Off-road vehicle crashes: dangers of alcohol and drug impairment.

BACKGROUND: Impaired driving is a public health issue, yet little is known concerning the prevalence of substance use in drivers involved in off-road vehicle crashes. The goal of the present study was to describe the demographics and prevalence of alcohol and drug use in drivers of off-road vehicle crashes. METHODS: In this observational substudy, we collected clinical and toxicological data on all moderately or severely injured off-road vehicle drivers who had blood samples obtained within 6 h of the crash. Clinical data were extracted from patients' medical charts and toxicology analyses were performed for blood alcohol, cannabinoids, recreational drugs, and impairing medications. RESULTS: Thirty-three injured drivers met the inclusion criteria. The mean age was 37.6 ± 13.4 years and 79% were male. Blood alcohol was detected in 58% of drivers and 42% of these were above the legal limit. Tetrahydrocannabinol was positive in 12% of drivers, and 18% were positive for recreational drugs. Opiates were detected in 21% of drivers. Overall, 85% were positive for at least one substance and 39% tested positive for multiple substances. CONCLUSION: This study presents the first evidence of alcohol and drug use in off-road vehicle drivers after cannabis legalization in Canada. Our results show that over half of drivers in off-road vehicle crashes test positive for alcohol and 30% tested positive for THC, cocaine, or amphetamines. Opiates are also commonly detected in off-road vehicle drivers. Emergency department (ED) visits resulting from drug driving of off-road vehicles serve as an opportunity for screening, initiating treatment, and connecting patients to interventions for substance use disorders.

ABSTRAIT: CONTEXTE: La conduite avec facultés affaiblies est un problème de santé publique, mais on sait peu de choses sur la prévalence de la toxicomanie chez les conducteurs impliqués dans des accidents de la route. L'objectif de la présente étude était de décrire la démographie et la prévalence de la consommation d'alcool et de drogues chez les conducteurs de véhicules hors route. MéTHODES: Dans le cadre de cette sous-étude observationnelle, nous avons recueilli des données cliniques et toxicologiques sur tous les conducteurs de véhicules hors route ayant subi des blessures modérées ou graves qui avaient reçu des échantillons de sang dans les 6 heures suivant l'accident. Les données cliniques ont été extraites des dossiers médicaux des patients et des analyses toxicologiques ont été effectuées pour l'alcool dans le sang, les cannabinoïdes, les drogues récréatives et les médicaments pour les facultés affaiblies. RéSULTATS: Trente-trois conducteurs blessés répondaient aux critères d'inclusion. L'âge moyen était de 37,6 13,4 ans et 79 % étaient des hommes. L'alcool dans le sang a été détecté chez 58 % des conducteurs et 42 % d'entre eux dépassaient la limite légale. Le tétrahydrocannabinol était positif chez 12 % des conducteurs et 18 % étaient positifs aux drogues récréatives. Des opiacés ont été détectés chez 21 % des conducteurs. Dans l'ensemble, 85 % étaient positifs pour au moins une substance et 39 % étaient positifs pour plusieurs substances. CONCLUSION: Cette étude présente les premières preuves de la consommation d'alcool et de drogues chez les conducteurs de véhicules hors route après la légalisation du cannabis au Canada. Nos résultats montrent que plus de la moitié des conducteurs de véhicules hors route ont un résultat positif au test de dépistage de l'alcool et 30 % ont un résultat positif au test de dépistage du THC, de la cocaïne ou des amphétamines. Les opiacés sont également couramment détectés chez les conducteurs de véhicules hors route. Les visites aux services d'urgence (SU) découlant de la conduite de véhicules hors route avec facultés affaiblies par la drogue constituent une occasion de dépistage, d'amorcer un traitement et de mettre les patients en contact avec des interventions pour les troubles liés à la consommation de substances.

Blood-Brain Barrier Dysfunction and Exposure to Head Impacts in University Football Players.

