bluuebunny/crossref_metadata_2025 huggingface dataset:
B.5 Prospective cohort analysis of normal versus mild cognitive impairment for quality of life outcome following DBS for Parkinson’s disease
Authors: Honey C , Almeida T , Honey CR
Published: June 2022

Background: All guidelines for DBS in Parkinson’s disease (PD) include a contraindication for ‘dementia’. It is unclear where this cut-off should occur and if patients with mild cognitive impairment (MCI) do not do as well. This prospective cohort analysis assessed if pre-operative cognition affected post-operative quality of life. Methods: PD patients receiving bilateral STN-DBS (n=100) were prospectively studied using STROBE guidelines. All had Montreal Cognitive Assessment (MoCA), motor (UPDRS), mood (BDI-II), and quality of life (Parkinson Disease Questionnaire summary index, PDQ-39-SI). Two cohorts, pre-operative MCI (MoCA:18-25) and normal cognition (MoCA:26-30), had post-operative PDQ-39-SI at 1-year. The primary outcome was the proportion of patients with an improved PDQ-39-SI at 1-year. Results: Cohorts were not significantly different in age, severity of illness, response to dopamine, or mood. MCI was present in 27/100. Improved quality of life at 1-year occurred in 75% with normal cognition and 70% with MCI (p=0.54) with RR=1.1 (95% CI, 0.8-1.5). Linear regression analysis showed no correlation between pre-operative cognition and post-operative outcome (R2=0.02). Conclusions: Parkinson’s patients with MCI should be offered DBS if their motor symptoms require surgery. Guidelines for DBS surgery in PD should change from “dementia is contraindicated” to “patients require adequate cognitive functioning, MoCA greater than equal to 18.”
C.3 Childhood Absence Epilepsy: Prevalence of neuropsychiatric comorbidities and predictors of treatment resistance
Authors: Lagacé M , Michoulas A , Demos M , Connolly M
Published: June 2022

Background: Seizures in childhood absence epilepsy (CAE) are typically easily controlled with anti-seizure medications (ASMs). Factors predictive of treatment resistance remain unclear. Our objectives were to assess prevalence of neuropsychiatric problems and factors influencing treatment resistance in a cohort of CAE at a single centre. Methods: We retrospectively reviewed patients with CAE diagnosed between January 1999 and December 2016 with at least 1-year follow-up. Treatment resistance was defined as failure to respond to two appropriate ASMs. Exclusion criteria included eyelid myoclonia with absence, myoclonic absence, and generalized tonic-clonic (GTC) seizures prior to absence seizures. Results: The study population comprised 164 patients (65 males) with mean age at seizures onset of 6.1years. 21% had treatment-resistant seizures. The first ASM was Ethosuximide (63.4%), Valproic acid (23.2%), and Lamotrigine (6.7%). 32.9% of children had learning disabilities, 28.7% ADHD, and 12.8 % anxiety.

A stepwise binary logistic regression analysis identified GTC seizures, learning disability (LD) and ongoing general spike and wave on EEG as predictors of treatment resistance. At last follow-up (average of 5.4 years), 43.3% of children were seizure-free off ASMs. Conclusions: 21% of children with CAE had treatment-resistant seizures. LD, GTC and failure of normalization of the EEG were associated with treatment resistance.
P.004 Dissecting the neuropathological causes of rapidly progressive dementia
Authors: Day GS , Lazar E , Ghayal NB , Roemer S , Graff-Radford NR , Dickson DW
Published: June 2022

Background: A clear understanding of the neuropathological causes of RPD is needed to inform the diagnosis and treatment of patients with rapidly progressive dementia (RPD). Methods: Patients with <4.0 years from symptom onset to death were identified within the Mayo Clinic Neurodegenerative Brain Bank (1998-2020). Relevant clinical details were extracted from available records. Neuropathological diagnoses were assigned following standard protocols. Results: 310/8586 (3.6%) cases met RPD criteria. Relative to typically progressive cases, prion disease most commonly presented as RPD (74%, 32/43), followed by progressive supranuclear palsy/corticobasal degeneration (PSP/CBD: 7.5%, 142/1894), other frontotemporal lobar degeneration (FTLD: 5.7%, 32/561), Lewy body disease (LBD: 4.1%, 49/1202), and Alzheimer disease (AD: 1.8%, 48/2687). Average age-at-symptom onset was 69.5±10.4 years. Average disease duration was 2.9±1.0 years. Prion diseases had the most rapid disease course (1.6±1.3 years). Comorbid cerebrovascular disease (25.5%), and clinically symptomatic depression (41.3%), psychoses (37.1%), and sleep disturbances (39.4%) were common across groups. Only psychosis was associated with shorter disease duration (β=-0.31 years, CI95% -0.53, -0.082, controlling for age-at-symptomatic onset). Conclusions: Although prion disease commonly presented as RPD, atypical presentations of more prevalent neurodegenerative diseases accounted for most cases of RPD. Rapidly progressive variants of typical neurodegenerative diseases warrant consideration in clinical practice.
P.010 Extreme delta brush in anti-NMDAR encephalitis correlates with poor functional outcome and death
Authors: Nathoo N , Anderson D , Jirsch J
Published: June 2022

