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Dive into the research topics where Lawrence Richer is active.

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Featured researches published by Lawrence Richer.


JAMA | 2016

Clinical Risk Score for Persistent Postconcussion Symptoms Among Children With Acute Concussion in the ED

Roger Zemek; Nick Barrowman; Stephen B. Freedman; Jocelyn Gravel; Isabelle Gagnon; Candice McGahern; Mary Aglipay; Gurinder Sangha; Kathy Boutis; Darcy Beer; William R. Craig; Emma Burns; Ken Farion; Angelo Mikrogianakis; Karen Barlow; Alexander Sasha Dubrovsky; Willem H. Meeuwisse; Gerard A. Gioia; William P. Meehan; Miriam H. Beauchamp; Yael Kamil; Anne M. Grool; Blaine Hoshizaki; Peter Anderson; Brian L. Brooks; Keith Owen Yeates; Michael Vassilyadi; Terry P Klassen; Michelle Keightley; Lawrence Richer

IMPORTANCE Approximately one-third of children experiencing acute concussion experience ongoing somatic, cognitive, and psychological or behavioral symptoms, referred to as persistent postconcussion symptoms (PPCS). However, validated and pragmatic tools enabling clinicians to identify patients at risk for PPCS do not exist. OBJECTIVE To derive and validate a clinical risk score for PPCS among children presenting to the emergency department. DESIGN, SETTING, AND PARTICIPANTS Prospective, multicenter cohort study (Predicting and Preventing Postconcussive Problems in Pediatrics [5P]) enrolled young patients (aged 5-<18 years) who presented within 48 hours of an acute head injury at 1 of 9 pediatric emergency departments within the Pediatric Emergency Research Canada (PERC) network from August 2013 through September 2014 (derivation cohort) and from October 2014 through June 2015 (validation cohort). Participants completed follow-up 28 days after the injury. EXPOSURES All eligible patients had concussions consistent with the Zurich consensus diagnostic criteria. MAIN OUTCOMES AND MEASURES The primary outcome was PPCS risk score at 28 days, which was defined as 3 or more new or worsening symptoms using the patient-reported Postconcussion Symptom Inventory compared with recalled state of being prior to the injury. RESULTS In total, 3063 patients (median age, 12.0 years [interquartile range, 9.2-14.6 years]; 1205 [39.3%] girls) were enrolled (n = 2006 in the derivation cohort; n = 1057 in the validation cohort) and 2584 of whom (n = 1701 [85%] in the derivation cohort; n = 883 [84%] in the validation cohort) completed follow-up at 28 days after the injury. Persistent postconcussion symptoms were present in 801 patients (31.0%) (n = 510 [30.0%] in the derivation cohort and n = 291 [33.0%] in the validation cohort). The 12-point PPCS risk score model for the derivation cohort included the variables of female sex, age of 13 years or older, physician-diagnosed migraine history, prior concussion with symptoms lasting longer than 1 week, headache, sensitivity to noise, fatigue, answering questions slowly, and 4 or more errors on the Balance Error Scoring System tandem stance. The area under the curve was 0.71 (95% CI, 0.69-0.74) for the derivation cohort and 0.68 (95% CI, 0.65-0.72) for the validation cohort. CONCLUSIONS AND RELEVANCE A clinical risk score developed among children presenting to the emergency department with concussion and head injury within the previous 48 hours had modest discrimination to stratify PPCS risk at 28 days. Before this score is adopted in clinical practice, further research is needed for external validation, assessment of accuracy in an office setting, and determination of clinical utility.


