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Biomedical subjects

R T Schultz

Publications and source records attributed to R T Schultz.

At least 19 recordsLinked to original sources
PubMed2003

A placebo-controlled trial of risperidone in Tourette syndrome.

OBJECTIVE: To evaluate the efficacy and safety of risperidone in children and adults with Tourette syndrome. METHODS: This was an 8-week, randomized, double-blind, placebo-controlled trial. The primary outcome measure was the Total Tic score of the Yale Global Tic Severity Scale (YGTSS). RESULTS: Thirty-four medication-free subjects (26 children and 8 adults) ranging in age from 6 to 62 years (mean = 19.7 +/- 17.0 years) participated. YGTSS Total Tic scores were similar at baseline (26.0 +/- 5.1 for risperidone vs 27.4 +/- 8.5 for placebo). After 8 weeks of treatment (mean daily dose of 2.5 +/- 0.85), the 16 subjects on risperidone showed a 32% reduction in tic severity from baseline, compared to a 7% reduction for placebo patients (n = 18) (F[2,64] = 6.07; p = 0.004). The 12 children randomized to risperidone showed a 36% reduction in tic symptoms compared to an 11% decrease in the 14 children on placebo (F[2,48] = 6.38; p = 0.004). Two children on risperidone showed acute social phobia, which resolved with dose reduction in one subject but resulted in medication discontinuation in the other. A mean increase in body weight of 2.8 kg was observed in the risperidone group compared to no change in placebo (F[2,64] = 10.68; p = 0.0001). No extrapyramidal symptoms and no clinically significant alterations in cardiac conduction times or laboratory measures were observed. CONCLUSION: Risperidone appears to be safe and effective for short-term treatment of tics in children or adults with Tourette syndrome. Longer-term studies are needed to evaluate the durability of efficacy and safety over time.

Adolescent↗
PubMed2001

A placebo-controlled study of guanfacine in the treatment of children with tic disorders and attention deficit hyperactivity disorder.

OBJECTIVE: This study evaluated the efficacy and safety of guanfacine in treating children with tic disorders and attention deficit hyperactivity disorder (ADHD). METHOD: Subjects from a specialty tic disorders clinic were randomly assigned to receive 8 weeks of treatment with guanfacine or placebo under double-blind conditions. Follow-up visits occurred every 2 weeks for safety monitoring and dose adjustment. RESULTS: Thirty-four medication-free subjects (31 boys and three girls with a mean age of 10.4 years) with ADHD, combined type, and a tic disorder participated. After 8 weeks of treatment, guanfacine was associated with a mean improvement of 37% in the total score on the teacher-rated ADHD Rating Scale, compared to 8% improvement for placebo. Nine of 17 subjects who received guanfacine were blindly rated on the Clinical Global Improvement scale as either much improved or very much improved, compared with none of 17 subjects who received placebo. The mean score on the parent-rated hyperactivity index improved by 27% in the guanfacine group and 21% in the placebo group, not a significant difference. On the Continuous Performance Test, commission errors decreased by 22% and omission errors by 17% in the guanfacine group, compared with increases of 29% in commission errors and of 31% in omission errors in the placebo group. Tic severity decreased by 31% in the guanfacine group, compared to 0% in the placebo group. One guanfacine subject with sedation withdrew at week 4. Guanfacine was associated with insignificant decreases in blood pressure and pulse. CONCLUSIONS: Guanfacine appears to be a safe and effective treatment for children with tic disorders and ADHD.

Adolescent↗
PubMed2000

Abnormal ventral temporal cortical activity during face discrimination among individuals with autism and Asperger syndrome.

BACKGROUND: Recognition of individual faces is an integral part of both interpersonal interactions and successful functioning within a social group. Therefore, it is of considerable interest that individuals with autism and related conditions have selective deficits in face recognition (sparing nonface object recognition). METHOD: We used functional magnetic resonance imaging (fMRI) to study face and subordinate-level object perception in 14 high-functioning individuals with autism or Asperger syndrome (the autism group), in comparison with 2 groups of matched normal controls (normal control group ] [NC1] and normal control group 2 [NC2]) (n = 14 for each). Regions of interest (ROIs) were defined in NC1 and then applied in comparisons between NC2 and the autism group. Regions of interest were also defined in NC2 and then applied to comparisons between NC1 and the autism group as a replication study. RESULTS: In the first set of comparisons, we found significant task x group interactions for the size of activation in the right fusiform gyrus (FG) and right inferior temporal gyri (ITG). Post hoc analyses showed that during face (but not object) discrimination, the autism group had significantly greater activation than controls in the right ITG and less activation of the right FG. The replication study showed again that the autism group used the ITG significantly more for processing faces than the control groups, but for these analyses, the effect was now on the left side. Greater ITG activation was the pattern found in both control groups during object processing. CONCLUSIONS: Individuals with autism spectrum disorders demonstrate a pattern of brain activity during face discrimination that is consistent with feature-based strategies that are more typical of nonface object perception.

Adult↗
PubMed2000

Social and emotional adjustment in children affected with Gilles de la Tourette's syndrome: associations with ADHD and family functioning. Attention Deficit Hyperactivity Disorder.

