These findings suggest neuronal dysfunction in the ACC and left DLPFC in autism, and also a relationship between social disability and metabolic dysfunction in these regions. Dysfunction in the ACC and the left DLPFC may contribute to the pathogenesis of autism.

SUMMARY Volume‐selective proton magnetic resonance spectroscopy (1H‐MRS) of the brain was performed with a 1.5 Tesla magnet in 47 healthy children and in six healthy adults. Peaks of N‐acetylaspartate (NAA), choline (Clio) and creatine (Cr) were observed in all cases, but a lactate peak was not observed. In the right parietal region, I H‐MRS revealed increases in the rations of NAAJCho and NAA/Cr and a decrease in Cho/Cr with advancing age. The most rapid changes were noted between one and three years of age. 1H‐MRS of the right frontal region also was performed in 21 cases (20 children and one adult). In the right frontal region, there was an increase in the ratio of NAA/Cho and a decrease in Cho/Cr with advancing age, while a developmental change was not observed in the ratio of NAA/Cr. The ratios of both NAA/Cho and NAA/Cr were lower in the right frontal region than in the right parietal region. These results show that developmental changes and regional variation of metabolites are observed in 1 H‐MRS of the brain, and need to be considered in its application. RÉSUMÉ Modifications développemental du vervain exploré par spectroscopic de résonance magnátique protonique Une spectroscopic de résonance magnétique protonique en sélection de volume (1H‐MRS) du cerveau a été réalisé avec un aimant de 1.5 tesla chez 47 enfants et six adultes, tous en bonne sante. Les pics de N‐acétylaspartate (NAA), choline (Cho) et créatine (Cr) furent observés dans tous les cas mais il ne fut pas observé de pic de lactate. Dans la région pariétale droite, l' 1 H‐MRS révéla un accroissement des rapports NAA/Cho et NAA/Cr. et une diminution du rapport Cho/Cr avec l'avance en àge. Les modifications les plus rapides furent notées entre un et trois ans. Une 1 H‐MRS de la région frontale droite fut aussi effectuée dans 21 cas (20 enfants et un adulte). Dans la region frontale droite, il y avait un accroissement avec l'âge du rapport NAA/Cho et une diminution du rapport Cho/Cr, sans modification developpemcntale du rapport NAA/Cr. Les rapports NAA/Cho et NAA/Cr étaient tous les deux plus faibles dans la region frontale droite que dans la région pariétale droite. Ces résultats démontrent que des modifications développemeniales et des variations régionales de métabolites sont observées dans l' 1H‐MRS du cerveau et doivent être prises en compte. ZUSAMMENFASSUNG Untersuchungen von Hintveranderungen mit der magnetischen Pmtonenresonnanzspcktroskopie Volumenselektive magnetische Protonenresonnanzspektroskopie (1H‐MRS) des Gehirns mit einem 1.5 Tesla Magneten wurde bei 47 gesunden Kindern und sechs gesunden Erwachsenen durchgeführt. Bei alien Probanden wurden Ausschlägc für N‐Azetylaspartat (NAA), Cholin (Cho) und Kreatin (Cr) beobachtet, jedoch kein Laktat Ausschlag. In der rechten Parietalregion zeigte die 1H‐MRS mit fortschreitendem Alter eine Zunahme der Verhältnis.se von NAA/Cho und NAA/Cr und eine Abnahme von Cho/Cr. Zwischen dem ersten und dem dritten Lebensjahr wurden die schnellsten Veränderungen beobachtet. Bei 21 Probanden (20 Kinder u...

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Children with infantile autism sometimes show hyperesthesia or hypoesthesia to touch, pain, and/or temperature. To clarify the pathophysiology, we examined short-latency somatosensory evoked potentials (S-SEPs), elicited by median nerve stimulation, in 24 children with infantile autism (17 males, seven females; age range 2y 2mo-9y; mean age 4y 2mo [SD 1y 7mo]). We also evaluated relationships between S-SEP findings and clinical manifestations. Of the 24 children, 10 showed abnormal S-SEPs as follows: prolonged peak latency of N20 (n=2), extended interpeak latency of P13/14-N20 (n=7), appearance of a giant SEP (n=1), and a more than twofold right hemispheric peak-to-peak amplitude predominance of N20-P25 (n=5). In addition, a peak-to-peak amplitude of N20-P25 elicited by left median nerve stimuli was significantly higher than that obtained with right median nerve stimuli, which indicated right hemispheric hyperactivity relative to the left (p=0.008). Infantile autism is frequently associated with somatosensory abnormalities and right hemispheric hyperactivity relative to the left, especially in the primary somatosensory area. This is believed to contribute to the pathophysiology of infantile autism, especially the idiopathic form.Infantile autism is defined by three major features: impairment of reciprocal social interaction, impairment in verbal and nonverbal communication, and a markedly restricted repertoire of activities and interests. 1 Although many studies have attempted to clarify the pathogenesis of this disorder, causes remain unclear. 2,3 In addition to the three cardinal symptoms, some children with autism also show sensory abnormalities such as hyperesthesia or hypoesthesia to touch, pain, and/or temperature. 4 Although physical examination of children with learning disabilities* or behavioural abnormalities such as infantile autism -especially examination of the sensory system -can be fraught with difficulty, somatosensory evoked potentials (SEPs) would be expected to provide information about somatosensory function even in such children. [5][6][7] Nevertheless, few studies have comprehensively examined somatosensory function in infantile autism using short-latency somatosensory evoked potentials (S-SEPs). 8 In contrast, results of dichotic listening tests, which can identify the dominant hemisphere with respect to auditory function, as well as electroencephalogram (EEG) examinations, 9,10 suggest that right cerebral hemispheric predominance in children with autism contributes significantly to this disorder. In addition, neuropsychological tests have indicated that certain children with autism and very low verbal function have normal or nearly normal visuospatial function. 11 A hypothesis was proposed, therefore, that in individuals with autism, the left hemisphere may be dysfunctional, while the function of the right hemisphere is normal but isolated from that of the left. 12 To shed light on these issues, we performed S-SEPs, elicited by stimulation of both median nerves, in 24 children with autis...

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