Anatomy of the accessory mental foramen in a Saudi subpopulation: A multicenter CBCT study

AimThe aim of this is to evaluate the prevalence and location of the accessory mental foramen (AMF) in a Saudi population using cone-beam computed tomography (CBCT).MethodologyCBCT data were retrieved from two dental facilities at two universities located in two different cities and filtered over a period of four years. The scans were aligned when the AMF was noticed, and then the size of both the AMF and mental foramen (MF), its location, and the distance from the AMF to the MF were recorded. The AMF measurements were compared between males and females and between the two sides of the mandible.ResultsIn total, 603 CBCT scans were investigated. The percentage of scans with an AMF was 9.95% (n = 60), and AMFs were almost equally distributed on both sides. Only four cases (0.66%) of a second AMF were detected among the scans. The MFs on both sides were significantly larger in males than in females (P > 0.05), but they showed no differences in the sizes of the AMFs. The AMFs were most commonly located inferior and posterior to the MF. The distance between the MF and AMF ranged from 2.32 to 5 mm.ConclusionsThe prevalence of the AMF in this Saudi population was 9.95%, and it was significantly more prevalent in males than in females. Its proximity to the MF makes it clinically important to conduct proper detailed planning prior to performing any procedure that might risk the vital structures.     

下腔静脉加压法与Valsalva动作在提高卵圆孔未闭检出率中的对比研究

目的 探讨下腔静脉加压法与Valsalva动作在经食道超声心动图(Transesophageal echocardiography,TEE)对卵圆孔未闭(Patent foramen ovale,PFO)检出率中的差异。方法 回顾性分析手术证实的PFO患者114例,包括对比增强经颅多普勒超声(Contrast-enhanced transcranial Doppler ultrasonography,c-TCD)少量右向左分流(Right-to-left shunt,RLS)(n=51)组、中量RLS(n=37)组、大量RLS(n=26)组,记录常规TEE超声、Valsalva动作配合下TEE检查、PFO封堵术前无痛TEE下下腔静脉加压检测,分析3组房间隔右向左一过性分流信号发生率的不同和其它临床因素在3组间的差异。结果 3组身体质量指数(Body mass index,BMI)、高血压病、高脂血症及冠心病的比例无明显差异(P>0.05); 大量RLS组患者年龄明显小于少量RLS及中量RLS组(P<0.05)。少量RLS及中量RLS组患者Valsalva动作和下腔静脉加压后较常规TEE下PFO的显示率均有提高(P<0.01); 大量RLS组患者Valsalva动作和下腔静脉加压后PFO显示率改变不明显(P>0.05)。结论 大量RLS患者较少量及中量RLS患者的年龄小,更容易早期出现临床症状; 下腔静脉加压法可以替代Valsalva动作提高TEE超声对PFO的检出率。     

西安地区成人改良Jackson骶骨棒棒道影像学测量

目的 通过收集西安地区成人的影像学资料，为改良Jackson骶骨棒的操作提供解剖学数据参考。方法 将100例健康成年人作为研究对象，对其进行三维CT扫描，获得所需数据，将数据录入Mimics软件中处理，利用软件确定棒道入口，测量棒道长度，对不同性别间进行统计学分析。结果 男性测得棒道长度为（35.05±6.19） mm，最大值为52 mm；女性为（34.19±5.84） mm，最大值为46 mm。男性骶骨棒棒道长度略大于女性，但差异无统计学意义（P＞0.05）。结论 经测量100例西安地区健康成人改良Jackson骶骨棒棒道长度得知，术中男性骶骨棒棒道深度应控制在52 mm以内，女性控制在46 mm以内，但个体差异较大，术前进行测量可指导手术医师制定手术方案，提高手术安全性。     

Using EMG to deliver lumbar dynamic electrical stimulation to facilitate cortico-spinal excitability

BackgroundPotentiation of synaptic activity in spinal networks is reflected in the magnitude of modulation of motor responses evoked by spinal and cortical input. After spinal cord injury, motor evoked responses can be facilitated by pairing cortical and peripheral nerve stimuli.ObjectiveTo facilitate synaptic potentiation of cortico-spinal input with epidural electrical stimulation, we designed a novel neuromodulation method called dynamic stimulation (DS), using patterns derived from hind limb EMG signal during stepping.MethodsDS was applied dorsally to the lumbar enlargement through a high-density epidural array composed of independent platinum-based micro-electrodes.ResultsIn fully anesthetized intact adult rats, at the interface array/spinal cord, the temporal and spatial features of DS neuromodulation affected the entire lumbosacral network, particularly the most rostral and caudal segments covered by the array. DS induced a transient (at least 1 min) increase in spinal cord excitability and, compared to tonic stimulation, generated a more robust potentiation of the motor output evoked by single pulses applied to the spinal cord. When sub-threshold pulses were selectively applied to a cortical motor area, EMG responses from the contralateral leg were facilitated by the delivery of DS to the lumbosacral cord. Finally, based on motor-evoked responses, DS was linked to a greater amplitude of motor output shortly after a calibrated spinal cord contusion.ConclusionCompared to traditional tonic waveforms, DS amplifies both spinal and cortico-spinal input aimed at spinal networks, thus significantly increasing the potential and accelerating the rate of functional recovery after a severe spinal lesion.     

Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion

Platypnea-orthodeoxia syndrome is an uncommon condition of positional dyspnea and hypoxemia; symptoms occur when the patient is upright and resolve with recumbency. Causes can be broadly categorized into 4 groups: intracardiac shunting, pulmonary shunting, ventilation-perfusion mismatch, or a combination of these.Platypnea-orthodeoxia syndrome should be suspected when normal arterial oxygen saturations are recorded while an individual is supine, followed by abrupt declines in those saturations when upright. Further investigations with use of imaging and cardiac catheterization aid in the evaluation. When platypnea-orthodeoxia syndrome is due to intracardiac shunting without pulmonary hypertension, intracardiac shunt closure can be curative.In this article, we report a case of platypnea-orthodeoxia syndrome in an 83-year-old woman who was successfully treated by means of percutaneous transcatheter closure of an atrial septal defect.     

Paradoxical Cerebral Embolism as Initial Manifestation of Chronic Thromboembolic Pulmonary Hypertension: A Case Report

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by chronic thrombi in the pulmonary arteries, causing pulmonary hypertension and right heart failure. Early and accurate diagnosis are essential for successful treatment but are often difficult because clinical signs and symptoms can be nonspecific and risk factors, such as history of venous thromboembolism, may not always be present. Here, we report a case involving a 76-year-old woman who demonstrated paradoxical cerebral embolism as the initial manifestation of CTEPH. She developed right hemiplegia without dyspnea or edema. Brain magnetic resonance imaging revealed multiple fresh infarctions, while transesophageal echocardiography revealed a patent foramen ovale. Based on these findings, she was diagnosed as having paradoxical cerebral embolism. During the search for the embolic source, right heart catheterization showed significant pulmonary hypertension and pulmonary angiography revealed chronic thrombi in the peripheral pulmonary arteries, consistent with a diagnosis of CTEPH. To our knowledge, this is the first case of CTEPH to be diagnosed with the onset of paradoxical cerebral embolism. Because CTEPH is the only potentially curable form of pulmonary hypertension, clinicians should consider paradoxical cerebral embolism as a possible initial manifestation of CTEPH.