Multiomic foundations of human prefrontal cortex tissue function.

The prefrontal cortex (PFC) is a region of the brain that in humans is involved in the production of higher-order functions such as cognition, emotion, perception, and behavior. Neurotransmission in the PFC produces higher-order functions by integrating information from other areas of the brain. At the foundation of neurotransmission, and by extension at the foundation of higher-order brain functions, are an untold number of coordinated molecular processes involving the DNA sequence variants in the genome, RNA transcripts in the transcriptome, and proteins in the proteome. These "multiomic" foundations are poorly understood in humans, perhaps in part because most modern studies that characterize the molecular state of the human PFC use tissue obtained when neurotransmission and higher-order brain functions have ceased (i.e., the postmortem state). Here, analyses are presented on data generated for the Living Brain Project (LBP) to investigate whether PFC tissue from individuals with intact higher-order brain function has characteristic multiomic foundations. Two complementary strategies were employed towards this end. The first strategy was to identify in PFC samples obtained from living study participants a signature of RNA transcript expression associated with neurotransmission measured intracranially at the time of PFC sampling, in some cases while participants performed a task engaging higher-order brain functions. The second strategy was to perform multiomic comparisons between PFC samples obtained from individuals with intact higher-order brain function at the time of sampling (i.e., living study participants) and PFC samples obtained in the postmortem state. RNA transcript expression within multiple PFC cell types was associated with fluctuations of dopaminergic, serotonergic, and/or noradrenergic neurotransmission in the substantia nigra measured while participants played a computer game that engaged higher-order brain functions. A subset of these associations - termed the "transcriptional program associated with neurotransmission" (TPAWN) - were reproduced in analyses of brain RNA transcript expression and intracranial neurotransmission data obtained from a second LBP cohort and from a cohort in an independent study. RNA transcripts involved in TPAWN were found to be (1) enriched for RNA transcripts associated with measures of neurotransmission in rodent and cell models, (2) enriched for RNA transcripts encoded by evolutionarily constrained genes, (3) depleted of RNA transcripts regulated by common DNA sequence variants, and (4) enriched for RNA transcripts implicated in higher-order brain functions by human population genetic studies. In PFC excitatory neurons of living study participants, higher expression of the genes in TPAWN tracked with higher expression of RNA transcripts that in rodent PFC samples are markers of a class of excitatory neurons that connect the PFC to deep brain structures. TPAWN was further reproduced by RNA transcript expression patterns differentiating living PFC samples from postmortem PFC samples, and significant differences between living and postmortem PFC samples were additionally observed with respect to (1) the expression of most primary RNA transcripts, mature RNA transcripts, and proteins, (2) the splicing of most primary RNA transcripts into mature RNA transcripts, (3) the patterns of co-expression between RNA transcripts and proteins, and (4) the effects of some DNA sequence variants on RNA transcript and protein expression. Taken together, this report highlights that studies of brain tissue obtained in a safe and ethical manner from large cohorts of living individuals can help advance understanding of the multiomic foundations of brain function.

Human Substantia Nigra Neurons Encode Reward Expectations.

Dopamine (DA) signals originating from substantia nigra (SN) neurons are centrally involved in the regulation of motor and reward processing. DA signals behaviorally relevant events where reward outcomes differ from expectations (reward prediction errors, RPEs). RPEs play a crucial role in learning optimal courses of action and in determining response vigor when an agent expects rewards. Nevertheless, how reward expectations, crucial for RPE calculations, are conveyed to and represented in the dopaminergic system is not fully understood, especially in the human brain where the activity of DA neurons is difficult to study. One possibility, suggested by evidence from animal models, is that DA neurons explicitly encode reward expectations. Alternatively, they may receive RPE information directly from upstream brain regions. To address whether SN neuron activity directly reflects reward expectation information, we directly examined the encoding of reward expectation signals in human putative DA neurons by performing single-unit recordings from the SN of patients undergoing neurosurgery. Patients played a two-armed bandit decision-making task in which they attempted to maximize reward. We show that neuronal firing rates (FR) of putative DA neurons during the reward expectation period explicitly encode reward expectations. First, activity in these neurons was modulated by previous trial outcomes, such that FR were greater after positive outcomes than after neutral or negative outcome trials. Second, this increase in FR was associated with shorter reaction times, consistent with an invigorating effect of DA neuron activity during expectation. These results suggest that human DA neurons explicitly encode reward expectations, providing a neurophysiological substrate for a signal critical for reward learning.