Pediatrics | 2010

Treatment of Children With Migraine in Emergency Departments: National Practice Variation Study

Lawrence Richer; Keri Laycock; Kelly Millar; Eleanor Fitzpatrick; Simi Khangura; Maala Bhatt; Chantal Guimont; Gina Neto; Steve Noseworthy; Ron Siemens; Serge Gouin; Brian H. Rowe

OBJECTIVE: Children with migraine may present to an emergency department (ED) when outpatient management has failed; however, only limited research has examined migraine-abortive medications among children. METHODS: A retrospective chart review of ED presentations for migraine or headache between July 1, 2004, and June 30, 2005, in 10 Canadian pediatric EDs was conducted. A priori, evidence-based treatments were defined as any treatment that was based on high-quality evidence and an absence of opioids as first-line agents. RESULTS: A total of 2515 records were screened, and 1694 (67.4%) met inclusion criteria. The average age of patients was 12.1 years, 14.5% (95% confidence interval [CI]: 12.1%–17.2%) of patients experienced headache >15 days per month, and 62.6% (95% CI: 55.7%–68.9%) had already used migraine-abortive therapy. Significant variations in practice for all classes of migraine-abortive medications were observed. Dopamine receptor antagonists (prochlorperazine, metoclopramide, or chlorpromazine) (39% [95% CI: 28.4%–50.8%]) and orally administered analgesics (acetaminophen and ibuprofen) (24.5% [95% CI: 23.9%–46.8%]) were prescribed most commonly. Predictors for the use of evidence-based treatment included older age (odds ratio: 1.15 [95% CI: 1.07–1.24]) and a discharge diagnosis of migraine (odds ratio: 1.84 [95% CI: 1.11–3.05]). CONCLUSIONS: Children presenting to EDs for treatment often have frequent attacks and have experienced failure of outpatient, migraine-abortive efforts. Practice variations were impressive for the care of children with migraine in these Canadian EDs.


Headache | 2007

Emergency Department Management of Acute Migraine in Children in Canada: A Practice Variation Study

Lawrence Richer; Lee Graham; Terry P. Klassen; Brian H. Rowe

Objectives.—Evidence‐based guidelines for the treatment of children with migraine are limited given the paucity of randomized controlled trials, especially in the emergency department (ED). Our objectives were to: (1) characterize the treatment of children with migraine in the ED; (2) determine whether treatment varies in pediatric versus mixed (pediatric and adult) EDs.


Journal of Child Neurology | 2008

Decompressive Hemicraniectomy in Children With Severe Ischemic Stroke and Life-Threatening Cerebral Edema

Vijay Ramaswamy; Vivek Mehta; Mary Bauman; Lawrence Richer; Patti Massicotte; Jerome Y. Yager

Decompressive hemicraniectomy has been discussed as a treatment option that increases survival in adults with malignant stroke. This approach has not been studied extensively in children. From a prospective cohort, we identified 4 children who underwent decompressive hemicraniectomy for malignant infarctions with life-threatening cerebral edema within 72 hours of their stroke. All 4 children had different causes for their stroke and experienced severe cerebral edema with increasing intracranial pressure and an impending fatal outcome. Despite massive cerebral infarction, all patients were ambulant and able to speak at the time of follow-up. Although a limited experience, decompressive hemicraniectomy is a life-saving approach for malignant stroke in children.


Journal of Child Neurology | 2014

Anti–N-Methyl-d-Aspartate (NMDA) Receptor Encephalitis An Unusual Cause of Autistic Regression in a Toddler

Ori Scott; Lawrence Richer; Karen Forbes; Lyn Sonnenberg; Angela Currie; Myroslava Eliyashevska; Helly R. Goez

Anti N-methyl-d-aspartate (NMDA) receptor encephalitis in children is associated with psychiatric changes, seizures, and dyskinesias. We present the first report of autistic regression in a toddler caused by this entity. A 33-month-old boy presented with decreased appetite, irritability, and insomnia following an upper respiratory tract infection. Over the next few weeks he lost language and social skills, and abnormal movements of his hand developed. Within a month, this patient came to fit the diagnostic criteria for autistic spectrum disorder. Upon investigation, anti-NMDA receptor antibodies were found in the boys cerebrospinal fluid. He was treated with intravenous immunoglobulins and steroids, resulting in reacquisition of language and social skills and resolution of movements. Our case emphasizes the significance of suspecting anti-NMDA receptor encephalitis as the cause of autistic regression, even in an age group where the diagnosis of autistic spectrum disorder is typically made, and especially when presentation follows a febrile illness.


