technetium-tc-99m-exametazime and Intellectual-Disability

The authors examined specific deficits of cerebral blood perfusion in autistic patients as measured with [(99m)Tc]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 with mental retardation but no autism comparable in chronological age, mental age, height, weight, and head circumference. All participants were examined with a comprehensive psychiatric and neuropsychological battery and received a [(99m)Tc]HMPAO SPECT scan. Autistic patients had significantly lower perfusion than the control group in the following brain regions: right temporal lobe (basal and inferior areas), occipital lobes, thalami, and left basal ganglia. The study demonstrated significant perfusion deficits in specific brain areas of moderately to severely mentally retarded autistic patients.

Topics: Autistic Disorder; Brain; Child; Female; Humans; Intellectual Disability; Magnetic Resonance Imaging; Male; Neuropsychological Tests; Radiopharmaceuticals; Severity of Illness Index; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Twenty-six people with Down's syndrome (DS) were investigated using 99Tc(m)-hexamethylpropylene amine oxime (99Tc(m)-HMPAO) and single photon emission tomography (SPET). Dementia was diagnosed using a structured carer interview giving a deterioration score and by studying the case notes. Five subjects were clinically demented, 7 showed mild deterioration and 14 no deterioration. Increased deterioration correlated with advancing age (correlation coefficient 0.5425; P<0.02), but there was no significant difference between older (>40 years) and younger (<40 years) patients. Only one of the subjects with dementia had a regional cerebral blood flow (rCBF) abnormality that was of the dementia of Alzheimer type. Three subjects with mild deterioration and three with no deterioration had abnormal SPET scans. There was no association between the SPET abnormality and clinical dementia or with evidence of deterioration.

Topics: Adult; Age Factors; Brain; Dementia; Down Syndrome; Female; Humans; Intellectual Disability; Male; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The mind's ability to think about the mind has attracted substantial research interest in cognitive science in recent decades, as 'theory of mind'. No research has attempted to identify the brain basis of this ability, probably because it involves several separate processes. As a first step, we investigated one component process-the ability to recognise mental state terms.. In Experiment 1, we tested a group of children with autism (known to have theory of mind deficits) and a control group of children with mental handicap, for their ability to recognise mental state terms in a word list. This was to test if the mental state recognition task was related to traditional theory of mind tests. In Experiment 2, we investigated if in the normal brain, recognition of mental state terms might be localised. The procedure employed single photon emission computerised tomography (SPECT) in normal adult volunteers. We tested the prediction (based on available neurological and animal lesion studies) that there would be increased activation in the orbito-frontal cortex during this task, relative to a control condition, and relative to an adjacent frontal area (frontal-polar cortex).. In Experiment 1, the group with autism performed significantly worse than the group without autism. In Experiment 2, there was increased cerebral blood flow during the mental state recognition task in the right orbito-frontal cortex relative to the left frontal-polar region.. This simple mental state recognition task appears to relate to theory of mind, in that both are impaired in autism. The SPECT results implicate the orbito-frontal cortex as the basis of this ability.

Topics: Adolescent; Adult; Affective Symptoms; Arousal; Autistic Disorder; Awareness; Brain Mapping; Child; Female; Frontal Lobe; Humans; Intellectual Disability; Male; Organotechnetium Compounds; Oximes; Regional Blood Flow; Semantics; Speech Perception; Technetium Tc 99m Exametazime; Thinking; Tomography, Emission-Computed, Single-Photon