Background: The electroencephalography (EEG) pattern extreme delta brush (EDB) is felt to be highly specific for anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. This study aimed to characterize EEG findings in anti-NMDAR encephalitis patients looking for the proportion of abnormal EEGs, presence of EDB, and to relate EDB to clinical outcomes (Glasgow Outcomes Scale (GOS) at 6 months, need for ICU admission, and death). Methods: This retrospective single centre study included anti-NMDAR encephalitis patients who had ≥1 EEGs obtained from 2014-2021. EEGs were retrospectively analyzed by 2 reviewers. Clinical outcomes of interest were extracted through hospital and clinic chart review. Results: Twenty-one patients with anti-NMDAR encephalitis were included. Sixty-four EEGs were analyzed. Four EEGs (6.3%) were within normal limits. Focal or generalized slowing (without EDB) was seen on 44 EEGs (68.8%). EDB was seen on 16 EEGs (25.0%) in 9 of 21 patients. The presence of EDB was significantly associated with need for ICU admission (p=0.02), poorer outcome at 6 months as per the GOS (p=0.002), and with death (p=0.02) Conclusions: The presence of EDB on EEG in anti-NMDAR encephalitis patients is associated with increased need for ICU admission, risk of death, and worse functional outcomes at 6 months.
P.018 Treatment patterns and healthcare resource utilization for patients with migraine in Alberta
Authors: Amoozegar F , Graves E , Ekwaru P , Mayer M , McMullen S , Bougie J , Ladouceur M , Hubert M
Published: June 2022

Background: As the second leading cause of years lived with disability in the world, and the first in people under 50, migraine represents a major burden to healthcare systems. This study examined treatment patterns and healthcare resource utilization (HRU) in patients with migraine using real-world data from Alberta. Methods: This was a retrospective cohort study of patients with ≥1 ICD-9-CM/ICD-10-CA code for migraine or ≥1 prescription for a triptan from April 1st, 2012 to March 31st, 2018. Descriptive statistics were used to characterize the study outcomes. Results: The incidence of migraine exceeded 1,000 cases per 100,000 person-years over the study period. The mean age of the cohort (n=199,931) was 40.0, and 72.3% were women. Migraine-related HRU accounted for 3%-10% of all HRU across endpoints (e.g., ED visits, hospitalization, physician visits). One-third of the cohort were prescribed acute medications (non-steroidal anti-inflammatories, triptans or other (including opioids)), whereas fewer than one-fifth were prescribed at least one migraine preventive such as tricyclic anti-depressants (proportion: 15%), anti-convulsants (13%), beta-blockers (7%), or neurotoxins (4%). Conclusions: The low medication prescription rates and high HRU indicates the potential unmet need and high disability in patients with migraine. The impact of migraine treatment patterns on HRU is an avenue for future research.
P.021 Evaluation of PREEMPT fixed-dose, fixed-site and follow the pain treatment paradigms in the PREDICT Study
Authors: Graboski C , Ong-Lam M , Becker W , Boudreau G , Davidovic G , Ma J , Sommer K , Finkelstein I
Published: June 2022

Background: Phase 3 PREEMPT established safety and efficacy of 155-195U onabotulinumtoxinA in adults with chronic migraine (CM). This analysis of the PREDICT study (NCT02502123) evaluates real-world effectiveness and safety of 155U, 156-195U and 195U-onabotulinumtoxinA in CM. Methods: Patients received onabotulinumtoxinA approximately every 12-weeks (≤7 treatment cycles [Tx]) per Canadian product monograph). Primary endpoint was mean change from baseline in Migraine-Specific Quality of Life (MSQ) at Tx4. Headache days, physician and patient satisfaction were evaluated. Analysis stratified safety population (≥1 onabotulinumtoxin A dose) into 3 groups (155U,156-195U,195U) by dose received on ≥3 of the first 4 Tx. Results: 184 patients received ≥1 onabotulinumtoxin A dose (155U, n=68; 156-195U, n=156; 195U, n=13 on ≥3 Tx). Headache days decreased over time compared to baseline (Tx4: -7.1[6.7] 155U; -6.5[6.7] 156-195U; -11.2[6.4] 195U). Physicians rated most patients as improved, and majority of patients were satisfied at final visit (80.8% 155U; 83.6% 156-195U; 90% 195U). Treatment-emergent adverse events (TEAEs) were reported in 18/68(26.5%) patients in 155U-group, 41/65(63.1%) in 156-195U-group and 10/13(76.9%) in 195U-group; treatment-related TEAEs were 9(13.2%), 10(15.4%) and 3(23.1%) respectively; serious TEAEs were 0, 3(4.6%) and 1(7.7%), none treatment-related. Conclusions: Long-term treatment with 155U, 156-195U, and 195U-onabotulinumtoxinA in PREDICT was safe and effective CM treatment. No new safety signals were identified.
P.022 Prognosis in arm and leg tremor onset Parkinson Disease
Authors: Noyes E , Rajput A , Rajput A
Published: June 2022

