The effects of hyperbaric oxygen therapy on oxidative stress, inflammation, and symptoms in children with autism: an open-label pilot study

Oxygen and the Spark of Human Brain Evolution: Complex Interactions of Metabolism and Cortical Expansion across Development and Evolution

Scientific theories on the functioning and dysfunction of the human brain require an understanding of its development-before and after birth and through maturation to adulthood-and its evolution. Here we bring together several accounts of human brain evolution by focusing on the central role of oxygen and brain metabolism. We argue that evolutionary expansion of human transmodal association cortices exceeded the capacity of oxygen delivery by the vascular system, which led these brain tissues to rely on nonoxidative glycolysis for additional energy supply. We draw a link between the resulting lower oxygen tension and its effect on cytoarchitecture, which we posit as a key driver of genetic developmental programs for the human brain-favoring lower intracortical myelination and the presence of biosynthetic materials for synapse turnover. Across biological and temporal scales, this protracted capacity for neural plasticity sets the conditions for cognitive flexibility and ongoing learning, supporting complex group dynamics and intergenerational learning that in turn enabled improved nutrition to fuel the metabolic costs of further cortical expansion. Our proposed model delineates explicit mechanistic links among metabolism, molecular and cellular brain heterogeneity, and behavior, which may lead toward a clearer understanding of brain development and its disorders.

Effects of hyperbaric oxygen therapy on autistic behaviors and GRIN2B gene expression in valproic acid-exposed rats

Introduction

Autism is a complex neurodevelopmental condition characterized by deficits in social interaction, communication, and restricted repetitive behaviors. Hyperbaric oxygen therapy (HBOT) has emerged as a potential treatment for autism, although its effects on behavior and gene expression are not well understood. The GRIN2B gene, known for its involvement in encoding a glutamate receptor subunit crucial for neuron communication and associated with autism, was a focus of this study.

Methods

Using a rat model induced by prenatal exposure to valproic acid, we examined the impact of HBOT on autism-like behaviors and GRIN2B gene expression. Male Wistar rats were categorized into four groups: control, VPA (valproic acid-exposed), VPA+HBOT [2 atmosphere absolute (ATA)], and VPA+HBOT (2.5 ATA). The rats underwent several behavioral tests to assess social behavior, anxiety, stereotype and exploratory behaviors, and learning. Following the behavioral tests, the HBOT groups received 15 sessions of HBOT at pressures of 2 and 2.5 (ATA), and their behaviors were re-evaluated. Subsequently, real-time PCR was employed to measure GRIN2B gene expression in the frontal lobe.

Results

Our results indicated that HBOT significantly increased social interaction and exploratory behaviors in VPA-exposed rats, alongside elevated GRIN2B gene expression in their frontal lobe.

Discussion

Our findings imply that HBOT might have a potential role in ameliorating autism-related behaviors in the VPA rat model of autism through potential modulation of GRIN2B gene expression. However, additional research is essential to fully comprehend the underlying mechanisms and refine the HBOT protocol for optimizing its effectiveness in improving autism-related symptoms.

A Descriptive Study on the Impacts of Hyperbaric Oxygen Therapy on Autistic Individuals Using Parent Testimonies

Introduction Hyperbaric oxygen therapy (HBOT) has been influential in treating many physical and psychological ailments, including the symptoms of autism. This current study aims to evaluate HBOT parents' goals and exit interviews describing the positive, negative, or no impacts experienced from the HBOT dives, asking the question, "Are your child's symptoms improving?" Methods Between January 2020 and July 2023, a Class B monoplace hyperbaric chamber (Sechrist 3300H, Sechrist Industries, Inc., Anaheim, California, United States) was used to administer HBOT sessions to patients with autism. Medical-grade oxygen was pressurized to 1.5-2.0 atmospheres absolute at a rate of 1-2 psi/min, with an average oxygen percentage of 100%, for up to five sessions per week. Retrospective descriptive data and patient information through parent testimonials were collected through a chart review of 30 children and one adult with autism who experienced HBOT sessions. Data were presented through exit interviews describing how parents felt about their child's progress toward goals. Four raters rated parent testimonies on a 5-point Likert scale (1 = Much worse, 2 = Somewhat worse, 3 = Stayed the same, 4 = Somewhat improved, and 5 = Much improved), and an inter-rater reliability estimate using interclass correlation (2) (r = 0.831) was derived, indicating excellent agreement between raters. Results Parents/caregivers provided testimony in an exit interview with a registered nurse after the individual with autism received an entire course of HBOT dives. Descriptive statistics resulted in Rater #1 (M = 4.19, median = 4, SD = 0.654): 87.1% of Rater #1 ratings were Somewhat improved and Much improved; Rater #2 (M = 4.23, median = 4, SD = 0.717): 83.9% of Rater #2 ratings were Somewhat improved and Much improved; Rater #3 (M = 4.23, median = 4, SD = 0.560): 93.5% of Rater #3 ratings were Somewhat improved and Much improved; and Rater #4 (M = 4.26, median = 4, SD = 0.631): 90.3% of Rater #4 ratings were Somewhat improved and Much improved. One-way ANOVA resulted in F (3,123) = 0.052, p = 0.984, which indicated a nonstatistically significant mean difference between rater groups. Conclusions The current study assessed HBOT parents'/caregivers' goals and exit interviews, describing the effects experienced from the complete course of HBOT dives on their children/individuals. A majority of parents/caregivers declared that their condition had "Much improved" or "Somewhat improved," based on the 5-point Likert scale. Based on parents'/caregivers' testimonies, HBOT was demonstrated as a safe and effective intervention, and side effects were primarily mild and did not lead to treatment discontinuation. As a result of this analysis, we recommend continued use of HBOT for treatment.

The Effects of Hyperbaric Oxygen Treatment on Verbal Scores in Children With Autism Spectrum Disorder: A Retrospective Trial

Introduction Autism spectrum disorder (ASD) is a neurodevelopmental condition that affects millions worldwide. Suggested pathophysiology includes cerebral hypoperfusion, inflammation, mitochondrial and immune dysregulation, and oxidative stress. Debate exists concerning the benefit of hyperbaric oxygen therapy (HBOT) in treating ASD and its impacts on verbal behavior. The present study directly assesses the impacts of HBOT treatments on verbal behavior using a novel and unique manner.  Materials and methods A two-group quasi-experimental trial using a pretest and a posttest was designed to retrospectively assess (n = 65) any association between HBOT and change in verbal scores in children (n = 65) with ASD. All children completed two verbal tests six months apart, either the Verbal Behavior Milestones Assessment and Placement Program (VBMAPP) or the Assessment of Basic Language and Learning Skills (ABLLS), based on their developmental age. The control cohort received applied behavior analysis (ABA) without HBOT. The experimental cohort received ABA and a minimum of 40 HBOT treatments, breathing 100% oxygen at 2.0 atmosphere absolute (ATA) for 60 minutes. Results Sixty-five children were included, of which 32 received HBOT (mean (M) = 5.1, standard deviation (SD) = 2.93), with an age range of two to 17 years. More than 63% of the subjects had an autism severity level of three. The 23 children administered VBMAPP who received HBOT showed substantial mean differences with high effect sizes (ESs) (-0.743 to -1.65) and a total score (TS) ES equal to -1.23 as measured by Cohen's d. There was a statistically significant improvement (p < 0.05) in all VBMAPP milestone domains and TS. TS change from baseline versus those in the non-HBOT (Control-ABA) group (n=12) was 46.41 ± 20.14 vs 14.42 ± 6.99; p < 0.0001, ES = -1.23. The 30 children administered the ABLLS showed substantial mean difference (TS) change from baseline 268.89 ± 182.05 vs 190.81 ± 135.26 and exhibited small to medium (-.114 to -.773) ESs with a TS ES = -0.487. Due to the high within-group variability (low statistical power) within the ABLLS cohort, there was a non-significant mean difference between the control (ABA) and experimental (ABA + HBO2) groups' difference scores (p > 0.2024), despite the medium (TS) ES. Conclusions The child cohorts administered the VBMAPP and the ABLLS demonstrated substantial improvements between the non-HBOT (control-ABA) and HBOT (experimental-ABA + HBO2) groups as measured by the significant mean differences and small to large ESs. Simply put, the children in the experimental cohort acquired more verbal skills than their counterparts in the control group.

