Relationship between texture perception and oral function: A preliminary study in young, healthy adults.

BACKGROUND: Oral frailty, characterised by reduced oral function, is associated with systemic health issues in older adults. Although the criteria for diminished oral function often focus on motor and secretory abilities, texture perception also plays a crucial role in health due to its impact on food intake and palatability. OBJECTIVE: This study aimed to explore the relationship between thickness discrimination ability (TDA) and oral motor and secretory functions in healthy young individuals. METHODS: Twenty-eight adults were assessed for texture perception using eight concentrations of aqueous xanthan gum solutions to determine TDA scores. Measurements of occlusal force, masticatory performance, tongue pressure, stimulated salivary flow rate and tongue-lip motor function were conducted. Spearman's correlation analysis was used to evaluate the relationship between TDA scores and oral functions. Participants were divided into high-sensitivity and low-sensitivity groups based on their TDA scores to compare oral function test results. RESULTS: The TDA scores varied among the participants, with higher scores correlating with higher masticatory performance (r = 0.41, p < .05). Masticatory performance in the high-sensitivity group was significantly higher than in the low-sensitivity group (211.9 ± 59.2 mg/dL vs. 157.9 ± 43.0 mg/dL, p = .013), with no significant differences in other oral functions. CONCLUSION: Masticatory performance was correlated with TDA, suggesting a link between the selection function of mastication and thickness discrimination. These findings highlight the potential relevance of texture perception in oral function and indicate the need for further exploration, particularly in older adults with declining oral health.

Socioeconomic inequalities in pediatric obstructive sleep apnea.

STUDY OBJECTIVES: To examine the association between multiple measures of socioeconomic status (SES) and objectively measured obstructive sleep apnea (OSA) in a Canadian pediatric population. METHODS: This was a cross-sectional study of 188 children (4-17 years, mean age 9.3 ± 3.5 years) prospectively recruited from two hospital sleep clinics in Canada, using multivariable-adjusted linear and logistic regression of five measures of SES including parental education, income, social class, geographic location, and perceived SES based on the MacArthur Scale of Subjective Social Status, assessed in relation to four polysomnographic OSA variables including apnea-hypopnea index, apnea index, mean oxygen saturation level, and oxygen desaturation index. RESULTS: Overall, low household-level SES appeared to be associated with both frequency (apnea index ≥ 1 events/h) and severity (apnea-hypopnea index ≥ 5 events/h) of OSA in children, with maternal education showing the most consistent and significant associations. Specifically, children with mothers reporting less than high school education had nearly three times the odds of having OSA after controlling factors including body mass index (odds ratio 2.96 [95% confidence interval, 1.05-8.37]), compared to university-educated participants. Consistent associations were also observed for geographic location with less frequency and severity of OSA among nonurban children. Perceived SES was minimally inversely associated with our outcomes. CONCLUSIONS: This cross-sectional, multicenter study demonstrated that SES factors are linked to the occurrence and severity of OSA in children. Results indicated the need to incorporate the screening of SES in the diagnostic process of pediatric OSA to provide more targeted intervention and patient-centered care. CITATION: Park JW, Hamoda MM, Almeida FR, et al. Socioeconomic inequalities in pediatric obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):637-645.

How Long Are Reperfusion Therapies Beneficial for Patients after Stroke Onset? Lessons from Lethal Ischemia Following Early Reperfusion in a Mouse Model of Stroke.

Ischemic stroke caused by cerebral artery occlusion induces neurological deficits because of cell damage or death in the central nervous system. Given the recent therapeutic advances in reperfusion therapies, some patients can now recover from an ischemic stroke with no sequelae. Currently, reperfusion therapies focus on rescuing neural lineage cells that survive in spite of decreases in cerebral blood flow. However, vascular lineage cells are known to be more resistant to ischemia/hypoxia than neural lineage cells. This indicates that ischemic areas of the brain experience neural cell death but without vascular cell death. Emerging evidence suggests that if a vascular cell-mediated healing system is present within ischemic areas following reperfusion, the therapeutic time window can be extended for patients with stroke. In this review, we present our comments on this subject based upon recent findings from lethal ischemia following reperfusion in a mouse model of stroke.

Early Reperfusion Following Ischemic Stroke Provides Beneficial Effects, Even After Lethal Ischemia with Mature Neural Cell Death.