Background: There is no biological marker of progression in early Parkinson Disease (PD). Upper limb (UL) tremor is the most common motor symptom at onset. The significance of lower limb (LL) tremor remains unknown. We report on longitudinally followed autopsy-verified PD tremor onset cases. Methods: A chart review of longitudinally followed autopsy-verified PD cases was performed. Age and mode of onset were recorded at initial evaluation. Prognosis was measured by change in Hoehn and Yahr scale while on levodopa (LD). Results: Forty-nine patients were included. Thirty-eight cases had upper limb (UL), four lower limb (LL), and seven upper and lower limb (ULL) onset tremor. UL had 86.8% response to LD, LL 50% and ULL 85.7%. Sub-analysis of UL responders found 20% mild improvement, 53.3% moderate and 26.7% marked. ULL had moderate response in 83.3% and marked in 16.7%. LL responders only had mild improvement with LD. Conclusions: Tremor onset is most common in UL, followed by ULL and then LL. LL onset tremor cases have an inferior response to LD when compared to UL and ULL cases. We plan for further pathophysiologic studies to investigate LL onset in PD.
P.027 Multiple Sclerosis Self-reflective Treatment Evaluation Program (MS-STEP): alignment of current practices to the 2020 Canadian MS Working Group recommendations
Authors: Bhan V , Giacomini PS , Lemieux C , Oh J
Published: June 2022

Background: New Canadian treatment optimization recommendations (TOR) were released in 2020 to guide clinicians on the optimal use of disease modifying treatments (DMTs). The alignment of current practices to TOR was investigated to identify potential areas for improvement in patient care. Methods: From January–July 2021, a chart audit of 160 patients was conducted by a sample of Canadian neurologists. Patient selection criteria included adult patients with relapsing-remitting MS, who had been switched from an initial DMT. Results: In alignment with TOR, most patients received a platform therapy initially (89%; n=143) and suboptimal efficacy response (MRI changes, relapses, disability progression) was the most common trigger for switching treatment. Furthermore, the expanded disability status scale was used in 94% (n=151) of cases during clinical assessment. In some instances, neurologists did not adhere to TOR. Only 10% (n=16) of patients were tested for cognitive function and over half (58%; n=93) did not receive gadolinium contrast at re-baseline MRI. Major criteria for switching therapies based on relapse rate, severity/recovery, or MRI were not followed in (n=4; n=27; n=7) patients respectively. Conclusions: Canadian neurologists are generally aligned with recent TOR for MS. However, they are not switching nearly as often or as early as per TOR criteria.
P.029 Assessing disability in MS during the COVID-19 pandemic: correlation between PDDS and EDSS scores obtained before and after virtual assessments
Authors: Ballendine S , Poliakov I
Published: June 2022

Background: Public health measures during the COVID-19 pandemic resulted in many multiple sclerosis (MS) patients being assessed virtually. Expanded Disability Status Scale (EDSS) scores, which are routinely obtained during MS consults, cannot be reliably calculated during virtual assessments. The Patient Determined Disease Steps (PDDS) is a validated patient-reported outcome measure of disability in MS. This study aimed to find real world evidence for the validity of PDDS as a surrogate of EDSS. Methods: Chart review of all MS patients from the MS Clinic in Saskatoon, Saskatchewan who completed PDDS forms emailed to them prior to their virtual visit (N = 277) was performed. 97 (35%) had documented EDSS scores prior to and following their self-reported PDDS. Correlational analysis between PDDS scores and pre and post EDSS scores was performed. Results: PDDS scores were highly correlated with EDSS scores before (r(95) = .79, p < .001) and after (r(95) = .84, p < .001) clinic closure occurred. Conclusions: This study provides real-world evidence that PDDS can accurately assess disability in MS when in-person assessments are not possible. Further investigation into patient demographics that increase the likelihood of completing PDDS assessments prior to appointments at our centre is ongoing.
P.032 NMDA receptor encephalitis with severe orofacial dyskinesias treated tramadol and clonazepam
Authors: Fernandes F , Clift F , Chu L
Published: June 2022

Background: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neuroinflammatory disease mediated by antibodies targeting the GluN1 subunit of the NMDAR. It presents with well-defined neuropsychiatric symptoms, including psychosis, agitation, seizures, and memory disturbances. Movement disorders including orofacial dyskinesias are common, but often difficult to manage, with no specific published guidelines. Methods: A 23-year-old female was diagnosed with NMDAR encephalitis. She was treated with ovarian teratoma removal, corticosteroids, intravenous immunoglobulin therapy, rituximab, and tocilizumab. She continued to experience severe, self-mutilating orofacial dyskinesias. Tetrabenazine, haloperidol, and diazepam did not yield any sustained improvement. Tramadol was started based on a prior case report suggesting its efficacy. Results: Tramadol 50 mg po q6h led to immediate improvement in symptoms. Over the next 5 days, tramadol was increased to 150mg NG q6h and further reduced movements. When tramadol was held for one day, the movements significantly worsened and improved when it was restarted. Clonazepam 1mg NG QID also led to further improvement. Conclusions: Tramadol and clonazepam effectively treated severe orofacial dyskinesias in a patient with NMDAR encephalitis and refractory symptoms despite aggressive management. We propose early use of tramadol and clonazepam be considered for severe orofacial dyskinesias secondary to NMDAR encephalitis.
P.034 Temporal lobe epilepsy associated with autoimmune conditions: a review
Authors: Alshahrani A , Mirsattari Seyed
Published: June 2022