Therapeutic Impacts of Hyperbaric Oxygen Therapy and Risperidone on Children with Autism: A Clinical Trial

Introduction

In this research, we investigated any possible effect of receiving hyperbaric oxygen therapy (HBOT) or risperidone on the core symptoms of autism in children diagnosed with autism spectrum disorder (ASD).

Methods

This study was a randomized, controlled clinical trial in Minia and Assiut University hospitals in Egypt with three parallel groups. One hundred and eighty children with autism, aged 5-8 years were divided into three equal groups (n=60). Group 1 (G1) received 40 sessions of HBOT within two months, group 2 (G2) received risperidone (dose: 0.25 mg per day in children weighing less than 20 kg and 0.5 mg per day in cases weighing more) for six months, and group 3 (G3) as the control group, received a placebo for six months. The assessment was done using childhood autism rating scale (CARS) and autism treatment evaluation checklist (ATEC) at the beginning of the study (baseline) and after one year.

Results

The mean total CARS and ATEC scores significantly decreased (improved) by varying degrees in the three groups after a year of follow-up compared to the baseline scores, but the best results were found in G1, G2, and G3, respectively.

Conclusion

Using HBOT or risperidone is effective in treating the core symptoms of autism in children diagnosed with autism spectrum disorder, but using HBOT gives better results than risperidone therapy.

Highlights

Non-pharmacologic therapy can be used for the treatment of the core symptoms of autism.Both hyperbaric oxygen therapy and risperidone reduce the core symptoms of autism.Hyperbaric oxygen therapy gives better effects than risperidone in reducing the core symptoms of autism.

Plain Language Summary

Since the long-term use of drug therapy in children with autism leads to the occurrence of side effects in addition to the difficulty in complying with the drugs for long-term use, efforts have begun to use non-traditional alternative treatments, such as hyperbaric oxygen therapy. The current study assessed the therapeutic effect of hyperbaric oxygen therapy and risperidone on the core symptoms of autism. The results revealed that both hyperbaric oxygen therapy and risperidone reduced the core symptoms of autism, but hyperbaric oxygen therapy gave better therapeutic results than risperidone.

Hyperbaric Oxygen Therapy Alleviates Social Behavior Dysfunction and Neuroinflammation in a Mouse Model for Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental disorder (NDD) characterized by impaired social communication and repetitive behavior, among other symptoms. ASD is highly heritable, with SHANK3 being one of the high-risk genes for ASD. In recent years, knowledge has been growing regarding the neuroplasticity effect induced by hyperbaric oxygen therapy (HBOT) and its potential use for ASD. Here, we characterized the effect of HBOT on a mouse model for ASD with the human genetic condition of InsG3680 mutation in the Shank3 gene. As compared to placebo, HBOT improved social behavior and reduced neuroinflammation in the cortex of the InsG3680(+/+) mice. Specifically, HBOT induced upregulation of Insulin-like growth factor 1 (Igf1) expression levels and reduced the number of Iba1-positive cells in the mouse model for ASD compared to placebo control. Together, our research suggests that HBOT has the potential to improve the clinical outcome of ASD by ameliorating some of the core pathophysiological processes responsible for the development of the disorder.

Applications of operant demand to treatment selection III: Consumer behavior analysis of treatment choice

Behavior analysts and psychologists advocate for the use of therapies and strategies based on credible, scientific evidence. Researchers and clinicians regularly advocate for Evidence-based Practices (EBPs) over questionable "alternatives" because caregivers seldom choose interventions based on scientific evidence alone. This study applied methods and concepts from Consumer Behavior Analysis to conduct a reinforcer-based evaluation of the consequences that influence treatment choices. Hypothetical Treatment Purchase Tasks (HTPTs) were designed to evaluate how utilitarian (UR; i.e., the efficacy of treatment) and informational sources of reinforcement (IR; i.e., community support for treatment) jointly influence treatment-related choices. A total of 104 caregivers were recruited using the Amazon Mechanical Turk (MTurk) framework to complete two HTPTs. Results indicated that caregivers overall favored treatments with greater IR over those with greater UR, suggesting that indirect contingencies for treatment choices exerted greater overall influence than the direct contingencies of treatment choices (i.e., efficacy). This finding extends the literature on treatment choice by providing a reinforcer-based perspective on why 'fad', questionable, and pseudoscientific practices can achieve and maintain high levels of adoption by caregivers. This work concludes with a discussion of Consumer Behavior Analysis and how reinforcer-based interpretations of choice can be used to improve efforts to support and advocate for evidence-based child behavior treatments.

Impact of Hyperbaric Oxygen Therapy on Cognitive Functions: a Systematic Review

Hyperbaric oxygen therapy (HBOT) is a modality of treatment in which patients inhale 100% oxygen inside a hyperbaric chamber pressurised to greater than 1 atmosphere. The aim of this review is to discuss neuropsychological findings in various neurological disorders treated with HBOT and to open new perspectives for therapeutic improvement. A literature search was conducted in the MEDLINE (via PubMed) database from the inception up 10 May 2020. Eligibility criteria included original articles published in English. Case studies were excluded. Full-text articles were obtained from the selected studies and were reviewed on the following inclusion criteria (1) performed cognitive processes assessment (2) performed HBOT with described protocol. Two neuropsychologists independently reviewed titles, abstracts, full texts and extracted data. The initial search retrieved 1024 articles, and a total of 42 studies were finally included after applying inclusion and exclusion criteria. The search yielded controversial results with regard to the efficiency of HBOT in various neurological conditions with cognitive disturbance outcome. To the best of our knowledge this is the first state-of-the art, systematic review in the field. More objective and precise neuropsychological assessment methods are needed to exact evaluation of the efficacy of HBOT for neuropsychological deficits. Future studies should widen the assessment of HBOT effects on different cognitive domains because most of the existing studies have focussed on a single process. Finally, there is a need for further longitudinal studies.

The Effects of Hyperbaric Oxygenation on Oxidative Stress, Inflammation and Angiogenesis

Hyperbaric oxygen therapy (HBOT) is commonly used as treatment in several diseases, such as non-healing chronic wounds, late radiation injuries and carbon monoxide poisoning. Ongoing research into HBOT has shown that preconditioning for surgery is a potential new treatment application, which may reduce complication rates and hospital stay. In this review, the effect of HBOT on oxidative stress, inflammation and angiogenesis is investigated to better understand the potential mechanisms underlying preconditioning for surgery using HBOT. A systematic search was conducted to retrieve studies measuring markers of oxidative stress, inflammation, or angiogenesis in humans. Analysis of the included studies showed that HBOT-induced oxidative stress reduces the concentrations of pro-inflammatory acute phase proteins, interleukins and cytokines and increases growth factors and other pro-angiogenesis cytokines. Several articles only noted this surge after the first HBOT session or for a short duration after each session. The anti-inflammatory status following HBOT may be mediated by hyperoxia interfering with NF-κB and IκBα. Further research into the effect of HBOT on inflammation and angiogenesis is needed to determine the implications of these findings for clinical practice.