Ischemic stroke is a critical disease caused by cerebral artery occlusion in the central nervous system (CNS). Recent therapeutic advances, such as neuroendovascular intervention and thrombolytic therapy, have allowed recanalization of occluded brain arteries in an increasing number of stroke patients. Although previous studies have focused on rescuing neural cells that still survive despite decreased blood flow, expanding the therapeutic time window may allow more patients to undergo reperfusion in the near future, even after lethal ischemia, which is characterized by death of mature neural cells, such as neurons and glia. However, it remains unclear whether early reperfusion following lethal ischemia results in positive outcomes. The present study used two ischemic mouse models-90-min transient middle cerebral artery occlusion (t-MCAO) paired with reperfusion to induce lethal ischemia and permanent middle cerebral artery occlusion (p-MCAO)-to investigate the effect of early reperfusion up to 8 w following MCAO. Although early reperfusion following 90-min t-MCAO did not rescue mature neural cells, it preserved the vascular cells within the ischemic areas at 1 d following 90-min t-MCAO compared to that following p-MCAO. In addition, early reperfusion facilitated the healing processes, including not only vascular but also neural repair, during acute and chronic periods and improved recovery. Furthermore, compared with p-MCAO, early reperfusion after t-MCAO prevented behavioral symptoms of neurological deficits without increasing negative complications, including hemorrhagic transformation and mortality. These results indicate that early reperfusion provides beneficial effects presumably via cytoprotective and regenerative mechanisms in the CNS, suggesting that it may be useful for stroke patients that experienced lethal ischemia.

Preliminary exploration for evaluating acuity of oral texture perception.

Despite the important role of oral texture perception in feeding and nutritional homeostasis, its impairment has not been of particular clinical interest, and no clinical protocol is available to evaluate its acuity. This preliminary study aimed to establish a method to evaluate the acuity of oral texture perception. Because texture perception is regarded as reflecting integrity of the sensorimotor system of the jaw and mouth, we hypothesized that the ability to perceive various aspects of food texture would correlate with each other, and tested our hypothesis in 11 healthy adults. First, we prepared three types of test foods with different dominant textures, each of which comprised a series of stimuli with different ingredient concentrations; we used these test foods in discrimination tests involving pairwise comparison. Tests performed using the up-down staircase method revealed significant correlation among the discrimination thresholds for three test foods, suggesting that acuities of texture perception correlated with each other across different textural attributes. Second, we examined the associations between the acuity of texture perception and some aspects of mechanical sensation of the tongue: tactile and two-point discrimination thresholds, as well as the graininess recognition threshold. The acuity of texture perception of the subjects whose sensitivity was low for at least one of these aspects of mechanical sensation (n = 5) was significantly lower than that exhibited by the other subjects (Wilcoxon rank-sum test, p = 0.0417). We concluded that oral texture perception ability can be evaluated by discrimination tests for specific aspects of texture, using appropriate test foods.

A surgical strategy using a fusion image constructed from 11C-methionine PET, 18F-FDG-PET and MRI for glioma with no or minimum contrast enhancement.

The objective of this study was to investigate the distribution of 11C-methionine (MET) and F-18 fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) imaging and the hyperintense area in T2 weighted imaging (T2WI) in glioma with no or poor gadolinium enhancement in magnetic resonance imaging (GdMRI). Cases were also analyzed pathologically. We prospectively investigated 16 patients with non- or minimally enhancing (< 10% volume) glioma. All patients underwent MET-PET and FDG-PET scans preoperatively. After delineating the tumor based on MET uptake, integrated 3D images from FDG-PET and MRI (GdMRI, T2WI or FLAIR) were generated and the final resection plane was planned. This resection plane was determined intraoperatively using the navigation-guided fencepost method. The delineation obtained by MET-PET imaging was larger than that with GdMRI in all cases with an enhanced effect. In contrast, the T2WI-abnormal signal area (T2WI+) tended to be larger than the MET uptake area (MET+). Tumor resection was > 95% in the non-eloquent area in 4/5 cases (80%), whereas 10 of 11 cases (90.9%) had partial resection in the eloquent area. In a case including the language area, 92% resection was achieved based on the MET-uptake area, in contrast to T2WI-based partial resection (65%), because the T2WI+/MET- area defined the language area. Pathological findings showed that the T2WI+/MET+ area is glioma, whereas 6 of 9 T2WI+/MET- lesions included normal tissues. Tissue from T2W1+/MET+/FDG+/GdMRI+ lesions gave an accurate diagnosis of grade in six cases. Non- or minimally enhancing gliomas were classified as having a MET uptake area that totally or partially overlapped with the T2WI hyperintense area. Resection planning with or without a metabolically active area in non- or minimally enhancing gliomas may be useful for accurate diagnosis, malignancy grading, and particularly for eloquent area although further study is needed to analyze the T2WI+/MET- area.