This study examined social-emotional functioning in children with Gilles de la Tourette's syndrome (TS) alone and children with TS and Attention Deficit Hyperactivity Disorder (ADHD). In addition, the contribution of family functioning to social competence was examined. Children with a clinical diagnosis of TS were recruited from the Yale Child Study Center TS specialty clinic. Unaffected control children were recruited through newspaper advertisements and announcements within the university and at area schools. The final sample consisted of 72 children (45 boys and 27 girls) between the ages of 8 and 14. Sixteen children met DMS-III-R criteria for TS, 33 children met criteria for TS and ADHD, and 23 children had no psychiatric diagnoses. Children with TS and ADHD evidenced more externalizing and internalizing behavior problems and poorer social adaptation than children with TS only or unaffected controls. Children with TS only were not significantly different from unaffected controls on most measures of externalizing behaviors and social adaptation but did exhibit more internalizing symptoms. Tic symptom severity was not associated with social, behavioral, or emotional functioning among children with TS, even after stratifying by medication status. However, ADHD diagnosis, obsessional symptom severity, and family functioning were significantly associated with social and emotional adjustment among TS children. Moreover, family functioning was associated with social and emotional adjustment even after controlling for TS and ADHD diagnostic status. These findings demonstrate that much of the social and behavioral dysfunction in children with TS is ADHD-specific and children with TS alone have a very different social-emotional profile than do those with TS plus ADHD. Finally, social-emotional adjustment in children with TS is best understood within the family context.

Adaptation, Psychological↗
PubMed1999

Segmentation and measurement of the cortex from 3-D MR images using coupled-surfaces propagation.

The cortex is the outermost thin layer of gray matter in the brain; geometric measurement of the cortex helps in understanding brain anatomy and function. In the quantitative analysis of the cortex from MR images, extracting the structure and obtaining a representation for various measurements are key steps. While manual segmentation is tedious and labor intensive, automatic reliable efficient segmentation and measurement of the cortex remain challenging problems, due to its convoluted nature. Here we present a new approach of coupled-surfaces propagation, using level set methods to address such problems. Our method is motivated by the nearly constant thickness of the cortical mantle and takes this tight coupling as an important constraint. By evolving two embedded surfaces simultaneously, each driven by its own image-derived information while maintaining the coupling, a final representation of the cortical bounding surfaces and an automatic segmentation of the cortex are achieved. Characteristics of the cortex, such as cortical surface area, surface curvature, and cortical thickness, are then evaluated. The level set implementation of surface propagation offers the advantage of easy initialization, computational efficiency, and the ability to capture deep sulcal folds. Results and validation from various experiments on both simulated and real three-dimensional (3-D) MR images are provided.

Algorithms↗
PubMed1999

Neuropsychological models of childhood obsessive-compulsive disorder.

Neuropsychological models of obsessive-compulsive disorder (OCD) point to a fairly consistent pattern of deficits in response inhibition, visual memory, and visuoperceptual functioning. However, little is known about these areas of functioning with respect to child onset OCD because most studies to date have focused on adults. Data from adult OCD studies nevertheless provide valuable heuristic models of functioning that need to be systematically assessed in children. Moreover, combining neuro-psychological assessment with neuroimaging methods is a particularly powerful approach that promises to delineate the pathobiology of these disorders more precisely and to determine the degree of overlap between child and adult onset forms of OCD.

Adolescent↗
PubMed1996

Lateral intertransverse process single-level fusion for salvage of the unstable failed posterior lumbar interbody fusion.

Our study was an attempt to salvage severely unstable posterior lumbar interbody fusions (PLIFs) by using the lateral bilateral intertransverse single-level (floating) fusion. A retrospective review of six patients with failed L4-L5 PLIFs was carried out. These patients underwent reoperation between 2 weeks and 2 years after the initial surgery. All patients had persistent symptoms, including low back pain and sciatica, interfering with activities of daily living. Computed tomography (CT) scans revealed extrusion of the bone plug into the spinal canal in five patients. All six had a nonunion of the PLIF, and three patients had grade 3 or 4 iatrogenic spondylolisthesis caused by the PLIF. The operation involved decompression followed by lateral intertransverse process fusion with autogenous bone graft. All patients were placed in external immobilization after the procedure for 3 months. Follow-up averaged 38.5 months (range, 21-55), at which time five had substantial pain improvement. Five were radiographically fused. One had a second nonunion, which subsequently healed after reoperation with repeat lateral fusion and Luque plate hardware. Our fusion rate was 83% without the use of instrumentation. In conclusion, we recommend the simplistic procedure of lateral bilateral intertransverse process single-level fusion along with liberal external immobilization for the difficult problem of salvage of failed PLIFs.

Adult↗
PubMed1994

Brain morphology in normal and dyslexic children: the influence of sex and age.

