Biomedical subjects

A Klin

Publications and source records attributed to A Klin.

25 records · Page 2Linked to original sources

PubMed1993

Auditory brainstem responses in autism: brainstem dysfunction or peripheral hearing loss?

The advent of electrophysiological techniques for audiologic and neurologic assessment in the late 60s has generated at least 11 auditory brainstem response (ABR) studies in autism designed to test the integrity of the auditory brainstem pathways. The results reported are contradictory, involving prolongation, shortening, and no abnormalities in central transmission latencies. When sample and methodological factors influencing the ABR are taken into consideration in the interpretation of results, the ABR data available at present can be seen as only suggestive, rather than supportive, of brainstem involvement in autism. Paradoxically, these studies revealed the presence of peripheral hearing impairment in a non-negligible number of autistic individuals. Additional evidence of auditory abnormalities as well as the implications for the clinician are considered.

Acoustic Stimulation↗

PubMed1993

Elective mutism and mental retardation.

The association of elective mutism and mental retardation is noted. Two cases of elective mutism associated with mental retardation are presented. Both individuals had long-standing patterns of inhibition, shyness, and anxiety manifested by general refusal to talk outside the home, particularly at school. The importance of assessment of intellectual functioning and linguistic skills for the establishment of intervention priorities and clinical management is discussed. The possibility of the presence of mental retardation in individuals with elective mutism should be considered.

Adolescent↗

PubMed1993

Integrating biological and behavioral perspectives in the study and care of autistic individuals: the future.

The core clinical feature of autism is a profound disturbance in the emergence of social relations, apparent as early as the very first months of life and almost always by age three years. Many different theories have been proposed to explain this dramatic developmental dysfunction, including cognitive, linguistic, arousal and, most recently, "theory of mind" hypotheses. There is great heterogeneity among autistic individuals and no single explanation captures all the clinical phenomena. Because of the divergent theories and their associated treatment approaches, parents are often burdened by conflicting advice. Field trials and other studies have provided excellent diagnostic criteria for autism for DSM-IV and ICD-10, with high sensitivity and specificity. Careful definition of the clinical phenotype is essential for neurobiological, genetic and behavioral research. While many lines of evidence point to underlying disturbances in brain maturation, no specific CNS dysfunction or biological correlate has been discovered. Rigorous research is not only essential for improving the understanding and treatment of autism; such studies may also help elucidate the normal preconditions for socialization and the pathways that allow a child to enter into the world of human relationships.

Autistic Disorder↗

PubMed1992

Listening preferences in regard to speech in four children with developmental disabilities.

In a previous experimental study of children's listening responses in regard to speech sounds, autistic children showed preferential patterns which were in sharp contrast to a group of mentally-handicapped and normally-developing children. The present study reports the data obtained for four children whose clinical diagnosis (1) became available only some time after the study was carried out, and/or (2) differed from previously recorded clinical impressions. The results obtained support previous findings according to which a lack of attraction to speech sounds appears to be a feature of young autistic children's overall disregard to people. The present technique is discussed as a viable method to examine experimentally young autistic children's social unresponsiveness.

Acoustic Stimulation↗

PubMed1992

Autistic social dysfunction: some limitations of the theory of mind hypothesis.

This study examined the extent to which the social disabilities found in autism can be accounted for by the "Theory of Mind" hypothesis. Items related to social development from the Vineland Adaptive Behavior Scales were administered to 29 CA-, MA- and IQ-matched pairs of young autistic and non-autistic, developmentally disabled children. These items were evaluated in relation to expected ages of acquisition based on the Vineland standardization database. Our results indicate that the social dysfunction in autism affects very basic and early emerging social behaviors which are typically present prior to the time at which even the earliest precursors of a theory of mind apparently emerge.

Age Factors↗

PubMed1991

Young autistic children's listening preferences in regard to speech: a possible characterization of the symptom of social withdrawal.

Autism is a childhood disorder diagnosed primarily in the presence of severe social unresponsiveness in the first 3 years of life (Volkmar, 1987). Since speech exerts a prepotent attraction on the attention of normally developing infants, hence facilitating social engagement, we designed a technique to examine whether this inborn reaction could be at fault in young autistic children. They were given a choice between their mothers' speech and the noise of superimposed voices (a sound effect obtained in a busy canteen). Data were obtained utilizing a specially designed automated and computerized device which recorded the children's responses in their own homes. In contrast to comparison groups of mentally retarded and normally developing children who showed the expected strong preference for their mothers' speech, the autistic children actively preferred the alternative sound or showed a lack of preference for either audio segment. These results suggest that such abnormal reactions to speech are a feature of these children's overall disregard to people.

Arousal↗

PubMed1983

Unique profile for erythrocyte membrane acetylcholinesterase in hereditary spherocytosis.

Acetylcholinesterase of human erythrocytes from healthy donors and from patients with hematological disorders was analysed in a search for differential membrane parameters. Two substrates were used to estimate the exposure of acetylcholinesterase active site in the membrane: phenylacetate, a hydrophobic substrate, to determine total enzyme activity, and acetylcholine, an ionic substrate, to measure the externally reactive enzyme. The sensitivity of acetylcholinesterase to added stearic acid was also analysed. Three categories of the disorders studied were discerned: (a) The erythrocyte acetylcholinesterase profile was indistinguishable from normal control in beta-thalassemia minor and groups of patients with autoimmune hemolytic anemia or congenital dyserythropoietic anemia type II. (b) A marked decline in acetylcholinesterase with both substrates and reduced sensitivity to stearic acid were exhibited by the erythrocytes of paroxysmal nocturnal hemoglobinuria, beta-thalassemia major and other autoimmune hemolytic anemia and congenital dyserythropoietic anemia type II patients. Normal erythrocytes, either aged or pretreated to 50 degrees C, also showed similar characteristics. (c) Hereditary spherocytosis was singly differentiated by an elevated acetylcholinesterase activity with acetylthiocholine and by a vastly diminished sensitivity to stearic acid, while activity with phenylacetate was equal to control. This distinct profile may reflect the unique organization of the erythrocyte membrane in hereditary spherocytosis.

Acetylcholinesterase↗