Insights into Colorectal Cancer Screening Awareness: A Study in the Community of Taif City.

Colorectal cancer (CRC) is highly prevalent among Saudi males and females. Understanding its symptoms, risk factors, and screening is vital. This study aims to gauge CRC awareness in Taif City, Saudi Arabia, based on demographics. An observational study in Taif City surveyed awareness on colorectal screening, gathering data from March-April 2023 via a questionnaire covering demographics, screening knowledge, symptoms, and risk factors. Involving 551 participants, most were 19-40 years old (59.2%), female (65.9%), and had a bachelor's degree (71.3%). Notably, 49.2% hadn't visited a family doctor. Awareness on CRC screening was low. 37.7% knew about fecal occult blood tests, 32.7% about sigmoidoscopy, and 34.8% about colonoscopy. Only 27.6% knew the recommended screening age, and 2.4% the frequency. Participants sought information mainly online (45.7%) or from friends (24.1%). Recognized risk factors included family history (57.0%), blood in stool (58.8%), and abdominal pain (47.9%). The study highlights inadequate awareness about CRC screening in Taif. It underscores the necessity for targeted education campaigns, collaboration with healthcare professionals, and diverse information sources to improve understanding among the population.

Retrieval of a Missing Translocated Intrauterine Contraceptive Device Using Combined Laparoscopic and Cystoscopic Techniques.

Background: Intrauterine contraceptive devices (IUCDs) are considered to be an effective way of preventing unwanted pregnancies. However, one significant complication associated with IUCDs is uterine perforation especially at the time of insertion and could reach the peritoneal cavity and the viscus of the adjacent organs. Intravesical migration is extremely rare. Case Presentation. We report a 41-year-old woman who was diagnosed with IUCD intravesical migration after she presented to our hospital complaining of persistent lower urinary tract symptoms. Laparoscopic removal was done after the failure of cystoscopic extraction. Conclusion: The IUCD must be monitored continuously by the gynaecologist, and suspicions of intravesical migration must be considered in those presenting with persistent, unexplained lower urinary tract symptoms.

Extended thoracic endovascular aortic repair is optimal therapy in acute complicated type B dissection.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) represents optimal therapy for complicated acute type B aortic dissection (aTBAD). Persistent knowledge gaps remain, including the optimal length of aortic coverage, impact on distal aortic remodeling, and fate of the dissected abdominal aorta. METHODS: Review of the Emory Aortic Database identified 92 patients who underwent TEVAR for complicated aTBAD from 2012 to 2018. Standard TEVAR covered aortic zones 3 and 4 (from the left subclavian to the mid-descending thoracic aorta). Extended TEVAR fully covered aortic zones 3 though 5 (from the left subclavian to the celiac artery). Long-term imaging, clinical follow-up, and overall and aortic-specific mortality were reviewed. RESULTS: Extended TEVAR (n = 52) required a greater length of coverage vs standard TEVAR (n = 40) (240 ± 32 mm vs 183 ± 23 mm; P < .01). In-hospital mortality occurred in 5.4% of patients (7.7% vs 2.5%; P = .27) owing to mesenteric malperfusion (n = 3) or rupture (n = 2). The overall incidences of postoperative stroke, transient paraparesis, paraplegia, and dialysis were 5.4% (3.9% vs 7.5%; P = .38), 3.2% (5.8% vs 0%; P = .18), 0%, and 0% respectively, equivalent between groups. Follow-up was 96.6% complete to a mean of 6.1 years (interquartile range, 3.5-8.6 years). There were significantly higher rates of complete thrombosis or obliteration of the entire thoracic false lumen after Extended TEVAR (82.2% vs 51.5%; P = .04). Distal aortic reinterventions were less frequent after extended TEVAR (5.8% vs 20%; P = .04). Late aorta-specific survival was 98.1% after extended TEVAR vs 92.3% for standard TEVAR (P = .32). CONCLUSIONS: Extended TEVAR for complicated aTBAD is safe, results in a high rate of total thoracic false lumen thrombosis/obliteration, and reduces distal reinterventions. Longer-term follow-up will be needed to demonstrate a survival benefit compared to limited aortic coverage.

The Prevalence and Impact of Urinary Incontinence on Multiple Sclerosis Patients in Taif City, Saudi Arabia.