Autism spectrum disorder (ASD)-associated mitochondrial deficits are revealed in children's platelets but unimproved by hyperbaric oxygen therapy

Mitochondrial and immune dysfunctions are often implicated in the aetiology of autism spectrum disorder (ASD). Here, we studied for the first time the relationship between ASD severity measures and mitochondrial respiratory rates in freshly isolated platelets as well as the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) in isolated neutrophils. We also verified the impact of hyperbaric oxygen therapy (HBOT) on mitochondrial and immune functions as well as on ASD severity measures. Blood samples were collected from three age-matched male groups (Control (Norm-N), autistic (Aut-N), and autistic + HBOT (Aut-H); N = 10 per group). Using high resolution respirometry, we found that routine basal respiration, complex I- and complex I + II-dependent oxidative phosphorylation rate were significantly impaired in Aut-N platelets. Similarly, deficits in immune response of neutrophils were evidenced through lower rates of oxygen consumption and reactive oxygen species (ROS) production by phagocytic NOX. ASD-related behavioural outcomes were found to moderately correlate with platelets' mitochondrial bioenergetic parameters as well as with NOX-mediated activity in neutrophils. HBOT was not able to improve mitochondrial dysfunctions or to counteract ASD-related behavioral deficits. Although HBOT improved one measure of the immune response; namely, NOX-mediated superoxide burst, this was not associated with significant changes in trends of recurrent infections between groups. Taken together, our data suggest that ASD-associated mitochondria and immune deficits are detectable in platelets and neutrophils. We also found no evidence that HBOT confers any significant improvement of ASD-associated physiological or behavioural phenotypes.

The role of balancing selection in maintaining human RhD blood group polymorphism: A preregistered cross-sectional study

Maintenance of genetic polymorphism remains one of the big questions of evolutionary biology, which for a long time tended to be explained by balancing selection. This explanation was later criticized, but now is again accepted as an important mechanism in evolution. Human blood group systems seem affected by balancing selection especially strongly. In this preregistered study, we focused on stable coexistence of RhD-positive and RhD-negative subjects in a population. This is an evolutionary conundrum, because carriers of the less frequent negative allele suffer from lower fecundity due to haemolytic disease of the newborn affecting RhD-positive infants born to RhD-negative women. One explanation of persisting stability of RhD polymorphism points to heterozygote advantage. Over the past decade, numerous studies demonstrated that RhD-positive subjects score better than RhD-negative homozygotes in psychomotor tests and physical health-related variables. Still, evidence of better health and performance of heterozygotes is scarce and merely indirect. We compared the physical and mental health of 2,539 subjects whose RhD genotype was estimated based on their and their parents' RhD phenotype. We confirmed that RhD-negative homozygotes fare worse in terms of physical and mental health than subjects with RhD-positive phenotype and that RhD-positive heterozygotes enjoy better health than both homozygotes. For the first time, we demonstrated that RhD-positive homozygotes might suffer from worse health than RhD-negative homozygotes. Our results strongly support the hypothesis that RhD polymorphism is maintained by heterozygote advantage and that balancing selection may have played an important role in human evolution in this context and in general.

Molecular and Therapeutic Aspects of Hyperbaric Oxygen Therapy in Neurological Conditions

In hyperbaric oxygen therapy (HBOT), the subject is placed in a chamber containing 100% oxygen gas at a pressure of more than one atmosphere absolute. This treatment is used to hasten tissue recovery and improve its physiological aspects, by providing an increased supply of oxygen to the damaged tissue. In this review, we discuss the consequences of hypoxia, as well as the molecular and physiological processes that occur in subjects exposed to HBOT. We discuss the efficacy of HBOT in treating neurological conditions and neurodevelopmental disorders in both humans and animal models. We summarize by discussing the challenges in this field, and explore future directions that will allow the scientific community to better understand the molecular aspects and applications of HBOT for a wide variety of neurological conditions.

Hyperbaric oxygen therapy for pediatric "hypospadias cripple"-evaluating the advantages regarding graft take

INTRODUCTION

Hypospadias cripple patients pose a major surgical challenge with high complication rates attributed mainly to graft contraction. Hyperbaric oxygen therapy (HBOT) is an established treatment for compromised grafts and used extensively as a salvage therapy for compromised grafts and ischemic non-healing wounds.

OBJECTIVE

We evaluated the graft-take rates in hypospadias cripple cases undergoing a staged tubularized autograft repair (STAG) and compared between patients treated with or without preemptive HBOT.

MATERIALS AND METHODS

All patients underwent a STAG. Patients receiving preemptive HBOT were compared with patients receiving the standard surgical procedure without HBOT. The HBOT protocol included a daily session, 5 days per week for four weeks before the surgery and 10 additional daily sessions immediately after first-stage surgery. Each HBOT session included 90 min exposure to 100% O₂ at 2 atmospheres absolute with 5 min air breaks every 20 min. The primary endpoint was graft take. Sequential tubularization without tension at second stage was defined as success.

RESULTS

Seven boys received HBOT and 14 boys comprised the control group. All patients in the HBOT group had good graft take with no graft contraction. In the control group, 57% had good graft take and could proceed to the second-stage surgery and 43% had graft contraction (Table). Except for one patient who had claustrophobia while entering the chamber, no significant side-effects developed during the HBOT.

DISCUSSION

The basic pathophysiology of compromised flaps includes both ischemia and reperfusion injury, which can be attenuated by HBOT. The beneficial effects of HBOT relates to several mechanisms, including hyperoxygenation, fibroblast proliferation, collagen deposition, angiogenesis, and vasculogenesis. Graft contraction is a well-known complication in hypospadias cripple population with reported failure rate of 39-63%. The HBOT procedure was found to be very effective and the entire HBOT group had a good graft take. Accordingly, all patients in the HBOT group proceeded to a successful second-stage tubularization. In addition, HBOT was found to be safe and generally well tolerated by this pediatric population. Study limitations were a relative small, non-homogenous sample size and lack of prospective randomization. Success was defined as sufficient graft elasticity sufficing for tubularization of the neourethra, and exact graft measurements are lacking in this study.

CONCLUSIONS

Preemptive HBOT can be used safely in the hypospadias cripple pediatric population and can potentially reduce the expected high surgical failure secondary to graft contraction.

Effects of Ovariohysterectomy and Hyperbaric Oxygen Therapy on Systemic Inflammation and Oxidation in Dogs

Introduction: Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen in a specialized compression chamber leading to hyperoxia. This treatment modality is associated with anti-inflammatory, antioxidant, and healing properties in people and laboratory animals. However, there are relatively few reports that evaluate the effects of HBOT in companion animals. The goal of this study was to investigate the physiological effects of HBOT on surgically induced systemic inflammation and oxidation in dogs.

Material and Methods: Twelve healthy female beagle dogs were spayed and randomized into control and HBOT groups (n = 6). Both groups received conventional post-ovariohysterectomy therapy, and the HBOT group received two hyperbaric treatments at 2.0 atmosphere of absolute pressure and 100% oxygen for 35 min, 6 and 18 h after surgery. Blood samples were collected 3 h prior to ovariohysterectomy, 6, 18, and 30 h after surgery, prior to HBOT when applicable. Inflammatory biomarkers, including C-reactive protein, circulating cytokines, and changes in iron homeostasis were evaluated at each time point to determine the effects of surgery and HBOT on inflammation. Similarly, serum total oxidant status and total antioxidant status were measured to assess the oxidative stress. Pain and incision scores were recorded and compared between groups.

