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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous work demonstrated enlargement of the neocerebellar vermis in Williams' syndrome (WS), despite diminished volumes in the cerebral hemispheres. We present the first in vivo volumetric study of any structure within the cerebellar hemispheres. Using MRI, we identified and reliably measured the neocerebellar tonsils in WS subjects; Down's syndrome (DS) subjects matched for age, IQ, and cerebral volume; and age-matched normal controls. WS tonsils were equal in size to control tonsils and larger than DS tonsils. In proportion to the cerebrum, WS tonsils were larger than controls'. These results coincide with the remarkable neuropsychological preservation of language and affect in WS, despite general cognitive impairment. They contrast with the neocerebellar vermal hypoplasia seen in autism, with its communicative and affective deficits. Additionally, two WS subjects showed Chiari type I malformations, but the average tonsillar position in WS was not found to be different than in controls.
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PMID:Specific neurobehavioral profile of Williams' syndrome is associated with neocerebellar hemispheric preservation. 140 82

A 17-year-old boy is described who experienced circling behavior interrupting his gait and complex stereotyped movements of the hands after a complicated repair of an aortic coarctation. An MRI scan showed a right putaminal infarct. The boy's behavior and stereotypies bear a close resemblance to those found in autism.
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PMID:Complex stereotypies after right putaminal infarction: a case report. 175 57

The neuropsychological performances, outcome of epilepsy and MRI topography of tubers of 23 children with tuberous sclerosis were reviewed. Seven children had normal intelligence, 10 had mental retardation, and six mental retardation and autism. An adverse association was found between the number of lesions and IQ, behaviour and severity of epilepsy. Posterior lesions, in addition to frontal-lobe dysfunction, were observed in children with autism. Tuberous sclerosis with well-defined cerebral lesions may represent a model for the relationship between different neuropsychiatric problems.
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PMID:Neuropsychological aspects of tuberous sclerosis in relation to epilepsy and MRI findings. 191 24

MRI was performed for 18 autistic patients, 11 patients with uncomplicated mental retardation (MR) and 18 controls. In autism and MR, and altered left/right relationship of the frontal lobe volume was observed. The altered asymmetry was more severe in autism than in MR. The brain stem was smaller in MR than in the controls, and the right operculum was smaller in MR than in autism. These findings are consistent with the hypothesis that some autisms may involve a type of early developmental abnormality. Furthermore, our results suggest that autism may involve a type of structural brain impairment different from MR.
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PMID:Magnetic resonance imaging in autism: preliminary report. 277 42

During the last five years, it has been recognized a very high incidence of autism in children affected by tuberous sclerosis; we believe that this association may be more than just a coincidence and that it may be that the autistic behavior spectrum is related to a great extent, to the anatomic localization of tubers in the frontal and temporoparietal areas. In this study we report our experience with 27 consecutive children, 12 boys and 15 girls with a diagnosis of tuberous sclerosis confirmed by clinical and MRI and or CT findings according to the diagnostic criteria developed by the Diagnosis Criteria Committee of the National Tuberous Sclerosis Association. They were studied during the period of 1988 to 1990. Ages range from 18 months to 16 years (mean: 6.5 years). Twenty-four had epilepsy and were receiving antiepileptic treatment. Seven of the 27 children (25.9 per cent) fulfilled the diagnostic criteria for autistic disorder according to the DSM-III-R. The autistic behavior was evident in all of them by three and half years. The seven children had mental retardation. MRI and CT findings with subependymal calcifications and cortical tubers of frontal and temporoparietal predominance were seen in five of the seven autistic children. In one child, CT was normal and in the other it was not performed. Five were girls and all had West syndrome; two were boys and neither had seizures. Most of the reported cases of children with tuberous sclerosis and autism had experiences West syndrome. In our patients, five of the seven children with autism had west syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Autism in tuberous sclerosis]. 760 68

MRI and autopsy evidence of early maldevelopment of cerebellar vermis and hemispheres in autism raise the question of how cerebellar maldevelopment contributes to the cognitive and social deficits characteristic of autism. Compared with normal controls, autistic patients and patients with acquired cerebellar lesions were similarly impaired in a task requiring rapid and accurate shifts of attention between auditory and visual stimuli. Neurophysiologic and behavioral evidence rules out motor dysfunction as the cause of this deficit. These findings are consistent with the proposal that in autism cerebellar maldevelopment may contribute to an inability to execute rapid attention shifts, which in turn undermines social and cognitive development, and also with the proposal that the human cerebellum is involved in the coordination of rapid attention shifts in a fashion analogous to its role in the coordination of movement.
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PMID:Impairment in shifting attention in autistic and cerebellar patients. 782 9

Cerebellum may be a common site of developmental abnormalities due to its protracted course of maturation. Recent studies have implicated morphological deviations of the cerebellum as responsible for specific behavioral and cognitive manifestations of autism. We investigated neuropsychology and quantitative MRI of the cerebellum in both high functioning subjects with autism and survivors of childhood leukemia treated with radiation and intrathecal chemotherapy. The results of neuropsychological testing revealed different patterns of cognitive deficits for the two groups, while the abnormal cerebellar morphology was similar for both groups. Since it is suggested that the cerebellum contributes to motor-attentional subsystems, the present data provide support for a cerebellar role in the governance of higher cognitive functions, found to be abnormal in both groups. However, the abnormal macromorphology of the cerebellar vermis described here appears to be non-specific to autism.
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PMID:Cerebellar abnormality in autism: a nonspecific effect of early brain damage? 805 11

