Background: Spinal dermoid cysts are uncommon, benign tumours of ectodermal origin, often associated with spinal dysraphism. Malignant transformation of spinal dermoid cysts is an exceptionally rare entity, with transformation into carcinosarcoma not previously reported. Methods: Case report and literature review Results: A 41-year-old male presented with a recurrent lumbar intradural mass, 28 years after resection of a dermal sinus tract and associated dermoid cyst. Intraoperative appearance and subsequent pathology were again consistent with a dermoid cyst. The patient re-presented 2 weeks after surgery with diplopia and headache due to hydrocephalus, thought to be due to chemical meningitis. Following ventriculoperitoneal shunt implantation, the patient rapidly deteriorated with progressive neurologic deficits and widespread leptomeningeal enhancement. A repeat spinal leptomeningeal biopsy was pursued, which revealed malignant transformation of the dermoid cyst into invasive carcinosarcoma. Without curative treatment options, the patient was palliated and died 85 days after admission. Conclusions: Malignant transformation of spinal dermoid cysts should be considered in the differential diagnosis of patients with dermoid cysts and progressive leptomeningeal enhancement. False negatives can occur with initial tumour pathology and repeat sampling may be warranted for diagnostic clarity. To the authors knowledge, this is the first report of a spinal dermoid cyst with malignant transformation into carcinosarcoma.

Background: Surgical delays are in common in Canada. Wait times in elective spine surgery and their impact on outcomes remain uncharacterized. Methods: This was a single-center analysis of elective spine surgery data between 2009-2020. Wait times between referral and consultation (T1), consultation and surgical booking (Ti), and booking and surgery (T2) were assessed. Results: 2041 patients were included. Longitudinal analyses were adjusted for age, sex, diagnosis, surgical volume, while outcomes analyses were age and sex-adjusted. Total T1+Ti+T2 increased 8.1% annually (p<0.001). T1 decreased 4.3% annually (p=0.032). It was not associated with adverse events (AEs) or disposition. Every 100 days of T1 was associated with 1.0% longer hospitalization (p=0.001). Ti increased 21.0% annually (p<0.001). Every 100 days of Ti was associated with 2.9% increased odds of an adverse event (p=0.002), 1.8% longer hospitalization (p<0.001), and 15.9% increased likelihood of discharge home (p<0.001). T2 increased 7.0% annually (p<0.001) and was not associated with AEs. Every 100 days of T2 was associated with 11.6% longer hospitalization (p<0.001) and 76.5% increased likelihood of discharge home (p<0.001). Conclusions: Total wait times for elective spine surgery have increased between 2009-2020. Notably, Ti increased ninefold and was associated with AEs. This study highlights areas of delay and targets for healthcare optimization.

Background: Obesity is increasingly implicated in the development of multiple sclerosis (MS), but its effect on disease disability is less well-established. This study aims to investigate the association between obesity and MS severity utilizing Mendelian Randomization (MR). Methods: Employing a two-sample MR setting, we examined the effects of various obesity measures and adiposity distribution metrics on MS severity. Genetic proxies for body mass index (BMI) were selected from a study of 806,834 participants, with MS severity determined from a genetic study of age-related MS severity scores in 12,584 individuals with MS. Results: The main analysis reveals an association between elevated BMI and increased MS severity (P = 0.03). This is supported by a significant effect of whole body fat (P = 0.04), aligning with the hypothesis that obesity exacerbates MS disability. Sensitivity analyses suggest minimal heterogeneity and bias, indicating a potential causal effect. Conclusions: Our findings suggest that obesity adversely influences long-term disability outcomes in MS. The convergence of this genetic evidence with some of the prior observational studies strengthens the argument for a causal relationship between obesity and MS severity. These insights highlight obesity as a potentially modifiable risk factor in managing MS, underscoring the importance of weight management in MS treatment strategies.

Background: Pituicytoma is a rare, low grade tumour typically of the sellar region. Here we present a pituicytoma located in the third ventricle. Methods: 56 year old female presented with amenorrhea, hyperprolactinemia, and progressive bitemporal hemianopsia. MRI revealed a suprasellar mass located within the third ventricle and appearing separate from the pituitary. A supraciliary and translamina terminalis surgical approach to tumour resection was completed without complication. Post-operatively, she developed transient DI which resolved by post-opertaive day 3 and she was discharged hoem without any neurological deficits. Pathology revealed pituicytoma, WHO grade I. Results: Pituicytomas are rare tumours arising from neuroepithelial cells of the pituitary. The majority of cases are pure sellar or sellar with suprasellar extension, or at least have some connection to the pituitary. In many cases, imaging findings are synonymous to pituitary adenomas. We present a unique case in which the tumour was suprasellar but appeared separate from the pituitary. Surgical intervention is the most highly predictive factor of recurrence, as gross totoal reseciton can be curable. Conclusions: Here we present a unique location of pituictyoma. Due to the exceedingly rare nature of pituicytoma, unique presentations and management help to provide better understanding of the breadth of this disease presentation.