Introduction Multiple sclerosis (MS) is a chronic inflammatory disease that results in demyelination and progressive loss of nerve cells within the central nervous system. Multiple sclerosis, as well as other neurological diseases that impact brain structures and spinal pathways involved in sphincter control, may cause lower urinary tract symptoms (LUTS) Our aims are to determine the prevalence, severity, and impact on the quality of life of urinary incontinence among MS patients in Taif, Saudi Arabia, as well as its potential association with demographics and clinical features. Method A cross-sectional study included 150 of MS patients aged 18 years and older who completed the validated Arabic versions of both the International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) and the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF). In addition, other clinical parameters were collected from the medical records of patients. The data were analyzed using Statistical Package for the Social Sciences (SPSS) version 26 (IBM Inc., Armonk, New York). Qualitative data were expressed as numbers and percentages, and the Chi-squared test (χ2) was employed. Quantitative data were expressed as means with standard deviation (mean ± SD). Result 67.3% of the participants were female; the mean ICIQ UI and ICIQ OAB scores in these MS patients were found to be 6.30 ± 6.26 and 5.32 ± 3.76, respectively. They were significantly higher in progressive MS patients compared to relapsing-remitting MS patients (p<0.05). There was a high positive correlation obtained between ICIQ UI and ICIQ OAB scores (rho=0.801, p<0.001). Conclusion The findings of this study showed that urinary incontinence was a common and distressing symptom experienced by individuals with MS. The severity of UI symptoms was significantly more in progressive multiple sclerosis compared to relapsing-remitting multiple sclerosis.

Pilomatrix carcinoma of the lower extremity: A rare case report and literature review.

INTRODUCTION: Pilomatrix carcinoma (PC) is a rare skin malignancy of the hair follicles matrix that tends to be locally aggressive with 10-16 % risk of metastasis mostly to the pulmonary and lymphatic system. There are no clear protocols for the management of PCs, however surgical intervention with clear margins has been highly considered in PC management to decrease risk of recurrence. CASE PRESENTATION: A 40 year-old male patient presented to our clinic to evaluate an asymptomatic, slow-growing nodule localized on his left thigh. A CT scan revealed a well-defined, enhanced lesion with microcalcification. "En bloc" surgical resection of the lesion was performed and histopathology confirmed the diagnosis of pilomatrix carcinoma. CLINICAL DISCUSSION: Given its rarity, there are no definitive guidelines regarding PC treatment. However, surgical intervention with clear margins including wide local excision or Mohs micrographic surgery has been highly considered. In our case, wide excision of the lesion with clear margins was performed with no evidence of recurrence one year later. CONCLUSION: Given the local aggressive nature of PC, appropriate surgical intervention is essential in decreasing the risk of recurrence. Wide excision with clear margins has been proposed to decrease the risk of recurrence. Additionally, total-body skin examination should be done 2-3 times annually to evaluate for recurrence or metastasis.

Acute Type B Intramural Hematoma: Novel Insights in the Endovascular Era.

BACKGROUND: The pathophysiology and behavior of acute type B intramural hematoma (TBIMH) is poorly understood. The purpose of this study is to characterize the pathophysiology, fate, and outcomes of TBIMH in the endovascular era. METHODS: A retrospective analysis of a US Aortic Database identified 70 patients with TBIMH from 2008 to 2022. Patients were divided into groups and analyzed based upon subsequent management: early thoracic endovascular aortic repair (TEVAR; Group 1) or hospital discharge on optimal medical therapy (OMT) (Group 2). RESULTS: Of 70 total patients, 43% (30/70) underwent TEVAR (Group 1) and 57% (40/70) were discharged on OMT (Group 2). There were no significant differences in age, demographics, or comorbidities between groups. Indications for TEVAR in Group 1 were as follows: 1) Penetrating atheroscletoic ulcer (PAU) or ulcer-like projection (n = 26); 2) Descending thoracic aortic aneurysm (n = 3); or 3) Progression to type B aortic dissection (TBAD) (n = 2). Operative mortality was zero. No patient suffered a stroke or spinal cord ischemia. During the follow-up period, 50% (20/40) of Group 2 patients required delayed surgical intervention, including TEVAR in 14 patients and open repair in 6 patients. Indications for surgical intervention were as follows: 1) Development of a PAU / ulcer-like projection (n = 13); 2) Progression to TBAD (n = 3), or 3) Concomitant aneurysmal disease (n = 4). Twenty patients did not require surgical intervention. Of the initial cohort, 71% of patients required surgery, 9% progressed to TBAD, and 19% had regression or stability of TBIMH with OMT alone. CONCLUSIONS: The most common etiology of TBIMH is an intimal defect. Progression to TBAD and intramural hematoma regression without an intimal defect occurs in a small percentage of patients. An aggressive strategy with endovascular therapy and close surveillance for TBIMH results in excellent short-term and long-term outcomes.