OBJECTIVE: To investigate the link between dysfunction of the blood-brain barrier (BBB) and exposure to head impacts in concussed football athletes. DESIGN: This was a prospective, observational pilot study. SETTING: Canadian university football. PARTICIPANTS: The study population consisted of 60 university football players, aged 18 to 25. Athletes who sustained a clinically diagnosed concussion over the course of a single football season were invited to undergo an assessment of BBB leakage. INDEPENDENT VARIABLES: Head impacts detected using impact-sensing helmets were the measured variables. MAIN OUTCOME MEASURES: Clinical diagnosis of concussion and BBB leakage assessed using dynamic contrast-enhanced MRI (DCE-MRI) within 1 week of concussion were the outcome measures. RESULTS: Eight athletes were diagnosed with a concussion throughout the season. These athletes sustained a significantly higher number of head impacts than nonconcussed athletes. Athletes playing in the defensive back position were significantly more likely to sustain a concussion than remain concussion free. Five of the concussed athletes underwent an assessment of BBB leakage. Logistic regression analysis indicated that region-specific BBB leakage in these 5 athletes was best predicted by impacts sustained in all games and practices leading up to the concussion-as opposed to the last preconcussion impact or the impacts sustained during the game when concussion occurred. CONCLUSIONS: These preliminary findings raise the potential for the hypothesis that repeated exposure to head impacts may contribute to the development of BBB pathology. Further research is needed to validate this hypothesis and to test whether BBB pathology plays a role in the sequela of repeated head trauma.

Spatial Hotspots and Sociodemographic Profiles Associated With Traumatic Brain Injury in Nova Scotia.

Traumatic brain injury (TBI) is a leading cause of death and disability, primarily caused by falls and motor vehicle collisions (MVCs). Although many TBIs are preventable, there is a notable lack of studies exploring the association of geographically defined TBI hotspots with social deprivation. Geographic information systems (GIS) can be used to identify at-risk neighborhoods (hotspots) for targeted interventions. This study aims to determine the spatial distribution of TBI by major causes and to explore the sociodemographic and economic characteristics of TBI hotspots and cold spots in Nova Scotia. Patient data for TBIs from 2003 to 2019 were obtained from the Nova Scotia Trauma Registry. Residential postal codes were geocoded and assigned to dissemination areas (DA). Area-based risk factors and deprivation status (residential instability [RI], economic dependency [ED], ethnocultural composition [EC], and situational vulnerability [SV]) from the national census data were linked to DAs. Spatial autocorrelation was assessed using Moran's I, and hotspot analysis was performed using Getis-Ord Gi* statistic. Differences in risk factors between hot and cold spots were evaluated using the Mann-Whitney U test for numerical variables and the χ2 test or Fisher's exact test for categorical variables. A total of 5394 TBI patients were eligible for inclusion in the study. The distribution of hotspots for falls exhibited no significant difference between urban and rural areas (p = 0.71). Conversely, hotspots related to violence were predominantly urban (p = 0.001), whereas hotspots for MVCs were mostly rural (p < 0.001). Distinct dimensions of deprivation were associated with falls, MVCs, and violent hotspots. Fall hotspots were significantly associated with areas characterized by higher RI (p < 0.001) and greater ethnocultural diversity (p < 0.001). Conversely, the same domains exhibited an inverse relationship with MVC hotspots; areas with low RI and ethnic homogeneity displayed a higher proportion of MVC hotspots. ED and SV exhibited a strong gradient with MVC hotspots; the most deprived quintiles displayed the highest proportion of MVC hotspots compared with cold spots (ED; p = 0.002, SV; p < 0.001). Areas with the highest levels of ethnocultural diversity were found to have a significantly higher proportion of violence-related hotspots than cold spots (p = 0.005). This study offers two significant contributions to spatial epidemiology. First, it demonstrates the distribution of TBI hotspots by major injury causes using the smallest available geographical unit. Second, we disentangle the various pathways through which deprivation impacts the risk of main mechanisms of TBI. These findings provide valuable insights for public health officials to design targeted injury prevention strategies in high-risk areas.

Memantine inhibits cortical spreading depolarization and improves neurovascular function following repetitive traumatic brain injury.

