Biomedical subjects

A L Krain

Publications and source records attributed to A L Krain.

6 recordsLinked to original sources

PubMed2000

The role of parental emotional distress in parent report of child anxiety.

Evaluated the role of maternal and paternal emotional distress in parent report of anxiety in their child. Participants were 239 children (ages 7.5 to 15 years) diagnosed with a primary anxiety disorder and their parents (193 fathers, 238 mothers). Parents individually completed the State-Trait Anxiety Inventory, the Beck Depression Inventory (BDI), and the State-Trait Anxiety Inventory for Children-Parent Version (a report of the child's anxiety). Children completed the State-Trait Anxiety Inventory for Children. Mothers and fathers reported more anxiety in their children than the children reported themselves. No significant relations were found between parental anxiety and parent report of child anxiety. When we examined girls only, both maternal and paternal BDI scores were significant predictors of parent report of the child's anxiety after we controlled for parental anxiety. Separate analyses by child age revealed that parent reports of child anxiety were more correlated with the self-reports of younger children. The implications of these findings are discussed.

Adolescent↗

PubMed1998

Cerebellum in attention-deficit hyperactivity disorder: a morphometric MRI study.

Clinical, neuroanatomic, neurobehavioral, and functional brain-imaging studies suggest a role for the cerebellum in cognitive functions, including attention. However, the cerebellum has not been systematically studied in attention-deficit hyperactivity disorder (ADHD). We quantified the cerebellar and vermal volumes, and the midsagittal areas of three vermal regions, from MRIs of 46 right-handed boys with ADHD and 47 matched healthy controls. Vermal volume was significantly less in the boys with ADHD. This reduction involved mainly the posterior inferior lobe (lobules VIII to X) but not the posterior superior lobe (lobules VI to VII). These results remained significant even after adjustment for brain volume and IQ. A cerebello-thalamo-prefrontal circuit dysfunction may subserve the motor control, inhibition, and executive function deficits encountered in ADHD.

Adolescent↗

PubMed1997

Quantitative morphology of the cerebellum and fourth ventricle in childhood-onset schizophrenia.

OBJECTIVE: Studies have suggested that the maldeveloped neural circuitry producing schizophrenic symptoms may include the cerebellum. The authors found further support for this hypothesis by examining cerebellar morphology in severely ill children and adolescents with childhood-onset schizophrenia. METHOD: Anatomic brain scans were acquired with a 1.5-T magnetic resonance imaging scanner for 24 patients (mean age = 14.1 years, SD = 2.2) with onset of schizophrenia by age 12 (mean age at onset = 10.0 years, SD = 1.9) and 52 healthy children. Volumes of the vermis, inferior posterior lobe, fourth ventricle, and total cerebellum and the midsagittal area of the vermis were measured manually. RESULTS: After adjustment for total cerebral volume, the volume of the vermis and the midsagittal area and volume of the inferior posterior lobe remained significantly smaller in the schizophrenic patients. There was no group difference in total cerebellar or fourth ventricle volume. CONCLUSIONS: These findings are consistent with observations of small vermal size in adult schizophrenia and provide further support for abnormal cerebellar function in childhood- and adult-onset schizophrenia.

Adolescent↗

PubMed1996

Quantitative brain magnetic resonance imaging in attention-deficit hyperactivity disorder.

BACKGROUND: Anatomic magnetic resonance imaging (MRI) studies of attention-deficit hyperactivity disorder (ADHD) have been limited by small samples or measurement of single brain regions. Since the neuropsychological deficits in ADHD implicate a network linking basal ganglia and frontal regions, 12 subcortical and cortical regions and their symmetries were measured to determine if these structures best distinguished ADHD. METHODS: Anatomic brain MRIs for 57 boys with ADHD and 55 healthy matched controls, aged 5 to 18 years, were obtained using a 1.5-T scanner with contiguous 2-mm sections. Volumetric measures of the cerebrum, caudate nucleus, putamen, globus pallidus, amygdala, hippocampus, temporal lobe, cerebellum; a measure of prefrontal cortex; and related right-left asymmetries were examined along with midsagittal area measures of the cerebellum and corpus callosum. Interrater reliabilities were .82 or greater for all MRI measures. RESULTS: Subjects with ADHD had a 4.7% smaller total cerebral volume (P = .02). Analysis of covariance for total cerebral volume demonstrated a significant loss of normal right > left asymmetry in the caudate (P = .006), smaller right globus pallidus (P = .005), smaller right anterior frontal region (P = .02), smaller cerebellum (P = .05), and reversal of normal lateral ventricular asymmetry (P = .03) in the ADHD group. The normal age-related decrease in caudate volume was not seen, and increases in lateral ventricular volumes were significantly diminished in ADHD. CONCLUSION: This first comprehensive morphometric analysis is consistent with hypothesized dysfunction of right-sided prefrontal-striatal systems in ADHD.

Adolescent↗

PubMed1996

A technique for single-channel MR brain tissue segmentation: application to a pediatric sample.

A segmentation method is presented for gray matter, white matter, and cerebrospinal fluid (CSF) in thin-sliced single-channel brain magnetic resonance (MR) scans. The method is based on probabilistic modeling of intensity distributions and on a region growing technique. Interrater and intrarater reliabilities for the method were high, and comparison with phantom studies and hand-traced results from an experienced rater indicated good validity. The method was designed to account for spatially dependent image intensity inhomogeneities. Segmentation of MR brain scans of 105 (56 male and 49 female) healthy children and adolescents showed that although the total brain volume was stable over age 4-18, white matter increased and gray matter decreased significantly. There were no sex differences in total gray and white matter growth after correction for total brain volume. White matter volume increased the most in superior and posterior regions and laterality effects were seen in hemisphere tissue volumes. These findings are consistent with other reports, and further validate the segmentation technique.

Adolescent↗

PubMedDate not supplied

Cerebral magnetic resonance image segmentation using data fusion.

OBJECTIVE: A semiautomated method is described for segmenting dual echo MR head scans into gray and white matter and CSF. The method is applied to brain scans of 80 healthy children and adolescents. MATERIALS AND METHODS: A probabilistic data fusion equation was used to combine simultaneously acquired T2-weighted and proton density head scans for tissue segmentation. The fusion equation optimizes the probability of a voxel being a particular tissue type, given the corresponding probabilities from both images. The algorithm accounts for the intensity inhomogeneities present in the images by fusion of local regions of the images. RESULTS: The method was validated using a phantom (agarose gel with iron oxide particles) and hand-segmented images. Gray and white matter volumes for subjects aged 20-30 years were close to those previously published. White matter and CSF volume increased and gray matter volume decreased significantly across ages 4-18 years. White matter, gray matter, and CSF volumes were larger for males than for females. Males and females showed similar change of gray and white matter volumes with age. CONCLUSION: This simple, reliable, and valid method can be employed in clinical research for quantification of gray and white matter and CSF volumes in MR head scans. Increase in white matter volume may reflect ongoing axonal growth and myelination, and gray matter reductions may reflect synaptic pruning or cell death in the age span of 4-18 years.

Adolescent↗