Paul E. Touchette

Brain size and cerebral glucose metabolic rate in nonspecific mental retardation and down syndrome

Brain size and cerebral glucose metabolic rate (GMR) were determined with magnetic resonance imaging (MRI) and positron emission tomography (PET) in individuals with mild mental retardation (MR), individuals with Down syndrome (DS) without dementia and in matched controls. The MRI data showed that the MR and the DS groups both had brain volumes of about 80% of controls; variance was greatest within the MR group. PET was obtained with [18F]-fluorodeoxyglucose (FDG) as the tracer during a test of attention (Continuous Performance Test; CPT). Whole brain cortex GMR was higher than the controls in both the MR and the DS groups. For all subjects combined, the correlation between brain size and IQ was .65 (p < .005).

Naltrexone reduces self-injury and improves learning.

Author(s): Sandman, CA; Hetrick, WP; Taylor, DV; Barron, JL; Touchette, P; Lott, I; Crinella, F; Martinazzi, V | Abstract: A cross-over study of 24 Ss with self-injurious behavior (SIB) was conducted over a continuous 10-week period. Treatment with naltrexone (NTX) was provided for 3 weeks in a randomized, reversal design with different doses or placebo each week. Videotaped observations (20 hr/subject), neurological examinations, and ratings of adaptive and maladaptive behavior were collected. Treatment with 2 mg/kg NTX produced at least a 50% reduction in SIB in a significant (p l.01) number of Ss. The 1.0 mg/kg was less effective (p l.02), and no significant change was observed at 0.5 mg/kg. Eighteen of 21 Ss achieved at least a 25% reduction in SIB after treatment of at least 1 dose of NTX (p l.0001). More than half of the Ss (52%) had a l 50% reduction (p l.001), and a significant number of Ss (33%) decreased SIB by more than 75% after at least 1 dose of NTX. Significant improvement was measured after NTX on measures of learning and attention.

Sequential analysis reveals a unique structure for self-injurious behavior.

Conditional probability, calculated using sequential analysis techniques in four time conditions (2, 10, 30, and 60 seconds), provided evidence that successive episodes of self-injury were sequentially dependent. This unique distribution of sequential association for self-injurious behavior (SIB) was not related to frequency or rate of occurrence. Compared with other environmental and behavioral events, the best predictor of SIB was an earlier SIB episode, consistent with a contagious distribution. This study is one of the few in which sequential analysis techniques were applied to data derived from a large group of individuals with severe behavior disorders. It may be the first in which this analytic tool was used to investigate systematically successive occurrences of SIB as it takes place in vivo.

Long-Term Effects of Naltrexone on Self-Injurious Behavior.

A subgroup of self-injuring patients responds positively to the opiate-blocking agent naltrexone in acute, double-blind studies. In this study we examined the effects of naltrexone after acute treatment and the long-term effects of naltrexone on SIB. Rates of SIB were collected from pretreatment baseline; a second baseline a year after the acute trial; and a subsequent 12-month double-blind, placebo-controlled treatment. A subgroup of patients decreased SIB for a year without treatment after acute exposure to naltrexone. Five participants who decreased SIB by 70% after acute treatment increased SIB to the long-term treatment with naltrexone. In contrast, those for whom SIB increased over the one-year treatment hiatus decreased their SIB after the first long-term treatment. Discussion of these complex effects considered the role of background opioid levels, dosing, and treatment regimen of naltrexone and other factors limiting receptor adaptation among patients who exhibit SIB.

Improving parent-child interactions for families of children with developmental disabilities

Child Management Training (CMT) involves compliance training with a focus on consistent use of antecedents and consequences. Planned Activities Training (PAT) focuses on teaching parents to plan for and engage in activities with their children. A multiple probe design counterbalancing PAT and CMT showed that PAT and CMT were about equally effective in improving mother-child interactions in four families with children with developmental disabilities. Responses to a social validation questionnaire indicated that parents were satisfied with the services received, and that PAT was the slightly preferred treatment. Prior research demonstrated that PAT enhanced the results of CMT. The practical advantages of PAT over CMT are discussed.