Background: Epilepsy mediated by immune cells must be identified early since immunotherapy has been associated with better clinical outcomes. This provides an overview of autoimmune TLE, emphasizing recent developments in its pathophysiology, imaging, and therapeutic interventions. Methods: Web-based research using advanced features of databases. Results: Epilepsy caused by immune dysfunction leads to inflammation of the brain. Inflammation play a role in the development of seizures. Proinflammatory molecules found to be overexpressed in neurons and glia of individuals with DRE, provoke a proinflammatory cytokines in the plasma and CSF. Autoimmune epilepsy is characterized by focal seizures refractory to ASMs accompanied by other neurological manifestations, as described by clinical scoring systems.Scoring systems are available to identify patients who are likely to be positive. The MRI findings include signal hyperintensities in the affected brain regions. EEG performed to exclude nonconvulsive seizures. Seizures resulting from autoimmune encephalitis are caused by antibodies to surface antigens and intracellular antigenes. Conclusions: Pathogenesis proposed to involve antibody-mediated ictogenesis. Immunotherapy is effective in autoimmune encephalitis with a positive prognosis if detected early. Limbic encephalitis has been shown to have a detrimental effect on cognition, mood, and behavior. Neuropsychology is an important outcome criterion for tracking disease progression and treatment success.
P.036 Exploring changes in functional connectivity after a first unprovoked seizure: an fMRI resting state and movie-driven data study
Authors: Paredes-Aragón EM , Mofrad M , Busch A , Kahn A , Johnsrude I , Muller L , Mirsattari S
Published: June 2022

Background: A single unprovoked seizure occurs in up to 10% of patients, but does not necessarily develop into epilepsy. It is unclear what determines the susceptibility to develop epilepsy. Although brain network changes have been ascertained in people with epilepsy, this field has not been studied in single seizure patients. Methods: Using 7T resting-state fMRI scanning, and co-registration watching a movie for naturalistic analysis of functional connectivity (Fc). Whole brain, Fc and Brodmann areas were analyzed using phase similarity measures and graph theory. Results: Ten patients with a single unprovoked seizure and fourteen age-and sex-matched healthy controls were recruited. Baseline characteristics were similar. Fc at baseline had no differences between groups. Movie-driven analysis did not show a significant difference overall regions but we observed significant differences in default mode and Visual association cortex as well as Dorsal posterior cingulate cortex (Dorsal PCC). Conclusions: Although no network connectivity differences were found between patients and controls, when movie-driven data was analyzed, differences were seen when comparing patients in the default mode network, visual association cortex, and dorsal posterior cingulate.
P.041 Characteristics of carpal tunnel syndrome in wild-type transthyretin amyloidosis
Authors: Russell A , Khayambashi S , Fine NM , Chhibber S , Hahn C
Published: June 2022

Background: Wild-type transthyretin amyloidosis (wtATTR) is an important cause of infiltrative cardiomyopathy in older adults. Carpal tunnel syndrome (CTS) is one of the most common extra-cardiac manifestations of wtATTR; however, the prevalence, severity, and risk of recurrence following carpal tunnel release (CTR) remain poorly understood. Methods: This retrospective cohort study reports findings from a single-centre experience of routine neurological screening of newly diagnosed wtATTR patients including nerve conduction studies. Consecutive wtATTR patients between 2014 and 2021 were included. Results: Seventy-nine wtATTR patients were included, 73 (92%) males, mean age of 79 years. Seventy-four (94%) had median neuropathy at the wrist (MNW), 50% having a prior diagnosis with the remaining 50% being diagnosed at screening. The majority with MNW were symptomatic (53, 67%) with moderate or severe disease (66, 84%) bilaterally (42, 53%) on electrophysiologic testing. Nineteen (24%) had recurrent CTS despite previous CTR. At the time of screening, 19 (24%) were prescribed wrist splinting and 36 (46%) were referred for CTR. Conclusions: Carpal tunnel syndrome is common in wtATTR. Most have bilateral disease with moderate to severe MNW at the time of wtATTR diagnosis. Recurrence of CTS after CTR is more common in wtATTR patients than in the general population.
P.045 Biopsies of the transverse carpal ligament and tenosynovium for tissue confirmation of transthyretin amyloidosis
Authors: Khayambashi S , Hahn C , Fine N , Mahe E , Elzinga K
Published: June 2022

Background: Transthyretin Amyloidosis (ATTR) is a common cause of both cardiomyopathy and carpal tunnel syndrome, with many patients needing carpal tunnel release (CTR). Although tafamidis is now an approved treatment of ATTR cardiomyopathy, insurers in most provinces require biopsy confirmation of amyloidosis. Endomyocardial biopsy is often the chosen approach due to optimal sensitivity, albeit with risk of serious adverse events such as stroke, cardiac tamponade, and arrhythmias. CTR may present an ideal opportunity for obtaining amyloidosis biopsy confirmation. Methods: ATTR patients undergoing CTR had biopsy of their transverse carpal ligament (TCL) and/or flexor tenosynovium to assess the sensitivity of both sites for biopsy confirmation of amyloidosis. Results: Twelve patients consecutively underwent biopsies during CTR, with 4 (33%) having bilateral CTR and biopsy. Among 16 TCL biopsies and 14 tenosynovium biopsies, 100% demonstrated amyloid deposition. Another patient had isolated tenosynovium biopsy without CTR and also demonstrated amyloidosis. There were no serious adverse events, and 1/13 (8%) had wound dehiscence requiring repeat suturing. Conclusions: Biopsy of the TCL and/or tenosynovium during CTR is safe, cost-effective, and sensitive, and may represent an alternative to endomyocardial biopsy in patients requiring tissue confirmation for tafamidis approval. ATTR patients eligible for tafamidis may benefit from early neurology assessment.
P.053 Insights from the first eighteen months of CBME implementation across Canadian neurology residency training programs
Authors: Li C , Li SX , Jenkins ME , Venance SL , Watling CJ , Florendo-Cumbermack A
Published: June 2022

