Background: CIDP is a rare immune-mediated demyelinating neuropathy which has significant phenotypic variability. Despite extensive efforts, a unifying immunopathologicalmechanism remains elusive and this is likely due to etiological heterogeneity among the variant presentations. This is best exemplified by the identification of nodal/paranodal antibodies, such as neurofascin 155 (NF155) in a small subgroup of CIDP patients, who present with a distinct phenotype and embody a poor response to IVIG. Methods: We present the case of a 39-year-old male who presented with a 2-year history of progressive stocking-glove sensory loss and sensory ataxia. Electrodiagnostics confirmed an acquired demyelinating neuropathy, with serum anti-NF155 IgG4. His case was refractory to standard immunomodulatory therapy, including adequate trials of IVIG, steroids, azathioprine, and rituximab. He also had a non-therapeutic trial of PLEX, methotrexate, and tacrolimus. Results: After cessation of all immunomodulatory therapy for 2 years, he had spontaneous remission of his CIDP and near-complete resolution of electrodiagnostic/clinicalabnormalities. Conclusions: This case highlights a unique supra-refractory seropositive CIDP variant which underwent spontaneous remission with near-complete resolution. Delayed effect from rituximab was posited as a contributor, however, the patient had no clinical or electrophysiological improvement 20-months after initiation of anti-CD20 therapy. Current data suggests that CIDP respond to rituximab within 6-12 months.

Background: This study aimed to assess the clinical features, Electroencephalography (EEG) findings, and brain imaging results in psychiatric patients diagnosed with epilepsy at Razi Psychiatric Hospital. Methods: This retrospective descriptive-analytical study was carried out on patients with epilepsy and psychiatric disorders admitted to Razi Psychiatric Hospital over two years. A total of 94 patient files seizure and epilepsy comorbidity, recorded in the hospital’s health information system (HIS), were reviewed. Data collection involved a demographic checklist and an epilepsy scale; the latter, developed by DiIorio, Colleen, et al., encompassed personal characteristics, mental disorders, epilepsy, and seizures. The Kruskal-Wallis and MannWhitney non-parametric tests were utilized to compare the mean scores of variables, with SPSS software, version 21 facilitating the analysis Results: Out of 94 patients with seizure and epilepsy, 9.6% had focal seizure, 26.6% had generalized epilepsy, 36.1% had focal-generalized seizure, and 26.8% had unknown seizure. About 12% had a structural etiology, while the remaining 88% had an etiology that remained unidentified. Conclusions: The findings indicate that epilepsy, affecting individuals from adolescence through to old age, can lead to psychiatric disorders. For many patients, the etiology of their condition remains elusive, and EEG findings and brain imaging appear normal in the majority of cases

Background: Over 1.3 million people in North America participate in tackle football annually. Football players experience a disproportionately higher risk for repetitive non-concussive impacts (NCIs) compared to other high-contact sports athletes. Quantifying how this exposure influences a player’s cognitive function is imperative. While NCIs share the same mechanism as concussions, they do not elicit immediate symptoms. Methods: This study tracked impact exposure in 13 male Queen’s Varsity Football players using six-axis mouthguard accelerometers throughout the season. Electroencephalography (EEG) recordings were conducted at two time points (pre-season and post-season) to measure event-related potentials (ERPs), evaluating auditory sensation, basic attention, and cognitive processing. Results: Analysis of pre- and post-season EEGs revealed group differences in N100 and N400 wave amplitudes but found no correlation between impact exposure metrics (including varying magnitudes, frequencies, and linear and angular accelerations) and deficits in attention or cognitive processing. Conclusions: These findings suggest that a single season of football-related NCIs may not be sufficient to produce detectable changes in cognitive function as measured through ERPs, despite the variation in impact exposure. Further longitudinal studies spanning multiple seasons and additional neurophysiological measures may be necessary to fully understand the cumulative effects of NCIs on cognitive function in football players.

