Attention deficit disorder without hyperactivity: a distinct behavioral and neurocognitive syndrome.

This study examined the issue as to whether or not children carefully diagnosed as having either attention deficit disorder with hyperactivity (ADDH) or without hyperactivity (ADDnoH) could be distinguished on selected cognitive, academic, rapid naming, and behavioral measures. Employing a previously validated multimodal, multi-informant diagnostic process that results in reliable clinical diagnoses, 10 ADDH and 10 ADDnoH children were examined. While no significant differences in cognitive ability were noted between groups, significant underachievement was found in the children diagnosed as ADDnoH, particularly in mathematics achievement. The ADDnoH children were also significantly slower on rapid naming tasks than the ADDH children. Further, 60% of the ADDnoH children had a codiagnosis of a developmental reading or arithmetic disorder while none of the ADDH children received such a codiagnosis. Conversely, 40% of the ADDH children had a codiagnosis of conduct disorder and were rated by their parent as significantly more motorically active, impulsive, and deviant in the demonstration of age-appropriate social skills. These findings are discussed as they relate to the notion that children with attention deficit disorder may suffer from a right hemispheric syndrome.

Regional cerebral blood flow (rCBF) in normal readers: bilateral activation with narrative text.

Based on recent evidence that suggests a more active participation of the right cerebral hemisphere in reading, this exploratory study examined changes in regional cerebral blood flow (rCBF) in three normal subjects during the reading of controlled narrative text. Narrative text presumably activates all neurocognitive processes important in reading including the semantic, pragmatic, emotional, and imagery components. Because of the small number of subjects, percentage change over a baseline at rest condition in rCBF during reading was compared to test/retest variability in control subjects. Effect size was also considered. The results indicated statistically significant bilateral central posterior activation during reading. These findings are consistent with an evolving model of bilateral language representation in which subcortical structures and right hemispheric systems are functionally and anatomically tied to the dominant left hemispheric language centers.