Ethical Considerations and Outcomes in Body Contouring Surgeries Among Adolescents: A Comprehensive Narrative Review.

BACKGROUND: Body contouring surgery (BCS) in adolescents, particularly following bariatric surgery, involves a complex array of ethical, psychological, and medical factors. This review focuses on adolescents who have experienced significant weight loss, often due to bariatric surgery, and subsequently require body contouring to address excess skin and soft tissue. METHODS: A literature narrative review was conducted using PubMed and Google Scholar databases. Relevant articles were screened and selected based on their discussion of post-bariatric and massive weight loss body contouring surgeries in adolescents, focusing on prevalence, outcomes, and ethical considerations. RESULTS: The prevalence of BCS among adolescents is rising, influenced by social media and societal perceptions of beauty. However, the percentage of adolescents receiving BCS after bariatric surgery remains low. Adolescents undergoing BCS experience improvements in physical functioning, body image, and psychological well-being. Complications, although common, are mostly minor. Ethical considerations include ensuring informed consent, assessing emotional maturity, managing patient expectations, and involving adolescents in decision-making. Comparative analysis reveals similar outcomes in adults and adolescents, but adolescents face unique ethical challenges related to autonomy, long-term effects, and ongoing physical and emotional development. CONCLUSION: BCS in adolescents following bariatric surgery can lead to improved physical and psychological outcomes. However, the decision to undergo BCS must be carefully considered, taking into account the adolescent's maturity, expectations, and long-term well-being. Ethical considerations are paramount, emphasizing the need for informed consent, realistic expectations, and a multidisciplinary approach. Further research is needed to assess long-term outcomes and the specific ethical implications of BCS in adolescents compared to adults. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Acetylcholine modulates the temporal dynamics of human theta oscillations during memory.

The cholinergic system is essential for memory. While degradation of cholinergic pathways characterizes memory-related disorders such as Alzheimer's disease, the neurophysiological mechanisms linking the cholinergic system to human memory remain unknown. Here, combining intracranial brain recordings with pharmacological manipulation, we describe the neurophysiological effects of a cholinergic blocker, scopolamine, on the human hippocampal formation during episodic memory. We found that the memory impairment caused by scopolamine was coupled to disruptions of both the amplitude and phase alignment of theta oscillations (2-10 Hz) during encoding. Across individuals, the severity of theta phase disruption correlated with the magnitude of memory impairment. Further, cholinergic blockade disrupted connectivity within the hippocampal formation. Our results indicate that cholinergic circuits support memory by coordinating the temporal dynamics of theta oscillations across the hippocampal formation. These findings expand our mechanistic understanding of the neurophysiology of human memory and offer insights into potential treatments for memory-related disorders.

Neuronal activity in the human amygdala and hippocampus enhances emotional memory encoding.

Emotional events comprise our strongest and most valuable memories. Here we examined how the brain prioritizes emotional information for storage using direct brain recording and deep brain stimulation. First, 148 participants undergoing intracranial electroencephalographic (iEEG) recording performed an episodic memory task. Participants were most successful at remembering emotionally arousing stimuli. High-frequency activity (HFA), a correlate of neuronal spiking activity, increased in both the hippocampus and the amygdala when participants successfully encoded emotional stimuli. Next, in a subset of participants (N = 19), we show that applying high-frequency electrical stimulation to the hippocampus selectively diminished memory for emotional stimuli and specifically decreased HFA. Finally, we show that individuals with depression (N = 19) also exhibit diminished emotion-mediated memory and HFA. By demonstrating how direct stimulation and symptoms of depression unlink HFA, emotion and memory, we show the causal and translational potential of neural activity in the amygdalohippocampal circuit for prioritizing emotionally arousing memories.

Current Practices and Guidelines for Perioperative Blood Management in Post-Bariatric Body Contouring Surgery: A Comprehensive Review of Literature.