Delayed diagnosis of duodenal duplication cyst in a child with recurrent pancreatitis operated by Whipple procedure: a case report.

Children with acute pancreatitis may experience abdominal pain; the causes of which include anatomical abnormalities and medications. The rare anatomical etiology of duodenal duplication cyst is typically asymptomatic and discovered incidentally. The authors present a unique case of a Whipple-operated duodenal duplication cyst. Case presentation: The authors present the case of a 12-year-old Arab male who was admitted to our hospital with worsening, severe epigastric pain, stabbing in nature, and radiating to the back, suggestive of acute pancreatitis. Serum lipase levels were significantly elevated. The patient received appropriate care. His medical history is notable for multiple bouts of pancreatitis in the last 18 months. Previous investigations at other hospitals were mostly unrevealing. A more extensive workup was performed, revealing a duodenal cystic structure. This led to the diagnosis of a duodenal duplication cyst. The Whipple procedure was decided upon due to his recurrent pancreatitis, which caused fibrotic adhesions and anatomic region distortion. The patient underwent surgery and recovered uneventfully. Discussion: Acute pancreatitis in children is frequent and can be caused by unrecognized duodenal duplication cysts. When symptomatic, the majority present with vague abdominal pain. Despite using ultrasound as an adjunctive for diagnosis, the cyst might not become apparent until the condition has progressed to an advanced stage. A delayed diagnosis may result in complications necessitating risky surgeries. Conclusion: Children with recurrent pancreatitis should be evaluated for a duodenal duplication cyst. Early use of computed tomography scans may be necessary to identify the cause and spare the patient from risky procedures like Whipple surgery.

Home Self-Massage Device Necessitates Public Awareness: Vertebral Artery Dissection Associated With a Home Massage Device.

Vertebral artery dissection (VAD) is a common cause of stroke in middle-aged individuals. Patients with VAD usually describe a trivial minor neck trauma preceding the event. Such traumas may be associated with spinal manipulation or sudden movements of the neck. Our case is a 43-year-old lady who presented with a history of sudden-onset dizziness, dysarthria, nausea/vomiting, tinnitus, and imbalance. Two days prior to her presentation, she experienced a new-onset moderate to severe intensity headache along with neck pain. The patient mentioned a first-time use of a home massage device three weeks prior to headache onset. After investigations, the patient was diagnosed with VAD, and treatment was initiated. She was discharged in stable condition. With the recent increased popularity of home massage devices, we report this case to raise awareness about the safe use of massage devices in order to prevent the occurrence of such injuries and complications.

Early Results of Thoracic Endovascular Aortic Repair for the Management of Acute Uncomplicated Type B Aortic Dissection.

Historically, optimal medical therapy (OMT) has been the primary therapy for acute uncomplicated type B aortic dissection (auTBAD). However, recent data suggest that OMT provides poor long-term results, and aortic remodeling induced by thoracic endovascular aortic repair (TEVAR) may improve survival. This study compares adverse events and survival among auTBAD patients receiving either TEVAR or OMT. A retrospective analysis identified 146 consecutive auTBAD patients presenting to a single institution between 1/2012 and 10/2020. Patients were divided into 2 groups based upon whether they received TEVAR (n = 50) or OMT (n = 96) at index hospitalization. Major morbidity and survival were compared between groups. 67.1% of patients presented with a Debakey IIIB dissection with maximum thoracic aortic diameter of 4.3 ± 1.0 cm. Over follow-up, 35% of OMT patients failed medical therapy and underwent intervention (n = 23 TEVAR, n = 11 open). An additional 13 died for an all-cause failure rate of 49%. The composite incidence of renal failure, stroke, spinal cord ischemia, and retrograde type A dissections was similar between groups (TEVAR:6.0% vs OMT:4.2%). In-hospital mortality was 0%. Kaplan-Meier analysis demonstrated a trend towards improved survival among the TEVAR group at 1 and 3 years but no difference in overall survival (HR:0.30, 95% CI:0.08-1.08, P = 0.066). Five-year survival was 91% with TEVAR and 82% with OMT. Complete false lumen thrombosis was achieved in 72.1% with TEVAR and 20.0% with OMT (P < 0.001). In experienced centers, there is equivalent early mortality in the treatment of auTBAD with TEVAR compared to OMT. TEVAR provides superior aortic remodeling to OMT in auTBAD, which may translate into improved long-term survival.

