SPECT findings in mentally retarded autistic individuals

The authors examined specific deficits of cerebral blood perfusion in autis tic patients as measured with [Tc-99m]HMPAO single-photon emission computed tomography (SPECT). The study, conducted in an outpatient clinic setting, included a consecutive series of 30 patients with autism and 14 patients wi th mental retardation but no autism comparable in chronological age, mental age, height, weight, and head circumference. All participants were examine d with a comprehensive psychiatric and neuropsychological battery and recei ved a [Tc-99m]HMPAO SPECT scan. Autistic patients had significantly lower p erfusion than the control group in the following brain regions: right tempo ral lobe (basal and inferior areas), occipital lobes, thalami, and left bas al ganglia. The study demonstrated significant perfusion deficits in specif ic brain areas of moderately to severely mentally retarded autistic patient s.