Background: Canadian neurology residency programs recently transitioned to Competence Based Medical Education (CBME), designed to provide residents with stage-appropriate learning to develop and demonstrate competence. The successful implementation of CBME requires iterative evaluation as the adoption process may differ from the intended design due to systemic or program-specific factors. This study aims to (1) examine the variability in CBME implementation across Canadian neurology residency programs; (2) determine the barriers toward uptake of CBME; and (3) identify the benefits and pitfalls of CBME in neurology residency programs. Methods: A separate national survey was developed for residents and staff neurologists who participated in CBME for at least six months. Surveys were distributed through email, and responses were anonymized. Quantitative data were analyzed by response frequency and mean, where applicable. Free-form responses were analyzed qualitatively. Results: Staff neurologists felt prepared for CBME, but were divided on its fairness and impact on education quality. Residents experienced frequent but not necessarily timely or high-quality feedback. Barriers to implementation included increased paperwork, dissatisfaction with online platforms used to facilitate CBME, and bidirectional burden of initiating evaluations. Conclusions: Staff and residents have expressed unique perspectives on the first iteration of CBME. There remain opportunities for improvement in subsequent iterations.
P.060 Clinical milestones in PSP and MSA as triggers for palliative care intervention
Authors: Bessemer R , Iansavitchene A , Jenkins ME , Finger E , Gofton T
Published: June 2022

Background: Progressive Supranuclear Palsy (PSP) and Multiple System Atrophy (MSA) are neurodegenerative disorders with disabling morbidities and premature death. Variable illness trajectories make the timing for initiating neuropalliative care unclear. This scoping review aims to identify milestones relevant to survival and neuropalliative care in PSP and MSA. Methods: A systematic literature search was performed in Medline and EMBASE databases to identify publications investigating predictors of survival in PSP and MSA. Titles and abstracts of 2091 articles were independently screened by two reviewers and 22 research studies published after 2010 were included. Results were qualitatively combined to suggest triggers for targeted palliative care throughout the disease trajectory. Results: ‘Milestones’ are well documented, clinically relevant disease points prompting further care. Important milestones include frequent falls, cognitive impairment, severe dysarthria, severe dysphagia, wheelchair dependence, urinary catheterisation, and institutionalization. Early disease milestones include falls and cognitive impairment in PSP, and urinary catherization and falls in MSA. Time from milestone to death is variable. Conclusions: Milestones can be used to follow disease progression and help predict survival. We propose a framework in which milestones are used as triggers for targeted neuropalliative care interventions including the early initiation of a primary palliative care or referral to specialised palliative care services.
P.061 How neurologists screen for occult cancer in acute ischemic stroke
Authors: Tremblay J , Rioux B , Laferrière A , Keezer MR , Gioia LC
Published: June 2022

Background: People with acute ischemic stroke (IS) have a higher prevalence of occult malignancy. Consensus is lacking, however, on the extent of cancer screening tests that should be offered in this population. We performed a single-center study to review curent cancer screening practices in acute IS. Methods: We reviewed consecutive admissions for acute IS at our institution between January and December 2020. We defined extensive cancer screening as i) a cancer investigation test falling outside Canadian guidelines, or ii) any chest, abdomen or pelvis imaging by CT, TEP/CT or ultrasound. We compared clinical features of people with and without extensive screening with Fisher and Mann-Whitney U tests. Results: Among 171 patients with acute IS, 11 (6.4%) underwent extensive cancer screening. A lower BMI was the only clinical feature associated with extensive cancer screening (p=0.013). Markers that were not associated with extensive screening included age (p=0.479), male sex (p=0.758), cryptogenic etiology (p=1.000), infarctions in multiple vascular territories (p=0.748), hemoglobin (p=0.505), fibrinogen (p=0.162) and C-reactive protein (p=0.442). Conclusions: Common predictors of occult cancer were not associated with more extensive cancer screening in this small sample of IS. Validated clinical prediction models may help clinicians guide cancer investigations in IS.
P.064 Clinical correlates of pre-morbid cancer in a consecutive sample of individuals with ischemic stroke
Authors: Laferrière A , Rioux B , Tremblay J , Keezer MR , Gioia LC
Published: June 2022

Background: Ischemic stroke (IS) may be the first sign of an occult cancer, due to an underlying paraneoplastic prothrombotic state. Predictors of occult cancer in acute IS, however, remain unclear. We performed a single-center study to identify clinical features that may distinguish cancer-associated IS from IS without recent cancer. Methods: We reviewed consecutive admissions for acute IS at our institution between January and December 2020. Recent cancer was defined as any new diagnosis of cancer up to five years prior to IS. We compared clinical features with Fisher and chi-squared tests for categorical data, as well as t-tests and Mann-Whitney U tests for continuous data. Results: We included 169 patients in the non-cancer group and 19 in the recent cancer group (median time for cancer diagnosis: 10.5 months). The most frequent primary site was the digestive system (n=5; 33.3%). Patients with recent cancer had a significantly lower mean BMI (19.3 vs 26.4 kg/m2; p=0.013), lower mean hemoglobin (123 vs 134 g/L; p=0.015), and more frequent prior venous thrombosis (15.8% vs 1.2%; p=0.008) than cancer-free patients. Conclusions: Clinical features such as lower BMI, lower hemoglobin and prior venous thrombosis may help identify cancer-associated mechanisms, as well as guide cancer screening, in IS.
P.066 The protective effect of influenza vaccination against stroke in adults
Authors: Holodinsky JK , Zerna C , Malo S , Svenson L , Hill MD
Published: June 2022