Risk factors of early postoperative cardiac arrhythmia after pediatric cardiac surgery: A single-center experience.

OBJECTIVES: To evaluate the incidence of arrhythmia in the early postoperative period and to identify its risk factors among pediatric patients following cardiac surgery at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia, between 2015-2020. METHODS: Out of 1242 patients, a total of 821 aged <18 years who underwent cardiac surgery were included in this retrospective cohort carried out in June 2021 at KAUH, Jeddah, Saudi Arabia. Information retrieved from the hospital medical records had patients' demographics, types of arrhythmias, hemodynamic stability, electrolyte disturbances, cardiopulmonary bypass (CPB), and aortic cross-clamp (AXC) durations. Univariate and multivariate logistic regression analyses were used to evaluate the possible risk factors associated with postoperative arrhythmia. RESULTS: Of the 821 patients, 140 (17.1%) developed arrhythmia postoperatively. The most common arrhythmias were junctional ectopic tachycardia (JET, 51.4%), atrioventricular block (27.1%), and supraventricular tachycardia (10%). The majority of cases occurred on the first day postoperatively (79.3%). Patients with postoperative arrhythmias had a more prolonged CPB (p=0.0001) and AXC (p=0.005) time, electrolytes disturbances (p=0.021), and hemodynamic instability (p=0.0001) than other patients. CONCLUSION: Postoperative arrhythmia, especially JET, is common after pediatric cardiac surgery. Prolonged cardiopulmonary bypass, prolonged aortic cross-clamping, electrolytes disturbances, and hemodynamic instability are possible risk factors for postoperative cardiac arrhythmias.

A Sustainable Business Model for a Neutral Host Supporting 5G and beyond (5GB) Ultra-Dense Networks: Challenges, Directions, and Architecture.

With the deployment of the fifth generation (5G) mobile network systems and the envisioned heterogeneous ultra-dense networks (UDNs), both small cell (SmC) and distributed antenna system (DAS) technologies are required by mobile network operators (MNOs) and venue owners to support multiple spectrum bands, multiple radio access technologies (RATs), multiple optical central offices (COs), and multiple MNOs. As a result, the neutral host business model representing a third party responsible for managing the network enterprise on behalf of multiple MNOs has emerged as a potential solution, mainly influenced by the desire to provide a high user experience without significantly increasing the total cost of ownership (TCO). However, designing a sustainable business model for a neutral host is a nontrivial task, especially when considered in the context of 5G and beyond (5GB) UDNs. In this paper, under an integrated optical wireless network infrastructure, we review how SmC and DAS technologies are evolving towards the adoption of the neutral host business model and identify key challenges and requirements for 5GB support. Thus, we explore recent candidate advancements in heterogeneous network integration technologies for the realization of an efficient 5GB neutral host business model design capable of accommodating both SmC and DAS. Furthermore, we propose a novel design architecture that relies on virtual radio access network (vRAN) to enable real-time dynamic resource allocation and radio over Ethernet (RoE) for flexible and reconfigurable fronthaul. The results from our simulations using MATLAB over two real-life deployment scenarios validate the feasibility of utilizing switched RoE considering end-to-end delay requirements of 5GB under different switching schemes, as long as the queuing delay is kept to a minimum. Finally, the results show that incorporating RoE and vRAN technologies into the neutral host design results in substantial TCO reduction by about 81% in an indoor scenario and 73% in an outdoor scenario.

CryoEM of endogenous mammalian V-ATPase interacting with the TLDc protein mEAK-7.

V-ATPases are rotary proton pumps that serve as signaling hubs with numerous protein binding partners. CryoEM with exhaustive focused classification allowed detection of endogenous proteins associated with porcine kidney V-ATPase. An extra C subunit was found in ∼3% of complexes, whereas ∼1.6% of complexes bound mEAK-7, a protein with proposed roles in dauer formation in nematodes and mTOR signaling in mammals. High-resolution cryoEM of porcine kidney V-ATPase with recombinant mEAK-7 showed that mEAK-7's TLDc domain interacts with V-ATPase's stator, whereas its C-terminal α helix binds V-ATPase's rotor. This crosslink would be expected to inhibit rotary catalysis. However, unlike the yeast TLDc protein Oxr1p, exogenous mEAK-7 does not inhibit V-ATPase and mEAK-7 overexpression in cells does not alter lysosomal or phagosomal pH. Instead, cryoEM suggests that the mEAK-7:V-ATPase interaction is disrupted by ATP-induced rotation of the rotor. Comparison of Oxr1p and mEAK-7 binding explains this difference. These results show that V-ATPase binding by TLDc domain proteins can lead to effects ranging from strong inhibition to formation of labile interactions that are sensitive to the enzyme's activity.

