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Background: overtreatment of neonatal seizures may result in neurological morbidity. aEEG, despite low sensitivity, is widely used, for ease of bedside interpretation. vEEG, is a limited resource needing expert interpretation. We hypothesize that using aEEG combined with vEEG will increase the sensitivity and specificity of seizure detection and reduce anti-convulsants use compared to aEEG alone. Methods: Prospective cohort of neonates admitted to CHEO NICU with suspected seizures between April 1st 2018 to present. Seizures (clinical/aEEG) were documented by bedside clinicians and compared to the vEEG. Bedside clinicians could call a neurologist for remote review of the vEEG. Outcomes include concordance of aEEG and vEEG events and number of episodes where management was changed based on both readings Results: 27 patients had both modalities recording simultaneously. No seizure was identified by either modality in 23 recordings. Seizures were identified in 4 vEEG recordings; the aEEG partially identified these seizures.
aEEG specificity of 0.87, negative predictive value 0.8, sensitivity 0.44 and positive predictive value 0.57
Bedside clinician contacted a neurologist 9 times; in 2 cases, this prevented unnecessary treatment.
Conclusions: In this small sample, aEEG had good specificity for ruling out seizures, but low sensitivity for detecting them. The new combined pathway may prevent unnecessary treatment.
Background: Cannabis has been shown to be an effective therapy for epilepsy in children with Dravet and Lennox-Gastaut syndrome. Despite the fact that many pediatric epilepsy patients across Canada are currently being treated with cannabis, little is known about pediatric neurologists’ attitudes towards it. Methods: A 26-item online survey was distributed to 148 pediatric neurologists across Canada. Results: 56/148 neurologists responded and reported that over 600 children with epilepsy are currently taking cannabinoids. 34% of neurologists authorized cannabis to children, 38% referred children for authorization, and 29% did not authorize or refer their patients. Of those neurologists who referred, 76% referred to a community-based non-neurologist. The majority of physicians authorized cannabis to patients with Dravet syndrome (68%) and Lennox-Gastaut syndrome (64%). Cannabis was never authorized as a first-line treatment. 54% of neurologists stated that their patients were taking CBD alone, despite this option not being available in Canada. All physicians reported having at least one hesitation regarding cannabis, the most common ones being poor evidence (66%), poor quality control (52%), and cost (50%). Conclusions: The majority of Canadian pediatric neurologists use cannabis as a treatment for epilepsy in children. However, there appear to be knowledge gaps and hesitations.
Background: Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is an increase in intracranial pressure due to unknown etiology. Presentation in infancy is extremely rare. Little is known about infantile IIH and age-specific treatment guidelines are lacking. Methods: Patient data was obtained from medical records at the Children’s Hospital of Eastern Ontario. A literature review of infantile IIH was performed. Results: A previously healthy 9-month-old boy presented with irritability, decreased appetite, and a bulging fontanelle. CT head imaging and cerebrospinal fluid studies revealed normal results. Symptoms transiently resolved after a lumbar puncture, but 11 days later, his fontanelle bulged again. A second lumbar puncture revealed an elevated opening pressure of 35 cm H2O and led to a diagnosis of IIH in accordance with the modified Dandy Criteria. Treatment with acetazolamide at a dose of 25 mg/kg/day was initiated and the patient remained symptom-free for 6 weeks, followed by another relapse. His acetazolamide was increased to 38 mg/kg/day, with no further relapses to date. Conclusions: A diagnosis of IIH is challenging in infants, since the patients cannot yet verbalize typical IIH-related symptoms, and papilledema is difficult to assess. If undetected and untreated, IIH may result in permanent visual deficits.
Background: 4H leukodystrophy is a genetic disorder typically characterized by hypomyelination, hypodontia and hypogonatotropic hypogonadism. Previously reported patients had considerable cognitive and motor deficits. We present a pair of siblings with a less severe phenotype. Methods: Patient data was obtained from medical records from the Children’s Hospital of Eastern Ontario. Results: The first patient was diagnosed with 4H leukodystrophy at the age of 21 years after genetic testing revealed a POLR3B mutation with a homozygous V523E variant. She has hypomyelination on MRI and a history of optic neuritis, as well as intermittent sensory and motor symptoms in the context of a diagnosis of multiple sclerosis. She has no clinical manifestations of 4H leukodystrophy. The patient is now 26 years old and has only mild neurological deficits. Her younger brother was diagnosed with 4H leukodystrophy at the age of 18 years and found to have the same genetic mutation as his sister. He has a history of seizures and mild learning disabilities. He is now 23 years old with no typical symptoms of 4H leukodystrophy. Conclusions: 4H leukodystrophy is usually associated with a severe, disabling phenotype and a poor prognosis. Our patients illustrate that a much milder phenotype exists.
