Biomedical subjects

L de Sonneville

Publications and source records attributed to L de Sonneville.

8 recordsLinked to original sources

PubMed2001

Disordered recognition of facial identity and emotions in three Asperger type autists.

In this report we aim to explore severe deficits in facial affect recognition in three boys all of whom meet the criteria of Asperger's syndrome (AS), as well as overt prosopagnosia in one (B) and covert prosopagnosia in the remaining two (C and D). Subject B, with a familially-based talent of being highly gifted in physics and mathematics, showed no interest in people, a quasi complete lack of comprehension of emotions, and very poor emotional reactivity. The marked neuropsychological deficits were a moderate prosopagnosia and severely disordered recognition of facial emotions, gender and age. Expressive facial emotion, whole body psychomotor expression and speech prosody were quasi absent as well. In all three boys these facial processing deficits were more or less isolated, and general visuospatial functions, attention, formal language and scholastic performances were normal or even highly developed with the exception of deficient gestalt perception in B. We consider the deficient facial emotion perception as an important pathogenetic symptom for the autistic behaviour in the three boys. Prosopagnosia, the absent facial and bodily expression, and speech prosody were important but varying co-morbid disorders. The total clinical picture of non-verbal disordered communication is a complex of predominantly bilateral and/or right hemisphere cortical deficits. Moreover, in B, insensitivity to pain, smells, noises and internal bodily feelings suggested a more general emotional anaesthesia and/or a deficient means of expression. It is possible that a limbic component might be involved, thus making affective appreciation also deficient.

Adult↗

PubMed2000

Visual sustained attention in a child psychiatric population.

OBJECTIVE: To increase knowledge of the diversity and specificity of sustained attention deficits in children with attention-deficit hyperactivity disorder (ADHD), with special reference to the issue of distinguishing between children with ADHD and children with other psychiatric diagnoses. METHOD: A visual sustained attention task was used to compare 52 boys with ADHD with 55 normal controls, 29 boys with oppositional defiant disorder or conduct disorder (ODD/CD), 29 boys with anxiety or dysthymia (ANX/DYS), 43 boys with pervasive developmental disorder, 24 boys with ADHD plus ODD/CD, and 14 boys with ADHD plus ANX/DYS. RESULTS: Compared with normal controls, children with ADHD were slower, were more inaccurate, were more impulsive, were less responsive to feedback, and showed less perceptual sensitivity and stability of performance, resulting in a marked decrease in vigilance over time. Unresponsiveness to feedback and the extent of the decrease in vigilance during time on task were found to be the only factors that distinguished children with ADHD from children with other diagnoses. CONCLUSION: Although only children with ADHD are characterized primarily by "attention deficit," sustained attention deficit is common to a certain extent to all children with psychiatric disorders.

Anxiety↗

PubMed1997

EEG coherence changes during finger tapping in acallosal and normal children: a study of inter- and intrahemispheric connectivity.

The EEG inter- and intrahemispheric coherences (ICoh and HCoh) in the theta, alpha and beta bands were studied in an acallosal group (ACCG) of five children and a normal group of 30 sex- and age-matched children (NG) during resting and tapping conditions. Being functionally deficient, tapping in the ACCG was characterized by increased intertap intervals and variability (in right-hand tapping) and by variability together with decreased synchronization (in bimanual tapping). In the ACCG, frontal, central and parietal ICohs were shown to be smaller, while temporal ICohs were larger under all conditions (see also Koeda, T., Knyazeva, M., Jonkman, J., Njiokiktjien, C., De Sonneville, L., Vildavsky, V., 1995. The resting EEG in acallosal children: compensatory left hemisphere mechanisms? Electroencephalogr. Clin. Neurophysiol. 95, 397-407). The effect was most pronounced in the EEG beta band. The sagittal HCohs, including fronto-central, fronto-parietal, and centro-parietal HCohs within both hemispheres, were larger in the ACCG, whereas temporal HCoh (fronto-temporal, centro-temporal, parieto-temporal and occipito-temporal) were smaller, suggesting rearrangement of intracortical activity associated with callosal agenesis. Tapping induced an increase in ICoh and HCoh between frontal, central and parietal areas in the NG, and weak enhancement only in the left temporal HCoh in the ACCG. The beta band, the most reactive band in the NG, was 'silent' in the ACCG, suggesting deviant cortical function during motor activity as well.

Adolescent↗

PubMed1995

Effect of high-dose tyrosine supplementation on brain function in adults with phenylketonuria.

OBJECTIVES: To characterize abnormalities of brain function in patients with phenylketonuria (PKU) who had relaxed or stopped the dietary regimen and to test whether oral high-dose tyrosine (Tyr) supplementation has a beneficial effect. DESIGN: Comparison with a control group; double-blind, placebo-controlled study comprising six test times; crossover treatment groups; oral high-dose Tyr therapy (100 mg/kg body weight per day) or placebo administration for 4 weeks. SUBJECTS: Twenty-four early-treated patients with PKU aged 20.8 (16 to 25) years; 24 control subjects. METHODS: Plasma concentrations of phenylalanine and Tyr were monitored. Neuropsychologic tasks, visual evoked potentials, and spectral analysis of electroencephalographic activity were used to evaluate brain function. RESULTS: When patients with PKU were compared with control subjects, deficits in certain aspects of brain function were confirmed (i.e., a decreased ability to sustain attention, prolonged latencies of visual evoked potential peaks N1 and P2, and a reduced amount of fast-wave activity on the electroencephalogram). Baseline plasma phenylalanine and Tyr concentrations were in the typical range of adult patients with PKU. The plasma Tyr concentration increased approximately 200% during Tyr supplementation, but no beneficial effects were observed. CONCLUSIONS: High-dose Tyr supplementation cannot be recommended as an "alternative" treatment for patients with PKU after relaxation or termination of strict dietary adherence.

