The relationship between 99mTc-HMPAO brain SPECT and the scores of real life rating scale in autistic children

Abstract

Childhood autism is a developmental disability of unknown origin with probable multiple etiologies. The purpose of this study was to compare the changes of regional cerebral blood flow (rCBF) in autistic and non-autistic controls, and to determine the relationship between rCBF on 99mTc-hexamethylpropylene amine oxime (HMPAO) brain SPECT and the scores of the Ritvo–Freeman Real Life Rating Scale (RLRS), IQ levels, and age of autistic children. Eighteen autistic children (four girls, 14 boys; mean age: 6.13±1.99 years) and 11 non-autistic controls (five girls, six boys, mean age: 6.5±3.39 years) were examined using 99mTc-HMPAO brain SPECT. All the children satisfying DSM-IV criteria for autistic disorder were taken into evaluation, and scored by the Ritvo–Freeman RLRS. IQ levels of these children were determined by Goodenough IQ test. Six cortical regions of interest (ROIs; frontal (F), parietal (P), frontotemporal (FT), temporal (T), temporo-occipital (TO), and occipital (O)) were obtained on transaxial slices for count data acquisition. The ratio of average counts in each ROI to whole-slice counts for the autistic children was correlated with the scores of Ritvo–Freeman RLRS. Hypoperfusion in rCBF in autistic children compared with the control group were identified in bilateral F, FT, T, and TO regions. We found no relationship between rCBF on 99mTc-HMPAO brain SPECT and the scores of the Ritvo–Freeman RLRS. There was a relationship between bilateral F regions perfusion on 99mTc-HMPAO brain SPECT and the age of autistic children. There was also a negative correlation between IQ levels and the scores of sensory responses, social relationship to people, and sensory-motor responses. Our results suggest that 99mTc-HMPAO brain SPECT is helpful to locate the perfusion abnormalities but no correlation is found between rCBF on 99mTc-HMPAO brain SPECT and the scores of Ritvo–Freeman RLRS.