Ahmed Kamal
Objective: The dysfunction of the autonomic nervous system investigated in Children with Autism compared with healthy one. Cardiovascular autonomic disturbances are possibly associated with the pathogenesis of Autism in children. The purpose of this study is to use the spectral and coherence analysis of heart rate variability signal (HRV), respiration signal and peripheral blood flow signal (PBF) to assess the autonomic activity of normal children and children with Autism for the clinical usefulness of the applied methods of signal processing and timefrequency analysis for screening and treatment of Autism in children.
Methods: Twenty four children who had Autism and who were not taking any medications and Twenty three age and sex matched controls (Children) were participated in this study at Department of Neurology at Johns Hopkins Hospital, Baltimore, MD, USA and Regional Medical Center, Cookeville, TN, USA. PBF and respiration signals as well as HRV signal derived from Electrocardiogram (ECG) were measured during supine and standing positions. Autopower, cross power and coherence spectra were produced to investigate the sympathetic and parasympathetic activity in both groups.
Results: The results clearly indicate that in children with Autism, the coherence values are less than in control group in both low frequency (LF) and high frequency (HF) bands at coherence spectra between HRV and PBF as well as HRV and respiration in both supine and standing position. Also, the ratio of amplitude at nearly frequency of 0.1 Hz in auto power spectra and coherence spectra is less in Autism group than in matched control (p<0.001).
Conclusion: Autopower and coherence spectra analysis for Children with Autism compared to normal Children seems useful in the assessment of autonomic function for Autism patients. The decreased of autonomic function specially parasympathetic activity in patients with Autism revealed by auto power and coherence spectra analysis is significant and may be related to the effective of treatment of Autism children in this disorder compared to controls. Further studies is needed using other tests and methods of signal analysis to introduce clinical indices for early detection of autonomic function in patients with Autism.