Background: Stroke is a leading cause of disability worldwide, resulting in long-term impairments requiring rehabilitation. Frailty, characterized by reduced physiological reserve and vulnerability to stressors, is associated with poor health outcomes. When assessed using the Clinical Frailty Scale (CFS), frailty has been linked to adverse outcomes; however, its role in stroke rehabilitation remains underexplored. This study investigates the impact of pre-stroke frailty on functional recovery during inpatient stroke rehabilitation. Methods: A retrospective cohort study was conducted on 206 stroke patients admitted between 2020-2022. Pre-stroke frailty was assessed using the CFS, and rehabilitation outcomes were measured using Functional Independence Measure (FIM) gain and efficiency. Differences across CFS categories, stroke location, age, and sex were statistically analyzed. Results: Among these patients, 42.7% were female, and 75.7% were aged 60 or above. There were no significant differences in FIM gain or efficiency across CFS categories (p > 0.05). Frailty was associated with lower admission (p = 0.041) and discharge (p = 0.032) FIM scores. Conclusions: Pre-stroke frailty, assessed retrospectively using the CFS, does not predict functional improvement or efficiency during inpatient rehabilitation. However, frailty was associated with poorer functional status at admission and discharge. All patients meeting the admission criteria benefited from rehabilitation, regardless of frailty level.

Background: Stroke therapies remain an area of ongoing research. Gene therapies offer a novel approach to repair tissue damage, particularly NeuroD1-mediated astrocyte-to-neuron conversion, which regenerates functional neurons after ischemic injury. Here, we applied NeuroD1 therapy in a non-human primates (NHPs) stroke model to evaluate its effects on corticospinal tract (CST) recovery and motor performance. Methods: Eight NHPs underwent middle cerebral artery occlusion (MCAO). Fourteen days later, six animals received intracranial NeuroD1 treatment (three high-dose, three low-dose), while two received a control solution. Neurological and functional performance were assessed daily. MRI scans were performed at baseline and at 7, 30, 90, 120, and 240 days post-MCAO, with the bilateral CST reconstructed at each time point. All procedures followed Canadian Council of Animal Care guidelines and were approved by Queen’s University’s Animal Use Subcommittee. Results: We found that NHPs receiving the control solution exhibited poorer motor recovery and minimal CST reconstruction. In contrast, those treated with a low dose of NeuroD1 demonstrated motor and functional recovery along with CST reconstruction. Notably, animals receiving the higher dose showed the most significant overall recovery including a greater CST integrity. Conclusions: NeuroD1 treatment promotes white matter tract restoration and facilitates motor recovery following stroke.

Background: Ischemic stroke increases the number of glial cells, such as astrocytes, and causes neuronal death, disrupting the neuron-to-glia balance, contributing to neurodegeneration. Treatment with NeuroD-adeno-associated virus (NeuroD1-AVV) may enhance neuronal transdifferentiation and improve motor function, but the optimal administration protocol for the drug has yet to be determined. Methods: Non-human primates (NHPs) underwent middle cerebral occlusion surgery. Fourteen days poststroke, subjects received NeuroD1-AVV according to two distinct protocols: Three high doses and three low doses. Neurological deficits and cognitive performance were measured using the NHP stroke scale and coloured glove shift of set task, respectively. Nine months post-stroke, NHPs were euthanized. Brains were harvested and stained for neuronal (NEUN and MAP2) and glial (GFAP, IBA1) markers using immunofluorescence techniques. Results: Our results indicate that both protocols effectively rebalance the neuron-to-glia cell ratio by decreasing GFAP+ cells in the P1 and P2 NHPS ipsilateral hemispheres. No cognitive performance differences were found across groups; however, P2 had better NHPSS outcomes from months 2 to 9. Conclusions: The findings support both injection protocols in restoring histological balance, with P2 being more effective for motor function rehabilitation. Investigations into neuronal functionality and development levels continue.

Background: Eccrine carcinoma is a rare skin tumor arising in eccrine sweat glands with a predilection for older adults. Over 30% of cases occur in the head and neck. Local and distal metastases are common. Prognosis is poor with regional recurrence in up to 19% of cases. Imaging is indicated in high-risk disease. Methods: We present a case report of eccrine carcinoma in the scalp with perineural metastasis to the left trigeminal nerve. Results: A seventy-nine-year-old male with a history of left temporal scalp pre-cancerous lesion treated with liquid nitrogen two years prior presented with left facial pain and paresthesia. The gadolinium-enhanced MRI head showed a tiny sub-centimetre spiculated subcutaneous lesion in the left temporal scalp and perineural enhancement along the left auricotemporal, V3 and trigeminal nerves. Subsequent excisional biopsy of the temporal lesion showed a poorly differentiated eccrine carcinoma without local perineural invasion. Conclusions: Undifferentiated facial pain is a frequent indication for head imaging, usually with low diagnostic utility. However, scrutiny for perineural enhancement is necessary to avoid missing a potentially deadly process. Eccrine carcinoma is a rare type of skin cancer. Small, painless, indolent primary lesions may be overlooked clinically. Radiologists can affect outcomes in these cases.