Background: Identifying functional biomarkers related to treatment success can aid in optimizing therapy and provide a better understanding of the neural mechanisms of treatment-resistant depression (TRD) and subcallosal cingulate deep brain stimulation (SCC-DBS). Methods: Magnetoencephalography data were obtained from 16 individuals with SCC-DBS for TRD and 25 healthy subjects. We identified region-specific oscillatory modulations that both (i) discriminate individuals with TRD (SCC-DBS OFF) from healthy controls and (ii) discriminate responders from non-responders (SCC-DBS ON). The effects of stimulation intensity and frequency were also explored. Results: Discriminative regions that differentiated responders from non-responders based on modulations of increased alpha (8-12 Hz) and decreased gamma (32-116 Hz) power included nodes of the default mode, central executive, and somatomotor networks, Broca’s area, and lingual gyrus. Furthermore, low stimulation frequency had stronger effects on oscillatory modulation. Conclusions: The identified functional biomarkers implicate modulations of TRD-related activity in brain regions involved in emotional control/processing, motor control, and interactions between speech, vision, and memory – all implicated in depression. These electrophysiological biomarkers have the potential to be used as functional proxies for therapy optimization. Additional stimulation parameter analyses revealed that oscillatory modulations are strengthened by increasing stimulation intensity or reducing frequency, which may benefit SCC-DBS non-responders.

This article analyzes and demonstrates the declining social selectivity of migration distance in Europe’s long nineteenth century and argues that this drove a radically new process of democratization of long-distance migration. It uses innovative spatial and quantitative analysis of nominal data on more than 5,000 international migrants who moved to the booming port city of Antwerp in present-day Belgium between 1850 and 1910. Examining the changes in migrants’ origins and trajectories on the one hand, and in their profiles in terms of gender and occupations on the other hand, it argues that the main evolutions observed represent an overall loosening of the ancien régime link between migration distance on the one hand and social selectivity on the other hand. By focusing on gender and social class as markers of social selectivity and by mapping the impressive expansion of the trajectories of Antwerp’s growing number of long-distance migrants, it lays bare the spatial, gender, and social dimensions that contributed to a general process of democratization of long-distance migration. As such, it sheds new light on the dynamics of Europe’s so-called “mobility transition” in the long nineteenth century.

Background: Interest in artificial intelligence (AI) and machine learning (ML) has been growing in neuroradiology, but there is limited knowledge on how this interest has manifested into research and the field’s trends, challenges, and future directions. Methods: The American Journal of Neuroradiology was queried for original research articles published since inception (Jan. 1, 1980) to Sept. 19, 2022 that contained any of the following key terms: “machine learning”, “artificial intelligence”, or “radiomics”. Articles were screened, categorized into Statistical Modelling (Type 1), AI/ML Development (Type 2), or End-user Application (Type 3) and then bibliometrically analyzed. Results: A total of 124 articles were identified with 85% being non-integration focused (Type 1 n = 41, Type 2 n = 65) and the remaining (n = 18) being Type 3. The total number of articles published grew two-fold in the last five years, with Type 2 articles mainly driving this growth. While most (66%) Type 2 articles were led by a radiologist with 55% possessing a postgraduate degree, a minority of Type 2 articles addressed bias (15%) and explainability (20%). Conclusions: The results of this study highlight areas for improvement but also strengths that stakeholders can consider when promoting the shift towards integrating practical AI/ML solutions in neuroradiology.

Background: Postural instability is a common symptom of progressive supranuclear palsy (PSP). Retropulsion is one form of postural instability. Spontaneous retropulsion involves loss of balance without external provocation. Others have reported on retropulsion in the clinical setting while testing for postural instability but rates of spontaneous retropulsion in the community have not been described. This study examines the prevalence of spontaneous retropulsion in PSP. Methods: A retrospective chart review examined 60 patients from the Saskatchewan Movement Disorders Program with clinical and pathology-confirmed diagnosis of PSP. We identified patients who endorsed spontaneous retropulsion. The data was analysed with univariate logistic regression. Results: The study included 43 males and 17 females. Spontaneous retropulsion was reported in 18 (30%) patients. Among the variables, only sex showed a statistical significance (p = 0.0184) with females more likely to report spontaneous retropulsion (OR = 4.25). Other variables (PSP onset age, onset age of balance impairment, gait impairment, and disease duration) were not statistically significant. Conclusions: Our data suggest that spontaneous retropulsion is common in PSP, with females being at a significantly higher risk than males. This is useful information when counselling patients on risk-avoidance behaviour to prevent falls.

