sleep and caused a significant (P < 0.02) increase in the standard deviation of normal R-R intervals (SDNN) and absolute low-frequency (LF) power. With normal respiratory patterns, SDNN, absolute VLF, LF, and high frequency (HF) power fell during each sleep stage (P < 0.01) compared with young subjects, with no significant sleep-stage dependent variations. An overall decrease (P < 0.01) in normalized HF/(LF + HF) was observed in the elderly, suggesting a predominant loss of parasympathetic activity which may be related to decreased slow-wave sleep duration. These results indicate that two distinct breathing features, implying different levels of autonomic drive to the heart, influence HRV in the elderly during sleep. The breathing pattern must be considered to correctly interpret HRV in the elderly.