Trials | 2014

A double-blind, placebo-controlled intervention trial of 3 and 10 mg sublingual melatonin for post-concussion syndrome in youths (PLAYGAME): study protocol for a randomized controlled trial

Karen Barlow; Brian L. Brooks; Frank P MacMaster; Adam Kirton; Trevor Seeger; Michael J. Esser; Susan Crawford; Alberto Nettel-Aguirre; Roger Zemek; Mikrogianakis Angelo; Valerie G. Kirk; Carolyn A. Emery; David W. Johnson; Michael D. Hill; Jeff Buchhalter; Brenda Turley; Lawrence Richer; Robert W. Platt; Jamie Hutchison; Deborah Dewey

BackgroundBy the age of sixteen, one in five children will sustain a mild traumatic brain injury also known as concussion. Our research found that one in seven school children with mild traumatic brain injury suffer post-concussion syndrome symptoms for three months or longer. Post-concussion syndrome is associated with significant disability in the child and his/her family and yet there are no evidence-based medical treatments available. Melatonin has several potential mechanisms of action that could be useful following mild traumatic brain injury, including neuroprotective effects. The aim of this study is to determine if treatment with melatonin improves post-concussion syndrome in youths following mild traumatic brain injury. Our hypothesis is that treatment of post-concussion syndrome following mild traumatic brain injury with 3 or 10 mg of sublingual melatonin for 28 days will result in a decrease in post-concussion syndrome symptoms compared with placebo.Methods/DesignNinety-nine youths with mild traumatic brain injury, aged between 13 and 18 years, who are symptomatic at 30 days post-injury will be recruited. This study will be conducted as a randomized, double blind, placebo-controlled superiority trial of melatonin. Three parallel treatment groups will be examined with a 1:1:1 allocation: sublingual melatonin 3 mg, sublingual melatonin 10 mg, and sublingual placebo. Participants will receive treatment for 28 days. The primary outcome is a change on the Post-Concussion Symptom Inventory (Parent and Youth). The secondary outcomes will include neurobehavioral function, health-related quality of life and sleep. Neurophysiological and structural markers of change, using magnetic resonance imaging techniques and transcranial magnetic stimulation, will also be investigated.DiscussionMelatonin is a safe and well-tolerated agent that has many biological properties that may be useful following a traumatic brain injury. This study will determine whether it is a useful treatment for children with post-concussion syndrome. Recruitment commenced on 4 December 2014.Trial registrationThis trial was registered on 6 June 2013 at ClinicalTrials.gov. Registration number: NCT01874847.


Headache | 2014

Randomized controlled trial of treatment expectation and intravenous fluid in pediatric migraine.

Lawrence Richer; William R. Craig; Brian H. Rowe

(1) The primary objectives were (1) to assess the response to intravenous (IV) fluid in children presenting to the ED with migraine and; (2) to assess the effect of treatment expectation on the response to I.


Current Pain and Headache Reports | 2015

Tic Versus TAC: Differentiating the Neuralgias (Trigeminal Neuralgia) from the Cephalalgias (SUNCT and SUNA)

Juliana VanderPluym; Lawrence Richer

Trigeminal neuralgia, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) are classified as distinct disorders in the International Classification of Headache Disorders 3 beta (ICHD-3 beta). SUNCT and SUNA are primary headache disorders included among the trigeminal autonomic cephalalgias. Trigeminal neuralgia is classified under painful cranial neuropathies and other facial pains. The classification criteria of these conditions overlap significantly which could lead to misdiagnosis. The reported overlap among these conditions has called into question whether they should be considered distinct entities or rather a continuum of the same disorder. This review explores the known overlap and how other features not included in the ICHD-3 beta criteria may better differentiate the “Tics” (trigeminal neuralgia) from the “TACs” (SUNCT and SUNA).