Results: Following ovariohysterectomy, all dogs had significantly increased serum concentrations of C-reactive protein, KC-like, IL-6, and increased unsaturated iron-binding capacity compared to their pre-surgical values (p < 0.02), while serum iron, total iron-binding capacity and transferrin saturation were significantly decreased after surgery (p < 0.02). There was no significant difference between the control group and the HBOT group for any of the variables. There were no overt adverse effects in the HBOT group.

Conclusion: This is the first prospective randomized controlled study to investigate the effects of HBOT on surgically induced systemic inflammation in dogs. While elective ovariohysterectomy resulted in mild inflammation, the described HBOT protocol portrayed no outward adverse effect and did not induce any detectable pro-inflammatory, anti-inflammatory, or antioxidant effects. Additional investigation is required to identify objective markers to quantify the response to HBOT and determine its role as an adjunctive therapy in dogs with more severe, complicated or chronic diseases.

Hyperbaric Oxygen Treatment Ameliorates Hearing Loss and Auditory Cortex Injury in Noise Exposed Mice by Repressing Local Ceramide Accumulation

Noise-induced hearing loss (NIHL) relates closely to auditory cortex (AC) injury, so countermeasures aiming at the AC recovery would be of benefit. In this work, the effect of hyperbaric oxygen treatment on NIHL was elucidated, which was imposed on mice before (HBOP), during (HBOD) or after (HBOA) noise exposure. Morphology of neurons was assayed by hematoxylin-eosin or Nissl staining. Ceramide (Cer) level was measured through immunohistochemistry analysis. Apoptotic neurons were counted using transferase-mediated dUTP nick end labeling (TUNEL) staining. We demonstrated that the intense, broad band noise raised the threshold of auditory brainstem response, evoked neuronal degeneration or apoptosis and triggered the Cer accumulation in AC, all of which were restored significantly by HBOP, but not HBOD or HBOA. Cer over-generation reversed the advantages of HBOP significantly, while its curtailment recapitulated the effect. Next, noise exposure raised the superoxide or malondialdehyde (MDA) production which was blocked by HBOP or Cer repression. Oxidative control not only attenuated the hearing loss or neurodegeneration but, in turn, reduced the Cer formation significantly. In summary, mutual regulation between Cer and oxidative stress underlies the HBOP’s curative effect on hearing loss and neuronal damage in noise-exposed mice.

Where is the Evidence? A Narrative Literature Review of the Treatment Modalities for Autism Spectrum Disorders

The most important thing about autism spectrum disorder (ASD) is that there is, in fact, no cure for this disorder; however, currently, there are many claims of pharmacological and dietary therapies and behavioral interventions that are said to improve outcome or even lead to “cure” or “recovery.” It continues to remain a challenging condition for children and their families. Research conducted on many of these treatment modalities is limited and, consequently, sufficient evidence does not exist to support their use. The primary aim of this paper was to search for the evidence of the efficacy of each treatment for autism till now. We reviewed different treatment modalities and randomized clinical trials on each treatment to look for the evidence. Although there are interventions that may be effective in alleviating some symptoms and improving skills that help autistic persons lead more productive lives, proven benefits were observed only with applied behavioral analysis (ABA) and some psychopharmacologic agents.

Early Effects of Hyperbaric Oxygen on Inducible Nitric Oxide Synthase Activity/Expression in Lymphocytes of Type 1 Diabetes Patients: A Prospective Pilot Study

This study aimed at examining the early effects of hyperbaric oxygen therapy (HBOT) on inducible nitric oxide synthase (iNOS) activity/expression in lymphocytes of type 1 diabetes mellitus (T1DM) patients. A group of 19 patients (mean age: 63 ± 2.1) with T1DM and with the peripheral arterial disease were included in this study. Patients were exposed to 10 sessions of HBOT in the duration of 1 h to 100% oxygen inhalation at 2.4 ATA. Blood samples were collected for the plasma C-reactive protein (CRP), plasma free fatty acid (FFA), serum nitrite/nitrate, and serum arginase activity measurements. Expression of iNOS and phosphorylation of p65 subunit of nuclear factor-κB (NFκB-p65), extracellular-regulated kinases 1/2 (ERK1/2), and protein kinase B (Akt) were examined in lymphocyte lysates by Western blot. After exposure to HBOT, plasma CRP and FFA were significantly decreased (p < 0.001). Protein expression of iNOS and serum nitrite/nitrate levels were decreased (p < 0.01), while serum arginase activity was increased (p < 0.05) versus before exposure to HBOT. Increased phosphorylation of NFκB-p65 at Ser⁵³⁶ (p < 0.05) and decreased level of NFκB-p65 protein (p < 0.001) in lymphocytes of T1DM patients were observed after HBOT. Decreased phosphorylation of ERK1/2 (p < 0.05) and Akt (p < 0.05) was detected after HBOT. Our results indicate that exposure to HBO decreased iNOS activity/expression via decreasing phosphorylation of ERK1/2 and Akt followed by decreased activity of NFκB.

Hyperbaric oxygen therapy reduces astrogliosis and helps to recovery brain damage in hydrocephalic young rats

PURPOSE

We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus.

METHODS

Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies.

RESULTS

The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group.

CONCLUSION

The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.

Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress

The present study was aimed at assessing endothelium-dependent vasorelaxation, at measuring superoxide production in the aorta and femoral artery, and at determining antioxidative enzyme expression and activity in aortas of male Sprague-Dawley rats (N = 135), randomized to an A-HBO₂ group exposed to a single hyperbaric oxygenation session (120′ of 100% O₂ at 2.0 bars), a 24H-HBO₂ group (single session, examined 24 h after exposure), a 4D-HBO₂ group (4 consecutive days of single sessions), and a CTRL group (untreated group). Vasorelaxation of aortic rings in response to acetylcholine (AChIR) and to reduced pO₂ (HIR) was tested in vitro in the absence/presence of NOS inhibitor L-NAME and superoxide scavenger TEMPOL. eNOS, iNOS, antioxidative enzyme, and NADPH oxidase mRNA expression was assessed by qPCR. Serum oxidative stress markers and enzyme activity were assessed by spectrometry, and superoxide production was determined by DHE fluorescence. Impaired AChIR and HIR in the A-HBO₂ group were restored by TEMPOL. L-NAME inhibited AChIR in all groups. Serum oxidative stress and superoxide production were increased in the A-HBO₂ group compared to all other groups. The mRNA expression of iNOS was decreased in the A-HBO₂ and 24H-HBO₂ groups while SOD1 and 3 and NADPH oxidase were increased in the 4D-HBO₂ group. The expression and activity of catalase and glutathione peroxidase were increased in the 4D-HBO₂ group as well. AChIR was NO dependent. Acute HBO₂ transiently impaired vasorelaxation due to increased oxidative stress. Vasorelaxation was restored and oxidative stress was normalized 24 h after the treatment.