Identification of Multipotent Stem Cells in Human Brain Tissue Following Stroke.

Perivascular regions of the brain harbor multipotent stem cells. We previously demonstrated that brain pericytes near blood vessels also develop multipotency following experimental ischemia in mice and these ischemia-induced multipotent stem cells (iSCs) can contribute to neurogenesis. However, it is essential to understand the traits of iSCs in the poststroke human brain for possible applications in stem cell-based therapies for stroke patients. In this study, we report for the first time that iSCs can be isolated from the poststroke human brain. Putative iSCs were derived from poststroke brain tissue obtained from elderly stroke patients requiring decompressive craniectomy and partial lobectomy for diffuse cerebral infarction. Immunohistochemistry showed that these iSCs were localized near blood vessels within poststroke areas containing apoptotic/necrotic neurons and expressed both the stem cell marker nestin and several pericytic markers. Isolated iSCs expressed these same markers and demonstrated high proliferative potential without loss of stemness. Furthermore, isolated iSCs expressed other stem cell markers, such as Sox2, c-myc, and Klf4, and differentiated into multiple cells in vitro, including neurons. These results show that iSCs, which are likely brain pericyte derivatives, are present within the poststroke human brain. This study suggests that iSCs can contribute to neural repair in patients with stroke.

Contrast-less stent placement for vertebral artery origin stenosis.

We performed stent placement under intravascular ultrasound (IVUS), without the use of contrast medium, in a male patient in his 70s who had vertebral artery origin stenosis and decreased renal function. Satisfactory dilatation was achieved without complications, and the patient remained asymptomatic at 2 years of follow-up. We now report the details of this procedure. Stent placement under IVUS guidance may be useful in patients in whom contrast medium is contraindicated.

Brain pericytes serve as microglia-generating multipotent vascular stem cells following ischemic stroke.

BACKGROUND: Microglia are the resident macrophage population of the central nervous system (CNS) and play essential roles, particularly in inflammation-mediated pathological conditions such as ischemic stroke. Increasing evidence shows that the population of vascular cells located around the blood vessels, rather than circulating cells, harbor stem cells and that these resident vascular stem cells (VSCs) are the likely source of some microglia. However, the precise traits and origins of these cells under pathological CNS conditions remain unclear. METHODS: In this study, we used a mouse model of cerebral infarction to investigate whether reactive pericytes (PCs) acquire microglia-producing VSC activity following ischemia. RESULTS: We demonstrated the localization of ionized calcium-binding adaptor molecule 1 (Iba1)-expressing microglia to perivascular regions within ischemic areas. These cells expressed platelet-derived growth factor receptor-ß (PDGFRß), a hallmark of vascular PCs. PDGFRß(+) PCs isolated from ischemic, but not non-ischemic, areas expressed stem/undifferentiated cell markers and subsequently differentiated into various cell types, including microglia-like cells with phagocytic capacity. CONCLUSIONS: The study results suggest that vascular PCs acquire multipotent VSC activity under pathological conditions and may thus be a novel source of microglia.

Endovascular treatment of acute ischemic stroke: Honolulu shock and thereafter.

Recently, use of mechanical clot retrievers for acute stroke has gradually spread. However, 3 recent randomized controlled trials failed to show superiority of endovascular treatment compared to intravenous recombinant tissue plasminogen activator (IV rt-PA) alone or standard care. On the other hand, a Japanese nationwide survey demonstrated the efficacy of endovascular treatment in the IV rt-PA failed and ineligible patients, especially with the proximal artery occlusion such as the internal carotid artery. Earlier initiation and higher reperfusion of endovascular treatment seemed to be the main reason for the better result in this survey compared with the reported randomized studies. Because next-generation devices such as stent retrievers have been shown to provide better effects in terms of clinical outcomes compared with the Merci retriever, the efficacy of endovascular treatment is expected to be confirmed again by randomized controlled trials in the near future.

Dimensional and occlusal accuracy of a novel three-dimensional digital model of articulated dental arches.