With the increase in obesity prevalence, a noticeable increase in bariatric surgeries has been reported in national and international statistics. Therefore, body contouring surgeries have increased to help individuals achieve their desired body shape. Plastic surgeons need to consider potential hematologic complications that may occur in this specific group of patients before performing body contouring surgery. This review illustrates the perioperative medical, laboratory, and management strategies needed to minimize blood loss and blood transfusion requirements during body contouring. Using Google Scholar and PubMed, a comprehensive literature review was conducted to identify articles discussing post-bariatric body contouring perioperative blood management strategies, including the effects of bariatric surgery on hemostasis as well as basic hematology and coagulation. In preoperative blood management, blood investigations aid in the early detection of electrolytes, protein, and vitamin deficiencies and anemia, resulting in the early correction of nutritional deficiencies. In order to reduce postoperative complications, surgical and anesthesia techniques, as well as intraoperative pharmacological therapy, play an essential role. Postoperative blood transfusion and restrictive transfusion thresholds are tailored to the patient's needs and depend on various physiological indicators, such as heart rate, blood pressure, urine output, and laboratory findings, such as acidosis and hematocrit level. Generally, post-bariatric body contouring blood management measures are still lacking, and more research is required to develop standardized guidelines for optimizing patient safety and satisfaction.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Adequacy of physician clinical rounds and nursing care elements for non-COVID-19 infected patients admitted during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic created many challenges for healthcare systems. Frontline workers and especially healthcare professionals were the most severely affected through increased working hours, burnout and major psychological distress. OBJECTIVES: To evaluate the changes in standard care elements which occurred during the COVID-19 pandemic, specifically the physician clinical rounds and nursing care provided to non-COVID-19 infected patients. DESIGN: Observational retrospective study. SETTINGS: The study was conducted at King Abdulaziz Medical City, Riyadh Saudi Arabia. KAMC is a 1200 bed tertiary care referral academic medical center. PATIENTS (MATERIALS) AND METHODS: We compared the physician clinical rounds and nursing care elements in all admissions due to non-COVID-19 pneumonia and ST elevation myocardial infarction during the lockdown period with similar admissions in a baseline period in the same weeks in the previous pre-lockdown. MAIN OUTCOME MEASURES: To evaluates the changes occurring during the COVID-19 pandemic in terms of the standard care elements, such as the physician rounds and nursing care. SAMPLE SIZE: Total of 113 patients records were analyzed. RESULTS: During the lock down period, a total of 113 patients were admitted to the medical and cardiology wards, (95 patients with pneumonia and 18 patients with ST segment elevation myocardial infarction (STEMI)) compared to 89 patients in the pre lockdown period (74 patients with pneumonia and 15 patients with STEMI). Both groups were similar in age, gender, disposition, length of stay, goal of care planning and outcome. Chronic respiratory disease and Diabetes were more present in patients admitted on the pre lockdown time. Azithromycin was more frequently used as part of the initial antibiotic regimen for pneumonia during the pre-lockdown while doxycycline was significantly more during the lockdown. For the 95 patients admitted in the medical wards during the lockdown, there were a total of 820 physicians' clinical rounds opportunities for senior and junior physicians each. The residents missed 133 (16.2%) and consultant missed 252 (30.7%) of those clinical rounds opportunities. Missed clinical rounds opportunities during the pre-lock down period was higher for residents and consultants at 19.3% (P = 0.429 ) and 36.3% respectively (P = 0.027 ). Similarly, missed clinical rounds opportunities was less during the lockdown period from 35.2% to 25% (p 0.022) and from 38.8% to 30.6% (p = 1 ) for junior staff and consultant cardiology respectively compared to pre lockdown period. For nursing care elements, there was a decrease in missed opportunities in vital signs measurement (p 0.47 and p 0.226), pain assessment (p 0.088 and p 0,366) and skin care (p 0.249 and p 0.576) for patients admitted during the lockdown period in medical and cardiology wards. CONCLUSIONS: Caring for patients admitted for non COVID 19 infection reasons, physicians' clinical rounds did marginally increase compared to pre lockdown period while nurses monitoring for those patients was significantly higher. No difference in mortality was observed for patients admitted pre and during lockdown. The number of missed opportunities to do clinical rounds by physicians remains high during both periods and measures to improve adherence of physicians to performed clinical rounds are needed.

Training medical students in physical examination and point-of-care ultrasound: An assessment of the needs and barriers to acquiring skills in point-of-care ultrasound.

