A controlled crossover trial of fenfluramine in autism

A Systematic Review on Autism and Hyperserotonemia: State-of-the-Art, Limitations, and Future Directions

Hyperserotonemia is one of the most studied endophenotypes in autism spectrum disorder (ASD), but there are still no unequivocal results about its causes or biological and behavioral outcomes. This systematic review summarizes the studies investigating the relationship between blood serotonin (5-HT) levels and ASD, comparing diagnostic tools, analytical methods, and clinical outcomes. A literature search on peripheral 5-HT levels and ASD was conducted. In total, 1104 publications were screened, of which 113 entered the present systematic review. Of these, 59 articles reported hyperserotonemia in subjects with ASD, and 26 presented correlations between 5-HT levels and ASD-core clinical outcomes. The 5-HT levels are increased in about half, and correlations between hyperserotonemia and clinical outcomes are detected in a quarter of the studies. The present research highlights a large amount of heterogeneity in this field, ranging from the characterization of ASD and control groups to diagnostic and clinical assessments, from blood sampling procedures to analytical methods, allowing us to delineate critical topics for future studies.

Movement Disorders Secondary to Novel Antiseizure Medications in Pediatric Populations: A Systematic Review and Meta-analysis of Risk

Novel antiseizure medications are thought to be safer than their conventional counterparts, though no dedicated analysis of movement disorder risk among pediatric populations using novel antiseizure medications has been completed. We report a systematic review with meta-analysis describing the relationship between novel antiseizure medications and movement disorders in pediatrics.MEDLINE, EMBASE, and the World Health Organization's International Clinical Trials Registry Platform were searched up to October 2020 for randomized controlled trials investigating novel antiseizure medications in pediatric populations. Antiseizure medications included lacosamide, perampanel, eslicarbazepine, rufinamide, fenfluramine, cannabidiol, and brivaracetam. Outcomes were pooled using random effects models; risk difference (RD) and 95% confidence intervals (CIs) were calculated.Twenty-three studies were selected from 1690 nonredundant manuscripts (n = 1912 total). There was a significantly increased risk of movement disorders associated with perampanel (RD 0.07, 95% CI 0.01-0.13; n = 133), though only 1 relevant trial was found. No increased risk of movement disorders was found with other antiseizure medications.Our findings indicate most novel antiseizure medications are safe to use in pediatric populations with respect to movement disorders. However, findings were limited by quality of adverse event reporting.

Autism

International school psychologists play an important professional role in providing early diagnostic, consultative and treatment-planning services for autistic children and their families. Recent advances in our understanding of this complex disorder necessitates updating professionals in the etiology and treatment of autism. The article describes components of making a differential diagnosis of autism from developmental language/speech disorders, mental retardation and schizophrenia. Etiological theories based on recent neurobiological data are outlined and the psychometric properties of cognitive ability and behavioral rating instruments frequently used with this population are delineated. Specific innovative educational and pharmacological treatment approaches are reviewed.

Pharmacotherapy for the core symptoms in autistic disorder: current status of the research

The current review covers extant literature on pharmacotherapy for core symptoms of autism. The core symptoms of autism include impairments in social interaction and communication, as well as the presence of restricted and repetitive behaviors. There are no known efficacious treatments for the core social symptoms, although effects on repetitive behaviors are indicated with some data. While studies of fenfluramine, secretin, opiates, and mood stabilizers generally find no effect, mixed results suggest more research is needed on antidepressants and atypical antipsychotics. Newer lines of research, including cholinergic and glutamatergic agents and oxytocin, will be of considerable interest in the future. However, research on the treatment of core symptoms is plagued by limitations in study design, statistical power, and other issues inherent to the study of treatments for autism (e.g., heterogeneity of the disorder) that continue to prevent the elucidation of efficacious treatments.

Catecholamines and their metabolites in children with asperger and kanner syndromes

Children with Asperger and Kanner syndromes in the stable state demonstrate similar decrease in plasma norepinephrine. In the aggravated state, these changes become more expressed and are characterized by a decrease in plasma tyrosine, norepinephrine, normetanephrine and by an increase in dopamine and homovanylic acid and a decrease in excretion of norepinephrine and an increase in excretion of homovanylic acid, epinephrine and MHPG. Only in children with Kanner syndrome in the aggravated state plasma MHPG increases, excretion of tyrosine decreases and excretion of normetanephrine increases. The observed imbalance in dopamine and epinephrine/norepinephrine systems justifies combined analysis of changes in catecholamines and their metabolites levels as the most informative approach in the study of the effect of autistic disorders.

Childhood autism: An appeal for an integrative and psychobiological approach

The difficulty that a person with autism has in establishing relationships, maintaining them (communicating and responding appropriately) is a common experience of those close to them., That impaired perceptual and cognitive processing can underlie this difficulty and the interactions of people with autism with the material environment has been established in the laboratory. The consequences at a psychological level of analysis may converge in the inadequacy of second-order representations of the world. An attenuation of such endogenous monitoring processes could also indirectly account for features of withdrawal and the stereotypies often observed. At another level of analysis there are delays in neurotransmission, in the CNS and a lack of flexibility of physiological response shown by evoked potential recordings. Tomographic studies of blood flow and metabolism illustrate a lack of correlation between information processing centres in the brain that may sometimes arise from diffuse gray matter atrophy. A "stop-go" form of modulation of central processing is mediated by anomalous ascending serotonergic and dopaminergic function (transmitters with inhibitory and switching functions). On these bases it is no wonder that representations are not formed and inappropriate and repetitive behaviors follow, although the link remains somewhat speculative. Both levels of analysis are useful for an explanation. As behavioral and pharmacotherapy, though helpful, are severely limited in their efficacy, more effort is required to synthesize the different levels of analysis into a psycho-biological approach, to remedial programs and new forms of therapy.