We evaluated stress and burden in epilepsy patient caregivers in a pediatric neurology clinic. Caregivers of 102 children with epilepsy completed the Caregivers’ Assessment of Difficulty Index and a questionnaire regarding caregiver sociocultural characteristics. A multiple linear regression statistical analysis found that caregiver burden was significantly increased for those who had a second child with a chronic disease, sole caregivers and for those with children with drug-resistant epilepsy. Caregiver stress was significantly increased for caregivers with a native language other than English or French, caregivers who had a second child with a chronic disease and sole caregivers.

Background: Deep Brain Stimulation (DBS) has become increasingly prevalent in the management of paediatric movement disorders, with the globus pallidus interna (GPi) serving as the most utilized target. However, limitations exist, including variable responses in genetic versus acquired forms of movement disorder and structural damage in the GPi would preclude its use as a target. Given these limitations, there is a pressing need to explore alternative targets. We investigated the application of non-GPi targets in paediatrics through a systematic review. Methods: Individual data points were gathered from references identified through a systematic electronic search and analysed descriptively. We included paediatric patients (0-18 years) with movement disorders who underwent non-GPi-DBS. We excluded adults and other indications. Results: Preliminarily, 64 patients were identified from 40 references. Dystonia was the most common movement disorder type, followed by tremor and chorea. The subthalamic nucleus was the frequent DBS target for dystonia, yielding promising outcomes of improvement as measured on the Burke-Fahn-Marsden movement scale ranging from 43% to 95%. The ventral intermediate nucleus was the second most employed target, demonstrating favourable results. Conclusions: Non-pallidal DBS targets hold promise as potentially efficient and safe. However, to further validate their effectiveness and safety, larger multi-centre randomized studies are required.

Background: The integration of Artificial Intelligence (AI) in medical education is an area of growing importance. While AI models have been evaluated extensively in multiple-choice question formats, their proficiency in written exams remains to be explored. Methods: Four AI models—GPT-4 (OpenAI), Claude-2.1 (Anthropic), Gemini Pro (Google), and Perplexity 70B (Perplexity)—were tested using the Canadian Royal College Sample Neurosurgery Exam. The written exam covered diagnostic reasoning, knowledge of neurosurgical conditions, and understanding of radiographic imaging techniques. Results: GPT-4 and Perplexity 70B both achieved a score of 68.42%, followed by Claude-2.1 with 60.53%, and Gemini Pro with 57.89%. The models showed proficiency in answering questions that required factual knowledge, such as identifying pathogens in spinal epidural abscess. However, they struggled with more complex diagnostic reasoning tasks, particularly in explaining the pathophysiology behind a sudden rise in blood pressure during surgery and interpreting radiographic characteristics of intracranial abscesses on MRI. Conclusions: The findings indicate that while AI models like GPT-4 and Perplexity 70B are adept at handling factual neurosurgical questions, their performance in complex diagnostic reasoning in a written format is less consistent. This underscores the need for more advanced and specialized AI training, particularly in the nuances of medical diagnostics and decision-making.

Background: Virtual neurological assessments were increasingly used and an important viable option during the COVID-19 pandemic. However, the accuracy of such assessments is unknown. Methods: Clinical records were reviewed in a predominant multiple sclerosis outpatient clinic at an academic teaching hospital from March 23rd 2020 to March 23rd 2021 during the COVID-19 pandemic. Patients assessed during this period were analyzed with an initial virtual assessment compared to subsequent in person evaluations. Results: 1036 patients were included. 27.8% (n=288) of consultations were video and 72.2% (n=748) telephone. A total of 13.8% (n=143) of virtual consultations revealed clinical disparities, specifically 13.5% (n=39) video and 13.9% (n=104) telephone consultations. Of all the 1036 cases, 2.32% (n=24) patients stated they were stable but significant changes were seen on the exam, changing the clinical impression. 11.5% (n=119) stated they were deteriorating virtually but not confirmed when examined in person, with an alternative explanation found. Conclusions: Virtual assessments were accurate in over 85% of the outpatient neurological cases during the pandemic. However, it should be noted that the in person neurological exam led to a change in clinical opinion in 13.8% of assessments. 2.32% patients described clinical stability, but different clinical management plans resulted when significant exam findings were identified.