Brain SPECT imaging was performed in 13 children with cerebral palsy (6 girls, 7 boys; age, 7-17 years) due to perinatal asphyxia with mental retardation and involved limbs were studied. The involved coronal slices were summated to a picture for the calculation of the perfusion defect indices as the quantitative and objective estimation of the perfusion defects in each brain. The records of IQ tests were scored from severe to mild mental retardation. Two experienced nuclear medicine physicians analyzed the results of the Tc-99m HMPAO brain SPECTs by visual interpretation. The involved limbs were judged by two pediatricians to be either the right or left side. The relationship among the Tc-99m HMPAO brain SPECTs, IQ test, and physical examinations of the extremities were established. The results showed that two cases of mild mental retardation had the smaller perfusion defect indices (< 0.1), six cases of severe mental retardation had the larger perfusion defect indices (> 0.30), and the other group was between the first two groups. Two cases of mild mental retardation did not have significant perfusion defects in the brain and involved limbs, and two cases with decreased visual acuity had definite perfusion defects in the occipital regions. The other cases had the matched perfusion defects of the brain with the involved limbs. The authors encourage the potential use of Tc-99m HMPAO brain SPECTs to predict the outcome of mental development and limb involvement.

Topics: Adolescent; Asphyxia Neonatorum; Brain; Cerebral Palsy; Cerebrovascular Circulation; Child; Extremities; Female; Humans; Infant, Newborn; Intellectual Disability; Intelligence Tests; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Alterations in regional cerebral blood-flow, as determined by single-photon emission computed tomography (SPECT) using technetium [99mTc] hexamethyl propylenamine oxime, were studied in two children presenting with alternating hemiplegia of childhood. Both experienced hemiplegic episodes several times per month, despite marked improvement on flunarizine therapy. SPECT images of both patients revealed focal areas of decreased uptake of the radiotracer, representing impaired regional cerebral blood-flow during, as well as between, seizures. The interictal finding of localized areas of reduced tracer uptake suggest that long-lasting hypoperfusion could be the pathophysiological mechanism by which the slowly resolving hemiplegia, and ultimately the permanent multifocal neurological deficits, are produced.

Topics: Brain; Brain Diseases; Cerebrovascular Circulation; Child, Preschool; Female; Flunarizine; Functional Laterality; Hemiplegia; Humans; Intellectual Disability; Language Disorders; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We evaluated regional cerebral blood flow with technetium 99mTc hexamethylpropyleneamineoxime single photon emission computed tomography (SPECT) in 20 children and adolescents with neurologic dysfunction of varied etiology and abnormal electroencephalograms (EEGs). All patients were also examined with computed tomography (CT) and magnetic resonance imaging (MRI). Abnormal perfusion was found in 17 (85%) of 20 SPECT scans. Abnormal CT or MRI scans were noted in nine (45%) and in 10 (50%) of 20 cases, respectively. In eight (73%) of 11 cases with normal CT scans and in seven (70%) of 10 with normal MRI scans, the SPECT scan was abnormal. Abnormal regional cerebral blood flow on SPECT scans correlated better with EEG abnormalities than with neurologic examination or CT or MRI scan findings. We conclude that in children and adolescents with a spectrum of neurologic diseases and abnormal EEGs, abnormalities of brain structure or function are more likely to be documented by SPECT than by CT or MRI scans. SPECT findings correlate well with the location and type of EEG abnormality.

Topics: Adolescent; Adult; Brain Diseases; Cerebrovascular Circulation; Child; Child, Preschool; Electroencephalography; Female; Humans; Infant; Intellectual Disability; Magnetic Resonance Imaging; Male; Nervous System Diseases; Organotechnetium Compounds; Oximes; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Thirteen mentally retarded pediatric patients aged 4 to 13 years with therapy-resistant epilepsy underwent Tc-99m HMPAO brain perfusion SPECT studies. The results (abnormal in 12 of the 13 patients) were compared with EEG results in 12 of the 13 patients (abnormal in all 12) and x-ray CT in 11 of the 13 patients (normal in 9). Patients with spikes on EEG had foci of increased uptake on HMPAO. This study confirms that HMPAO is sensitive in detecting perfusion abnormalities and localizing epileptic foci in this group of patients.

Topics: Brain; Cerebrovascular Circulation; Child; Electroencephalography; Epilepsy; Female; Humans; Intellectual Disability; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed