Heart rate variability in children with cerebral palsy: review of the literature and meta-analysis.

OBJECTIVE: A systematic review which aims to assess the evidence regarding the function of the autonomic heart rate regulation system among children with cerebral palsy (CP).

METHODS: The target population included children with CP of diverse severity, aged 1.5 to 18 years. Databases searched for English language studies from 1960 to 2013: PubMed, EMBASE, CINAHL, Cochrane Library, The Physiotherapy Evidence Database (PEDro), and ClinicalTrials.gov site. Search terms included 'cerebral palsy' or 'spastic diplegia' or 'hemiplegia' or 'quadriplegia' and 'autonomic nervous system' or 'heart rate variability' or 'sympathetic' or 'para sympathetic'. Twenty five articles were identified and included if (1) participants were less than 18 years of age, (2) diagnosis of CP was made after the age of 18 months (3) more than 80% of cases had a diagnosis of CP and (4) autonomic cardiac heart rate regulation system state or response to a stimuli was described for all the participants. Six articles met the criteria for inclusion.

RESULTS: Evidence suggests that reduced Heart Rate Variability (HRV) time domain parameters close to birth are associated with a CP diagnosis at the age of three years. In addition, HRV parameters' mean values, are significantly lower among children with CP compared to typically developed (TD) control. While performing head up, tilt or standing position, HRV was significantly reduced only among TD control, but no effect was seen in those variables among children with CP.

CONCLUSION: Further studies are needed to assess the potential to predict CP by assessing HRV parameters among newborn children. In addition, assessing HRV among children with CP may improve our understanding of the heart rate autonomic system and its response to different stimulus such as muscle contraction, paced breathing and aerobic training.