Background: Respiratory infection can be an immediate precursor to stroke and myocardial infarction (MI). Influenza vaccination is associated with reduced risk of MI. This relationship has also been suggested for stroke although it is unclear if the effect is consistent across age and risk groups. Methods: Using administrative data in Alberta from September 2009 – December 2018 we modelled the hazard of any stroke for individuals recently exposed (< 182 days) to the influenza vaccine compared to those without recent exposure adjusted for age, sex, anticoagulant use, atrial fibrillation, COPD, diabetes, hypertension, income quintile, and rural/urban home location. Results: 4,141,209 adults (29,687,899 person-years) were included; 1,769,565 (43%) received at least one vaccination in the 10-year time span. 38,126 stroke events were recorded. Adjusted for demographics and comorbidities, recent influenza vaccination significantly reduced the hazard of stroke (HR: 0.77; 95% CI: 0.76 – 0.79). This effect persisted across all stroke subtypes and across all ages and risk profiles. Conclusions: There is a 23% reduction in hazard of stroke among those recently vaccinated against influenza compared to those who were not. Protection extended to the entire adult population and was not limited to high-risk groups only.
P.074 An assessment of next-generation panel testing in epilepsy
Authors: Leduc-Pessah H , Hartley T , Pohl D , Dyment D
Published: June 2022

Background: With the now routine use of next-generation sequencing it is important to know the baseline outcomes as they relate to clinical care for pediatric epilepsy in Ontario. We sought to assess the diagnostic yield of genetic epilepsy panel testing and characterize the impact on patient care. Methods: We conducted a retrospective chart review of patients with epilepsy seen at CHEO between 2012-2020 with genetic testing. 227 patients met our inclusion criteria. Patient charts were reviewed for clinical details, co-morbidities, genetic testing results, and changes to management. Results: Diagnostic yield was 19% for multi-gene epilepsy panel testing. A further 10% received a diagnosis from additional genetic testing. The diagnostic yield was significantly higher in patients with a younger age of onset of seizures. A direct change in clinical management as a result of the molecular diagnosis was evident for 9% of patients; however, all diagnoses impacted prognosis and family counselling. Conclusions: The diagnostic yield of genetic epilepsy panel testing conducted at CHEO is comparable to other reported rates. Genetic testing resulted in clinical benefits of recurrence risk counselling, prognostic information and though a direct change in management was advised in a minority of individuals, targeted treatment recommendations will continue to increase with ongoing testing.
P.077 Response to the ketogenic diet in refractory epileptic spasms at BC Children’s Hospital
Authors: Webb PM , Datta A
Published: June 2022

Background: Epileptic spasms (ES) are a devastating seizure type with poor neurodevelopmental outcome; 1/3 are resistant to treatment with first line therapies. Recently attention has been drawn to the ketogenic diet (KD) as a potentially effective therapy, though data regarding optimal time of initiation, and its sustained effectiveness, are lacking. Methods: Retrospective chart review of all patients with ES treated with KD at BC Children’s Hospital between 2002 and 2020 (n=28) with comparison of spasm response based on age of initiation of KD in two groups: < 12 months (n=11) and ≥ 12 months (n=17). Results: Comparing the <12 months and ≥ 12 months groups showed: unknown etiology in 9% vs 25%; spasm freedom for 3 months on KD in 18% vs 41%; median time to spasm freedom was 2 vs 6 weeks; relapse after a period of spasm freedom occurred in 66% vs 70%. Conclusions: Although more effective in children ≥ 12 months of age in the first 3 months, spasm freedom in either group was not sustained with KD. KD is recommended as early therapy for refractory ES, but this study suggests clinicians be aware the KD has limited efficacy in long-term control of ES and must be used with other therapies.
P.078 Children with Trisomy 21 and Lennox-Gastaut Syndrome with predominant myoclonic seizures
Authors: MacDonald MJ , Crawford J , Datta A
Published: June 2022

Background: Background: Lennox-Gastaut syndrome (LGS) is a severe form of pediatric epilepsy that is classically defined by a triad of drug-resistant seizures, characteristic EEG patterns, and intellectual disability. Long-term prognosis is generally poor with progressive intellectual deterioration and persistent seizures. At present, there are few reported cases of LGS and Trisomy 21 (T21) in the literature. To further delineate the spectrum of epilepsy in T21, we reviewed children with T21 and LGS at one center over 28 years. Methods: Methods: This is a retrospective case series. At our institution, all EEG results are entered into a database, which was queried for patients with T21 from 1992-2019. Pertinent electro-clinical data was obtained from medical records. Results: Results: 63 patients with T21 and epilepsy, 6 (10%) had LGS and were included in the study. Four of the six patients were male and 5/6, had neuro-imaging, which was normal. Follow-up ranged from 3-20 years. Notably, 5/6 had predominant myoclonic seizures throughout the course of their epilepsy, associated with generalized spike-wave discharges. Conclusions: Conclusions: Myoclonic seizures appear to be a predominant seizure type in patients with T21, suggestive that T21 patients may have a unique pattern of LGS.
P.082 Using machine-based learning to predict neonatal hypoxic-ischemic encephalopathy (HIE) severity based on patient-specific clinical factors
Authors: Woodward K , DeJesus P , Mohammad K , Esser M
Published: June 2022