BACKGROUND: With growth of the use of point of care ultrasound (PoCUS) around the world, some medical schools have incorporated this skill into their undergraduate curricula. However, because of epidemiology of disease and regional differences in approaches to patient care, global application of PoCUS might not be possible. Before creating a PoCUS teaching course, it is critical to perform a needs analysis and recognize the training obstacles. MATERIALS AND METHODS: A validated online questionnaire was given to final-year medical students at our institution to evaluate their perceptions of the applicability of specific clinical findings, and their own capability to detect these signs clinically and with PoCUS. The skill insufficiency was assessed by deducting the self-reported clinical and ultrasound skill level from the perceived usefulness of each clinical finding. RESULTS: The levels of expertise and knowledge in the 229 students who participated were not up to the expected standard. The applicability of detection of abdominal aortic aneurysm (AAA) (3.9 ± standard deviation [SD] 1.4) was the highest. However, detection of interstitial syndrome (3.0 ± SD 1.1) was perceived as the least applicable. The deficit was highest in the detection of AAA (mean 0.95 ± SD 2.4) and lowest for hepatomegaly (mean 0.57 ± SD 2.3). Although the majority agreed that training of preclinical and clinical medical students would be beneficial, 52 (22.7%) showed no interest, and 60% (n = 136) reported that they did not have the time to develop the skill. CONCLUSION: Although medical students in Saudi Arabia claim that PoCUS is an important skill, there are significant gaps in their skill, indicating the need for PoCUS training. However, a number of obstacles must be overcome in the process.

Epidemiological Features and Clinical Manifestations of Patients With Somatoform Disorder at a Tertiary Medical City in Riyadh, Saudi Arabia.

Background Somatoform disorder (SD), known as the presence of physical symptoms suggesting a physical condition, for which there are no demonstrable organic findings or established physiological mechanisms with positive evidence that the symptoms are related to psychological causes. The aim of this study was to highlight the epidemiological characteristics, demographic features, comorbidities, and clinical presentations of patients with SD. Materials and methods This was a retrospective study of SD patients at King Abdulaziz Medical City in Riyadh, Saudi Arabia. We reviewed the patients' electronic health records from January 2015 to December 2020 for collecting the patients' demographic information, including gender, age, marital status, and occupation. The types of SD, presenting symptoms of each disorder, department to which patients initially presented, comorbidities, and management were also documented. The diagnosis of SD was based on the International Classification of Diseases, Tenth Revision (ICD-10). Results In total, 89 patients were included in the study. The majority (n=50, 56.2%) were female, with a mean age of 42.7±17.1 years. More than half of the sample was married (n=54, 60.7%). The most common subtype of SD was somatization disorder followed by conversion disorder, pain disorder, and hypochondriasis, diagnosed in 69 (77.5%), 12 (13.5%), 5 (5.6%), and three (3.4%) patients, respectively. Neurological symptoms and pain were the most frequent presenting symptoms for all the somatoform patients. More than half of the sample (n=48, 53.9%) initially presented at an outpatient clinic. Conclusions The number of SD patients was less than expected, and a third did not receive any treatment. This emphasizes the need for more SD awareness among clinicians in various medical specialties. Appropriate SD and other mental disorders education for physicians may support achieving a better identification of SD and subsequently an improved quality of life for the patients.

Domestic Violence Against Married Women During the COVID-19 Quarantine in Saudi Arabia.

Background  Before the coronavirus disease 2019 (COVID-19) pandemic, cases of domestic abuse and aggressive behaviour between Saudi married couples were increasing annually, a topic of growing concern both socially and medically. With the forced indoor confinement enacted as a containment measure, international studies regarding domestic abuse indicated an almost unanimous increase in prevalence. This cross-sectional national study aimed to assess the change between the pre-and intra-pandemic prevalence of abuse in Saudi Arabia.  Material and methods  Anonymous data were gathered using a web-based Arabic version of the World Health Organization (WHO) multi-country instrument measuring violence against women residing in Saudi Arabia. The previously validated questionnaire included a series of multiple-choice questions related to demographic information, family infrastructure, experienced situations of abuse, and the severity and form of abuse during the quarantine period, from March 23, 2020, to June 21, 2020. Associations were tested using a two-tailed Pearson's Chi-square test and odds ratios. A binary multivariate logistic regression was used to identify the independent factors associated with domestic violence.  Results  In total, 2254 participants were included in the present study. The majority (n=2129, 94.7%) were Saudi nationals. The highest proportion (n=1022, 45.3%) was in the 30 to 40 years age group. The self-reported prevalence of domestic violence before COVID-19 pandemic and quarantine was 25.4% and 16.6% during the confinement, indicating an overall decrease of 8.8% in the reported cases. Regarding the type of violence, of the 315 (16.6%) women who endured violence since the confinement, the majority (n=301, 95.6%) experienced multiple forms of violent abuse, 264 (87.7%) suffered from psychological/emotional violence, 114 (37.9%) from physical violence, and 50 (16.6%) from sexual violence. Of the group who experienced multiple forms of violence, 120 (39.9%) reported an increase in the frequency and perceived intensity of the violence since the confinement. The only variable that directly increased the likelihood of suffering domestic violence had more than three children [OR = 1.59, P = 0.018]. Conclusions  Contrary to trends observed in other countries, the national prevalence of abusive conduct towards married women showed a marked decrease during the quarantine period-more children directly correlated with a higher reported frequency of being abused. Further studies in neighbouring countries with comparable societies and structures must be conducted to assess the validity of our findings in the context of the global trends of violence in the marital home.