Background: Intracranial extension of temporomandibular joint (TMJ) lesions is uncommon and may lead to radiological misinterpretation. This review aimed to identify clinical and radiological features of these lesions and whether radiological misinterpretation contributed to delayed or incorrect intervention. Methods: A comprehensive search of MEDLINE, SCOPUS, and Embase identified 2,256 records. Studies with clinical and imaging details of TMJ lesions extending intracranially were included. Reviews and non-English studies were excluded. After screening, 113 studies involving 132 patients were included. Results: Patients had an average symptom duration of 32 months until diagnosis (47% female, mean age 50±15 years). The most common diagnoses were pigmented villonodular synovitis/tenosynovial giant cell tumor (46%) and synovial chondromatosis (24%). Neurological symptoms were reported in 48% of cases, most frequently hearing loss (35%). Diagnostic accuracy increased from 38% to 62% when both CT and MRI were used. Most lesions were non-enhancing on CT (85%) and MRI (74%), and demonstrated no edema (96%). In one case, a ganglion cyst was misdiagnosed as a cystic brain tumor, leading to neurosurgical resection. Conclusions: TMJ lesions extending intracranially have neurological symptoms in less than half of cases and demonstrate no enhancement or edema. Familiarity with these characteristics is essential to avoiding misdiagnoses and ensuring timely management.

Background: Large language models (LLMs) offer potential for clinical decision support but may not fully adhere to current guidelines. Retrieval-augmented generation (RAG) may address this gap by dynamically incorporating external knowledge. This study evaluated LLM adherence with and without RAG to Canadian neuroimaging guidelines. Methods: A novel RAG framework was developed that integrated Canadian Association of Radiologists (CAR) Diagnostic Imaging Referral Guidelines with GPT-4o and o1 models. Clinical scenarios were curated to represent various central nervous system conditions, such as acute stroke, subarachnoid hemorrhage, and multiple sclerosis. Models were prompted with the clinical scenarios, and responses were scored for adherence to the CAR imaging recommendations. Results: Overall, 300 clinical scenarios were used to prompt each model. Adherence rates were 83.8% for GPT-4o, 94.0% for GPT-4o+RAG, 85.5% for o1, and 93.2% for o1+RAG. A Kruskal-Wallis test (H(3)=44.1, p<0.001) identified significant differences among models. Post-hoc comparisons showed RAG-enabled LLMs significantly outperformed standalone models (p<0.001). No significant differences were observed between GPT-4o and o1 without RAG (p=0.531), or between GPT-4o+RAG and o1+RAG (p=0.532). Conclusions: RAG integration significantly improved LLM adherence to Canadian neuroimaging guidelines, even when baseline models demonstrated moderate performance. Future work should validate and explore broader applications of RAG-enabled tools to advance evidence-based care.

Background: Polymicrobial brain abscess (PBA) is a complex infection caused by two or more pathogens and a life-threatening condition with diagnostic and therapeutic challenges. Methods: We retrospectively identified PBAs in 31 patients (a median of 58 years; 24 male, and 7 female) then examined their clinical, radiological and pathological characteristics. These characteristics of PBAs were compared with those of monomicrobial BAs (MBAs) in the previously reported 113 patients. Results: PBAs and MBAs had a few similarities such as nonspecific clinical presentations and overall similar prognosis following surgical intervention with broad-spectrum antimicrobial therapy. However, PBAs were highly heterogeneous with more complexity on MRI/CT imaging and histopathology. While PBAs were typically rim-enhancing lesions at late-stages, 30/31 (97%) of PBAs showed the lobulation of enhancing rims/walls; on MRI, 14/26 (54%) of cases demonstrated marked difference in the thickness of enhancing rim, marked difference in the degree of DWI signal, and/or marked variation in intra-lesional MRI signal. PBA histopathology was characterized by alternating early-stage and late-stage features with a combinations of 2-4 pathogens. Conclusions: BPAs share some features with MBAs, but they are more heterogeneous with greater complexity on imaging and histopathology. Their diagnosis and disease staging require a clinico-radiologico-pathological approach.