Autism: fifty years on from Kanner

It is now 50 years since Leo Kanner first described autism as a distinctive pattern of symptoms in some children with severe developmental problems. Since then the assessment and diagnosis of children with pervasive disorders of development has been refined and much is known about the phenomenology and epidemiology. Autism is a biological disorder of the central nervous system (CNS) of unknown cause. It is associated with a number of organic disorders such as epilepsy and has comorbidity with other psychiatric disorders such as tic disorder. Cognitive abnormalities in social interactions, affect and language are present but there is still debate regarding which of these, if any, is the primary cognitive deficit. Special education and behavioral management has led to modest but important developmental improvement in many children with autism. Autism remains a life-long condition but patterns of symptoms change and skills develop from childhood into adult life.

Fenfluramine and methylphenidate in children with mental retardation and attention deficit hyperactivity disorder: laboratory effects

Twenty-eight children took part in a double-blind, placebo-controlled, crossover study of fenfluramine and methylphenidate. Fenfluramine dosage was gradually increased to a standardized dose of 1.5 mg/kg per day, whereas methylphenidate was given in doses of 0.4 mg/kg per day. The children were assessed on laboratory tests of selective and sustained attention, visual matching, and color matching, during which seat activity was monitored automatically. Results showed fenfluramine to be superior to placebo on the memory task, whereas methylphenidate reduced commission errors on a continuous performance test. Methylphenidate caused shorter response times, and fenfluramine caused increases, on two of the tests. Examiner behavior ratings indicated significant improvements with both drugs on the domains of attention, activity level, and mood. These findings, together with those from a companion clinical study, suggest that the drugs may have contrasting mechanisms of action, but both appear to have useful clinical effects in these children.

Fenfluramine and methylphenidate in children with mental retardation and ADHD: clinical and side effects

Each of 28 nonautistic children with attention-deficit hyperactivity disorder and mental retardation received placebo, methylphenidate (0.4 mg/kg/day), and fenfluramine (gradually increased to 1.5 mg/kg/day) for 4 weeks each in a double-blind, crossover design. Teacher ratings indicated significant improvements with both active drugs on subscales designated as Conduct Problem, Hyperactivity, and Irritability, but methylphenidate alone produced improvements on an Inattention subscale. Parent ratings indicated significant improvements with both drugs on subscales labeled Hyperactivity, Motor Excess, and Conduct Problem. Fenfluramine alone caused improved parent ratings on Irritability and Inappropriate Speech, and on Conners' Abbreviated Symptom Questionnaire. Unlike a previous study, subgroup analyses failed to show a significantly better clinical response to methylphenidate for subjects with higher mental ages, although children with higher IQs responded better than those with IQs less than 45. The active drugs had contrasting effects on heart rate and blood pressure. Fenfluramine caused significant weight reductions relative to both placebo and methylphenidate. These findings suggest that both methylphenidate and fenfluramine have useful, but somewhat different, clinical effects in certain children with attention-deficit hyperactivity disorder and mental retardation.

Pediatric psychopharmacotherapy: a review of recent research

In the past 5 years, we have witnessed the continuation of important trends in clinical research that began earlier in the decade. With regard to the treatment of specific disorders in children and adolescents, the most significant developments have been the examination of the tricyclics for the treatment of depression and the initiation of controlled studies for the treatment of Tourette syndrome. Unfortunately, the findings from the depression studies have been uniformly negative, and the results of research on both depression and tic disorders show a relatively high rate of placebo responsivity, which raises nagging questions about the role of case reports and open trials. Another important trend in pediatric psychopharmacotherapy is the search for substitutes for the neuroleptics. Potential candidates include agents such as lithium, naltrexone, fenfluramine, clonidine, and carbamazepine. The most underresearched disorders are a combination of the least common (e.g. schizophrenia, mania) and those that are apparently perceived as less serious (e.g. sleep disorders, certain anxiety disorders). Not surprisingly, the most studied disorder and treatment is hyperactivity and stimulant medication, respectively. Considerable progress has been made in understanding the social implications of the associated symptoms and their response to stimulant drugs, aided greatly by the use of direct observation procedures. Researchers are beginning to attend to the implications of comorbidity for assessing response to medication. There has been additional confirmation of efficacy of stimulant treatment for preschoolers and adolescents. Dose-response issues remain to some extent unresolved, the primary impediments being interpretive misconceptions associated with trend analysis, an overreliance on the syndromal perspective and too little attention to target behaviors and their clinical implications, and the failure to operationalize the minimal effective dose with regard to the normalization and supranormalization of target and collateral behaviors. Disagreement over whether hyperactivity is a learning or a behavior disorder (or both) and what academic underproductivity means clinically and socially is also impeding progress. With regard to developmental disorders, controlled studies indicate that fenfluramine and naltrexone are effective for managing associated symptoms in some individuals. However, given the limited amount of research on these agents, their status as clinically useful palliatives must be considered tentative.(ABSTRACT TRUNCATED AT 400 WORDS)