The uniqueness of speech among motor systems

This paper considers evidence that the speech muscles are unique in their genetic, developmental, functional and phenotypical properties. The literature was reviewed using PubMed, ScienceDirect, ComDisDome and other literature‐retrieval systems to identify studies reporting on the craniofacial and laryngeal muscles. Particular emphasis was given to studies of muscle fibre composition. A number of studies on mandibular, lingual, palatal and laryngeal muscles in humans show that these muscles are distinct from limb and other muscles. These speech‐related muscles typically contain diverse fibre types and these types can vary regionally within a muscle. In general, the muscles of the speech production system are designed for fast and/or variable contraction and fatigue resistance. The craniofacial and laryngeal muscles are unique among the muscle systems of the human body and the specialized properties of these muscles are relevant to understanding the biomechanics of speech and various speech disorders.     

Acoustic analysis of voice in dysarthria following stroke

Although perceptual studies indicate the likelihood of voice disorders in persons with stroke, there have been few objective instrumental studies of voice dysfunction in dysarthria following stroke. This study reports automatic analysis of sustained vowel phonation for 61 speakers with stroke. The results show: (1) men with stroke and healthy elderly men exhibited an identical voice profile, and men with stroke had only one significantly larger noise parameter (SPI—soft phonation index) than young healthy men; and (2) women with stroke and healthy elderly women exhibited an identical voice profile, except that women with stroke exhibited a significantly higher SPI than healthy elderly women. Although there were no significant differences in smoothed pitch perturbation quotient (sPPQ) and SPI between healthy elderly women and healthy young women, women with stroke exhibited significantly larger sPPQ and SPI than healthy young women. It is suggested that studies on sub‐groups of the stroke population that use a combination of perceptual and acoustic analyses will better illuminate the voice dysfunction in dysarthria following stroke.     

Clinical characteristics and outcomes of neurogenic stress cadiomyopathy in aneurysmal subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is an often devastating form of stroke. Aside from the initial hemorrhage, cardiac complications can occur resulting in neurogenic stress cardiomyopathy (NCM), leading to impaired cardiac function. We investigated whether aSAH patients with NCM had poorer long term functional outcomes than patients without NCM. Mortality, vasospasm, and delayed ischemic complications were also evaluated.

Methods

A retrospective study of all patients admitted for aneurysmal subarachnoid hemorrhage (aSAH) from January 2006 to June 2011 (n = 299) was conducted. Those patients who underwent an echocardiogram were identified (n = 120) and were assigned to the NCM (n = 49) category based on echocardiographic findings defined by a depressed ejection fraction (EF%) along with a regional wall motion abnormality (RWMA) in a non-vascular pattern. Primary outcome measures included in-hospital mortality and functional outcomes as measured by the Modified Barthel Index (mBI) at 3 months and one year. Secondary analysis determined if there was an association between NCM, cerebral vasospasm and delayed cerebral ischemia.

Results

16% of aSAH patients developed NCM. Mortality was higher (p < .001) in the NCM group (n = 23[46.9%]) than in the non-CM group (n = 28[11.2%]). Patients with NCM had poorer functional outcomes as measured by the mBI at both 3 months (p = .002) and 12 months (p = .014). The Hunt–Hess score was predictive of functional outcome as measured by the mBI at both 3 months (p = .002) as well as at 1 year (p = .014). NCM was associated with both death (p = .047 CI, 1.012–7.288) and vasospasm (p = .008 CI, 1.34–6.66) after correction for Hunt–Hess grade. Tobacco use (p < .001) and a history of diabetes mellitus (p < .009) were also associated with vasospasm. NCM was associated with higher in-hospital mortality (p = .047) in multivariate analysis.

Conclusion

NCM is seen in a substantial number of aSAH patients and when present, it is associated with higher mortality and poorer long-term functional outcomes. This finding may guide further prospective studies in order to determine if early recognition of NCM as well as optimization of cardiac output would improve mortality.     

Three-dimensional finite element stress analysis: the technique and methodology of non-linear property simulation and soft tissue loading behavior for different partial denture designs

The purpose of this study was to develop and report upon a methodology for a non-linear capacity 3D modeling finite element analysis evaluating the loading behavior of different partial denture designs. A 3D finite element model using human CT data was constructed. An original material constant conversion program was implemented in the data simulation of non-linear tissue behavior. The finite element method material properties of residual ridge mucosa were found to have seven material constants and six conversion points of stress values. Periodontal tissues were found to have three constants, and two conversion points. Three magnetic attachment partial denture designs with different bracing elements were evaluated. Technical procedures for finite element model simulation of nonlinear tissue behavior properties evaluating the oral behavior of prosthetic device designs are reported for prosthodontic testing. The use of horizontal cross-arch bracing positively impacts upon the comparative stability of the partial denture designs tested.     