Incidence Rate and Predictors of Delayed Graft Function Among Adult Kidney Transplant Recipients at a Tertiary Care Hospital in Riyadh, Saudi Arabia.

Background Delayed graft function (DGF) is the most common early postoperative complication of renal transplantation. The occurrence of DGF can lead to both early and late devastating consequences on the allograft's survival. The risk of developing this complication can increase with certain factors that are related to both the donor and the recipient. In the present study, we aimed to detect the incidence rate of DGF among patients attending a tertiary care hospital in Riyadh, Saudi Arabia, and to investigate potential predictors of DGF. Materials and methods This retrospective chart review was conducted at King Abdulaziz Medical City (KAMC), a tertiary care hospital in Riyadh, Saudi Arabia. The inclusion criteria were all patients, 18 years or older, who had renal transplantation from January 1, 2016, to March 31, 2020. Patients who had a second renal transplant, or renal transplantation in a different hospital and were followed up at KAMC were excluded. Patients' medical records were accessed using the BESTCare electronic system to obtain the patients' demographic data. A Chi-square test was used to test for the association between a predictor and a delay in graft function. Results A total of 344 patients were enrolled in the present study, approximately half of whom were males (56.6%, n=189). Around one-half (49.4%) were aged between 40 and 64 years. The most common cause of renal failure was hypertension, which was found in 117 (35%) patients, followed by diabetes mellitus (DM) in 94 (28.1%) patients. Most organ donors 258 (77.2%) were alive. A total of 23 (6.9%) participants developed DGF. Mycophenolate mofetil (MMF) was found to be significantly associated with DGF (P < 0.001). Those who took MMF (5.9%) had a significantly lower rate of DGF compared to those who did not (36.4%). A significantly higher rate of DGF was seen in patients whose transplants were taken from deceased donors (15.5%) compared to living donor transplants (3.9%). Gender, age, body mass index (BMI), recipient blood type, donor blood type, and cause of renal failure were not associated with DGF. Conclusions Only 6.9% of the study's participants exhibited DGF. The observed rate was lower than the ones detected in the literature. Those who took MMF had a significantly lower rate of DGF compared to those who did not. Transplants of deceased donors (15.5%) showed a significantly higher rate of DGF. Larger multicenter studies are required to further investigate DGF in a region with a high prevalence of organ failure and a higher need for transplantations, such as Saudi Arabia.

Phase precession in the human hippocampus and entorhinal cortex.

Knowing where we are, where we have been, and where we are going is critical to many behaviors, including navigation and memory. One potential neuronal mechanism underlying this ability is phase precession, in which spatially tuned neurons represent sequences of positions by activating at progressively earlier phases of local network theta oscillations. Based on studies in rodents, researchers have hypothesized that phase precession may be a general neural pattern for representing sequential events for learning and memory. By recording human single-neuron activity during spatial navigation, we show that spatially tuned neurons in the human hippocampus and entorhinal cortex exhibit phase precession. Furthermore, beyond the neural representation of locations, we show evidence for phase precession related to specific goal states. Our findings thus extend theta phase precession to humans and suggest that this phenomenon has a broad functional role for the neural representation of both spatial and non-spatial information.

Factitious Disorder in Seven Patients: A Saudi Experience.

