Biomedical subjects

Jennifer R Zarcone

Publications and source records attributed to Jennifer R Zarcone.

11 recordsLinked to original sources

PubMed2006

A crossover study of risperidone in children, adolescents and adults with mental retardation.

Risperidone has shown safety and efficacy for aggressive and destructive behaviors in short-term studies. This longer-duration study includes a broad sample. Forty subjects, aged 8-56 years (mean=22), all with mental retardation and 36 with autism spectrum disorders participated in this 22-week crossover study, with 24 weeks of open maintenance thereafter. Of 40 subjects, 23 (57.5%) responded fully (50% decrease in Aberrant Behavior Checklist-Community Irritability subscale score), while 35 subjects (87.5%) showed a 25% decrease. Gender, mood disorder, and antiseizure medications did not alter response. Increased appetite and weight gain were common. Low dose risperidone was effective for aggressive behavior in persons with MR. More long-term studies are needed, incorporating weight control interventions.

Adolescent↗

PubMed2006

Neural mechanisms underlying hyperphagia in Prader-Willi syndrome.

OBJECTIVE: Prader-Willi syndrome (PWS) is a genetic disorder associated with developmental delay, obesity, and obsessive behavior related to food consumption. The most striking symptom of PWS is hyperphagia; as such, PWS may provide important insights into factors leading to overeating and obesity in the general population. We used functional magnetic resonance imaging to study the neural mechanisms underlying responses to visual food stimuli, before and after eating, in individuals with PWS and a healthy weight control (HWC) group. RESEARCH METHODS AND PROCEDURES: Participants were scanned once before (pre-meal) and once after (post-meal) eating a standardized meal. Pictures of food, animals, and blurred control images were presented in a block design format during acquisition of functional magnetic resonance imaging data. RESULTS: Statistical contrasts in the HWC group showed greater activation to food pictures in the pre-meal condition compared with the post-meal condition in the amygdala, orbitofrontal cortex, medial prefrontal cortex (medial PFC), and frontal operculum. In comparison, the PWS group exhibited greater activation to food pictures in the post-meal condition compared with the pre-meal condition in the orbitofrontal cortex, medial PFC, insula, hippocampus, and parahippocampal gyrus. Between-group contrasts in the pre- and post-meal conditions confirmed group differences, with the PWS group showing greater activation than the HWC group after the meal in food motivation networks. DISCUSSION: Results point to distinct neural mechanisms associated with hyperphagia in PWS. After eating a meal, the PWS group showed hyperfunction in limbic and paralimbic regions that drive eating behavior (e.g., the amygdala) and in regions that suppress food intake (e.g., the medial PFC).

Adolescent↗

PubMed2005

Neural mechanisms underlying food motivation in children and adolescents.

Dramatic increases in childhood obesity necessitate a more complete understanding of neural mechanisms of hunger and satiation in pediatric populations. In this study, normal weight children and adolescents underwent functional magnetic resonance imaging (fMRI) scanning before and after eating a meal. Participants showed increased activation to visual food stimuli in the amygdala, medial frontal/orbitofrontal cortex, and insula in the pre-meal condition; no regions of interest responded in the post-meal condition. These results closely parallel previous findings in adults. In addition, we found evidence for habituation to food stimuli in the amygdala within the pre-meal session. These findings provide evidence that normal patterns of neural activity related to food motivation begin in childhood. Results have implications for obese children and adults, who may have abnormal hunger and satiation mechanisms.

Adolescent↗

PubMed2005

A double-blind, placebo-controlled study of valproate for aggression in youth with pervasive developmental disorders.

OBJECTIVE: The aim of this study was to study valproate efficacy and safety for aggression in children and adolescents with pervasive developmental disorders (PDD). METHODS: In this prospective double-blind, placebo-controlled study, 30 subjects (20 boys, 10 girls) 6-20 years of age with PDD and significant aggression were randomized and received treatment with valproate (VPA) or placebo (PBO) for 8 weeks as outpatients. Mean VPA trough blood levels were 75.5 mcg/mL at week 4 and 77.8 mcg/mL at week 8. RESULTS: No treatment difference was observed statistically between VPA and PBO groups. The Aberrant Behavior Checklist--Community Scale (ABC-C) Irritability subscale was the primary outcome measure (p = 0.65), and CGI--Improvement (p = 0.16) and OAS (p = 0.96) were secondary outcome measures. Increased appetite and skin rash were significant side effects. Only 1 subject was dropped from the study owing to side effects, notably a spreading skin rash, which then resolved spontaneously. Two subjects receiving VPA developed increased serum ammonia levels, one with an associated parent report of slurred speech and mild cognitive slowing. Poststudy, of 16 VPA and PBO subjects receiving VPA, 10 subjects demonstrated sustained response, 4 of whom later attempted taper, with significant relapse of aggression. CONCLUSION: The present negative findings cannot be viewed as conclusive, partly owing to the large placebo response, subject heterogeneity, and size of the groups. Larger studies are needed to expand upon these findings.

Adolescent↗

PubMed2005

Risperidone-induced prolactin elevation in a prospective study of children, adolescents, and adults with mental retardation and pervasive developmental disorders.

