title: Comorbidities in cerebral palsy and their relationship to neurologic subtype and GMFCS level.
abstract: OBJECTIVE
  Utilizing a population-based registry, the burden of comorbidity was ascertained in a sample of children with cerebral palsy and stratified according to both neurologic subtype and functional capability with respect to gross motor skills.
  
  
  METHODS
  The Quebec Cerebral Palsy Registry was utilized to identify children over a 4-year birth interval (1999-2002 inclusive) with cerebral palsy. Information on neurologic subtype classified according to the qualitative nature and topographic distribution of the motor impairment on neurologic examination, Gross Motor Function Classification System (GMFCS) categorization of motor skills, and the presence of certain comorbidities (cortical blindness, auditory limitations, nonverbal communication skills, gavage feeding status, and coexisting afebrile seizures in the prior 12 months) was obtained.
  
  
  RESULTS
  The frequency of individual comorbidities, their proportional distribution, and mean number of occurrences basically falls into a significant dichotomous distribution. Across the spectrum of comorbidities considered, these comorbidities are relatively infrequently encountered in those with spastic hemiplegic or spastic diplegic variants or ambulatory GMFCS status (levels I-III), while these entities occur at a frequent level for those with spastic quadriplegic, dyskinetic, or ataxic-hypotonic variants or nonambulatory GMFCS status (levels IV and V).
  
  
  CONCLUSIONS
  The enhanced burdens of comorbidity are unevenly distributed in children with cerebral palsy in a manner that can be associated with either a specific neurologic subtype (spastic quadriplegic, dyskinetic, ataxic-hypotonic) or nonambulatory motor status (Gross Motor Function Classification System levels IV and V). This provides enhanced value to the utilization of these classification approaches.
authors.affiliation: Department of Neurology, McGill University, Montreal, Quebec, Canada. michael.shevell@muhc.mcgill.ca
authors.forename: Michael I
authors.initials: MI
authors.lastname: Shevell
authors.forename: Lynn
authors.initials: L
authors.lastname: Dagenais
authors.forename: Nicholas
authors.initials: N
authors.lastname: Hall
mesh_terms: D001259:Ataxia / Q000453:epidemiology / Q000503:physiopathology; D019575:Blindness, Cortical / Q000453:epidemiology*; D002547:Cerebral Palsy / Q000145:classification / Q000453:epidemiology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D002965:Classification / Q000379:methods; D015331:Cohort Studies; D015897:Comorbidity; D003680:Deglutition Disorders / Q000453:epidemiology*; D004185:Disability Evaluation; D004827:Epilepsy / Q000453:epidemiology*; D005260:Female; D006313:Hearing Loss, Central / Q000453:epidemiology*; D006801:Humans; D008297:Male; D019957:Motor Skills Disorders / Q000453:epidemiology; D009069:Movement Disorders / Q000453:epidemiology / Q000503:physiopathology; D009123:Muscle Hypotonia / Q000453:epidemiology / Q000503:physiopathology; D011782:Quadriplegia / Q000453:epidemiology / Q000503:physiopathology; D012720:Severity of Illness Index