Background Factitious disorder (FD) is a psychiatric disease where signs and symptoms are produced, falsified, or exaggerated consciously in the absence of clear external motivations. Through needless medical visits, costly investigatory testing, and potentially long hospital stays, patients with FD waste valuable time and resources, which affects both the patient and the healthcare system. It can be very challenging for physicians who have never encountered patients with FD to recognize them promptly as symptoms of FD vary greatly. Methodology This was a retrospective study of patients diagnosed with FD attending King Abdulaziz Medical City in Riyadh, Saudi Arabia, a tertiary care military hospital and one of the most prominent academic and referral medical institutions in the country. Using the BESTCare health information system, we reviewed patients' electronic health records from January 2015 to December 2020. The diagnosis of FD was based on the International Classification of Diseases and Related Health Problems 10th edition. Results A total of seven patients were included in the study, of whom five (71%) were males and two (29%) were females. Of the total seven patients, three were 21 years old and younger, one was 38 years old, and three were 56 years old and older. Three (43%) patients were married and four (57%) were single. In terms of occupation, three (43%) patients were retired, one (14%) worked in a private company, one (14%) was unemployed, and two (29%) were students. A total of four (57%) patients initially presented to the Emergency Department (ED), and only three (43%) presented to the outpatient clinics. Induced disease or injury was found in five (71%) patients. Induced skin injury was found in four (57%) patients. Counseling and psychotherapy were only offered to one (14%) patient. Conclusions FD remains a rare psychiatric condition that is difficult to recognize. Despite a small sample size, FD in the present study showed a male predominance, affecting patients of all age groups. About half of the patients presented initially to the ED. Induced disease or injury was the most commonly reported pattern of clinical presentation. Induced skin injury was the most common clinical presentation found in around half of the patients. We believe that the number of FD patients in the present study is likely underreported and is expected to be higher. This highlights the need for better awareness of FD among physicians in different medical fields. We emphasize that there is a need for better professional training in the identification of FD.

The effect of gender, age, and body mass index on the medial and lateral posterior tibial slopes: a magnetic resonance imaging study.

BACKGROUND: The posterior tibial slope (PTS) is crucial in knee joint stability and in maintaining the natural movement of the knee. An increase in the PTS is associated with various knee pathologic conditions, such as anterior cruciate ligament (ACL) injury and anterior tibial translation (ATT). In the present study, we aimed to establish native medial and lateral PTS values for adult Saudis and to identify any association between PTS and gender, age, and body mass index (BMI). MATERIALS AND METHODS: A total of 285 consecutive, normal, magnetic resonance imaging (MRI) studies of the knee were included in the study. The PTS was measured using the proximal anatomical axis of the tibia. The Kruskal-Wallis test was used to compare the medial and lateral PTS angles between age groups. The difference between the medial and lateral posterior tibial slopes was assessed using the Wilcoxon signed-rank test. The Mann-Whitney U test was performed to compare the medial and lateral PTS angles between men and women. Age, gender, and BMI were analyzed by multivariate linear regression to determine whether they positively predict the medial and lateral PTS angles. RESULTS: The mean physiological medial PTS was 5.86 ± 3.0° and 6.61 ± 3.32°, and the lateral PTS was 4.41 ± 3.35° and 4.63 ± 2.85° in men and women, respectively. This difference showed no statistically significant gender dimorphism (p > 0.05). The medial PTS was significantly larger than the lateral PTS (p < 0.0001). There was no statistically significant difference in the medial and lateral PTS angles between age groups (p > 0.05). Higher BMI was significantly associated with a steeper medial PTS (p = 0.001). CONCLUSIONS: This study provided native values for medial and lateral PTS angles in Saudis, which can assist surgeons in maintaining normal knee PTS during surgery. The PTS was not influenced by age. The medial PTS was significantly larger than the lateral PTS in men and women. The PTS showed no significant gender dimorphism. BMI was significantly associated with the medial PTS.

A Case of Seronegative Pediatric Neurobrucellosis Presenting With Ataxia.

Neurobrucellosis is an uncommon and dangerous complication of brucellosis. Meningitis is the most common presentation of neurobrucellosis, but it may present in a wide range of clinical manifestations such as myelitis, brain abscess, radiculopathy, and cranial nerve involvement. It tends to present insidiously with symptoms appearing gradually. Acute presentation of neurobrucellosis is very uncommon. Here, we report a case of a female child who presented with an acute onset of ataxia and slurred speech with positive cerebrospinal fluid (CSF) and neuroimaging findings for neurobrucellosis. In endemic countries such as Saudi Arabia, neurobrucellosis should be considered as a differential diagnosis for patients presenting with unexplained neurological symptoms.