Cortical spreading depolarization (CSD) is a promising target for neuroprotective therapy in traumatic brain injury (TBI). We explored the effect of NMDA receptor antagonism on electrically triggered CSDs in healthy and brain-injured animals. Rats received either one moderate or four daily repetitive mild closed head impacts (rmTBI). Ninety-three animals underwent craniectomy with electrocorticographic (ECoG) and local blood flow monitoring. In brain-injured animals, ketamine or memantine inhibited CSDs in 44 to 88% and 50 to 67% of cases, respectively. Near-DC/AC-ECoG amplitude was reduced by 44 to 75% and 52 to 67%, and duration by 39 to 87% and 61 to 78%, respectively. Daily memantine significantly reduced spreading depression and oligemia following CSD. Animals (N = 31) were randomized to either memantine (10 mg/kg) or saline with daily neurobehavioral testing. Memantine-treated animals had higher neurological scores. We demonstrate that memantine improved neurovascular function following CSD in sham and brain-injured animals. Memantine also prevented neurological decline in a blinded, preclinical randomized rmTBI trial.

Joint pain, physical function, and balance self-confidence in acromegaly versus nonfunctioning pituitary adenoma patients.

CONTEXT: Patients with acromegaly (PWA) experience balance issues, despite achieving biochemical remission, that may significantly impair their quality of life. OBJECTIVE: We sought to assess the prevalence of falls and balance self-confidence in PWA in comparison with a control group. Furthermore, we investigated the effect of joint pain and function as predictors for their balance self-confidence. DESIGN: Cross-sectional, case-controlled. SETTING: Tertiary care centers. PARTICIPANTS: In this case-control study, we surveyed PWA (n = 94) and nonfunctioning pituitary adenoma (PNA; n = 82) with similar age, sex, and body mass index from two Canadian centers. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Data were obtained on number of falls during the past 12 months, self-confidence to maintain balance, joint pain, joint surgery, pain medication usage, and upper and lower extremity musculoskeletal disability. RESULTS: While both PWA and PNA had a similarly high risk of falls, PWA had lower self-confidence to maintain balance (P < .01). Patients with acromegaly had higher joint pain scores and more functional impairment in upper extremity, hip, knee, and ankle joints (all P < .01). In both groups, age, sex, and ankle functional score were predictors of balance self-confidence. For PWA, hip functional score was also a predictor of balance self-confidence in contrast to knee and back pain scores being predictors for the PNA group. CONCLUSIONS: We confirmed an increased prevalence of falls in both groups with diminished balance confidence in PWA. This reduced balance self-confidence seems to be related to their increased hip functional impairment in comparison with PNA.

Association between traumatic brain injury and mental health care utilization: evidence from the Canadian Community Health Survey.

BACKGROUND: Mental health disorders are a common sequelae of traumatic brain injury (TBI) and are associated with worse health outcomes including increased mental health care utilization. The objective of this study was to determine the association between TBI and use of mental health services in a population-based sample. METHODS: Using data from a national Canadian survey, this study evaluated the association between TBI and mental health care utilization, while adjusting for confounding variables. A log-Poisson regression model was used to estimate unadjusted and adjusted prevalence ratios (PR) and 95% confidence intervals (CI). RESULTS: The study sample included 158,287 TBI patients and 25,339,913 non-injured individuals. Compared with those were not injured, TBI patients reported higher proportions of chronic mental health conditions (27% vs. 12%, p < 0.001) and heavy drinking (33% vs. 24%, p = 0.005). The adjusted prevalence of mental health care utilization was 60% higher in patients with TBI than those who were not injured (PR = 1.60, 95%; CI 1.05-2.43). CONCLUSIONS: This study suggests that chronic mental health conditions and heavy drinking are more common in individuals with TBI. The prevalence of mental health care utilization is 60% higher in TBI patients compared with those who are not injured after adjusting for sociodemographic factors, mental health conditions, and heavy drinking. Future longitudinal research is required to examine the temporality and direction of the association between TBI and the use of mental health services.

Intraosseous Cavernous Hemangioma of the Middle Turbinate: A Case Report.