Cerebral hypoperfusion in autism spectrum disorder

Cerebral hypoperfusion, or insufficient blood flow in the brain, occurs in many areas of the brain in patients diagnosed with autism spectrum disorder (ASD). Hypoperfusion was demonstrated in the brains of individuals with ASD when compared to normal healthy control brains either using positron emission tomography (PET) or single‑photon emission computed tomography (SPECT). The affected areas include, but are not limited to the: prefrontal, frontal, temporal, occipital, and parietal cortices; thalami; basal ganglia; cingulate cortex; caudate nucleus; the limbic system including the hippocampal area; putamen; substantia nigra; cerebellum; and associative cortices. Moreover, correlations between symptom scores and hypoperfusion in the brains of individuals diagnosed with an ASD were found indicating that the greater the autism symptom pathology, the more significant the cerebral hypoperfusion or vascular pathology in the brain. Evidence suggests that brain inflammation and vascular inflammation may explain a part of the hypoperfusion. There is also evidence of a lack of normal compensatory increase in blood flow when the subjects are challenged with a task. Some studies propose treatments that can address the hypoperfusion found among individuals diagnosed with an ASD, bringing symptom relief to some extent. This review will explore the evidence that indicates cerebral hypoperfusion in ASD, as well as the possible etiological aspects, complications, and treatments.

Hyperbaric oxygen therapy is not associated with oxidative stress assessed using plasma F2-isoprostanes and isofurans

BACKGROUND AND AIMS

Hyperbaric oxygen (HBO) therapy is increasingly used in medical practice as a means of enhancing the formation of collagen matrix and angiogenesis, thus promoting healing in wounds and necrotic tissue. However, there are concerns that oxygen can also associate with increased production of oxygen free radicals and oxidative stress. F₂-Isoprostanes (F₂-IsoPs) formed by non-enzymatic oxidation of arachidonic acid (AA) are reliable measures for assessing oxidative stress in vivo. In addition, under conditions of high oxygen tension isofurans (IsoFs) are preferentially formed from AA and are considered to better reflect oxidative stress in the setting of high oxygen tension. This study aimed to measure plasma IsoFs and F₂-IsoP in patients receiving HBO therapy to treat osteonecrosis secondary to radiation therapy. Our hypothesis was that IsoFs would continue to rise with increasing oxygen pressures in contrast to F₂-IsoPs whose synthesis would be reduced.

METHODS

Twelve patients receiving hyperbaric therapy to treat osteonecrosis secondary to radiation therapy were studied during hyperbaric treatment. Blood samples were collected prior to, during and after cessation of HBO therapy that lasted for 119min. Seven serial blood samples were collected for measurement of plasma F₂-IsoPs and IsoFs, blood gases and haemoglobin.

RESULTS

Oxygen saturation and venous oxygen partial pressure (PvO₂) rose significantly during hyperbaric therapy. However, there were no significant changes in plasma IsoFs or F₂-IsoPs during the hyperbaric therapy session.

CONCLUSION

In this study of patients with osteonecrosis, HBO therapy at a maximum pressure of 2.4atm with up to 100% oxygen did not worsen oxidative stress assessed using plasma F₂- IsoFs and IsoPs.

Hyperbaric oxygenation and 20-hydroxyeicosatetreanoic acid inhibition reduce stroke volume in female diabetic Sprague-Dawley rats

NEW FINDINGS

What is the central question of this study? Is there a beneficial effect and what are the mechanisms of acute and multiple hyperbaric oxygenation (HBO₂ ) exposures on the outcome of cerebral tissue injury induced by a transient middle cerebral artery occlusion model in diabetic female rats? Are 20-hydroxyeicosatetreanoic acid and epoxyeicosatrienoic acids involved? What is the main finding and its importance? Equal reduction of cortical and total infarct size in rats treated with HBO₂ and HET0016 (20-hydroxyeicosatetreanoic acid production inhibitor) and significant mRNA upregulation of epoxyeicosatrienoic acid-producing enzymes (Cyp2J3 and Cyp2C11) in treated groups suggest that HBO₂ and HET0016 are highly effective stroke treatments and that cytochrome P450 metabolites are involved in this therapeutic effect. We evaluated the effects of acute and repetitive hyperbaric oxygenation (HBO₂ ), 20-hydroxyeicosatetreanoic acid (20-HETE) inhibition by N-hydroxy-N'-(4-butyl-2methylphenyl)-formamidine (HET0016) and their combination on experimental stroke outcomes. Streptozotocin-induced type 1 diabetic Sprague-Dawley female rats (n = 42; n = 7 per group), were subjected to 30 min of transient middle cerebral artery occlusion (t-MCAO)-reperfusion and divided into the following groups: (1) control group, without treatment; and groups exposed to: (2) HBO₂ ; (3) multiple HBO₂ (HBO₂ immediately and second exposure 12 h after t-MCAO); (4) HET0016 pretreatment (1 mg kg^-1 , 3 days before t-MCAO) combined with HBO₂ after t-MCAO; (5) HET0016 treatment (1 h before, during and for 6 h after t-MCAO); and (6) HET0016 treatment followed by HBO₂ after t-MCAO. Messenger RNA expression of CYP2J3, CYP2C11, CYP4A1, endothelial nitric oxide synthase and epoxide hydrolase 2 was determined by real-time qPCR. Cortical infarct size and total infarct size were equally and significantly reduced in HBO₂ - and HET0016-treated rats. Combined treatment with HET0016 and HBO₂ provided no significant additive effect compared with HET0016 treatment only. Messenger RNA of Cyp2J3 was significantly increased in all study groups, and mRNA of Cyp2C11 was significantly increased in the multiple HBO₂ group and the HET0016 treatment followed by HBO₂ group, compared with the control group. Expression of endothelial nitric oxide synthase was significantly increased after HBO₂ treatments, and expression of epoxide hydrolase 2 was increased in all groups compared with the control group. In diabetic female Sprague-Dawley rats, HBO₂ and HET0016 are highly effective stroke treatments, suggesting the involvement of cytochrome P450 metabolites and the NO pathway in this therapeutic effect.

Hyperbaric oxygen therapy for children with autism spectrum disorder

Question As autism spectrum disorder (ASD) is a multifactorial condition, with genetic and environmental risk factors contributing to children's unique presentation and symptom severity, a range of treatments have been suggested. Parents of children with ASD in my clinic are asking me about alternative therapies to improve their children's condition. One of those therapies is hyperbaric oxygen therapy (HBOT); commercial advertisement in the past has suggested good results with this approach. Should I recommend the use of HBOT for children with ASD? Answer Hyperbaric oxygen therapy provides a higher concentration of oxygen delivered in a chamber or tube containing higher than sea level atmospheric pressure. Case series and randomized controlled trials show no evidence to support the benefit of HBOT for children with ASD. Only 1 randomized controlled trial reported effectiveness of this treatment, and those results have yet to be repeated.

Neuroprotective effect of hyperbaric oxygen therapy in a juvenile rat model of repetitive mild traumatic brain injury

Repetitive mild traumatic brain injury (rmTBI) is an important medical concern for adolescent athletes that can lead to long-term disabilities. Multiple mild injuries may exacerbate tissue damage resulting in cumulative brain injury and poor functional recovery. In the present study, we investigated the increased brain vulnerability to rmTBI and the effect of hyperbaric oxygen treatment using a juvenile rat model of rmTBI. Two episodes of mild cortical controlled impact (3 days apart) were induced in juvenile rats. Hyperbaric oxygen (HBO) was applied 1 hour/day × 3 days at 2 atmosphere absolute consecutively, starting at 1 day after initial mild traumatic brain injury (mTBI). Neuropathology was assessed by multi-modal magnetic resonance imaging (MRI) and tissue immunohistochemistry. After repetitive mTBI, there were increases in T2-weighted imaging-defined cortical lesions and susceptibility weighted imaging-defined cortical microhemorrhages, correlated with brain tissue gliosis at the site of impact. HBO treatment significantly decreased the MRI-identified abnormalities and tissue histopathology. Our findings suggest that HBO treatment improves the cumulative tissue damage in juvenile brain following rmTBI. Such therapy regimens could be considered in adolescent athletes at the risk of repeated concussions exposures.

