The value of head computed tomography (CT) in children presenting with focal seizures to a paediatric ambulatory unit in a resource constrained setting

Date
2016-01-29
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT : BACKGROUND Children presenting to the ED with new onset focal seizures are often evaluated using urgent head computed tomography (CT). Although MRI is the preferred neuroimaging modality in children as it avoids the radiation risk of CT, with added superior resolution, MRI is not routinely available in the emergency setting1 2 3. The recommendations for neuroimaging, and specifically CT, in children presenting with new-onset focal seizures is poorly defined and the diagnostic yields tend to vary according to study settings and population. OBJECTIVE This study evaluated the utility, diagnostic yield and therapeutic interventions of head CT scans in children admitted with first onset focal seizures to the Paediatric Ambulatory & Emergency Unit at Tygerberg Children’s Hospital (TCH); and examined potential historical and clinical variables associated with abnormal head CT findings. METHODS A retrospective cohort analysis of 168 previously well children with new-onset focal seizures, admitted to TCH between January 2013 and December 2014, was undertaken. Demographic data, clinical details and head CT findings were abstracted from the radiological and medical hospital records. Data was analysed using Stata. Descriptive statistics was used to analyse demographic data and outcome. Univariate Comparisons and multiple biniary logistic regression analysis were done to determine adjusted associations between historical and/or clinical findings and CT scan results. RESULTS Clinical significant CT scan abnormalities were identified in 32% (n=54/168) of children and head CT findings were of therapeutic significance in 81% (n=44/54) of children. The majority of CT abnormalities were related to infectious granulomas (n=21/54); followed by TB meningitis (n=12/54) and cerebral venous thrombosis (n=4/54). An abnormal neurological clinical examination as indicator for abnormal CT scan was statistically significant (p < 0.001). Three quarters of patients (n=26/35) with an abnormal neurological examination, had an abnormal CT scan result. Age, HIV-status, malnutrition, duration of seizures, exposure to a household TB contact and travel history was not shown to be statistically predictive of abnormal CT results, but the sample size was too small for multivariate logistic regression analysis to determine adjusted associations. CONCLUSION We recommend strongly the use of urgent CT imaging in all children with neurological abnormalities. Our findings further suggest that imaging is valuable for therapeutic decisions in children suspected of neuro-infections (other than neurocycticercosis), vascular abnormalities, and space occupying lesions based on history and physical examination. Suspected structural abnormalities in infants younger than 2 years of age are best evaluated with a MRI in the non-urgent setting. Our findings further suggest that in a TB endemic setting, an initial CXR and tuberculin test may identify children requiring a TB work-up to diagnose tuberculous neuro-infection without the need for a CT scan.
AFRIKAANSE OPSOMMING : AGTERGROND Kinders wat by ‘n noodeenheid presenteer met eerste aankoms fokale konvulsies word dikwels evalueer met behulp van ‘n nood brein skandering. Alhoewel magnetiese resonansie die gekose ondersoek is in kinders as gevolg van die vermyding van die bestralingsrisiko van brein skanderings en beter resolusie, is MRI nie roetineweg beskikbaar in noodeenhede nie. Die aanbevelings vir skandering in kinders wat presenteer met eerste aankoms fokale konvulsie is nie goed omskryf nie en die diagnostiese en terapeutiese waarde verskil afhangend van die plek en populasie. UITKOMSTE Die studie het die gebruik, en diagnostiese en terapeutiese impak van breinskanderings ondersoek in kinders wat presenteer het met eerste aankoms fokale konvulsies in die Tygerberg Hospitaal se Ambulatoriese en Noodeenheid; asook gekyk na moontlike historiese en kliniese ondersoek indikasies wat geassosieer kan word met ‘n abnormale brein skandering. METODE ‘n Retrospektiewe kohort studie van 168 voorheen gesonde kinders met nuwe aankoms fokale konvulsies wat toegelaalt is te Tygerberg tussen Januarie 2013 en Desember 2014, is onderneem. Demografiese data, kliniese tekens en brein skanderig verslae is verkry van die hospitaal se radiologiese en pasient rekords. Data is geanaliseer met Stata. Beskrywende statistiek asook univariate en multipel binere logistiese regressie analise is onderneem. RESULTATE Klinies belangrike breinskanderingabnormaliteite is gevind in 32% (n=54/168) van kinders; wat tot terapeutiese intervensie gelei het in 81% (n=44/54) van gevalle. Die meerderheid abnormaliteite is veroorsaak deur infektiewe granulome (n=21/54); gevolg deur tuberkulose meningitis (n=12/54) en serebrale veneuse trombose (n=4/54). ‘n Abnormale kliniese neurologiese ondersoek was statisties betekenisvol (p < 0.001) as aanduiding van ‘n abnormale breinskandering. Driekwart van pasiente (n=26/35) met ‘n abnormale neurologiese ondersoek, het ‘n abnormale skandering gehad. Ouderdom. MIV status, gewig, duur van konvulsies, blootstelling aan tuberkulose kontak, en ‘n onlangse reisgeskiedenis was nie statisties betekenisvol nie; die getal pasiente was egter nie genoeg om ‘n assosiasie tussen geskiedenisen kliniese faktore en abnormale breinskandering te toon nie. GEVOLGTREKKING Ons beveel aan dat ‘n spoed breinskandering gedoen word vir alle kinders wat presenteer met ‘n kliniese abnormale neurologiese ondersoek. Ons bevindinge verder dui daarop dat breinskandering behulpsaam is in die hantering van kinders met moontlike intrakraniale infeksies (uitsluitend neurosistiserkose), vaskulere abnormaliteiete, en spasie opnemende letsels; soos vermoed na geskiedenis en ondersoek. Verder kan ‘n inisiele borskasplaat en tuberkulien toets die nodigheid van ‘n breinskandering voorkom aangesien dit die TB opwerk kan fokus.
Description
Thesis (MMed)--Stellenbosch University, 2016
Keywords
Paediatric care, Tomography, Focal seizures, Seizures -- Diagnosis, Pediatric emergency services -- South Africa -- Western Cape
Citation