BACKGROUND: We report a case of an intraosseous cavernous hemangioma originating from the middle turbinate that expanded into the anterior skull base, without traversing the cribriform plate. METHODS: The mass was found incidentally after a computed tomography head was ordered for unrelated reasons. On questioning, the patient denied any nasal symptoms. Magnetic resonance imaging showed an enhancing mass and the radiological imaging supported a broad differential. RESULTS: The lesion was removed by endoscopic image-guided surgery, and the pathology was that of a benign intraosseous cavernous hemangioma. There was no residual hemangioma on postoperative imaging and the nasal mucosa healed well. This is the first report of an intraosseous cavernous hemangioma of the middle turbinate showing superior expansion to the anterior skull base. CONCLUSION: This case demonstrates the extent to which cavernous hemangiomas may expand into surrounding tissues. While these lesions are uncommon, they can be considered as part of a broad differential diagnosis of sinonasal tumors.

Concussion susceptibility is mediated by spreading depolarization-induced neurovascular dysfunction.

The mechanisms underlying the complications of mild traumatic brain injury, including post-concussion syndrome, post-impact catastrophic death, and delayed neurodegeneration remain poorly understood. This limited pathophysiological understanding has hindered the development of diagnostic and prognostic biomarkers and has prevented the advancement of treatments for the sequelae of mild traumatic brain injury. We aimed to characterize the early electrophysiological and neurovascular alterations following repetitive mild traumatic brain injury and sought to identify new targets for the diagnosis and treatment of individuals at risk of severe post-impact complications. We combined behavioural, electrophysiological, molecular, and neuroimaging techniques in a rodent model of repetitive mild traumatic brain injury. In humans, we used dynamic contrast-enhanced MRI to quantify blood-brain barrier dysfunction after exposure to sport-related concussive mild traumatic brain injury. Rats could clearly be classified based on their susceptibility to neurological complications, including life-threatening outcomes, following repetitive injury. Susceptible animals showed greater neurological complications and had higher levels of blood-brain barrier dysfunction, transforming growth factor ß (TGFß) signalling, and neuroinflammation compared to resilient animals. Cortical spreading depolarizations were the most common electrophysiological events immediately following mild traumatic brain injury and were associated with longer recovery from impact. Triggering cortical spreading depolarizations in mild traumatic brain injured rats (but not in controls) induced blood-brain barrier dysfunction. Treatment with a selective TGFß receptor inhibitor prevented blood-brain barrier opening and reduced injury complications. Consistent with the rodent model, blood-brain barrier dysfunction was found in a subset of human athletes following concussive mild traumatic brain injury. We provide evidence that cortical spreading depolarization, blood-brain barrier dysfunction, and pro-inflammatory TGFß signalling are associated with severe, potentially life-threatening outcomes following repetitive mild traumatic brain injury. Diagnostic-coupled targeting of TGFß signalling may be a novel strategy in treating mild traumatic brain injury.

Staged reflexive artificial intelligence driven testing algorithms for early diagnosis of pituitary disorders.

BACKGROUND: Sellar masses (SM) frequently present with insidious hormonal dysfunction. We previously showed that, by utilizing a combined reflex/reflecting approach involving a laboratory clinician (LC) on common endocrine test results requested by non-specialists, and subsequently adding further warranted tests, previously undiagnosed pituitary disorders can be identified. However, manually employing these strategies by an LC is not feasible for wider screening of pituitary disorders. OBJECTIVE: The aim of this study was to compare the accuracy and financial impact of an Artificial Intelligence (AI) based, fully computerized reflex protocol with manual reflex/reflective intervention protocol led by an LC. METHODS: We developed a proof-of-concept AI-based framework to fully computerize multi-stage reflex testing protocols for pituitary dysfunction using automated reasoning methods. We compared the efficacy of this AI-based protocol with a reflex/reflective protocol based on manually curated retrospective data in identifying pituitary dysfunction based on 12 months of laboratory testing. RESULTS: The AI-based reflex protocol, as compared with the manual protocol, would have identified laboratory tests for add-on that either directly matched or included all manual add-on tests in 92% of cases, and recommended a similar specialist referral in 90% of the cases. The AI-based protocol would have issued 2.8 times the total number of manual add-on laboratory tests at an 85% lower operation cost than the manual protocol when considering marginal test costs, technical staff and specialist salary. CONCLUSION/DISCUSSION: Our AI-based reflex protocol can successfully identify patients with pituitary dysfunction, with lower estimated laboratory cost. Future research will focus on enhancing the protocol's accuracy and incorporating the AI-based reflex protocol into institutional laboratory and hospital information systems for the detection of undiagnosed pituitary disorders.