Kinase-independent synthesis of 3-phosphorylated phosphoinositides by a phosphotransferase.

Despite their low abundance, phosphoinositides play a central role in membrane traffic and signalling. PtdIns(3,4,5)P3 and PtdIns(3,4)P2 are uniquely important, as they promote cell growth, survival and migration. Pathogenic organisms have developed means to subvert phosphoinositide metabolism to promote successful infection and their survival in host organisms. We demonstrate that PtdIns(3,4)P2 is a major product generated in host cells by the effectors of the enteropathogenic bacteria Salmonella and Shigella. Pharmacological, gene silencing and heterologous expression experiments revealed that, remarkably, the biosynthesis of PtdIns(3,4)P2 occurs independently of phosphoinositide 3-kinases. Instead, we found that the Salmonella effector SopB, heretofore believed to be a phosphatase, generates PtdIns(3,4)P2 de novo via a phosphotransferase/phosphoisomerase mechanism. Recombinant SopB is capable of generating PtdIns(3,4,5)P3 and PtdIns(3,4)P2 from PtdIns(4,5)P2 in a cell-free system. Through a remarkable instance of convergent evolution, bacterial effectors acquired the ability to synthesize 3-phosphorylated phosphoinositides by an ATP- and kinase-independent mechanism, thereby subverting host signalling to gain entry and even provoke oncogenic transformation.

Detection and quantification of the vacuolar H+ATPase using the Legionella effector protein SidK.

Acidification of secretory and endocytic organelles is required for proper receptor recycling, membrane traffic, protein degradation, and solute transport. Proton-pumping vacuolar H+ ATPases (V-ATPases) are responsible for this luminal acidification, which increases progressively as secretory and endocytic vesicles mature. An increasing density of V-ATPase complexes is thought to account for the gradual decrease in pH, but available reagents have not been sufficiently sensitive or specific to test this hypothesis. We introduce a new probe to localize and quantify V-ATPases. The probe is derived from SidK, a Legionella pneumophila effector protein that binds to the V-ATPase A subunit. We generated plasmids encoding fluorescent chimeras of SidK1-278, and labeled recombinant SidK1-278 with Alexa Fluor 568 to visualize and quantify V-ATPases with high specificity in live and fixed cells, respectively. We show that V-ATPases are acquired progressively during phagosome maturation, that they distribute in discrete membrane subdomains, and that their density in lysosomes depends on their subcellular localization.

Esthetic Dentistry on Twitter: Benefits and Dangers.

OBJECTIVES: The demand for esthetic dentistry is growing, and social media constitute the main driving force behind this revolution. Twitter is a leading social media platform; however, there is a lack of research on the pattern of communications and the impact of Twitter on esthetic dentistry. The purpose of this study was to analyze the content of tweets related to esthetic dentistry and to investigate how Twitter has affected the perception of, and demand for, esthetic dentistry. Moreover, it aimed to assess the potential benefits and risks of esthetic dentistry advertising strategies on Twitter as a potential social media platform. MATERIALS AND METHODS: Using a specialized web scrapping tool made available by the Python programming language, a total of 54,000 public tweets were downloaded from Twitter at real-time by matching specific keywords. The downloaded tweets were manually filtered, and 13,787 tweets were included and categorized into four tweet sets by content. RESULTS: The main categories were tweets regarding specific cosmetic procedure, totaling 56.53% (43.2% for veneers, 13.3% for whitening), advertisements (36.72%), information (5.53%), and general cosmetic dentistry (1.22%). Negative opinions towards veneers and whitening were the most common themes (68.03% and 43.44%). For veneers, illegal use for kids was the most common negative theme (59.7%) and being destructive for whitening (86.3%). Positive opinions counted 6.26% of veneers and 4.3% of whitening tweets. Advertising for whitening products was the second most common between all tweets (16.6%), and advertising for dental practices was the third (14.7%). Presenting facilities/services was the most common marketing strategy for dental practices (49.7%). Twitter was weakly used to circulate educational content (5.5%) and to post reviews (0.75%). CONCLUSION: Twitter was extensively used to share experiences/opinions towards dental cosmetic interventions. Advertising is another vital use of this platform. However, circulating information was the least common use of this social media. Additionally, tweeters were rarely to post online reviews and specific advices and recommendations regarding esthetic dentistry. Moreover, females tended to participate and tweet more significantly in cosmetic-related topics than males. This platform should be tailored efficiently to target users' priorities and to improve health literacy and self-care. Twitter was weakly used to circulate educational content according to this study and rarely used to share online reviews.