PURPOSE: To develop a method for capturing the three-dimensional (3D) shapes of dental arches in a position relative to that of maximum intercuspation and to evaluate its dimensional and occlusal accuracy. MATERIALS AND METHODS: The conventional custom-tray impression technique was used to capture detailed and dimensionally accurate impressions of individual teeth, and a modified bite-registration technique was used to register the relative positions of the maxillary and mandibular teeth in maximum intercuspation. It was hypothesized that this procedure may help to eliminate the occlusal inaccuracy caused by mouth opening-induced mandibular flexion. Two types of rigid frames (buccal and palatal) were used to prevent deformation of the interocclusal record. Their effects were tested on an articulated full-arch master cast and compared in terms of dimensional accuracy. In addition, the procedure was applied to a healthy volunteer to visually evaluate occlusal accuracy based on the form and distribution of the occlusal contacts. RESULTS: The mean decrements of the dental arch width were 0.037 ± 0.017 mm and 0.269 ± 0.114 mm when using the palatal and buccal frames, respectively. The dimensional accuracy of the palatal frame was comparable to that of the custom-tray impression technique. The form and distribution of the occlusal contacts between the 3D dental arches were similar to those observed in the transilluminated image of the interocclusal record, indicating the occlusal accuracy of this method. CONCLUSION: The dimensional and occlusal accuracy of the method proposed here is suitable for clinical application when used in combination with the palatal frame.

A novel technique of multiple-site epidural blood patch administration for the treatment of cerebrospinal fluid hypovolemia.

OBJECT: An epidural blood patch (EBP) is a widely accepted standard procedure to treat CSF hypovolemia, especially when the epidural CSF leak is detected by spinal MRI or CT myelography (CTM). In quite a few cases, however, the leaked CSF is spread over a large area along the spinal epidural space, making it difficult for the surgeon to clearly identify the true leakage points. In such cases, autologous blood can be infused at multiple spinal levels with multiple entries. In this paper, the authors have devised a new multiple-site EBP method with a single lumbar entry point by way of using an intravenous catheter as a slidable device for continuous infusion. In this report, they introduce this new, single-entry, continuous multiple-site EBP administration technique and report some of the results that they have obtained. METHODS: An EBP was applied via an epidural catheter in 5 patients with spontaneous CSF hypovolemia (3 men and 2 women; mean age 47.2 years, range 34-65 years). The detection of an epidural CSF leak was based on MRI and/or CTM findings. In all cases, however, the leakage sites could not be identified clearly. The main symptoms of these patients were recurrent spontaneous chronic subdural hematoma with orthostatic headache (3 patients) and orthostatic headache only (2 patients). All patients underwent surgery in the prone position on an angiography table, and biplane fluoroscopy was used for accurate manipulation. After administration of a local anesthetic, the authors inserted a 4-Fr short sheath (which is standard in angiography) through the lumbar interlaminar window and placed it in the dorsal epidural space. They then introduced a 4.2-Fr straight catheter through the sheath and navigated it upward along a 35-gauge guidewire whose tip was moved upward beyond the cranial end of the detected CSF leakage. Blood was obtained from each patient from a previously secured venous entry on the forearm, and it was injected slowly into the epidural catheter. Each time, the authors tried to infuse as much autologous blood as possible into the epidural space, while moving the catheter gradually in the caudal direction in response to the patient's expression of pain. RESULTS: In all 3 cases of chronic subdural hematoma, its recurrence was prevented. In 1 patient, the orthostatic headache disappeared completely, and it was relieved in the other 4 patients. CONCLUSIONS: An efficient treatment option for CSF hypovolemia is provided by the new application method of EBP with the aid of an intravenous catheter as a slidable device, which enables infusion of a sufficient amount of autologous blood into multiple epidural areas with a single lumbar entry point.

[Lacunar infarction in brain tumor patients: chronic stage complication after radiation therapy].

The authors reported two relatively young adults with lacunar infarction that took place many years after radiation therapy. The first case was that of a 41-year-old male presenting with a slight decrease in consciousness and right hemiparesis of sudden occurrence. MRI revealed a lacunar infarction in the left internal capsule. This patient had received radiation therapy and chemotherapy for a right basal ganglia germinoma when he was 24 years old. The tumor completely disappeared and he was able to return to work. The second case was a 24-year-old female presenting with dysesthesia in the right upper extremity and nausea of sudden occurrence. MRI disclosed a lacunar infarct in the right corona radiata. The patient had received radiation therapy for a suprasellar tumor when she was 11 years old. The tumor considerably decreased in size and the patient conducted normal social life thereafter. MRI showed a lacunar infarction in the right corona radiata. Review of the literature was made and the possibility of radiation therapy as a causative factor of the lacunar infarction in relatively young adults was discussed.