OBJECTIVE: Risperidone is widely prescribed for aggression and self-injury in children, adolescents, and adults with mental retardation (MR) and pervasive developmental disorders (PDD). Risperidone elevates prolactin more than other atypical antipsychotic medications. Females may show greater prolactin elevation than males. METHOD: In this relatively long-term study of risperidone efficacy and safety for aggression and self-injury in children, adolescents, and adults with MR and PDDs, serum prolactin was measured in a 21-subject subset during the course of a double-blind, placebo-controlled trial. Prolactin was measured in ng/mL at baseline, once during acute treatment, and once during maintenance. RESULTS: In children and adolescents (n=10), mean age of 12.5 years, prolactin increased from mean 13.2+/-8.6 at baseline to 31.0+/-11.6 acutely and remained elevated at 37.9+/-10.4 in maintenance. In adults, mean age of 35.3 years, prolactin increased more markedly from 11.6+/-7.4 baseline (n=11) to 93.3+/-54.2 acutely but decreased to 67.8+/-62.9 in maintenance (n=7). Prolactin remained significantly elevated above normal in all subjects for at least 26 weeks. Mean prolactin of adult females, while similar to that of adult males at baseline, was 2.2 times male levels acutely and 3.7 times greater in maintenance. CONCLUSION: In this small subset, mean prolactin elevation persisted for at least 26 weeks. In adults, females showed significantly greater elevations than males.

Adolescent↗

PubMed2005

Use of an antecedent analysis and a force sensitive platform to compare stereotyped movements and motor tics.

Stereotyped movements displayed by 6 participants and tics displayed by 6 children were evaluated using an antecedent behavioral analysis and a force sensitive platform. We found that tics occurred more often in an alone condition when compared to high preference toy and play conditions, whereas stereotyped movements were more variable across conditions. Using temporal measures and spectral analysis data from the force sensitive platform, we found that stereotyped movements tended to be longer in duration and displayed more rhythmic qualities when compared to tics. Results indicate that stereotyped movements and tics differ both quantitatively and qualitatively and support the use of new technologies, such as force plate technology, to more accurately evaluate these differences.

Antipsychotic Agents↗

PubMed2004

Effects of risperidone on destructive behavior of persons with developmental disabilities: III. Functional analysis.

Functional analyses were conducted during a double-blind, placebo-controlled study of the atypical antipsychotic medication risperidone with 13 individuals. Risperidone was effective in reducing destructive behavior (compared to placebo) for 10 participants. For 7 of these responders, an undifferentiated pattern of responding occurred across their baseline functional analysis conditions (i.e., a similar rate of responding across conditions), and risperidone treatment produced nonspecific reductions of their destructive behavior across functional analysis conditions. For the remaining 3 responders, a differentiated pattern of responding occurred across their baseline functional analysis conditions (i.e., an elevated rate of responding occurred in a specific condition), and risperidone treatment produced function-specific reductions of their destructive behavior.

Adult↗

PubMed2003

Use of functional analysis methodology in the evaluation of medication effects.

The atypical antipsychotic medication risperidone was evaluated using a double-blind, placebo-controlled design in the treatment of destructive behavior in two individuals with autism. Pre-medication functional analyses indicated that destructive behavior was maintained by escape from demands, attention, or access to tangible items. For both individuals, destructive behavior during the demand condition was significantly reduced during the medication phases, whereas destructive behavior continued to occur to obtain tangible items (Reggie) and attention (Sean). In addition, there appeared to be a differential effect of the medication on self-injurious behavior (SIB) versus aggression for Sean. Results of the study demonstrate how functional analysis may provide information on those conditions and behaviors that are most likely to be affected by a specific medication.

Adult↗

PubMed2002

Multimodal evaluation of risperidone for destructive behavior: functional analysis, direct observations, rating scales, and psychiatric impressions.

Risperidone, an atypical neuroleptic, has become a popular option for treating destructive behaviors of persons with developmental disabilities. A few studies have been conducted that evaluate the effects of risperidone on destructive behavior; however, none of these studies have combined objective measures with rating scales to evaluate the effects of risperidone on destructive behavior across home and clinical settings. This study evaluated the wide range of effects of risperidone on destructive behavior of 2 persons with developmental disabilities using weekly functional analysis sessions, daily observations, hourly home data, weekly rating scales, and monthly psychiatric impressions. Results indicate that risperidone does decrease destructive behavior and that, for the most part, all of the various measures yielded similar results.

Adult↗

PubMed2002

Effects of risperidone on aberrant behavior in persons with developmental disabilities: II. Social validity measures.

Consumer satisfaction and social validity were measured during a double-blind, placebo-controlled evaluation of the atypical neuroleptic risperidone in treating severe aberrant behavior of persons with developmental disabilities. First, a satisfaction survey was completed after a medication trial by each participant's caregiver. Results showed that 100% of the caregivers felt that participation was a positive experience for themselves and participants. Second, 52 community members viewed videotapes of 5 participants during a clinical interview when they were taking either placebo or risperidone. Raters also indicated that when on the medication, participants displayed fewer aberrant behaviors, were less irritable, in a better mood, and were more responsive to their environment.

Adolescent↗

PubMed2002

A comparison of multiple reinforcer assessments to identify the function of maladaptive behavior.

Functional analysis results indicated that maladaptive behaviors displayed by a 25-year-old man with profound mental retardation were maintained by attention from caregivers and possibly, to a lesser degree, by access to tangible items. A concurrent-schedules procedure was then used to study the relative reinforcing value for maladaptive behavior of attention versus tangible items. Results of the concurrent-schedules assessment and subsequent functional communication training indicated that preference for attention versus access to a tangible object varied.

Adult↗