Long-Term Trends in the Epidemiology of Major Traumatic Brain Injury.

Traumatic brain injury (TBI) is a leading cause of death and disability among adults. Falls and motor vehicle collisions (MVCs) are the most common causes of TBI hospitalizations in Canada. The purpose of this study was to determine whether, at the provincial level, there have been significant changes in the injury rate and causes of major TBI. This was a retrospective cohort study of all patients in Nova Scotia who presented with major TBI (Abbreviated Injury Scale Head score ≥ 3) between 2002 and 2018. Prospectively entered data were collected from the Nova Scotia Trauma Registry. Annual injury rates were calculated based on 100,000 population (all ages) using population estimates from Statistics Canada. Linear regression was performed to analyze annual trends of major TBI within the province. There were 5590 major TBI patients in Nova Scotia during the 16-year study period. The overall annual rate of major TBI was 37 per 100,000 population. There was a 39% increase in the rate of major TBI over the study period (r = - 0.72, R2 = 0.51, p < 0.002). Patients had a mean age of 51 ± 25 years; 72% were male. The proportion of TBIs in males decreased significantly from 76% in 2002 to 69% in 2017 (p < 0.001). Mechanisms of injury were predominantly falls (45%) and MVCs (29%); the proportion of violent injuries was 11.5%. The rate of fall-related TBIs more than doubled between 2002 and 2017, increasing from 9.1 to 20.5 injuries per 100,000 (p < 0.001). Our findings demonstrate an increasing incidence of major TBI over a 16-year period with a greater than two-fold increase in the rate of fall-related TBI. These results are important for targeting TBI prevention efforts in reducing falls, especially in older adults.

Preclinical Evaluation of the Stealth Autoguide Robotic Guidance Device for Stereotactic Cranial Surgery: A Human Cadaveric Study.

INTRODUCTION: Stereotactic procedures are routinely performed for brain biopsies, deep brain stimulation, and placement of stereoelectroencephalography (SEEG) electrodes for epilepsy. The recently developed Stealth Autoguide (Medtronic, Minneapolis, MN, USA) device does not require patients to don a stereotactic frame. In this preclinical study, we sought to quantitatively compare the Stealth Autoguide robotic system to 2 devices commonly used in clinical practice: the Navigus biopsy system (Medtronic) and the Leksell stereotactic frame (Elekta Ltd., Stockholm, Sweden). METHODS: In the first experimental setup, we compared target accuracy of the Stealth Autoguide to the Navigus system by using phantom heads filled with gelatin to simulate the brain tissue. In the second experimental setup, we inserted SEEG electrodes to targets within cadaveric heads in a simulated operating room environment. RESULTS: Using a homogeneous gelatin-filled phantom 3D reconstruction of a human head, we found that using the Stealth Autoguide system, while maintaining accuracy, was faster to use than the Navigus system. In our simulated operating room environment using nonliving human cadaveric heads, we found the accuracy of the Stealth Autoguide robotic device to be comparable to that of the Leksell frame. DISCUSSION/CONCLUSION: These results compare the use of the Stealth Autoguide robotic guidance system with commonly used stereotactic devices, and this is the first study to compare its use and accuracy with the Leksell frame. These findings provide mounting evidence that Stealth Autoguide will have potential clinical uses in various stereotactic neurosurgical procedures.

Validation of 3D fluoroscopy for image-guidance registration in depth electrode implantation for medically refractory epilepsy.

