title: Normal imaging in patients with cerebral palsy: what does it tell us?
abstract: OBJECTIVE
  To identify distinctive clinical features characterizing children with cerebral palsy (CP) and normal-appearing magnetic resonance imaging (MRI) findings.
  
  
  METHODS
  Using a population-based CP registry, the Registre de la Paralysie Cérébrale au Québec (Quebec Cerebral Palsy Registry), various antenatal, perinatal, and postnatal predictor variables, as well as current phenotype, were compared in patients with normal-appearing MRI findings and those with abnormal MRI findings.
  
  
  RESULTS
  Of the 213 patients evaluated, 126 (60%) had MRI imaging results available and were included in our analysis. Of these 126 patients, 90 (71%; 51 males, 39 females) had abnormal findings and 36 (29%; 17 males and 19 females) had normal-appearing findings. Compared with other CP variants, normal-appearing MRI was more prevalent (P = .001) in dyskinetic CP (72.7%; 8 of 11) and less prevalent (P = .002) in spastic hemiplegic CP (10%; 4 of 40). There were no significant differences between the 2 groups (P > .05) in terms of the prevalence of perinatal or postnatal clinical features or clinical outcomes. Furthermore, 42% (15 of 36) of the children with normal-appearing MRI exhibited a high degree of functional disability (Gross Motor Functional Classification System IV-V), compared with 33% (30 of 90) with abnormal MRI.
  
  
  CONCLUSIONS
  No clinical features, except a higher prevalence of dyskinetic CP, was identified in the children with normal-appearing MRI. More refined imaging techniques may be needed to evaluate patients with normal-appearing MRI findings. Furthermore, genetic or functional, rather than gross structural lesions, may underlie the pathophysiology of CP in this cohort. Finally, the high proportion of substantial functional disability underscores the importance of continuous follow-up even in the absence of early structural abnormalities on imaging.
authors.affiliation: Division of Pediatric Neurology, McGill University, Montreal, Canada.
authors.forename: Ruba
authors.initials: R
authors.lastname: Benini
authors.forename: Lynn
authors.initials: L
authors.lastname: Dagenais
authors.forename: Michael I
authors.initials: MI
authors.lastname: Shevell
mesh_terms: D002547:Cerebral Palsy / Q000175:diagnosis*; D002675:Child, Preschool; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012016:Reference Values