Background: The brachial plexus provides motor and somatosensory innervation to the upper limb and upper chest. Evaluation of brachial plexus disease is based on history, physical examination etc but imaging plays an important role for lesion localization, characterization and its classification. Effective reporting of imaging findings requires that neuroradiologist should be familiar with the brachial plexus anatomy, relevant landmarks, the spectrum and categories of brachial plexopathies. All above objectives will be discussed in this oral presentation. Methods: Normal brachial plexus anatomy is assumed for five anatomic landmarks: neural foramen, interscalene triangle, lateral border of the first rib, medial border of the coracoid process, and lateral border of the pectoralis minor corresponding to level of roots, trunks, divisions, cords and terminal branches. Conventional radiography has role in evaluating bony injuries. CT has limited role. MR used for comprehensive evaluation of the brachial plexus. Causes of brachial plexopathy are divided into traumatic and nontraumatic with specific features of each. Results: Imaging of brachial plexus is important part of treatment planning and rehabilitation of brachial plexopathies. Confident reporting can be done by knowing basics and injury patterns. Conclusions: Neuroradiologist should have sound knowledge of brachial plexus imaging in order to better contribute to pateint care.

Background: This study evaluates the utility of CT angiography (CTA) and the Expanded Denver Criteria (EDC) in detecting blunt cerebrovascular injuries (BCVI) in blunt cervical trauma, assaults, and strangulation. Methods: A retrospective review of 748 patients undergoing CTA for blunt cervical trauma, assaults, and strangulation (2013–2023) was conducted. After exclusions, 344 CTA reports were analyzed. Inclusion criteria: patients ≥18 years with complete medical records who underwent CTA for trauma evaluation. Exclusions: penetrating injuries, preexisting cerebrovascular abnormalities, incomplete records, or CTA not performed. Results: BCVI was identified in 38/344 cases (11%), with 55% classified as Grade I (Biffl). Posterior circulation (71%) and internal carotid arteries (36.8%) were most affected. Eight BCVI cases (21%) did not meet EDC; MVCs accounted for seven. MVCs (68%) and falls (29%) were the leading causes, while no BCVIs were observed in assaults or strangulations. Conclusions: MVCs and high-impact falls pose the highest BCVI risk, warranting CTA beyond EDC indications. In contrast, CTA may be less necessary for assaults and strangulations. Further studies across trauma centers are needed to confirm these findings.

Background: Reversible cerebral vasoconstriction syndrome (RCVS) is defined clinically by headaches associated sometimes with seizures and neurological deficits, and radiologically with intermittent spasms in cerebral arteries that would resolve in 3 months. It can present with multiple bleeding patterns. Intraventricular hemorrhage (IVH) is a rare presentation for RCVS as there are 4 reported cases. Methods: This is a case report and review of literature. Results: A 36-year-old patient sought medical attention due to the acute onset of thunderclap headache. A computed tomography (CT), and CT angiogram (CTA) of his head and neck were done. It showed large IVH associated with hydrocephalus and no underlying vascular abnormalities. An external ventricular drain was placed and he was on nimodipine. A CTA was done on day 17 because he had acute global aphasia, right hemibody weakness, and right homonomous hemianopia, which showed severe diffuse intracranial stenosis involving the circle of Willis. He was taken to the angiography suite for chemical spasmolysis with verapamil. There was radiographic improvement and clinical resolution. Conclusions: This case highlights the rarity of RCVS presentations and further signifies the utility of intraarterial spasmolytics as an adjunct in the diagnosis of difficult cases. Further retrospective and prospective data are needed.

Background: Neck vessel imaging is often performed in hyperacute stroke to allow neurointerventionalists to estimate access complexity. This study aimed to assess clinician agreement on catheterization strategies based on imaging in these scenarios. Methods: An electronic portfolio of 60 patients with acute ischemic stroke was sent to 53 clinicians. Respondents were asked: (1) the difficulty of catheterization through femoral access with a regular Vertebral catheter, (2) whether to use a Simmons or reverse-curve catheter initially, and (3) whether to consider an alternative access site. Agreement was assessed using Fleiss’ Kappa statistics. Results: Twenty-two respondents (7 neurologists, 15 neuroradiologists) completed the survey. Overall there was slight interrater agreement (κ=0.17, 95% CI: 0.10–0.25). Clinicians with >50 cases annually had better agreement (κ=0.22) for all questions than those with fewer cases (κ=0.07). Agreement did not significantly differ by imaging modality: CTA (κ=0.18) and MRA (κ=0.14). In 40/59 cases (67.80%), at least 25% of clinicians disagreed on whether to use a Simmons or reverse-curve catheter initially. Conclusions: Agreement on catheterization strategies remains fair at best. Our results suggest that visual assessment of pre-procedural vessels imaging is not reliable for the estimation of endovascular access complexity.

Background: Endovascular coiling is a minimally invasive technique for managing carotid blowout in head and neck malignancies. Internal carotid artery (ICA) coil extrusion is a rare complication of this procedure, with an increased risk in post radiated neck. Methods: We present a case of advanced nasopharyngeal carcinoma with cervical nodal metastasis treated with chemoradiation and complicated with left ICA blowout which was successfully coiled and embolized endovascularly. Results: He was subsequently presented with left-sided nosebleed. Imaging demonstrated patent occluded left ICA, however with extrusion of coil material into the nasopharynx which was most likely attributed by the soft tissue necrosis in the left parapharyngeal space. He was managed conservatively as his symptoms was mild and self-limiting. Subsequent follow-up imaging confirmed stable coil extrusion. Conclusions: This case highlights the importance of identifying and assessing coil extrusion on imaging, which includes assessment of the location of extrusion, vessel occlusion patency, and potential causes of extrusion. Goals of management for symptomatic patients aims to remove extruded foreign bodies and stabilize the wound to prevent massive bleeding or further coil migration.

Background: Neurointerventional radiology (NIR) is a growing field, offering minimally invasive treatments for cerebrovascular conditions like ischemic stroke. However, no comprehensive analysis of the current NIR landscape in Canada exists. This study aims to evaluate the NIR landscape through analysis of hospital-based services and training programs. Methods: Publicly available hospital data, fellowship programs, and national workforce statistics were analyzed to assess the expansion of NIR centers, practitioners, and services in Canada. The analysis focused on temporal trends in geographic distributions, specialists, and training programs. Results: From 2022 to 2024, the number of NIR centers increased by 20% (from 25 to 30), with new sites established in British Columbia, Quebec, and Newfoundland. Seven accredited RCPSC NIR training programs were identified, with 2 new programs expected to begin training fellows by 2030. Annual trainee enrollment also increased by about 10% per year, with over 50% being from radiology backgrounds. Endovascular thrombectomy, the most common NIR procedure, has seen an annual volume increase of approximately 13% since 2019. Conclusions: NIR is experiencing substantial growth in Canada across centers and training sites, aligning with public health goals. However, continued investment in infrastructure and workforce development is required to ensure equitable access to life-saving neurointerventional therapies nationally.

Background: Large language models (LLMs) have gained popularity in medicine, however, their roles in neuroradiology remain underexplored. This study aimed to evaluate the current landscape, identify evidence gaps, and propose future directions for LLMs in neuroradiology. Methods: A systematic literature search of PubMed, Embase, Web of Science, and Scopus was conducted to identify relevant studies published between January 1, 2010, and October 1, 2024. Two reviewers screened eligible studies and selected original research applying LLMs in neuroradiology for inclusion. Included studies were evaluated using thematic and geographical analyses to identify trends. Results: Of 287 identified studies, 57 met the inclusion criteria. Findings revealed a significant upward trend in publications since 2018, with an annual growth rate of 78.2%. Three main themes emerged: Operational Workflow Optimization (n=26, 45.6%), Diagnostic Decision Support (n=20, 35.1%), and Education and Training (n=11, 19.3%). Geographically, most studies originated from North America (n=23, 40.4%), Europe (n=19, 33.3%), and Asia (n=12, 21.1%), with limited contribution from other regions (n=3, 5.3%). Key knowledge gaps included strategies to mitigate hallucinations, enhance transparency, and safeguard patient privacy. Conclusions: LLMs are being applied in neuroradiology to support diagnostics, streamline workflows, and enhance education. Future research should prioritize clinical validation, promote ethical practices, and expand global involvement.