Background: Benign spasms of infancy (BSI), previously described as benign non-epileptic infantile spasms or benign myoclonus of early infancy, are non-epileptic movements manifesting during the first year of life and spontaneously resolving in the second year of life. BSI are characterized by spasms typically lasting 1-2 seconds, involving to varying degrees the head, neck, trunk, shoulders and upper extremities. Ictal and interictal EEG recordings are normal. BSI are not associated with developmental retardation and do not require treatment. Distinction between BSI and infantile epileptic disorders, such as epileptic spasms or myoclonic epilepsy of infancy, can be challenging given the clinical similarities. Moreover, interictal EEGs can be normal in all conditions. Epileptic spasms and myoclonic epilepsy require timely treatment to improve neurodevelopmental outcomes. Methods: We describe a 6-month old infant presenting with spasm-like movements. His paroxysms as well as a positive family history for epileptic spasms were in keeping with a likely diagnosis of West syndrome. Results: Surprisingly, ictal video EEG did not reveal epileptiform activity, and suggested a diagnosis of BSI. Conclusions: We emphasize that ictal EEG is the gold standard for classification of infantile paroxysms as either epileptic or non-epileptic, thereby avoiding overtreatment of BSI and facilitating timely targeted treatment of infantile epilepsies.
Background: Non-convulsive seizures are common in critically ill patients and are best detected by continuous EEG (cEEG) monitoring. A recent consensus statement from the American Clinical Neurophysiology Society (ACNS) outlines the indications for EEG monitoring in critically ill patients. Our aim was to assess adherence to these indications, barriers to cEEG utilization as well as to optimize cEEG monitoring in critically ill children. Methods: We conducted a retrospective review of electronic medical records, analyzing patients admitted to the PICU from January 1st until June 23rd 2018, followed by an 8-week mentorship period, consisting of educational interventions as well as daily patient rounds to help identify patients meeting cEEG monitoring criteria. Results: Prevalence of patients meeting cEEG monitoring indications were similar in both the retrospective and mentorship period (18% vs. 23%). During the retrospective period, 23% of patients received cEEG monitoring, reaching 100% at the end of the mentorship period. The median delay for initiation of monitoring was 17 hours, largely due to restrictions in the availability of technologists. All cEEGs performed informed anti-convulsive management. Conclusions: An educational intervention was effective in increasing PICU cEEG monitoring. However, limited hours of technologist availability represented the largest barrier to timely cEEG monitoring.
Background: Seizure monitoring via amplitude-integrated EEG (aEEG) is standard of care in many NICUs; however, conventional EEG (cEEG) is the gold standard for seizure detection. We compared the diagnostic yield of aEEG interpreted at the bedside, aEEG interpreted by an expert, and cEEG. Methods: Neonates received aEEG and cEEG in parallel. Clinical events and aEEG were interpreted at bedside and subsequently independently analyzed by experienced neonatology and neurology readers. Sensitivity and specificity of bedside aEEG as compared to expert aEEG interpretation and cEEG were evaluated. Results: Thirteen neonates were monitored for an average duration of 33 hours (range 15-94). Fourteen seizure-like events were detected by clinical observation, and 12 others by bedside aEEG analysis. None of the bedside aEEG events were confirmed as seizures on cEEG. Expert aEEG interpretation had a sensitivity of 13% with 46% specificity for individual seizure detection (not adjusting for patient differences), and a sensitivity of 50% with 46% specificity for detecting patients with seizures. Conclusions: Real-world bedside aEEG monitoring failed to detect seizures evidenced via cEEG, while misclassifying other events as seizures. Even post-hoc expert aEEG interpretation provided limited sensitivity and specificity. Considering the poor sensitivity and specificity of bedside aEEG interpretation, combined monitoring may provide limited clinical benefit.
Background: The classic ketogenic diet is the main non-pharmacological treatment for refractory epilepsy; however, adherence is often challenging. The low glycemic index diet (LGID) is less strict, almost equally effective, and associated with improved adherence. Little is known about the quality of life of children treated with LGID. The objective of this study was to explore changes in the quality of life of children with epilepsy transitioning to the LGID. Methods: Patients on LGID and their parents filled out Pediatric Quality of Life Epilepsy Module questionnaires; one while being on the LGID, and one retrospectively for the time prior to starting the LGID. Results: Data was collected from five children ages 3-13 and their parents. Complete seizure control was seen in two children, >50% seizure reduction in one, and no change in two children. Parental reported quality of life while on the LGID increased with two participants but decreased in all child self reports. Conclusions: Although the LGID led to improved seizure control in three out of five patients, the child-reported quality of life decreased in all children. Larger prospective studies are warranted to reliably assess the impact of the LGID on the quality of life in children with epilepsy.
