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Dive into the research topics where Adrianna Ranger is active.

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Featured researches published by Adrianna Ranger.


Pediatric Critical Care Medicine | 2009

External ventricular drains in pediatric patients.

Quang N. Ngo; Adrianna Ranger; Ram N. Singh; Alik Kornecki; Jamie A. Seabrook; Douglas D. Fraser

Objective: To determine the indications and complications of external ventricular drain (EVD) placement in pediatric patients. Design: Retrospective chart review. Setting: University associated, tertiary–level Children’s Hospital. Patients: Sixty-six [median age, 10.1 years (interquartile range, 5.9)] patients between 1994 and 2006 with 96 EVDs. Measurements and Results: Clinical indications for EVD insertion include traumatic brain injury (TBI; 36%), acute hydrocephalus (35%), and ventriculoperitoneal shunt failure (29%). Of the 96 EVDs, 65% were inserted at the bedside in the pediatric critical care unit (PCCU) and 33% in the operating room (OR). Median duration of EVD insertion was 7.0 days (interquartile range, 8.8). Complications occurred with 26% of EVD insertions and included infection (9.4%), misplacement (6.3%), hemorrhage (4.2%), obstruction (3.1%), and malfunction (3.1%). The primary infectious etiology was coagulase-negative Staphylococcus (67% of infections). Despite patients with TBI having significantly smaller lateral ventricles than hydrocephalus patients (p < 0.05), EVD complications were similar (risk ratios 1.41; 95% confidence interval 0.68–2.72). Furthermore, the complication rate was the same for EVDs inserted in either the PCCU or OR (risk ratios 1.10; 95% confidence interval 0.55–2.29). Conclusion: EVDs were placed for TBI, ventriculoperitoneal shunt failure and new-onset hydrocephalus. The overall complication rate was 26%. Complication rates were similar in TBI and hydrocephalus patients, and with EVDs inserted in either the PCCU or OR. Prophylactic antibiotics or antimicrobial-impregnated catheters directed against coagulase-negative Staphylococcus may reduce EVD infections.


Neurosurgery | 2003

Risk factors for intracranial hemorrhage among full-term infants: a case-control study.

Jhawar Bs; Adrianna Ranger; David A. Steven; Del Maestro Rf

OBJECTIVETo investigate the cause of intracranial hemorrhage among full-term infants. METHODSA retrospective, hospital-based, matched case-control study was conducted at London Health Sciences Center, in southwestern Ontario, for the period from January 1, 1985, to December 31, 1996. Cases were diagnosed with magnetic resonance imaging, computed tomography, or ultrasonography within 7 days after birth. Control subjects were matched with respect to year of birth, sex, and, for nontransferred case patients only, obstetrician. RESULTSSixty-six full-term infants with intracranial hemorrhage were identified, and 104 control subjects were matched. Each factor was independently associated with increased risk of intracranial hemorrhage, as follows: forceps assistance (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.2–15.1), compared with spontaneous vaginal delivery; 1-minute Apgar scores of 1 through 4 (OR, 110; 95% CI, 5.0–2400) and 5 through 8 (OR, 4.9; 95% CI, 1.3–18.3), compared with scores of 9 or 10 (corresponding 5-min Apgar scores were also statistically significant); and requirements for resuscitation (OR, 5.1; 95% CI, 1.8–14.1), compared with no resuscitation requirements. Of the 52 case patients for whom platelet counts were recorded within 48 hours after birth, 30.8% (95% CI, 18.3–43.3%) exhibited counts of less than 70 × 109/L. Platelet counts of less than 50 × 109/L were specifically associated with intraparenchymal hemorrhage and a more severe radiological grade. Forceps-associated hemorrhage was more frequently subarachnoid and subdural and less frequently intraparenchymal. Such hemorrhage also tended to be more caudal in location. CONCLUSIONThrombocytopenia seems to be an important cause of intraparenchymal hemorrhage, and the use of forceps is more likely to be associated with subarachnoid and subdural hemorrhage.