Hyperbaric oxygen therapy for people with autism spectrum disorder (ASD)

BACKGROUND

The rising prevalence of autism spectrum disorder (ASD) has increased the need for evidence-based treatments to lessen the impact of symptoms. Presently, no therapies are available to effectively treat individuals with all of the symptoms of this disorder. It has been suggested that hyperbaric oxygen therapy may alleviate the biochemical dysfunction and clinical symptoms of ASD.

OBJECTIVES

To determine whether treatment with hyperbaric oxygen:1. improves core symptoms of ASD, including social communication problems and stereotypical and repetitive behaviors;2. improves noncore symptoms of ASD, such as challenging behaviors;3. improves comorbid states, such as depression and anxiety; and4. causes adverse effects.

SEARCH METHODS

On 10 December 2015, we searched CENTRAL, Ovid MEDLINE, Embase, and 15 other databases, four of which were Chinese language databases. We also searched multiple trial and research registers.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) and quasi-RCTs of any dose, duration, and frequency for hyperbaric oxygen therapy compared with no treatment or sham treatment for children and adults with ASD.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration, in that three review authors independently selected studies, assessed them for risk of bias, and extracted relevant data. We also assessed the quality of the evidence by using the GRADE approach.

MAIN RESULTS

We included one trial with a total of 60 children with a diagnosis of ASD who randomly received hyperbaric oxygen therapy or a sham treatment. Using GRADE criteria, we rated the quality of the evidence as low because of the small sample size and wide confidence intervals (CIs). Other problems included selection bias and short duration or follow-up.Overall, study authors reported no improvement in social interaction and communication, behavioral problems, communication and linguistic abilities, or cognitive function. With regard to the safety of hyperbaric oxygen therapy (adverse events), they reported minor-grade ear barotrauma events. Investigators found significant differences between groups in total number of side effect events (Peto odds ratio (OR) 3.87, 95% CI 1.53 to 9.82) and in the number of children who experienced side effects (Peto OR 4.40, 95% CI 1.33 to 14.48).

AUTHORS' CONCLUSIONS

To date, there is no evidence that hyperbaric oxygen therapy improves core symptoms and associated symptoms of ASD. It is important to note that adverse effects (minor-grade ear barotrauma events) can occur. Given the absence of evidence of effectiveness and the limited biological plausibility and possible adverse effects, the need for future RCTs of hyperbaric oxygen therapy must be carefully considered.

Hyperbaric oxygen can induce neuroplasticity and improve cognitive functions of patients suffering from anoxic brain damage

Purpose: Cognitive impairment may occur in 42–50% of cardiac arrest survivors. Hyperbaric oxygen therapy (HBO₂) has recently been shown to have neurotherapeutic effects in patients suffering from chronic cognitive impairments (CCI) consequent to stroke and mild traumatic brain injury.

The objective of this study was to assess the neurotherapeutic effect of HBO₂ in patients suffering from CCI due to cardiac arrest.

Methods: Retrospective analysis of patients with CCI caused by cardiac arrest, treated with 60 daily sessions of HBO₂. Evaluation included objective computerized cognitive tests (NeuroTrax), Activity of Daily Living (ADL) and Quality of life questionnaires. The results of these tests were compared with changes in brain activity as assessed by single photon emission computed tomography (SPECT) brain imaging.

Results: The study included 11 cases of CCI patients. Patients were treated with HBO₂, 0.5–7.5 years (mean 2.6 ± 0.6 years) after the cardiac arrest. HBO₂ was found to induce modest, but statistically significant improvement in memory, attention and executive function (mean scores) of 12% , 20% and 24% respectively. The clinical improvements were found to be well correlated with increased brain activity in relevant brain areas as assessed by computerized analysis of the SPECT imaging.

Conclusions: Although further research is needed, the results demonstrate the beneficial effects of HBO₂ on CCI in patients after cardiac arrest, even months to years after the acute event.

Identification and Treatment of Pathophysiological Comorbidities of Autism Spectrum Disorder to Achieve Optimal Outcomes

Despite the fact that the prevalence of autism spectrum disorder (ASD) continues to rise, no effective medical treatments have become standard of care. In this paper we review some of the pathophysiological abnormalities associated with ASD and their potential associated treatments. Overall, there is evidence for some children with ASD being affected by seizure and epilepsy, neurotransmitter dysfunction, sleep disorders, metabolic abnormalities, including abnormalities in folate, cobalamin, tetrahydrobiopterin, carnitine, redox and mitochondrial metabolism, and immune and gastrointestinal disorders. Although evidence for an association between these pathophysiological abnormalities and ASD exists, the exact relationship to the etiology of ASD and its associated symptoms remains to be further defined in many cases. Despite these limitations, treatments targeting some of these pathophysiological abnormalities have been studied in some cases with high-quality studies, whereas treatments for other pathophysiological abnormalities have not been well studied in many cases. There are some areas of more promising treatments specific for ASD including neurotransmitter abnormalities, particularly imbalances in glutamate and acetylcholine, sleep onset disorder (with behavioral therapy and melatonin), and metabolic abnormalities in folate, cobalamin, tetrahydrobiopterin, carnitine, and redox pathways. There is some evidence for treatments of epilepsy and seizures, mitochondrial and immune disorders, and gastrointestinal abnormalities, particularly imbalances in the enteric microbiome, but further clinical studies are needed in these areas to better define treatments specific to children with ASD. Clearly, there are some promising areas of ASD research that could lead to novel treatments that could become standard of care in the future, but more research is needed to better define subgroups of children with ASD who are affected by specific pathophysiological abnormalities and the optimal treatments for these abnormalities.

Hyperbaric oxygen therapy as a potential treatment for post-traumatic stress disorder associated with traumatic brain injury

Traumatic brain injury (TBI) describes the presence of physical damage to the brain as a consequence of an insult and frequently possesses psychological and neurological symptoms depending on the severity of the injury. The recent increased military presence of US troops in Iraq and Afghanistan has coincided with greater use of improvised exploding devices, resulting in many returning soldiers suffering from some degree of TBI. A biphasic response is observed which is first directly injury-related, and second due to hypoxia, increased oxidative stress, and inflammation. A proportion of the returning soldiers also suffer from post-traumatic stress disorder (PTSD), and in some cases, this may be a consequence of TBI. Effective treatments are still being identified, and a possible therapeutic candidate is hyperbaric oxygen therapy (HBOT). Some clinical trials have been performed which suggest benefits with regard to survival and disease severity of TBI and/or PTSD, while several other studies do not see any improvement compared to a possibly poorly controlled sham. HBOT has been shown to reduce apoptosis, upregulate growth factors, promote antioxidant levels, and inhibit inflammatory cytokines in animal models, and hence, it is likely that HBOT could be advantageous in treating at least the secondary phase of TBI and PTSD. There is some evidence of a putative prophylactic or preconditioning benefit of HBOT exposure in animal models of brain injury, and the optimal time frame for treatment is yet to be determined. HBOT has potential side effects such as acute cerebral toxicity and more reactive oxygen species with long-term use, and therefore, optimizing exposure duration to maximize the reward and decrease the detrimental effects of HBOT is necessary. This review provides a summary of the current understanding of HBOT as well as suggests future directions including prophylactic use and chronic treatment.