Isolated tuberculosis liver abscess in an immunocompetent patient.

Isolated TLA is an extremely rare condition, but should always be considered in a patient presented with liver abscess, especially from an endemic area. Diagnosis depends on histological identification, with treatment being quadruple therapy.

Current status of patient-reported outcome measures in vascular surgery.

A previously published review focused on generic and disease-specific patient-reported outcome measures (PROMs) relevant to vascular surgery but limited to arterial conditions. The objective of this project was to identify all available PROMs relevant to diseases treated by vascular surgeons and to evaluate vascular surgeon perceptions, barriers to widespread implementation, and concerns regarding PROMs. We provide an overview of what a PROM is and how they are developed, and summarize currently available PROMs specific to vascular surgeons. We also report results from a survey of 78 Society for Vascular Surgery members serving on committees within the Policy and Advocacy Council addressing the barriers and facilitators to using PROMs in clinical practice. Finally, we report the qualitative results of two focus groups conducted to assess granular perceptions of PROMS and preparedness of vascular surgeons for widespread implementation of PROMs. These focus groups identified a lack of awareness of existing PROMs, knowledge of how PROMs are developed and validated, and clarity around how PROMs should be used by the clinician as main subthemes for barriers to PROM implementation in clinical practice.

Structural Characterization of Endogenous Tuberous Sclerosis Protein Complex Revealed Potential Polymeric Assembly.

Tuberous sclerosis protein complex (pTSC) nucleates a proteinaceous signaling hub that integrates information about the internal and external energy status of the cell in the regulation of growth and energy consumption. Biochemical and cryo-electron microscopy studies of recombinant pTSC have revealed its structure and stoichiometry and hinted at the possibility that the complex may form large oligomers. Here, we have partially purified endogenous pTSC from fasted mammalian brains of rat and pig by leveraging a recombinant antigen binding fragment (Fab) specific for the TSC2 subunit of pTSC. We demonstrate Fab-dependent purification of pTSC from membrane-solubilized fractions of the brain homogenates. Negative stain electron microscopy of the samples purified from pig brain demonstrates rod-shaped protein particles with a width of 10 nm, a variable length as small as 40 nm, and a high degree of conformational flexibility. Larger filaments are evident with a similar 10 nm width and a ≤1 µm length in linear and weblike organizations prepared from pig brain. Immunogold labeling experiments demonstrate linear aggregates of pTSC purified from mammalian brains. These observations suggest polymerization of endogenous pTSC into filamentous superstructures.

Model-based analysis of implanted hypoglossal nerve stimulation for the treatment of obstructive sleep apnea.

STUDY OBJECTIVES: Individuals with obstructive sleep apnea (OSA), characterized by frequent sleep disruptions from tongue muscle relaxation and airway blockage, are known to benefit from on-demand electrical stimulation of the hypoglossal nerve. Hypoglossal nerve stimulation (HNS) therapy, which activates the protrusor muscles of the tongue during inspiration, has been established in multiple clinical studies as safe and effective, but the mechanistic understanding for why some stimulation parameters work better than others has not been thoroughly investigated. METHODS: In this study, we developed a detailed biophysical model that can predict the spatial recruitment of hypoglossal nerve fascicles and axons within these fascicles during stimulation through nerve cuff electrodes. Using this model, three HNS programming scenarios were investigated including grouped cathode (---), single cathode (o-o), and guarded cathode bipolar (+-+) electrode configurations. RESULTS: Regardless of electrode configuration, nearly all hypoglossal nerve axons circumscribed by the nerve cuff were recruited for stimulation amplitudes <3 V. Within this range, monopolar configurations required lower stimulation amplitudes than the guarded bipolar configuration to elicit action potentials within hypoglossal nerve axons. Further, the spatial distribution of the activated axons was more uniform for monopolar versus guarded bipolar configurations. CONCLUSIONS: The computational models predicted that monopolar HNS provided the lowest threshold and the least sensitivity to rotational angle of the nerve cuff around the hypoglossal nerve; however, this setting also increased the likelihood for current leakage outside the nerve cuff, which could potentially activate axons in unintended branches of the hypoglossal nerve. CLINICAL TRIAL REGISTRATION: NCT01161420.