Journal of Child Neurology | 2012

Central Pontine and Extrapontine Myelinolysis in Children A Review of 76 Patients

Adrianna Ranger; Navjot Chaudhary; Michael Avery; Douglas D. Fraser

This study aimed to identify the causes and contributing factors, neurologic presentation, and outcomes of central pontine and extrapontine myelinolysis and to examine any trends in the presentation and course of these disorders over the past 50 years. Seventy-six pediatric cases were identified in the literature. Age, sex, decade of diagnosis, neurologic presentation, outcome, and attributed causes were extracted. The results showed that the diagnosis, course, and outcomes of central pontine and extrapontine myelinolysis clearly have changed over the past few decades. Early cases generally were diagnosed at autopsy as opposed to computed tomography or magnetic resonance imaging more recently. Ninety-four percent of cases prior to 1990 and only 7% of cases from 1990 onward resulted in patient mortality. The decade in which the case was reported was the strongest predictor of outcome (P < .001), followed by sodium dysregulation (P = .045) and dehydration (P = .07).


Pediatric Neurosurgery | 2007

Spontaneous Spinal Epidural Hematoma in an 11-Month-Old Girl

N. Poonai; M.J. Rieder; Adrianna Ranger

An 11-month-old girl was admitted for a 2-month history of regression of motor milestones and lateralizing neurologic findings. Tests for hypercoagulability were all within normal limits except for a moderately elevated fibrinogen level. Urine and blood cultures were negative for growth. Complete MRI of the spine revealed a well-defined extradural inhomogeneous signal intensity extending from C4 to T3 suggestive of a subacute hematoma with evidence of evolving hemorrhagic change. There was no evidence of underlying arterial venous fistula or malformation. She underwent a cervicothoracic laminoplasty and evacuation of the hematoma. The clot was confirmed to be a hematoma on pathologic investigation. She made an uneventful recovery with gradual return of neurologic function. This case represents the longest known duration between initial symptoms and definitive management of spontaneous spinal epidural hematoma.


Neurosurgery | 2004

Suturing technique and the integrity of dural closures: an in vitro study.

Joseph F. Megyesi; Adrianna Ranger; Warren MacDonald; Rolando F. Del Maestro

OBJECTIVE:The watertight closure of the dura mater is fundamental to intracranial procedures in neurosurgery. Nevertheless, for any given operator and type of suture, it is still not certain which suturing technique affords the most watertight dural closure. We have developed a laboratory model that allows us to compare the pressures at which dural closures leak when different suturing techniques are used. METHODS:Human cadaveric dura was secured to a glass cylinder filled with colored saline. By application of force to a bag of saline attached to the cylinder, the pressure at which sutured dural incisions leak can be recorded. Using this method, we have compared the closure of 2-cm dural incisions with 3-0 silk using the following techniques (10 per group): 1) interrupted simple, 2) running simple, 3) running locked, and 4) interrupted vertical mattress. We have also compared the closure of 1- × 3-cm dural windows with cadaveric dura and 3-0 silk using the same suturing techniques (10 per group). RESULTS:The pressure at which 2-cm linear dural incisions leaked was significantly higher when they were closed with the interrupted simple suturing technique (P < 0.05). There was no significant difference among the different suturing techniques when they were used to close a 1- × 3-cm dural window with a duraplasty. Overall, the pressures at which sutured linear dural incisions leaked were higher than the pressures at which sutured dural windows closed with duraplasties leaked. CONCLUSION:In the experimental model described, an interrupted simple suturing technique affords the most watertight dural closure for linear incisions, whereas no suturing technique proved advantageous for the closure of a duraplasty.


Journal of Craniofacial Surgery | 2010

Chiari type 1 malformation in an infant with type 2 Pfeiffer syndrome: further evidence of acquired pathogenesis.