Morphometric magnetic resonance imaging techniques were used to compare the convolutional surface area of the planum temporale, temporal lobe volume and superior surface area, and an estimate of overall brain volume in a homogeneous sample of 17 dyslexic children (7 girls) and 14 nonimpaired children (7 girls). Substantial sex differences were apparent for all measured regions, with all the measurements in boys being significantly larger. Age, even within the narrow range employed here (7.5-9.7 years), was positively correlated with the size of each brain region. While initial analyses suggested smaller left hemisphere structures in dyslexics compared to control subjects, subsequent analyses controlling for age and overall brain size revealed no significant differences between dyslexics and nonimpaired children on a variety of measures, in particular surface area and symmetry of the planum temporale. We suggest that differences in subject characteristics (i.e., sex, age, handedness, and definition of dyslexia) as well as procedural variations in the methods used to acquire images and to define and measure anatomical regions of interest such as the planum temporale all may play an important role in explaining apparent discrepant results in the neuroimaging literature on dyslexia.

Age Factors↗
PubMed1990

Subjective utility ratings of neuroleptics in treating schizophrenia.

This study developed a method for measuring subjective costs and benefits of psychiatric treatments. Forty-one patients rates the relative bothersomeness of symptoms of schizophrenia and side effects of neuroleptics. Thirty-four psychiatrists made parallel ratings from the perspective of the average patient (individual utility) and of the patient's family and society (institutional utility). Psychiatrists predicted patients' ratings moderately well, but misjudged the bothersomeness to patients of 24% of side effects and 20% of symptoms. When considering the patient's perspective, both schizophrenic patients and psychiatrists rated symptoms as no more bothersome than side effects. However, psychiatrists saw side effects as significantly less bothersome than symptoms when considering costs to society. The subjective utility of neuroleptic medications for schizophrenia is most justifiable from an institutional perspective.

Antipsychotic Agents↗
PubMed1989

Nutrition and the rheumatoid hand patient.

The incidence of nutritional depletion in 40 rheumatoid patients and the factors that influence these patients' nutritional status were investigated. More than half of the patients (52.5%) were found to be nutritionally deficient.

Adult↗
PubMed1985

Relation of the hepatic and splenic microcirculations to the development of lesions in experimental amyloidosis.

By the use of a perfusion technique for identifying blood vessels, it was found that amyloid lesions in mice have a close relation to the underlying microcirculation. The earliest lesions develop about arteriolar capillaries. With the onset of the lesions, circulation of plasma not only continues through the affected vessels but also extends into the entire volume of the surrounding lesions. Progression of the lesions follows the underlying microcirculation, and there is a continuing presence of circulating proteins. Other observations, from tracer studies using labeled plasma proteins and studies of unfixed, frozen, tissue sections following saline extraction, indicate that much of the early amyloid lesions in these animals is circulating plasma. It would appear that the onset and site of formation of the lesions is determined by arteriolar capillary injury rather than by polymorphism of SAA proteins. Structural amyloid fibril proteins may gain access to the lesions by either entry from the circulation or local formation.

Amyloidosis↗
PubMed1985

Ultrastructural studies of vascular lesions in experimental amyloidosis of mice.

Definite lesions of arteriolar capillaries have been demonstrated in early amyloid lesions of mice. Pathologic changes include multiple endothelial gaps, the loss of an identifiable basal lamina, variable degrees of endothelial alteration, and the presence of the developing amyloid lesions surrounding the affected vessels. Despite these changes, the vessels remain functional part of the local microcirculation as demonstrated by intravascular injection of electron dense markers. These structural changes of arteriolar capillaries explain the presence of circulating plasma as a constant and major component of the early amyloid lesions in these animals and on this basis may determine the time of onset and site of formation of the lesions. The vascular injury appears to be caused by immunologic reactions to injected foreign antigens which gain a close relation to the structures of these vessels.

Amyloid↗
PubMed1979

Antibody formation in experimental amyloidosis.

In endotoxin-induced amyloidosis of mice it was found that all mouse strains formed antibodies specific for the type of endotoxin injected. In casein-induced amyloidosis, the animals form antibodies to certain components of the casein and most likely to whatever contaminating endotoxin is present. The antibodies formed seemed to be primarily of the IgG 1 subclass. Their appearance in high titer shows a good correlation with the onset of amyloid formation especially in mice given casein. Failure to form amyloid in these experimental models does not seem to be related to failure of antibody formation but may be explained by more effective clearance of immune complexes or other such factors.

Amyloid↗
PubMed1977

Role of altered vascular permeability amyloid formation.

Heavily radiolabeled plasma proteins were injected intravenously into mice with experimentally induced amyloid lesions, and the distribution of the labeled protein with respect to vascular spaces and the amyloid lesions determined by autoradiography. Radiolabeled albumin and IgG entered early amyloid lesions so quickly and in such high concentration as to indicate that much of the volume of these early lesions must be occupied by circulating plasma. Entry of these same proteins into advanced lesions was definitely reduced. High-molecular-weight proteins remained largely in vascular spaces. In situ saline perfusion resulted in considerable removal of protein from early lesions but very little alteration in their greenish-yellow birefringence when stained with Congo red. An initial alteration in vascular permeability with circulation of plasma proteins in tissue spaces quickly followed by a progressively increasing deposition of fibrous proteins on an underlying cellular framework may be the sequence of events in amyloid formation.

Amyloidosis↗