Background: Severity of HIE is based on Sarnat classification; however, it is difficult to predict precise neurodevelopmental outcomes as this only provides a single snapshot in time. We aimed to use machine-based learning to better understand variables contributing towards HIE severity. Methods: Patients with HIE treated with hypothermia were studied between 2014 and 2020 at level 3 NICUs in Calgary, Alberta. Clinical information contained 23 features including specifics of clinical examination, blood work, MRI and EEG findings, and medications. Random forest models were trained to examine features most predictive of HIE severity. Results: Two hundred and six patients were eligible. By grouping patients based on the initial Sarnat score and post-cooling exam, features correctly predicted groups 43% and 73% of the time, respectively. Precision, accuracy, and recall was best for the mild group. Using MRI and day 1 seizures it was 54% and 67% predictive, respectively. Features contributing most included arterial pH, initial lactate, and overall EEG findings. There are ongoing analyses for further classification. Conclusions: Machine-based learning can improve predictive models for patient outcomes. There is benefit in using variables outside of the initial examination to improve classification. We aim to expand this model to include detailed neurodevelopmental outcomes to improve prognostication.
P.087 The landscape of paediatric tuberous sclerosis complex (TSC) neurological care in canada: results from a national survey
Authors: Nabavi Nouri M , Zak M , Whitney R , Haile D
Published: June 2022

Background: Tuberous Sclerosis Complex (TSC) is a genetic disease that affects multiple body systems with the neurological manifestations causing the greatest disease burden. The objective of this study was to understand the scope of neurological TSC care delivery across Canada. Methods: A survey was developed after literature review and discussion amongst two Paediatric Epileptologists and one Nurse Practitioner with expertise in TSC. Canadian Paediatric Neurologists participated via an anonymous web-based survey through the Canadian League Against Epilepsy (CLAE) and Canadian Neurological Sciences Federation (CNSF). Results: Fifty-eight responses were received. A dedicated TSC clinic was reported by 24% (n=14). Sixty percent (n= 35) reported preforming serial screening EEG monitoring in infants and 58% (n= 34) started prophylactic therapy when EEG abnormalities occurred. Vigabatrin was used in 37% (n=21). For management of drug-resistant epilepsy, surgery was reported as the preferred therapeutic option in 57% (n=32) of respondents. Barriers to treatment identified were a lack of multi-disciplinary care, unfamiliarity with new therapies and insufficient resources. Conclusions: Our findings demonstrate the variability in neurological care delivery of patients with TSC. With few dedicated TSC clinics, there is a need for the establishment of a national network to support clinical practice, research and education.
P.088 Family identified barriers to accessing services for children with attention deficits and neurodevelopmental disorders
Authors: Wiley B , Taylor K , Murias K
Published: June 2022

Background: Obtaining early intervention services is crucial for improving outcomes in children with neurodevelopmental disorders (NDDs) such as Autism or Attention Deficit/Hyperactivity Disorder. Identifying barriers in accessing services in the healthcare system is necessary to optimize the Patient and Family-Centered Care approach. Methods: Parents of children with an NDD co-occurring with attention deficits were recruited from the Neurodevelopmental Attention Clinic at the Alberta Children’s Hospital. Parents completed a semi-structured interview and the Barriers to Accessing Services (BAS) questionnaire. Results: Nine families participated representing 10 children. Interviews were evenly spread between biological mothers and fathers. All children had attention deficits; 4 children were also diagnosed with Autism and 5 with “other” neurologic conditions. The two barriers most identified by families (67%) through the BAS questionnaire were “Didn’t know where to find help” and “Steps to seek help are too overwhelming”, consistent with information obtained in the interview. Conclusions: Children with an NDD and attention deficits often have complex medical needs. Parents have identified challenges initiating, and navigating the many steps involved to secure services. We will collect information from more families to determine how services for children with complex medical needs can become more accessible.
P.090 Symptomatic neonatal seizure treatment duration and seizure recurrence: a retrospective single center study
Authors: Martinez A , De Carolis M , Marandyuk B , Tremblay S , Lodygensky G , Birca A , Pinchefsky E
Published: June 2022

Background: While seizures have adverse neurological effects, the prescribed antiseizure medications (ASMs) may also have a negative impact on neonatal brains and contribute to detrimental neurodevelopmental outcomes. The objectives were to evaluate: 1) the impact of implementing a neonatal seizure treatment protocol in 2016; 2) the influence of ASM duration and other clinical factors on seizure recurrence and epilepsy onset. Methods: Retrospective chart review of 139 term newborns born between 2013 and March 2021 admitted at Sainte-Justine University Center Hospital with acute symptomatic seizures. Associations were assessed using Student T-test and Fisher exact test. Results: We did not observe significant change in the number of ASMs prescribed for acute seizure control (33% required 33 ASMs before vs 22% after 2016) nor significant change in frequency of prescription of ASM at discharge over time. ASM continuation at discharge was not associated with seizure recurrence (p=0.14, OR 2.14, 95%CI 0.78-5.86) or epilepsy (p=0.78, OR 1.32, 95% CI 0.45-3.90). Epilepsy occurred in 15 (12%) of children between 15 days to 72 months of age. Conclusions: No association was found between ASM maintenance at discharge following acute symptomatic neonatal seizures and the occurrence of epilepsy. Discontinuation of ASMs should be considered prior to discharge.
P.091 Multi-modal analysis of outcomes in pediatric mild traumatic brain injury (mTBI)
Authors: de Jesus P , Craig B , Forkert ND , D’Arcy R , Fritzler M , Barlow K , Esser MJ
Published: June 2022