Background: Long-term EEG monitoring (LTEM), including amplitude-integrated (aEEG) or conventional EEG (cEEG), is increasingly being used in critically ill neonates. Despite an abundance of studies regarding the clinical utility of LTEM, much is unknown regarding provider attitudes toward this tool. We aimed to evaluate neurologist and neonatologist opinions regarding LTEM in the NICU and describe current Canadian practices. Methods: A 15-item questionnaire was developed with input from neonatologists and pediatric neurologists at two Canadian centres. The questionnaire was piloted at our hospital and subsequently distributed to Canadian neonatologists and pediatric neurologists. Results: All 16 local respondents use LTEM in the NICU. Neonatologists were more likely to combine aEEG and cEEG, and monitor for longer durations than pediatric neurologists. However, most pediatric neurologists would like to monitor more (71%), compared to neonatologists who were more likely to say that current monitoring practices are sufficient. High rates of neonatologists (88%) and neurologists (85%) are interested in attending an education session on LTEM. Conclusions: Preliminary data suggests neonatologists and pediatric neurologists differ in their approach to LTEM. Results from our national questionnaire will be analyzed shortly, and may inform the development of educational materials as well as future studies that involve multi-centre efforts.
In agriculture, tank mixtures with several plant protection products (PPP) are frequently used, which makes it impossible to apply specific plant protection products to specific areas. Therefore a prototype of a field sprayer with a direct injection system was developed as part of a joint project between the company Herbert Dammann GmbH and the Julius Kühn- Institute. This framework enables a real-time site-specific dosing of plant protection products and water from separate containers with direct mixing before the application without residual amounts. Results show a high accuracy in the working range of the selected dosing pumps by means of test bench measurements and field tests Field tests for site-specific weed control in winter wheat demonstrate the applicability of the system under practical conditions and enable a precise application of various herbicides.
Oxtotitlán Cave paintings have been considered among the earliest in Mesoamerica on stylistic grounds, but confirmation of this hypothesis through absolute dating has not been attempted until now. We describe the application of advanced radiocarbon strategies developed for situations such as caves with high carbon backgrounds. Using a low-temperature plasma oxidation system, we dated both the ancient paint and the biogenic rock coatings that cover the paint layers at Oxtotitlán. Our research has significantly expanded the time frame for the production of polychrome rock paintings encompassing the Early Formative and Late Formative/Early Classic periods, statistically spanning a long era from before ca. 1500 cal B.C. to cal A.D. 600.
This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-BIO, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we present the first preliminary flux limits from AMANDA-II on the search for continuous emission from astrophysical point sources, and report on the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
We report multifrequency observations of the γ-ray blazar 0528+134 with the Effelsberg 100-m telescope, the IRAM 30-m telescope at Pico Veleta and the NRL Green Bank Interferometer. The observing methods are described elsewhere (Reich et al., 1993; Pohl et al., 1995). The radio lightcurves are given in Fig.1 in comparison to the status of 0528+134 in the EGRET energy range. The uncertainties in the flux densities quoted there are less than 5% at 10.55 GHz and lower frequencies, while slightly exceeding this value at 32 GHz and 86 GHz.
Pediatric acquired demyelinating syndromes have overlapping clinical and imaging features, but management and prognosis vary. We describe four children between the ages of 3 and 10 presenting with inflammatory brain disease - one with polyfocal neurological symptoms, one with severe bilateral optic neuritis and two with transverse myelitis, all without encephalopathy. All brain MRIs had extensive involvement of both deep grey and subcortical white matter. Three patients had longitudinally extensive spinal cord lesions. Clinical and radiological findings did not meet criteria for multiple sclerosis, acute disseminated encephalomyelitis, or neuromyelitis optica (NMO). NMO IgG testing was negative. All patients had resolution of clinical and imaging findings after treatment with steroids and IVIg. We found, elevated levels of anti-myelin oligodendrocyte glycoprotein antibodies in all four patients. Three of the children receive monthly IVIg infusions. Two of the patients relapsed once within 18 months of their initial attack and have since remained relapse free for 32 months and 43 months, respectively. The third patient (transverse myelitis) has not had any relapses since her initial attack 15 months ago. It appears that children with this syndrome may have more favourable outcomes when compared to other CNS relapsing inflammatory conditions.
By a transfer operator approach to Maass cusp forms and the Selberg zeta function for cofinite Hecke triangle groups, Möller and the present author found a factorization of the Selberg zeta function into a product of Fredholm determinants of transfer-operator-like families:
In this article we show that the operator families
arise as families of transfer operators for the triangle groups underlying the Hecke triangle groups, and that for
, the operator
) has a 1-eigenfunction if and only if there exists an even (respectively odd) Maass cusp form with eigenvalue
. For non-arithmetic Hecke triangle groups, this result provides a new formulation of the Phillips–Sarnak conjecture on non-existence of even Maass cusp forms.