Biomedical subjects

Lonnie L Sears

Publications and source records attributed to Lonnie L Sears.

2 recordsLinked to original sources

PubMed2004

Sleep problems in children with autism.

Autism is a developmental disability characterized by severe deficits in social interaction and communication, and the presence of repetitive-ritualistic behaviors. Sleep problems are frequently reported by parents of children with autism with prevalence estimates of 44-83% for sleep disorders in this population. To better understand sleep in autism, we surveyed sleep problems in 210 children with autism using a Likert-based questionnaire for parent report. The most frequently reported sleep problems included difficulty in falling asleep, restless sleep, not falling asleep in own bed, and frequent wakenings. Least frequently reported sleep problems were sleep walking, morning headaches, crying during sleep, apnea, and nightmares. When surveys were divided into mental retardation (MR)/not MR categories, no significant differences were identified in frequencies of reported sleep problems except for waking at night which occurred much more frequently in the MR group. There was also no difference in sleep problems related to age of the child other than nocturnal enuresis. An association was noted between certain medical problems and sleep problems. Vision problems, upper respiratory problems, and runny nose were associated with decreased nighttime sleep. Vision problems, poor appetite, and poor growth were associated with increased nighttime waking. Poor appetite and poor growth were associated with decreased willingness to fall asleep. This study confirms a high prevalence of sleep problems reported by parents of children with autism and points to the need for more systematic research as an initial step in developing treatment strategies.

Adolescent↗

PubMed2002

Manual and semiautomated measurement of cerebellar subregions on MR images.

Previous structural and functional imaging studies suggest that the corticocerebellar-thalamic-cortical circuit is dysfunctional in schizophrenia. Accurate identification and volumetric measurement of cerebellar subregions are essential to the assessment of the cerebellum's role in healthy and disease states. Manual parcellation of the cerebellum on MR images was performed with the use of guide traces. Guide traces identified relevant fissures and borders in several planes, and their intersections with the primary tracing plane were used to maintain consistency and accuracy during the parcellation. The cerebellum was parcellated into right and left anterior lobes, superior posterior lobes, inferior posterior lobes, and corpus medullare. A systematic review of the final traces ensured their accuracy. An artificial neural network was trained using a novel landmark-warped method to help account for wide variability in structure size and location. Overlaps of the manually traced lobes (intersection/union) ranged from 0.78 to 0.85 and intraclass correlations (r2) ranged from 0.82 to 0.94. In a comparison of the semiautomated method with the manual method overlaps ranged from 0.83 to 0.88 and intraclass correlations ranged from 0.92 to 0.97. For two raters using the semiautomated method overlaps ranged from 0.83 to 0.88 and intraclass correlations ranged from 0.97 to 0.99. The semiautomated method was built on the groundwork of the manual method to produce more reliable results in a fraction of the time, making valid measurements possible on a large number of subjects.

Cerebellar Nuclei↗