BACKGROUND: Frame registration is a critical step to ensure accurate electrode placement in stereotactic procedures such as stereoelectroencephalography (SEEG) and is routinely done by merging a computed tomography (CT) scan with the preoperative magnetic resonance (MR) examination. Three-dimensional fluoroscopy (XT) has emerged as a method for intraoperative electrode verification following electrode implantation and more recently has been proposed as a registration method with several advantages. METHODS: We compared the accuracy of SEEG electrode placement by frame registration with CT and XT imaging by analyzing the Euclidean distance between planned and post-implantation trajectories of the SEEG electrodes to calculate the error in both the entry (EP) and target (TP) points. Other variables included radiation dose, efficiency, and complications. RESULTS: Twenty-seven patients (13 CT and 14 XT) underwent placement of SEEG electrodes (319 in total). The mean EP and TP errors for the CT group were 2.3 mm and 3.3 mm, respectively, and 1.9 mm and 2.9 mm for the XT group, with no statistical difference (p = 0.75 and p = 0.246). The time to first electrode placement was similar (XT, 82 ± 10 min; CT, 84 ± 22 min; p = 0.858) and the average radiation exposure with XT (234 ± 55 mGy*cm) was significantly lower than CT (1245 ± 123 mGy*cm) (p < 0.0001). Four complications were documented with equal incidence in both groups. CONCLUSIONS: The use of XT as a method for registration resulted in similar implantation accuracy compared with CT. Advantages of XT are the substantial reduction in radiation dose and the elimination of the need to transfer the patient out of the room which may have an impact on patient safety and OR efficiency.

Knowledge transfer and retention of simulation-based learning for neurosurgical instruments: a randomised trial of perioperative nurses.

Introduction: Previous studies have shown that simulation is an acceptable method of training in nursing education. The objectives of this study were to determine the effectiveness of tablet-based simulation in learning neurosurgical instruments and to assess whether skills learnt in the simulation environment are transferred to a real clinical task and retained over time. Methods: A randomised controlled trial was conducted. Perioperative nurses completed three consecutive sessions of a simulation. Group A performed simulation tasks prior to identifying real instruments, whereas Group B (control group) was asked to identify real instruments prior to the simulation tasks. Both groups were reassessed for knowledge recall after 1 week. Results: Ninety-three nurses completed the study. Participants in Group A, who had received tablet-based simulation, were 23% quicker in identifying real instruments and did so with better accuracy (93.2% vs 80.6%, p<0.0001) than Group B. Furthermore, the simulation-based learning was retained at 7 days with 97.8% correct instrument recognition in Group A and 96.2% in Group B while maintaining both speed and accuracy. Conclusion: This is the first study to assess the effectiveness of tablet-based simulation training for instrument recognition by perioperative nurses. Our results demonstrate that instrument knowledge acquired through tablet-based simulation training results in improved identification and retained recognition of real instruments.

In-Hospital Endocrinology Consultation After Transsphenoidal Surgery: Is It Always Necessary?

BACKGROUND: Patients with sellar masses undergoing transsphenoidal surgery (TSS) frequently develop endocrine dysfunction; therefore, in-hospital endocrinology consultation (IHEC) is recommended. However, we wondered whether routine endocrinology assessment of all TSS patients is always necessary. METHODS: We developed an IHEC Physician's Guide to identify patients who would require peri-operative IHEC. An analysis of all patients undergoing TSS for a sellar mass over a 4-year period was conducted to assess the predictive value of the IHEC Physician's Guide in identifying patients who required IHEC. RESULTS: A total of 116 patients underwent TSS; 24 required IHEC. As expected, the risk of endocrine complications requiring peri-operative endocrine management was significantly higher in the IHEC group versus no-IHEC group (96% vs. 1%; p < 0.001). The negative predictive value of the IHEC Physician's Guide in identifying patients who did not require IHEC was 0.99 (95% CI 0.9409-0.9997); Fisher's exact test, p < 0.001), meaning that the IHEC Physician's Guide successfully identified all but one patient who truly required IHEC. CONCLUSION: Results from our study show that most patients do not need IHEC after TSS and that those patients requiring IHEC can be reliably predicted at surgery by using a simple IHEC Physician's Guide.

Polysialylated - neural cell adhesion molecule (PSA-NCAM) promotes recovery of vision after the critical period.