Predicting alcohol dependence from multi-site brain structural measures

To identify neuroimaging biomarkers of alcohol dependence (AD) from structural magnetic resonance imaging, it may be useful to develop classification models that are explicitly generalizable to unseen sites and populations. This problem was explored in a mega-analysis of previously published datasets from 2,034 AD and comparison participants spanning 27 sites curated by the ENIGMA Addiction Working Group. Data were grouped into a training set used for internal validation including 1,652 participants (692 AD, 24 sites), and a test set used for external validation with 382 participants (146 AD, 3 sites). An exploratory data analysis was first conducted, followed by an evolutionary search based feature selection to site generalizable and high performing subsets of brain measurements. Exploratory data analysis revealed that inclusion of case- and control-only sites led to the inadvertent learning of site-effects. Cross validation methods that do not properly account for site can drastically overestimate results. Evolutionary-based feature selection leveraging leave-one-site-out cross-validation, to combat unintentional learning, identified cortical thickness in the left superior frontal gyrus and right lateral orbitofrontal cortex, cortical surface area in the right transverse temporal gyrus, and left putamen volume as final features. Ridge regression restricted to these features yielded a test-set area under the receiver operating characteristic curve of 0.768. These findings evaluate strategies for handling multi-site data with varied underlying class distributions and identify potential biomarkers for individuals with current AD.     

Residual small artery impairment in hypertensive patients with normal albumin–creatinine ratio

Objectives Previous studies have suggested that urine albumin excretion (UAE) mirrors generalized vascular damage; however, it is unclear to which degree UAE mirrors small artery impairment. Design We enrolled 67 patients with uncomplicated essential hypertension (EH) during stable antihypertensive therapy. F-R_min, ACR on three non-consecutive morning urine samples, pulse wave velocity (PWV), and 24-h ambulatory blood pressure (ABPM) were measured. Results ACR was low (0.39 and 0.30–0.60), but abnormal small artery structure defined as F-R_min?>_?mean?+?2 standard deviations of normotensive value (1.99?+?1?mmHg min/(ml/100?ml)) was present in 45% (n?=?30). The mean F-R_min was 2.89?±?0.09?mmHg min/(ml/100?ml). ACR correlated significantly to PWV (r^2?=^?0.11; p?<?0.05) and pulse pressure (r^2?=^?0.15; p?<?0.001), but not F-R_min and (r^2?=^?0.05, p?=?0.07). Conclusions Abnormal microvascular structure was present even in EH patients with low UAE. ACR correlated to arterial stiffness and not to small artery structure; therefore, UEA did not reflect microvascular damage in this population. ACR and F-R_min thus reflect two distinct types of subclinical organ damage in hypertension.     

Fatal Taxus baccata ingestion with perimortem serum taxine B quantification

Introduction: Common yew (Taxus baccata) is a common decorative evergreen shrub with potentially fatal toxicity hallmarked by seizure, arrhythmia and cardiovascular collapse if ingested. Taxine B has been identified as one of the most cardiotoxic taxine alkaloids in Taxus spp, and another alkaloid, 3,5-dimethoxyphenol (3,5-DMP), is used as a marker of ingestion. We present a fatal case of ingestion of yew with perimortem serum and gastric taxine B, and 3,5-DMP concentrations.

Case presentation: A 22-year-old woman was brought to the emergency department (ED) from a nearby botanical garden after she was found apneic and pulseless after a witnessed generalized tonic clonic seizure. The patient was found to have a wide complex rhythm with persistent cardiovascular collapse and expired despite maximal supportive care in the ED. A baggie of plant material was found on the patient, identified as Taxus baccata. Perimortem serum and gastric samples were analyzed to quantify serum and gastric taxine B and 3,5-DMP concentrations.

Results: Perimortem serum showed a 3,5-DMP concentration of 86.9 ng/mL, and taxine B of 80.9 ug/mL.

Conclusion: We report a perimortem serum and gastric taxine B and 3,5-DMP concentrations in a fatal case of T. baccata toxicity.