Complementary and Alternative Therapies for Autism Spectrum Disorder

Background. Complementary and alternative medicine (CAM) represents a popular therapeutic option for patients with autism spectrum disorder (ASD). Unfortunately, there is a paucity of data regarding the efficacy of CAM in ASD. The aim of the present systematic review is to investigate trials of CAM in ASD. Material and Methods. We searched the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, CINAHL, Psychology and Behavioral Sciences Collection, Agricola, and Food Science Source. Results. Our literature search identified 2687 clinical publications. After the title/abstract screening, 139 publications were obtained for detailed evaluation. After detailed evaluation 67 studies were included, from hand search of references we retrieved 13 additional studies for a total of 80. Conclusion. There is no conclusive evidence supporting the efficacy of CAM therapies in ASD. Promising results are reported for music therapy, sensory integration therapy, acupuncture, and massage.

Complementary and alternative medicine treatments for children with autism spectrum disorders

There are many treatments in current use for core and associated symptoms of autism spectrum disorders (ASD). This review discusses the complementary and alternative medical (CAM) treatments commonly added to conventional interventions for children with ASD, including natural products, mind and body practices, and other biomedical treatments. The article focuses on factors associated with use of CAM, the empirical evidence for the most frequently used treatments, and how clinicians work with families who choose CAM treatments. Some treatments have been ineffective, some have unacceptable potential side effects, and others require more study in depth.

Comparison of urinary oxidative biomarkers in Iranian children with autism

Autism is a complex neurodevelopmental disorder usually presents in early childhood and thought to be influenced by genetic and environmental factors. Individuals with autism vary widely in abilities, intelligence, and behaviors. It is common for children with autism to exhibit eating disorders and some have preferences for soft and sweetened food making them susceptible to caries. Furthermore, a wide spectrum of medical and behavioral symptoms exhibited by children with autism makes routine dental care very difficult. Intellectual disability is evident in approximately 70% of individuals with autism and most psychiatric disorders, including autism, are associated with increased oxidative stress. 29 subjects diagnosed with autism, in the age group of 6 to 12 years, were a part of the study. Furturemore, 24 normal healthy siblings of same age group were taken as the control group. The present study aimed to evaluate oxidative stress biomarkers such as urinary total antioxidant concentration (TAC), catalase activity (CAT) and total thiol molecules (TTM). The results showed the autism group have significantly higher CAT activity and concomitant lower TAC and TTM concentration in comparison with control group. The results are discussed in relation to an increased vulnerability to oxidative damage, which may contribute to the development and clinical manifestation of symptoms of autism.

Inflammation in children and adolescents with neuropsychiatric disorders: a systematic review

OBJECTIVE

There has been rapid growth in research regarding inflammation in neuropsychiatric disorders as it relates to youth. We therefore set out to systematically review the literature on inflammation and neuropsychiatric disorders in children and adolescents.

METHOD

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were included if proinflammatory markers (PIMs) in children and/or adolescents with neuropsychiatric disorders were measured.

RESULTS

Sixty-seven studies were included, involving 3,952 youth. Evidence for a proinflammatory state is strongest for autism spectrum disorders (ASD). PIMs are elevated in children and adolescents with major depressive disorder (MDD), bipolar disorder (BD), post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), Tourette's disorder (TD), attention-deficit/hyperactivity disorder (ADHD), and schizophrenia (SZ). However, the data are inconsistent. Evidence for specific PIMs is equivocal at this stage, although the findings in youth with MDD, BD, and PTSD converge with the extant adult literature in these areas. Definitive conclusions are limited by methodologic factors including cross-sectional and retrospective study design, between-study differences in specific markers and methods of analysis, small sample size, and other sources of heterogeneity.

CONCLUSION

The literature regarding inflammation among children and adolescents with neuropsychiatric disorders represents nearly 4,000 youth. There is preliminary evidence for elevated markers of inflammation in this population. Larger, prospective studies are needed to realize the goal of inflammatory markers informing clinical practice. In the interim, present findings suggest that further examination of this topic is warranted.

The medical use of oxygen: a time for critical reappraisal

Oxygen treatment has been a cornerstone of acute medical care for numerous pathological states. Initially, this was supported by the assumed need to avoid hypoxaemia and tissue hypoxia. Most acute treatment algorithms, therefore, recommended the liberal use of a high fraction of inspired oxygen, often without first confirming the presence of a hypoxic insult. However, recent physiological research has underlined the vasoconstrictor effects of hyperoxia on normal vasculature and, consequently, the risk of significant blood flow reduction to the at-risk tissue. Positive effects may be claimed simply by relief of an assumed local tissue hypoxia, such as in acute cardiovascular disease, brain ischaemia due to, for example, stroke or shock or carbon monoxide intoxication. However, in most situations, a generalized hypoxia is not the problem and a risk of negative hyperoxaemia-induced local vasoconstriction effects may instead be the reality. In preclinical studies, many important positive anti-inflammatory effects of both normobaric and hyperbaric oxygen have been repeatedly shown, often as surrogate end-points such as increases in gluthatione levels, reduced lipid peroxidation and neutrophil activation thus modifying ischaemia-reperfusion injury and also causing anti-apoptotic effects. However, in parallel, toxic effects of oxygen are also well known, including induced mucosal inflammation, pneumonitis and retrolental fibroplasia. Examining the available 'strong' clinical evidence, such as usually claimed for randomized controlled trials, few positive studies stand up to scrutiny and a number of trials have shown no effect or even been terminated early due to worse outcomes in the oxygen treatment arm. Recently, this has led to less aggressive approaches, even to not providing any supplemental oxygen, in several acute care settings, such as resuscitation of asphyxiated newborns, during acute myocardial infarction or after stroke or cardiac arrest. The safety of more advanced attempts to deliver increased oxygen levels to hypoxic or ischaemic tissues, such as with hyperbaric oxygen therapy, is therefore also being questioned. Here, we provide an overview of the present knowledge of the physiological effects of oxygen in relation to its therapeutic potential for different medical conditions, as well as considering the potential for harm. We conclude that the medical use of oxygen needs to be further examined in search of solid evidence of benefit in many of the current clinical settings in which it is routinely used.

My experience learning about autism

I remember the first time I heard the word "autistic." I was 10 years old, and my mom mentioned that someone had a child who was autistic. I was confused because I mistook her description as "artistic." In April 2001, our first child, Isaiah, was born. My wife, Lanier, was concerned that he had autism at about 11 months of age, but I did not recognize his obvious problems, even though he was not responding to his name, was obsessed with spinning objects, and did not play with toys appropriately. He also had no language, did not walk until 18 months, and had significant gastrointestinal (GI) problems including severe reflux requiring medication and chronic diarrhea. At 19 months of age, Isaiah was diagnosed with autistic disorder.

Hyperbaric oxygen therapy attenuates neuropathic hyperalgesia in rats and idiopathic trigeminal neuralgia in patients

BACKGROUND

Neuropathic pain after nerve injury is severe and intractable, and current drug and non-drug therapies offer very limited pain relief. Hyperbaric oxygen (HBO 2) has been clinically used for protection of the nervous system after acute injury. We investigated whether HBO 2 treatment could prevent and/or attenuate neuropathic pain in animals and in patients.

METHODS

Mechanical allodynia and thermal hyperalgesia and neurochemical alterations of neuropathic pain were analysed in male, adult, Sprague-Dawley rats with sciatic nerve injury. Clinical trials were conducted in patients with idiopathic trigeminal neuralgia.