Background: Occipital nerve stimulation (ONS) is a promising therapy for craniofacial pain syndromes refractory to conventional treatments. This study evaluates the long-term efficacy and safety of ONS over a 15-year period at Hôpital Enfant-Jésus, CHU de Québec, based on patient-reported outcomes and complication rates. Methods: A retrospective cohort analysis was conducted on patients with occipital neuralgia, cluster headaches, migraines, and other craniofacial pain syndromes who underwent ONS implantation. Pain intensity, quality of life, and patient-reported improvements were assessed at baseline, one year, and the latest follow-up. Trial stimulation was performed before permanent implantation. Results: Among 45 patients (mean age: 53.7 years), diagnoses included occipital neuralgia, migraines, cluster headaches, cervicogenic pain, and other pain syndromes. At follow-up (mean: 4.72 ± 1.02 years), NPRS scores decreased by 3.8 ± 1.7 points, BPI showed a 45% ± 18% reduction, and SF-36 revealed improvements in physical (20% ± 25%) and social functioning (30% ± 22%). Adverse events occurred in 27% of patients, with surgical revisions required in 14%. Conclusions: ONS provides significant, long-term pain relief and quality-of-life improvements in refractory craniofacial pain, particularly for occipital neuralgia and cluster headaches. While complications remain notable, advancements in techniques and technology may improve outcomes, supporting ONS in tailored pain management protocols.

Background: Trigeminal neuralgia (TN) is more common in multiple sclerosis (MS) patients than in the general population, likely due to demyelination impacting the trigeminal pathways. While brainstem lesions are associated with MS-TN, their precise role remains unclear. Methods: This study investigates the relationship between brainstem MS plaque location, TN symptoms, and treatment response. We retrospectively analyzed brain MRIs of MS-TN patients, segmenting and coregistering brainstem plaques in MNI space. A tractographic atlas of the trigeminal system was generated using high-resolution diffusion imaging from 30 patients. Lesion involvement was determined by intersection with the trigeminal tract, and its association with pain intensity and treatment outcomes was analyzed using linear regression. Results: Our research revealed 83% of MS-TN patients had brainstem lesions near the fourth ventricle. No single lesion hot spot was identified. Lesion volume did not predict symptom recurrence or treatment response. However, 97% of lesions intersected the trigeminal tract, supporting its association with TN symptoms. Conclusions: The strong overlap between lesions and the trigeminal tract suggests a potential pain generator in MS-TN. Further research is needed to determine whether similar lesions exist in asymptomatic MS patients and to confirm this hypothesis. Future studies will explore whether tract involvement better predicts clinical response to treatment.

Background: Due to the peculiar location of central neurocytoma, gross total resection is often challenging, and adjuvant radiotherapy is sometimes indicated. Factors associated with outcome are not well addressed in the literature Methods: A multicenter retrospective cohort study among 11 centers in Saudi Arabia including histologically confirmed central neurocytoma between 2000-2022. Results: A total of 104 patients were included. Pre-operative mRS was 0-2 in 93% of the cases. Gross total resection (GTR) was achieved in 50.7%. Radiotherapy was needed in 40% and Ventriculoperitoneal shunt in 38.6%. Favorable outcome was observed in 81.7%. Factors associated with worse outcome included initial mRs of ≥3, tumor size ≥50 mm, and atypical/anaplastic histology. Disease progression was observed in 18 (17.8%). Five-year absolute survival rate was 91.55%. The only significant predictor of disease progression was the presence of atypical features or anaplasia (P .007). Extent of surgical resection (P 0.877) wasn’t associated with disease progression. Post operative radiotherapy didn’t alter residual progression in patients with subtotal resection (P .170) nor the recurrence rate in those with GTR (.365) Conclusions: Central Neurocytoma cases have a high survival rate with a favourable mRs score at long-term follow up. The extent of resection didn’t alter disease progression nor did the adjuvant radiotherapy