Adrianna Ranger; Ali Al-Hayek; Damir B. Matic

There seems to be an association between type 1 Chiari malformation (CM) and some congenital craniosynostosis syndromes. Type 2 Pfeiffer syndrome is a condition associated with premature fusion of multiple cranial sutures, cloverleaf skull (kleeblatschädel deformity), prominent ptosis, thumb and first toe abnormalities, variable syndactyly, and mutated genes for type 1 or 2 fibroblast growth factor receptor. These children generally do poorly because of significant often severe neurologic and cognitive defects, and many die very young. Roughly half of all patients with Pfeiffer syndrome, and virtually all with type 2 disease, also have type 1 CM. Chiari malformation may not be congenital but acquired as a consequence of the skull deformities and other associated intracranial factors in patients with craniosynostosis. We report a term male infant with type 2 Pfeiffer syndrome, who was not noted to have any CM on initial brain imaging done at 2 months but in whom repeated imaging demonstrated clear evidence of CM by 4 months, despite reconstructive craniotomies and unilateral ventriculoperitoneal shunt insertion. Posterior fossa decompression yielded a good result. This patient provides further evidence to support the concept of acquired tonsillar herniation in patients with craniosynostosis syndromes. The etiology seems multifactorial and related to (1) the disproportionately slow growth of the skull relative to the brain, particularly in the posterior fossa, secondary to early fusion of skull sutures, in turn secondary to congenital deficiencies in fibroblast growth factor receptors; (2) impaired venous sinus drainage; (3) hydrocephalus; and (4) resultant elevations in intracranial pressure.


Journal of Neurosurgery | 2009

Pediatric thalamic glioblastoma associated with Ollier disease (multiple enchondromatosis): a rare case of concurrence

Adrianna Ranger; Artur Szymczak; Robert Hammond; Shayna Zelcer

Ollier disease and Maffucci syndrome are rare syndromes in which there is deforming dysplasia of cartilage, primarily but not exclusively involving the metaphyses and diaphyses of long bones. In a minority of patients, dysplasia can lead to sarcomatous degeneration, producing chondrosarcomas. There also appears to be an association with other neoplasms. Little has been written about the association between Ollier disease and intracranial tumors, and these papers have largely consisted of case reports in adults. The authors present the case of a 6-year-old girl with left arm osseous changes consistent with Ollier disease and a biopsy-proven thalamic glioblastoma multiforme. They then examine the co-occurrence of brain tumors in conjunction with a dyschondroplasia syndrome in children and adolescents to assess the presentation, treatment offered, and disease course of similar cases. Eight other such cases were identified, 6 in patients with Ollier disease (ranging in age from 7 to 18 years), and 2 with Maffucci syndrome (both in late adolescence). Including our own patient, 7 of the 9 cases of comorbid dyschondroplasia and intracranial malignancy occurred in girls. Some patients presented soon after the acute onset of symptoms, and others had a more subtle, protracted course over as many as 2 years. Some tumors were deemed resectable and others not. In only 1 instance was follow-up beyond 1 year reported.


Journal of Craniofacial Surgery | 2012

Incidence of major and minor brain injuries in facial fractures.

Aaron L. Grant; Adrianna Ranger; G. Bryan Young; Arjang Yazdani

Background Facial fractures can be associated with brain and cervical spine injuries because impact forces are transmitted through the head and neck. Although major brain injury is commonly recognized in these patients, incidence of minor brain injury is not well-known, despite potential morbidity and mortality. Objectives This prospective study aimed to determine the incidence of both major and minor brain injuries in 100 patients presenting to a craniofacial surgery service with facial fractures and to identify characteristics associated with brain injury. Methods Data were collected for a 9-month period by a craniofacial surgeon at a level I trauma center. A questionnaire and checklist were designed to capture information about major and minor brain injury in patients with facial fractures. Assessments were completed in the outpatient clinic, emergency department, hospital ward, or intensive care unit during the first patient encounters. Results The average age of patients was 34 years; 79% were male. Time between injury and assessment ranged from less than a few hours to 4 months. Incidence of brain injury was 67% overall: 29% with major brain injury and 38% with minor injury. Major brain injury was commonly diagnosed early in the emergency department or intensive care unit. Conversely, minor brain injury tended to be diagnosed late in the clinic. Patient age, mechanism of injury, and type of facial fracture predicted brain injuries overall, but mechanism of injury was the sole predictor of minor brain injury. Conclusions Facial fractures are often associated with brain injury. A high level of suspicion is warranted for minor traumatic brain injuries.