The authors obtained neurological assessments and psychiatric family history data for 40 children with autistic spectrum disorders (autism, Asperger syndrome and pervasive developmental disorder). Neurological evaluation included EEG, MRI, karyotyping and positron emission tomography as indicated. Family history data were obtained from family members during long-term follow-up. 20 probands had positive neurological findings, 18 with negative family history. 14 had no neurological findings and positive family histories; they tended to have higher function. Six had neither, and two had both. The segregation of neurological findings and familial affective disorder was highly significant. These findings suggest that an important subgroup of autistic spectrum disorders may be related etiologically to familial major affective disorders, and may represent the early-life onset of a severe phenotype of major affective, particularly bipolar, disease.
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PMID:Psychiatric family history and neurological disease in autistic spectrum disorders. 816 63

Infantile autism is a neurologic disorder of social, cognitive, and language development. Earlier MRI studies found hypoplasia of posterior vermal lobules VI and VII and cerebellar hemispheres in the majority of autistic patients, and recent autopsy analyses find severe Purkinje neuron loss in the posterior vermis (lobules VI and VII and VIII to X) and hemispheres. A second type of cerebellar pathology in infantile autism was recently found: hyperplasia (excessive enlargement) of posterior vermal lobules VI and VII. If the autistic samples in some MRI studies that did not detect cerebellar hypoplasia were actually composed of both the hypoplasia and hyperplasia subtypes, then the autistic mean size reported in such studies would have appeared to be near the normal mean size only because it would be the sum of the two opposite subtypes. To test this possibility, we statistically reanalyzed previously published vermal area measures of 78 autistic patients from four separate studies. The results revealed that the autistic patient samples from these four studies were indeed composed of both the hypoplasia subtype (87%, 92%, 89%, and 84% of patients) and the hyperplasia subtype (13%, 8%, 11%, and 16% of patients). Cerebellar abnormalities have been found in 15 autopsy and quantitative MRI reports from nine laboratories involving a total of 226 autistic cases. Autism may be one of the first developmental neuropsychiatric disorders for which substantial concordance exists among several independent microscopic and macroscopic studies as to the location and type of neuroanatomic maldevelopment. Onset might be as early as the second trimester. Discovery of the etiologies underlying cerebellar maldevelopment may be the key to uncovering some of the causes of infantile autism.
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PMID:The brain in infantile autism: posterior fossa structures are abnormal. 830 59

Autism is a syndrome with multiple etiologies, as is made clear both by the evidence of neurobiological research and by the catalog of disorders that present with autistic behaviors. What remains unclear are the specific neuropathological mechanisms that produce autistic behaviors; for example, is there a common neuroanatomic pathology for all cases of autism, or can autistic behaviors emerge from different pathological sequences within the brain? Although it is premature to generalize, neuropathological studies appear to have identified common abnormalities in the cerebellum and limbic system of at least five autistic subjects. These subjects, with variable levels of mental retardation, demonstrated marked Purkinje cell loss in the cerebellar hemispheres, together with retained fetal neuronal circuitry in cerebellar nuclei and increased neuronal packing in specific regions of the limbic system, amygdala, and hippocampus. The architecture of the cerebral cortex was not affected. Although our knowledge of brain functioning is incomplete, alterations of the kind noted in the cerebellum and limbic system could reasonably produce autistic behaviors. For more detail, readers are directed to a review of cerebellar contributions to higher functions by Schmahmann (1991). Neuroimaging studies allow less resolution of brain structure than do neuroanatomic studies, and the reported findings from neuroimaging are somewhat contradictory. However, a number of investigators have reported structural abnormalities in ventricle size and cerebral hemispheric asymmetry using CT. MRI, which offers greater resolution, has uncovered some consistent findings, along with a variety of nonspecific abnormalities. Common abnormalities include reduced volume of cerebellar hemispheres and vermal lobules--findings not inconsistent with the above-mentioned neuropathological defects. It is also interesting to note that individuals with fragile X syndrome have similar cerebellar findings. PET and NMR studies of autism are at a preliminary stage, but these methodologies allow insight into the functioning of the brain, rather than simply brain anatomy. Recent PET studies indicating decreased association between paired regions of the brains of autistic subjects are of interest, particularly if they can be confirmed and refined by additional studies. Neurophysiological studies also offer insight into brain function, but are subject to numerous methodological criticisms. Nevertheless, recent reports of diminished P300 waves and absent NC components in autistic subjects seem to indicate fundamental defects in attention and secondary processing, which could help explain the self-stimulatory behaviors often seen in autism. The disturbances in brain development associated with autism can be produced in a number of ways, and at different times during development of the nervous system.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The neurobiology and genetics of infantile autism. 846 65


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