Vision loss has long since been considered irreversible after a critical period; however, there is potential to restore limited vision, even in adulthood. This phenomenon is particularly pronounced following complete loss of vision in the dominant eye. Adult neural cell adhesion molecule (NCAM) knockout mice have an age-related impairment of visual acuity. The underlying cause of early deterioration in visual function remains unknown. Polysialylated (PSA) NCAM is involved in different forms of neural plasticity in the adult brain, raising the possibility that NCAM plays a role in the plasticity of the visual cortex, and therefore, in visual ability. Here, we examined whether PSA-NCAM is required for visual cortical plasticity in adult C57Bl/6J mice following deafferentation and long-term monocular deprivation. Our results show that elevated PSA in the contralateral visual cortex of the reopened eye is accompanied by changes in other markers of neural plasticity: increased brain-derived neurotrophic factor (BDNF) levels and degradation of perineuronal nets (PNNs). The removal of PSA-NCAM in the visual cortex of these mice reduced BDNF expression, decreased PNN degradation, and resulted in impaired recovery of visual acuity after optic nerve transection and chronic monocular deprivation. Collectively, our results demonstrate that PSA-NCAM is necessary for the reactivation of visual cortical plasticity and recovery of visual function in adult mice. It also offers a potential molecular target for the therapeutic treatment of cortically based visual impairments.

Secondary pituitary hormonal dysfunction patterns: tumor size and subtype matter.

PURPOSE: Patients with sellar masses (SM) frequently have secondary hormonal deficiency (SHD) at initial presentation. While larger SM are more likely to present with SHD, it is unclear whether SHD at presentation is influenced by the type of SM. METHODS: We conducted a retrospective analysis of patients with SM prospectively enrolled in our comprehensive provincial neuropituitary registry between November 2005 and December 2018. SM were subdivided based on size: < 1 cm, 1-1.9 cm, 2-2.9 cm, and > 3 cm. RESULTS: A total of 914 patients met the inclusion criteria, including: 346 nonfunctioning adenomas (NFA), 261 prolactinomas (PRLoma), 51 growth hormone adenomas, 36 adrenocorticotropic adenomas, 93 Rathke's cleft cysts, 70 craniopharyngiomas and 57 meningiomas. The overall rate of SHD at presentation was highest in PRLoma (62.8%) and craniopharyngiomas (64.3%) and lowest in meningiomas (14%). While larger SM were significantly more likely to have SHD, the rate of SHD within each group was significantly different despite similar size (p < 0.001). Of the two largest groups of SM (NFA and PRLoma), NFA had significantly higher odds ratio (3.34, CI 1.89-5.89) of having multiple SHDs when compare with PRLoma, even when corrected for age, gender and size of tumor (p < 0.001). CONCLUSION: Our study shows that the rate and distribution of SHD in SM vary dependent upon the size of the tumor and specific pathology; in particular, NFA are more likely to present with multiple SHDs. Our data will help clinicians in determining adequate hormonal testing strategy for different SM.

Securing the position of the nasoseptal flap in endoscopic transsphenoidal surgery: No need for a Foley catheter (technical report).

BACKGROUND: The pedicled nasoseptal mucoperiosteal flap is currently widely used for the reconstruction of a skull base defect following transsphenoidal surgery. The flap is generally secured in position by a Foley catheter balloon. We describe an alternative technique using cylinders of Gelfoam™ (Pfizer Incorporated) to buttress the flap in place, obviating the need for a balloon catheter. MATERIAL AND METHODS: A review of our database identified patients who underwent endoscopic transsphenoidal surgery for a pituitary macroadenoma with nasoseptal flap, secured with small rolls of Gelfoam™ (Pfizer Incorporated) rather than a nasal Foley catheter. Minimum follow-up clinical and MRI assessments: 3 months. RESULTS: 73 patients (mean follow-up: 22 months) met the inclusion criteria: 56 non-functioning and 17 functioning pituitary adenomas. 36 patients had an intraoperative CSF leak: 30 high flow and 6 low flow leaks. The surgical repair in 35 patients included fat +/- fascia graft. One patient had a post-operative CSF leak repaired by subsequent surgery without the use of a Foley catheter. CONCLUSION: Securing the nasoseptal flap using rolls of Gelfoam™ (Pfizer Incorporated) as described can be achieved without the use of a nasal Foley catheter.