Canadian Journal of Neurological Sciences | 2009

Effects of surgical excision and radiation on medulloblastoma cell invasiveness.

Adrianna Ranger; Warren McDonald; Glenn Bauman; Rolando F. Del Maestro

OBJECTIVES Surgical resection and adjuvant radiation are mainstays of medulloblastoma (MB) patient management. We utilized a novel 3-dimensional assay to identify how (a) radiation, (b) excision of the primary tumour aggregate, and (c) both treatments combined influence MB cell invasiveness. METHODS Five MB cell lines (UW228-1, 2 and 3; Daoy, and Madsen) were implanted onto a 3-dimensional, type I collagen gel assay to assess tumour invasion distance over five days, in response to (1) needle-assisted excision of the central cell aggregate; (2) pre-exposure to single-dose and fractionated dose irradiation in doses from 6-25 and 8-24 Gy, respectively; and (3) excision plus either single-dose or fractionated radiation. RESULTS Within hours, individual MB cells detached from the surface of the cell aggregates and invaded the collagen matrix, to distances up to 1200 microm and at rates up to 300 microm daily. The UW228-1 cell line was less invasive than the other cell lines and was dropped from further analysis. In the four remaining lines, a dose-dependent decline in tumour invasiveness was identified, both for single-dose and fractionated radiation, which achieved statistically decreased invasion distances at higher doses, especially of fractionated irradiation. Excision of the central tumour aggregate tended towards exerting a late effect on cell invasion, but exerted no significant influence on the radio-sensitivity of residual cells. CONCLUSIONS Both single-dose and fractionated dose irradiation appear to inhibit MB cell invasiveness in a dose-dependent manner, whereas excision of the central cell aggregate exerts no effect on residual invading cells.


Journal of Craniofacial Surgery | 2010

Craniosynostosis involving the squamous temporal sutures: a rare and possibly underreported etiology for cranial vault asymmetry.

Adrianna Ranger; Navjot Chaudhary; Damir B. Matic

Craniosynostosis is a condition in which 1 or more cranial sutures fuse prematurely, often secondary to a fibroblast growth factor receptor (FGFR) mutation, typically involving FGFR2 or FGFR3. This mutation may occur sporadically or in the setting of a genetic syndrome and typically presents within the first few days of life or in early infancy. Most commonly, the sagittal and coronal sutures are involved, although involvement of the lambdoidal and/or metopic sutures is not uncommon. Surgical correction is undertaken both for cosmetic purposes and to relieve raised intracranial pressure, both of which can be severe, depending on the sutures involved. We report on 2 children who presented in their first year of life with synostosis involving: in one instance, a single squamous temporal suture, and in the other, both squamous temporal sutures. The initial presentation and clinical courses of these 2 patients are highly distinct from one another, although both ultimately did quite well after extensive cranial remodeling. To the best of our knowledge, only a handful of patients with squamous synostosis have been reported in the medical literature.

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Douglas D. Fraser

University of Western Ontario

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Robert Hammond

University of Western Ontario

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Arjang Yazdani

University of Western Ontario

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Ibrahim M. Alharfi

University of Western Ontario

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Michael Avery

University of Western Ontario

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Navjot Chaudhary

University of Western Ontario

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Navjot Chaudhary

University of Western Ontario

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Damir B. Matic

University of Western Ontario

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David Diosy

University of Western Ontario

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