Background: mTBI is the most common type of head injury among children but diagnosing and managing symptoms are challenging due to heterogeneity. This study used multi-modal analysis to examine how acute mTBI symptoms transition to chronic deficits. Methods: Subjects included a cohort with mild TBI (n=40, 8-18 years old) and age/sex-matched controls (n=27). All participants received symptom assessment, neuropsychological evaluation, ERP assessment, neuroimaging, and serum cytokine analysis. Results were analyzed individually and in multi-modal models to identify important outcome predictors. Results: mTBI resulted in higher symptom burdens compared to controls. There were no group differences in measures of balance, ERP, FA, or MD. Female mTBI participants had lower CNSVS Neurocognition Index scores (p=0.0401) and faster reaction times (p=0.0385) than controls. Repetitive mTBI males had faster psychomotor speed than symptomatic mTBI males (p=0.0260). CTACK levels were higher in female mTBI groups (p= 0.0043), SCGF- levels were lower in male mTBI groups (p=0.0486), and MDC levels were lower in female mTBI groups (p=0.0377) compared to controls. Multi-modal models revealed key predictors from all modalities, despite most measures producing non-statistically significant results in individual analyses. Conclusions: Multi-modal analysis may afford the opportunity to delineate complex mTBI pathology and provide better identification of biomarkers than unimodal analysis.
P.094 The three sisters of fate: Genetics, pathophysiology and outcomes of animal models of neurodegenerative diseases
Authors: Klonarakis M , De Vos M , Woo E , Ralph L , Thacker J , Gil-Mohapel J
Published: June 2022

Background: Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease are neurodegenerative disorders characterized by progressive structural and functional loss of specific neuronal populations, protein aggregation, insidious adult onset, and chronic progression. Modeling these diseases in animal models is useful for studying the relationship between neuronal dysfunction and abnormal behaviours and for screening therapies. Methods: We conducted a comprehensive descriptive review of the numerous animal models currently available to study these three diseases with a focus on their utilities and limitations. Results: A vast range of genetic and toxin-induced models have been generated. Our review outlines how these models differ with regards to the genetic manipulation or toxin used and the brain regions lesioned, describes the extent to which they mimic the neuropathological and behavioral deficits seen in the human conditions, and discusses the advantages and drawbacks of each model. Conclusions: We recommend the adoption of a conservative approach when extrapolating findings based on a single animal model and the validation of findings using multiple models. Investing in additional preclinical studies before embarking on more expensive human trials will improve our understanding of the neuropathology underlying neuronal demise and enhance the chances of identifying effective therapies.
P.096 Bi-insular responsive neurostimulation artifact on scalp electroencephalogram
Authors: Paredes-Aragón EM , Chávez-Castillo M , Barkley GL , Burneo JG , Suller-Martí A
Published: June 2022

Background: Responsive Neurostimulation (RNS) has proven efficacy in the treatment of medically resistant epilepsy as an intracranial system that detects, records and treats seizures automatically. No information exists pertaining to artifact characteristics of RNS findings in scalp EEG. Methods: A 30 year-old female was diagnosed, using intracranial electroencephalography (iEEG), with refractory bi-insular epilepsy, of unknown cause. Due to her large number of focal unaware non-motor seizures and frequent seizures with progression to bilateral tonic-clonic, she was implanted with bi-insular Responsive Neurostimulation (RNS). Results: Results: During scalp EEG recordings, a prominent artifact was seen corresponding to an automatized discharge suspectedly evoked by the RNS trying to minimize the frequent epileptiform activity in her case. Figure 1 and 2 depict these findings. Conclusions: The artifact seen by the RNS in scalp EEG has not been previously described in scientific literature. These findings must be identified to better characterize the role of the RNS in EEG and treatment of seizure activity visible on scalp recordings.
P.098 Usefulness of language mapping during cortical stimulation for presurgical planning in Stereo-encephalograph
Authors: McShane M , Asim A , Paredes-Aragón EM , Mirsattari S
Published: June 2022

Background: Background: Language determination is a pivotal part of presurgical investigations. Presurgical cortical stimulation (CS) with language mapping (LM) in patients with intracranial recordings (SEEG) is a growing practice in some Comprehensive Epilepsy Centers. Methods: Methods: This retrospective, single center study included patients implanted with SEEG that underwent CS for LM in our Epilepsy Monitoring Unit. We describe frequencies, demographic characteristics of these patients and whether or not CS with LM was useful. Results: Results: From January 2015 to June2021, a total of 177 patients were implanted with SEEG and analyzed. 95 patients had CS and 44 of these had CS with LM. The mean age was 33 (ranging from 15-70). During LM, anomia was induced in 26 (58%), speech arrest in 22 (49%), paraphasic errors in 13 (29%), and hesitation in 9 (20%). LM results were recorded as influencing surgical decision in 7 (16%) patients, 4 (9%) did not undergo surgery due to expected language deficits and 3 (7%) proceeded with surgery due to an acceptable risk of language deficit. Conclusions: Conclusions: Cortical stimulation language mapping is useful for decision-making in presurgical evaluation and should be encouraged whenever involvement of language is suspected when determining the epileptogenic zone.