β-endorphin and ACTH are dissociated after self-injury in adults with developmental disabilities

Relations between self-injuring behavior (SIB), the hypothalamic-pituitary-adrenal (HPA) stress axis, and response to an opiate antagonist were examined. Subjects were observed in their residential settings, while behavior was recorded. Blood was collected in the morning, evening, and immediately after SIB. Plasma beta-E was uncoupled from ACTH after SIB but not during the morning baseline. A significant number of the subjects (a) reduced their SIB at least 25% at all doses of naltrexone (NTX) and (b) reduced their SIB over 50% for at least one dose of NTX. The lowest dosage of NTX significantly reduced SIB in subjects with baseline levels of beta-E higher than after SIB. Results support previous reports that the HPA axis is disturbed among subjects exhibiting SIB.

Effect of naltrexone upon self-injurious behavior, learning and activity: a case study

Naltrexone significantly attenuated self-injurious behavior in a 20-year-old mildly retarded autistic male patient. The patient was videotaped daily and behavior was evaluated with a time-sampling procedure. Behavioral ratings of SIB frequency, SIB severity, and activity were collected automatically with a computerized system. Learning and memory were tested on a weekly basis with a modification of a paired associate learning test (PALT). Treatment with naltrexone resulted in (a) attenuation of SIB in the unstructured setting and (b) improvements in learning and memory without influencing activity levels.

The role of proopiomelanocortin (POMC) in sequentially dependent self-injurious behavior.

Self-injuring behavior (SIB) is a life-threatening behavior exhibited by many species, including humans, and has no known cause and no agreed upon treatment. The role of the stress axis in the maintenance of this mysterious behavior was examined in subjects with life-long SIB. Over a 6-year period, 40 hr of direct observations of behavior and the environment were recorded on palmtop computers while 36 residential subjects (28 target and 8 control subjects) conducted their daily activities. Blood samples were collected in morning and evening for all subjects and within minutes after a self-injuring act in 28 target subjects who exhibited SIB to determine levels of ACTH and B-endorphin (BE). Self-injuring events in the patient group were significantly sequentially dependent (i.e., the only predictor of a self-injuring act was an antecedent self-injuring act). Higher morning levels of BE relative to ACTH predicted [r(df=27) = .57, p < .001] the sequentially dependent pattern of SIB. This effect was validated in a subgroup retested several months later [r(df=22) = .60, p < .001]. A subgroup of seven subjects exhibiting sequentially dependent patterns were administered an opiate blocker (naltrexone) in a double-blind, crossover design with an additional 14 hr/week of observation for 7 weeks. Naltrexone challenge interrupted the sequential pattern (improved behavior) in subjects with elevated BE immediately following SIB (r = .85, p < .01). The pattern of results supported the conclusion that the stress axis played a significant role in the maintenance of complex episodes of self-injury.

An analysis of home-cased oral rehydration therapy in the Kingdom of Lesotho

Mothers in developing countries are being successfully taught to give an oral rehydration solution (ORS) at home. The quantity of oral rehydration fluid that mothers administer to their child remains a critical question. Inadequate quantities render oral rehydration therapy (ORT) ineffective. The primary focus of our investigation was direct measurement of the quantity of fluid unsupervised mothers gave their children at home. This study validates a methodology that provides precise information on ORS administration in the home, information essential for evaluating the effectiveness of home-based therapy and for planning programmes to influence unsupervised mothers to correctly administer ORS to their sick children. This study, conducted in the Kingdom of Lesotho, assessed the impact on home care of the national control of diarrhoeal disease (CDD) programme. Direct observations in the home established each childs status and the quantity of fluid used 24 hr after children left the ORT unit where mothers were instructed to give ORS at home. Data were gathered on natural consequences that might discourage use of ORS, such as vomiting, increased frequency of watery stools and distaste for the solution. The health status of most of the 197 children followed improved. The average volume of ORS administered was 544 ml. A full liter was given by 21% of the mothers. Only 3% of the mothers gave no ORS. The average dose was 65 ml/kg. Younger children got about the same volume as older children; thus, they received a higher ml/kg dose. Mothers gave more ORS to children who had more symptoms of diarrhoeal disease at the time they were brought to the clinic.(ABSTRACT TRUNCATED AT 250 WORDS)

Naltrexone improves learning and attention in self-injurious individuals with developmental disabilities

In the primary study, 10 patients were enrolled in a 10-week double-blind evaluation of the effectiveness of naltrexone in reducing self-injurious behavior (SIB) in adults with developmental disabilities. Within this study, the effects of naltrexone on acquisition of a paired associates task were investigated. The effects of three doses of naltrexone (0.5, 1.0, and 2.0 mg/kg orally) were tested on separate weeks. Learning evaluations were conducted on Wednesday of each week. Naltrexone improved measures of independence and attention, and decreased trial rate.