Adolescent↗

PubMed1994

Callosal size in children with learning disabilities.

The corpus callosum (CC), the main structure subserving hemispheric collaboration, that is necessary for efficient cognitive functioning, undergoes developmental processes such as axonal retraction and myelination. Callosal growth therefore is vulnerable for adverse events such as perinatal asphyxia, but there are also genetic and epigenetic factors that determine form and thickness. MRI scans of 110 children, either with specific learning disabilities (LD), i.e. dysphasia/dyslexia, or with several degrees of general LD, showed callosa that were highly variable in size. The callosal size corrected for brain size did not vary significantly according to the severity of the LD, although it tended to be smaller in severe LD, i.e. mental retardation. Callosal size varied however, due to the likely presence of genetic influences or of adverse perinatal events. Children with familial dysphasia/dyslexia, had a thicker CC, possibly reflecting a poorly understood neurodevelopmental mechanism that inhibits the establishment of cerebral dominance. LD children (all subgroups together) with perinatal adverse events had a smaller CC than the familial cases, suggesting CC damage. Despite a multitude of developmental factors influencing the final size, this study suggests that total callosal size, supposedly linked to interhemispheric function, may contribute to the pathophysiological mechanisms that give rise to LD.

Adolescent↗

PubMed1994

Neuropsychological and biochemical investigations in heterozygotes for phenylketonuria during ingestion of high dose aspartame (a sweetener containing phenylalanine).

Aspartame, a high intensity sweetener, is used extensively worldwide in over 5,000 products. Upon ingestion, aspartame is completely metabolized to two amino acids and methanol (approximately 50% phenylalanine, 40% aspartic acid, and 10% methanol). The effects of aspartame on cognitive function, electroencephalograms (EEGs) and biochemical parameters were evaluated in 48 adult (21 men, 27 women) heterozygotes for phenylketonuria (PKUH), PKUH subjects whose carrier status had been proven by DNA analysis ingested aspartame (either 15 or 45 mg/kg/day) and placebo for 12 weeks on each treatment using a randomized, double-blind, placebo-controlled, crossover study. A computerized battery of neuropsychological tests was administered at baseline weeks -2 and -1, and during treatment at weeks 6, 12, 18, and 24. Samples for plasma amino acids and urinary organic acids were also collected during these visits. EEGs were evaluated by conventional and spectral analysis at baseline week -1 and treatment weeks 12 and 24. The results of the neuropsychological tests demonstrated that aspartame had no effect on cognitive function. Plasma phenylalanine significantly increased, within the normal range for PKUH, at 1 and 3 h following the morning dose of aspartame in the group receiving the 45 mg/kg per day dose only. There were no significant differences in the conventional or spectral EEG analyses, urinary organic acid concentrations, and adverse experiences when aspartame was compared with placebo. This study reaffirms the safety of aspartame in PKUH and refutes the speculation that aspartame affects cognitive performance, EEGs, and urinary organic acids.

Adolescent↗

PubMed1994

Sustained attention in adult phenylketonuria: the influence of the concurrent phenylalanine-blood-level.

The effect of concurrent phenylalanine levels (Phe-level) on sustained attention was tested in a group of 19 early treated adult PKU patients. Mean age was 20.5 years; WAIS IQs were in the normal range (M = 109.3). Phe-levels were manipulated in a high-low-high design by reintroduction of a strict phenylalanine-reduced diet for 4 to 5 weeks between test time 1 and 2 and returning to usual diet between test time 2 and 3. A control group of 20 healthy subjects, mean age 20.7 years was tested twice. Results of a sustained attention task are presented. In adult PKU patients with high concurrent Phe-levels, sustained attention is significantly impaired and reaction times are prolonged. In the low Phe-level condition, performance improved significantly. Nevertheless, the PKU group did not reach the level of performance of the control group. Results are not influenced by IQ and suggest a sustained attention deficit in adult PKU patients that varies according to the concurrent Phe-level. The partial reversibility of the deficits provides support for the hypothesis that biochemical mechanisms rather than structural changes of the brain underlie the relationship between concurrent Phe-level and sustained attention.

Adolescent↗

PubMed1993

EEGs in phenylketonuria. I: Follow-up to adulthood; II: Short-term diet-related changes in EEGs and cognitive function.

The authors report the results of two EEG studies on adult patients with phenylketonuria (PKU) who had been treated early. Part I: the authors followed the EEGs of 34 PKU patients from birth to age 21. The frequency of abnormal EEG findings (especially epileptiform activity) steadily increased until age 12, then decreased. IQ correlated significantly with quality of dietary control during follow-up. Part II: frequency analysis of the EEG and neuropsychological testing were performed on eight adult patients after periods of four weeks with low and high levels of phenylalanine. Only five patients followed the strict dietary regulations. With high levels of phenylalanine, the dominant peak of EEG background activity shifted to the slower frequency spectrum in all patients; in addition, neuropsychological testing revealed impairment of cognitive function. The significance of different approaches of EEG examinations is discussed with respect to the problems of monitoring PKU patients and the pathogenic mechanisms of CNS damage in phenylketonuria.

Adolescent↗