Brucellosis in Saudi Children: Presentation, Complications, and Treatment Outcome.

Background Brucellosis, an endemic disease in Saudi Arabia, has an infection rate of 70 per 100,000 people, with a varying morbidity rate in different parts of the country. The aim of this study was to assess the epidemiological and clinical features, laboratory findings, treatment modalities, complications, and outcomes in children with brucellosis. Materials and methods The medical records of 153 patients attending King Abdullah Specialist Children's Hospital in Riyadh, Saudi Arabia, from January 2015 to January 2019 were reviewed retrospectively. Demographic data, laboratory test results, serum agglutination test titer, and the results of the blood cultures were obtained. The diagnosis of brucellosis was based on compatible signs and symptoms with a positive serology titer of ≥1:160 or a blood culture positive for Brucella species. Results The majority of the sample (69.6%, n=107) were males, with a mean age of 7.75 ± 3.28 years. Ingestion of unpasteurized camel dairy products was the most frequent transmission risk factor. The most prevalent presenting symptoms were constitutional and musculoskeletal symptoms. Six patients (3.9%) had complicated brucellosis, with neurobrucellosis diagnosed in three cases. Hospitalization for brucellosis was required in 15% of the patients. The majority (99.35%, n=152) of the patients had a serum agglutination test (SAT) titer of ≥1:160. A blood culture was positive in 52 (34%) of the 111 patients tested. The most frequently prescribed regimen was rifampicin + co-trimoxazole in 81 (52.9%) patients. Relapse occurred in a small proportion (4.6%, n=7), and the majority (95.4%, n=146) had a complete remission. Conclusions The main route of transmission was the ingestion of unpasteurized dairy products. Brucellosis had a wide range of clinical presentation, involving multiple organ systems. Neurobrucellosis was the most frequent complication. The SAT was the most useful and reliable test for the diagnosis of brucellosis. Most patients were successfully treated with rifampicin and co-trimoxazole for six weeks.

Variability of the Posterior Tibial Slope in Saudis: A Radiographic Study.

Aim The present study aimed to establish the normal range of the posterior tibial slope (PTS) angle in the Saudi adult population and to identify whether there was an association between the angle and gender or age. Materials and methods A total of 524 normal knee radiographs of 410 patients aged 18-85 years were included in the study. The PTS was measured using the anterior tibial cortex method. Data were matched with gender and age for statistical analysis. Results  The mean physiological PTS angle was 13.6 ± 3.4˚ (range: 3.8-23.9˚). Age and gender did not influence the PTS value (P >0.05). The two-way analysis of variance (ANOVA) test showed no interaction effect between age and gender on the PTS (P >0.05). Conclusions This study provided a reference range for the normal PTS among Saudis, which can assist in decision-making during different knee procedures. The PTS value did not significantly differ between male and female subjects, and there was no significant association between the PTS angle and age.

Functionally distinct high and low theta oscillations in the human hippocampus.

Based on rodent models, researchers have theorized that the hippocampus supports episodic memory and navigation via the theta oscillation, a ~4-10 Hz rhythm that coordinates brain-wide neural activity. However, recordings from humans have indicated that hippocampal theta oscillations are lower in frequency and less prevalent than in rodents, suggesting interspecies differences in theta's function. To characterize human hippocampal theta, we examine the properties of theta oscillations throughout the anterior-posterior length of the hippocampus as neurosurgical subjects performed a virtual spatial navigation task. During virtual movement, we observe hippocampal oscillations at multiple frequencies from 2 to 14 Hz. The posterior hippocampus prominently displays oscillations at ~8-Hz and the precise frequency of these oscillations correlates with the speed of movement, implicating these signals in spatial navigation. We also observe slower ~3 Hz oscillations, but these signals are more prevalent in the anterior hippocampus and their frequency does not vary with movement speed. Our results converge with recent findings to suggest an updated view of human hippocampal electrophysiology. Rather than one hippocampal theta oscillation with a single general role, high- and low-frequency theta oscillations, respectively, may reflect spatial and non-spatial cognitive processes.