Retrospective consecutive case series of children aged 1 month to less than 18 years who presented to the Royal Children's Hospital, Melbourne (RCH) ED with (AIS) during the five year period between January 2003 and December 2008. The study was approved by the institutional hospital research ethics committee at Royal Children's Hospital with a waiver of consent for enrolled patients.
RCH is the tertiary pediatric referral centre for the state of Victoria, Australia, with a population of 5 million. Annual ED census is 67, 000 and hospital census is 280, 000 patients.
Case identification, inclusion and exclusion criteria
Cases were ascertained from our institutional stroke registry, established in 2002. Patients identified were cross-referenced with a separate ED electronic hospital admission database to ensure all potential patients were included. Patients with perinatal arterial ischemic stroke, primary haemorrhagic stroke, subdural, extradural hemorrhage and cerebral sino-venous thrombosis were excluded from this study. Patients with incomplete medical records and patients that did not present first to the ED (e.g. direct admission to ICU or ward) were also excluded.
AIS was defined as acute neurological deficits lasting more than 24 hrs caused by cerebral ischemia, with neuroimaging showing parenchymal infarction, conforming to known arterial territories and corresponding to the clinical presentation . Anterior circulation stroke was defined at infarction in the anterior and middle cerebral artery territories and posterior circulation stroke as infarction in the vertebrobasilar territories.
ED triage urgency was assessed using the national Australian triage scale (ATS) . Patients with ATS category 1, 2, 3, 4 and 5 are to be seen immediately, within 10, 30, 60 and 120 minutes respectively. For young children a modified Glasgow Coma Scale was used .
A pediatric modification of the TOAST classification system was used to define stroke subtypes including sickle cell disease, cardiac embolism, cervical arterial dissection, Moyamoya disease, steno-occlusive cerebral arteriopathy, other determined etiology, multiple probable/possible etiologies and undetermined etiology. All patients with undetermined etiology had normal investigations including cerebrovascular imaging, echocardiogram, and prothrombotic studies [14, 15].
Data was abstracted from electronic and written ED records and from the medical record admission and progress notes. Laboratory and radiology reports were also reviewed. Data collected included demographics, age, timing of onset of symptoms and presenting symptoms and signs. Clinical variables were selected on the basis of symptoms or signs found to be useful for discriminating stroke from non-stroke at the bedside in adult studies [6, 9, 11, 16]. Symptoms and signs were extracted based on the first ED physician's notes and the first neurologist's or neurosurgeon's notes in the ED and medical records. Portions of the data were abstracted by two investigators and entered twice.
Two adult stroke recognition tools were retrospectively applied to our population. The FAST prehospital stroke recognition tool has been shown to have high positive predictive value when used by paramedics, primary care physicians and emergency physicians. It has also been used by the National Stroke Foundation of Australia in community stroke awareness campaigns. FAST variables include facial palsy, arm weakness and speech impairment [6, 10, 17]. A positive result is defined as the presence of at least one variable.
The ROSIER scale was also retrospectively applied to our stroke population . This tool has been developed for emergency physicians and it has also been demonstrated to be a simple, sensitive and specific tool for assisting non neurologists in the clinical assessment of potential stroke patients. The ROSIER is a seven item scoring system ranging from -2 to +5 that includes the following neurological signs and symptoms: loss of consciousness or syncope, seizure activity, acute onset asymmetrical facial weakness, asymmetrical arm weakness, asymmetrical leg weakness, speech disturbance and visual defect. The first two items are more discriminatory for non stroke diagnosis and are given a score of -1 and the remainder are more discriminatory for stroke and are given a score of +1. The optimum cut off point for stroke is a total score of +1 or above.
Clinical parameters of AIS were analysed descriptively. Data were entered in an Epidata database and analysed using Stata (version 10.0 Stata Corporation, Texas, USA).