Background: The fragility index (FI) is the minimum number of patients whose status would have to change from a nonevent to an event to turn a statistically significant result to a non-significant result. We used this to measure the robustness of trials comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS). Methods: A search was conducted in MEDLINE, Embase, and PubMed on RCTs comparing CEA to CAS. The trials need to have statistically significant results and dichotomous primary endpoints to be included. Results: Our literature search identified 10 RCTs which included 9382 patients (4734 CEA, 4648 CAS). The primary end points of all included trials favoured CEA over CAS. The median FI was 9.5 (interquartile range 2.25 - 21.25). All of the studies that reported lost-to-follow-up (LTFU) had LTFU greater than its fragility index, which raises concern that the missing data could change the results of the trial from statistically significant to statistically insignificant. Conclusions: A small number of events (FI, median 9.5) were required to render the results of carotid artery stenosis RCTs comparing CEA to CAS statistically insignificant. All of the studies that reported LTFU had LTFU greater than its fragility index.

There are several factors that can cause the excessive accumulation of biofluid in human tissue, such as pregnancy, local traumas, allergic responses or the use of certain therapeutic medications. This study aims to further investigate the shear-dependent peristaltic flow of Phan–Thien–Tanner (PTT) fluid within a planar channel by incorporating the phenomenon of electro-osmosis. This research is driven by the potential biomedical applications of this knowledge. The non-Newtonian fluid features of the PTT fluid model are considered as physiological fluid in a symmetric planar channel. This study is significant, as it demonstrates that the chyme in the small intestine can be modelled as a PTT fluid. The governing equations for the flow of the ionic liquid, thermal radiation and heat transfer, along with the Poisson–Boltzmann equation within the electrical double layer, are discussed. The long-wavelength ($\delta \ll 1$) and low-Reynolds-number approximations ($Re \to 0$) are used to simplify the simultaneous equations. The solutions analyse the Debye electronic length parameter, Helmholtz–Smoluchowski velocity, Prandtl number and thermal radiation. Additionally, streamlines are used to examine the phenomenon of entrapment. Graphs are used to explain the influence of different parameters on the flow and temperature. The findings of the current model have practical implications in the design of microfluidic devices for different particle transport phenomena at the micro level. Additionally, the noteworthy results highlight the advantages of electro-osmosis in controlling both flow and heat transfer. Ultimately, our objective is to use these findings as a guide for the advancement of lab-on-a-chip systems.

Background: Cerebral venous thrombosis (CVT)most commonly affects younger women. Diagnosis may be delayed due to its distinct presentation and demographic profile compared to other stroke types. Methods: We examined delays to diagnosis of CVT in the SECRET randomized trial and TOP-SECRET parallel registry. Adults diagnosed with symptomatic CVT within <14 days were included. We examined time to diagnosis and number of health care encounters prior to diagnosis and associations with demographics, clinical and radiologic features and functional and patient-reported outcomes (PROMS) at days 180&365. Results: Of 103 participants, 68.9% were female; median age was 45 (IQR 31.0-61.0). Median time from symptom onset to diagnosis was 4 (1-8) days. Diagnosis on first presentation to medical attention was made in 60.2%. The difference in time to diagnosis for single versus multiple presentations was on the order of days (3[1-7] vs. 5[2-11.75], p=0.16). Women were likelier to have multiple presentations (OR 2.53; 95% CI1.00-6.39; p=0.05) and longer median times to diagnosis (5[2-8]days vs. 2[1-4.5] days; p=0.005). However, this was not associated with absolute or change in functional, or any patient reported, outcome measures (PROMs) at days 180&365. Conclusions: Diagnosis of CVT was commonly delayed; women were likelier to have multiple presentations. We found no association between delayed diagnosis and outcomes.

Background: Pituitary adenomas are treated with endoscopic surgery, while stereotactic radiosurgery addresses complex cases. Our study highlights AI’s role in accurate segmentation, improving treatment planning workflow efficiency Methods: In a retrospective study at Na Homolce Hospital (January 2010 to October 2022), SRS for pituitary adenomas was analyzed. Data were split 80:20 for training and validation. Using nnU-net, a medical image segmentation tool, a model predicted precise tumor, optic nerve, and pituitary gland segmentation. Accuracy was evaluated quantitatively with Dice similarity coefficient and qualitatively by human experts. The study explored the impact of tumor volume and hormonal activity status on segmentation accuracy. Results: The study comprised 582 and 146 patients in training and validation sets, respectively. The model achieved Dice similarity coefficients of 83.1% (tumor), 62.9% (normal gland), and 78.0% (optic nerve). Expert assessments deemed 41% directly applicable, 31.5% needing minor adjustments, and 27.4% unsuitable for clinical use. Larger tumor volume and non-functioning adenomas correlated with higher accuracy. Including T2 weighted scans improved DSC for optic nerve and normal gland. Conclusions: The study showcases deep learning’s potential in automating pituitary adenoma segmentation from MRI data, particularly excelling in large, hormonally inactive macroadenomas. Encourages collaborative use with clinicians for improved neurosurgical patient care.