Clinical obesity | 2011

Autonomic nervous system dysfunction in obesity and Prader–Willi syndrome: current evidence and implications for future obesity therapies

Andrea M. Haqq; D. S. DeLorey; Arya M. Sharma; M. Freemark; F. Kreier; Michelle L. Mackenzie; Lawrence Richer

The autonomic nervous system (ANS) controls essential functions like breathing, heart rate, digestion, body temperature and hormone levels. Evidence suggests that ANS dysfunction is associated with adult and childhood obesity and plays a role in the distribution of total body fat and the development of obesity‐related complications in humans. This review summarizes our current understanding of ANS involvement in the pathogenesis of obesity and Prader–Willi syndrome. Available evidence of ANS dysfunction in the control of energy balance is limited and, in some cases, contradictory. Further investigation in this area is warranted in order to better understand the important contributions of the ANS to regulation of body fat, development of obesity and its comorbidities. Results from these studies will guide the development of novel obesity therapeutics targeting specific ANS dysfunction.


Metabolism-clinical and Experimental | 2017

The use of magnetic resonance imaging to characterize abnormal body composition phenotypes in youth with Prader–Willi syndrome

Camila E. Orsso; Michelle L. Mackenzie; Angela S. Alberga; Arya M. Sharma; Lawrence Richer; Daniela A. Rubin; Carla M. Prado; Andrea M. Haqq

INTRODUCTION Magnetic resonance imaging (MRI) provides detailed assessment of body composition compartments. No studies have employed state-of-the-art MRI methods to accurately examine abdominal adipose tissue (AT) and skeletal muscle in youth with Prader-Willi syndrome (PWS). Therefore, this study aimed to describe AT distribution and skeletal muscle in the abdominal region of youth with PWS using MRI. METHODS Anthropometric measures and whole-abdominal T1-weighted MRI were performed in sixteen (5 males and 11 females) youth diagnosed with PWS, and seventeen (10 males and 7 females) youth who did not have PWS (controls). Volume of subcutaneous, visceral, intermuscular, and total AT, and skeletal muscle in the abdominal region were quantified using a semiautomatic procedure. Results were summarized using median and interquartile range (IQR, 25th-75th), and ANCOVA test was used (with age and sex as covariates) to examine differences in body composition compartments between PWS and control group. RESULTS PWS group had similar age (10.5, 6.6-13.9 vs. 12.8, 10.0-14.4years; P=0.14) and BMI z-score (0.5, 0.2-1.3 vs. 0.2, -0.3 to 1.0; P=0.33) when compared with controls. Significant differences were observed in absolute volumes of total AT (PWS: 4.1, 2.0-6.6L; control: 2.9, 2.0-4.5L; P=0.01), subcutaneous AT (PWS: 2.8, 1.4-4.8L; control: 1.8, 1.1-3.2L; P=0.01), and intermuscular AT (PWS: 0.3, 0.1-0.4L; control: 0.3, 0.2-0.3L; P<0.005). Visceral AT/subcutaneous AT was lower in PWS (0.4, 0.3-0.5) compared to controls (0.5, 0.4-0.6), P=0.01. In addition, skeletal muscle volume was lower in PWS (1.5, 1.0-2.6L) compared to controls (3.1, 1.6-3.9L), P=0.03. Ratios of abdominal AT compartments to skeletal muscle were all higher in PWS compared to controls (all P<0.005). CONCLUSIONS PWS youth have greater abdominal adiposity, particularly subcutaneous AT and intermuscular AT, and lower volume of skeletal muscle compared to controls. The decreased ratio of visceral AT/subcutaneous AT in youth with PWS suggests an improved metabolic profile for the level of adiposity present; however, elevated ratios of AT to skeletal muscle suggest a sarcopenic obesity-like phenotype, which could lead to worse health outcomes.

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Roger Zemek

Children's Hospital of Eastern Ontario

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Karen Barlow

Alberta Children's Hospital

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Brian L. Brooks

Alberta Children's Hospital

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