Prediction of group membership in developmental dyslexia, attention deficit hyperactivity disorder, and normal controls using brain morphometric analysis of magnetic resonance imaging.

This study explored the utility of using selected brain morphometric indices for predicting group membership for children with developmental dyslexia (n = 10), attention deficit hyperactivity disorder: combined type (n = 10), and a control group (n = 10). Subjects ranged in age from 6.1 to 16 years (M = 10.5 years, SD = 2.8). None of the subjects were diagnosed with mental retardation, nor did any of the subjects have a history of seizure disorder, head trauma, or other neurodevelopmental disorders. WISC-R Full Scale IQ ranged from 87 to 149 (M = 114.4, SD = 13.3) with no significant differences noted between the clinical groups. Six brain regions, as defined by MRI scans, were selected a priori for inclusion in a discriminant function analysis. Reliability of the morphometric measures ranged from 0.94 to 0.97. One significant discriminant function was generated which accounted for about 61.4% of the variance between groups. The predictive discriminant analysis using the six morphometric MRI measurements classified subjects with an overall 60% accuracy with the best accuracy found for the developmental dyslexia and control groups. A predictive discriminant analysis incorporating these six morphometric measures as well as chronological age and FSIQ increased the overall classification accuracy to 87% with the misclassfied subjects assigned to one of the clinical groups. The findings support the presumed neurological basis for many neurodevelopmental disorders. They also underline the importance of including brain morphometric measures in predictive models.

Anomic aphasia in childhood.

Documented cases of anomic aphasia in childhood are rare, due to their low prevalence and relatively subtle clinical manifestations and because of probable referral bias. Such cases are important, however, because they may shed light on the nature of lesions that produce anomia in children and because they may contribute to our understanding of brain-behavior relations in children. This case involves a 10-year-old girl who experienced a left temporoparietal hematoma. Recovery over an 8-month period was good, with near normal verbal-expressive (Verbal IQ = 86) and normal perceptual-motor abilities (Performance IQ = 100). Reading, spelling, and repetition were preserved. Spontaneous speech was good, although initially circumlocutory and marked by obvious word-finding difficulty. Consistent with reports involving adults, there was significant disturbance in naming characterized by frequent literal and semantic paraphasias. Although she had significant difficulty on confrontational naming, she could accurately spell and read the name of the objects presented to her. This case is discussed relative to localization of lesions producing anomic aphasia and regarding the course of recovery in childhood.

Attention deficit-hyperactivity disorder and asymmetry of the caudate nucleus.

The neurologic basis of attention deficit-hyperactivity disorder (ADHD) is poorly understood. Based on previous studies that have implicated metabolic deficiencies in the caudate-striatal region in ADHD, we employed magnetic resonance imaging to investigate patterns of morphology of the head of the caudate nucleus in normal and ADHD children. In normal children, 72.7% evidenced a left-larger-than-right (L > R) pattern of asymmetry, whereas 63.6% of the ADHD children had the reverse (L < R) pattern of asymmetry of the head of the caudate nucleus. This reversal of normal asymmetry in ADHD children was due to a significantly smaller left caudate nucleus. The reversal in asymmetry of the head of the caudate was most notable in ADHD males. These results suggest that normal (L > R) morphologic asymmetry in the region of the caudate nucleus may be related to asymmetries observed in neurotransmitter systems implicated in ADHD. The behavioral symptoms of ADHD may reflect disinhibition from normal levels of dominant hemispheric control, possibly correlated with deviations in asymmetric caudate-striatal morphology and deficiencies in associated neurotransmitter systems.

Clinical differentiation of the attention deficit disorder subtypes: do sensorimotor deficits characterize children with ADD/WO?

Previous researchers found that children with Attention Deficit Disorder Without Hyperactivity (ADD/WO) tended to perform more poorly than children with Attention Deficit Disorder With Hyperactivity (ADD/H) on measures of motor and sensory functions. In the present study, a prototype sensorimotor soft sign battery was developed which limited cognitive involvement. It was hypothesized that ADD/WO children would exhibit a greater number of soft signs than ADD/H children who in turn would show more soft signs than normal children. Participants were 31 children ranging in age from 72 to 144 months. The SNAP checklist (Pelham & Murphy, 1981) was used in arriving at an experimental diagnosis. No differences were found between the ADD/WO and normal groups. The ADD/H group exhibited more soft signs than the normal group at all ages and more than the ADD/WO group above 96 months of age.