RESULTS

Repetitive HBO 2 treatment [a combination of pressure at 3 atmosphere absolute (ATA) and pure oxygen] greatly inhibited behavioural signs of neuropathic pain manifested as thermal hyperalgesia and mechanical allodynia. Such an HBO 2 treatment also inhibited nerve injury-induced induction of c-Fos and activation of astrocytes and increased phosphorylation of NR2B receptor and the subsequent Ca 2+-dependent signals in rats. Neither high pressure (up to 3 ATA) nor pure oxygen alone resulted in analgesic effect. In clinical trials, one course of HBO 2 therapy (10 consecutive days) produced a rapid-onset, dose-dependent and long-lasting analgesic effects evidenced by the decreased doses of carbamazepine required for keeping patient pain at a minimum and decreased scores of visual analogue scales, which was used for patient's self-evaluation.

CONCLUSIONS

These findings support that HBO 2 therapy is an effective approach for treating neuropathic pain in both animals and human beings and suggest that neural protection, anti-inflammation and inhibition of nerve injury-induced altered neural activity may contribute to the analgesic effect of HBO 2 therapy.

Evaluating mitochondrial DNA variation in autism spectrum disorders

Despite the increasing speculation that oxidative stress and abnormal energy metabolism may play a role in Autism Spectrum Disorders (ASD), and the observation that patients with mitochondrial defects have symptoms consistent with ASD, there are no comprehensive published studies examining the role of mitochondrial variation in autism. Therefore, we have sought to comprehensively examine the role of mitochondrial DNA (mtDNA) variation with regard to ASD risk, employing a multi-phase approach. In phase 1 of our experiment, we examined 132 mtDNA single-nucleotide polymorphisms (SNPs) genotyped as part of our genome-wide association studies of ASD. In phase 2 we genotyped the major European mitochondrial haplogroup-defining variants within an expanded set of autism probands and controls. Finally in phase 3, we resequenced the entire mtDNA in a subset of our Caucasian samples (∼400 proband-father pairs). In each phase we tested whether mitochondrial variation showed evidence of association to ASD. Despite a thorough interrogation of mtDNA variation, we found no evidence to suggest a major role for mtDNA variation in ASD susceptibility. Accordingly, while there may be attractive biological hints suggesting the role of mitochondria in ASD our data indicate that mtDNA variation is not a major contributing factor to the development of ASD.

Hyperbaric oxygen treatment in autism spectrum disorders

Traditionally, hyperbaric oxygen treatment (HBOT) is indicated in several clinical disorders include decompression sickness, healing of problem wounds and arterial gas embolism. However, some investigators have used HBOT to treat individuals with autism spectrum disorders (ASD). A number of individuals with ASD possess certain physiological abnormalities that HBOT might ameliorate, including cerebral hypoperfusion, inflammation, mitochondrial dysfunction and oxidative stress. Studies of children with ASD have found positive changes in physiology and/or behavior from HBOT. For example, several studies have reported that HBOT improved cerebral perfusion, decreased markers of inflammation and did not worsen oxidative stress markers in children with ASD. Most studies of HBOT in children with ASD examined changes in behaviors and reported improvements in several behavioral domains although many of these studies were not controlled. Although the two trials employing a control group reported conflicting results, a recent systematic review noted several important distinctions between these trials. In the reviewed studies, HBOT had minimal adverse effects and was well tolerated. Studies which used a higher frequency of HBOT sessions (e.g., 10 sessions per week as opposed to 5 sessions per week) generally reported more significant improvements. Many of the studies had limitations which may have contributed to inconsistent findings across studies, including the use of many different standardized and non-standardized instruments, making it difficult to directly compare the results of studies or to know if there are specific areas of behavior in which HBOT is most effective. The variability in results between studies could also have been due to certain subgroups of children with ASD responding differently to HBOT. Most of the reviewed studies relied on changes in behavioral measurements, which may lag behind physiological changes. Additional studies enrolling children with ASD who have certain physiological abnormalities (such as inflammation, cerebral hypoperfusion, and mitochondrial dysfunction) and which measure changes in these physiological parameters would be helpful in further defining the effects of HBOT in ASD.

Hyperbaric oxygen therapy for treatment of children with autism: a systematic review of randomized trials

There is a controversy about the efficacy of hyperbaric oxygen (HBO) therapy for the treatment of autism. This study systematically reviews the current evidences for treating of autism with HBO therapy. According to PRISMA guidelines for a systematic review, the databases of MEDLINE/Pubmed, Google Scholar, and Randomised Controlled Trials in Hyperbaric Medicine were electronically searched. In addition, medical subject heading terms and text words for hyperbaric oxygen therapy and autism were used. The main inclusion criteria were published studies which reported the original data from the trials conducted on the patients with autism and assessed outcomes with a valid and reliable instrument. A quality assessment was also conducted. The electronically search resulted in 18 title of publications. Two studies were randomized, double-blind, controlled-clinical trials. While some uncontrolled and controlled studies suggested that HBO therapy is effective for the treatment of autism, these promising effects are not replicated. Therefore, sham-controlled studies with rigorous methodology are required to be conducted in order to provide scientific evidence-based HBO therapy for autism treatment.

The potential role of the antioxidant and detoxification properties of glutathione in autism spectrum disorders: a systematic review and meta-analysis

BACKGROUND

Glutathione has a wide range of functions; it is an endogenous anti-oxidant and plays a key role in the maintenance of intracellular redox balance and detoxification of xenobiotics. Several studies have indicated that children with autism spectrum disorders may have altered glutathione metabolism which could play a key role in the condition.

METHODS

A systematic literature review and meta-analysis was conducted of studies examining metabolites, interventions and/or genes of the glutathione metabolism pathways i.e. the γ-glutamyl cycle and trans-sulphuration pathway in autism spectrum disorders.

RESULTS

Thirty nine studies were included in the review comprising an in vitro study, thirty two metabolite and/or co-factor studies, six intervention studies and six studies with genetic data as well as eight studies examining enzyme activity.

CONCLUSIONS

The review found evidence for the involvement of the γ-glutamyl cycle and trans-sulphuration pathway in autistic disorder is sufficiently consistent, particularly with respect to the glutathione redox ratio, to warrant further investigation to determine the significance in relation to clinical outcomes. Large, well designed intervention studies that link metabolites, cofactors and genes of the γ-glutamyl cycle and trans-sulphuration pathway with objective behavioural outcomes in children with autism spectrum disorders are required. Future risk factor analysis should include consideration of multiple nutritional status and metabolite biomarkers of pathways linked with the γ-glutamyl cycle and the interaction of genotype in relation to these factors.

A review of research trends in physiological abnormalities in autism spectrum disorders: immune dysregulation, inflammation, oxidative stress, mitochondrial dysfunction and environmental toxicant exposures

Recent studies have implicated physiological and metabolic abnormalities in autism spectrum disorders (ASD) and other psychiatric disorders, particularly immune dysregulation or inflammation, oxidative stress, mitochondrial dysfunction and environmental toxicant exposures ('four major areas'). The aim of this study was to determine trends in the literature on these topics with respect to ASD. A comprehensive literature search from 1971 to 2010 was performed in these four major areas in ASD with three objectives. First, publications were divided by several criteria, including whether or not they implicated an association between the physiological abnormality and ASD. A large percentage of publications implicated an association between ASD and immune dysregulation/inflammation (416 out of 437 publications, 95%), oxidative stress (all 115), mitochondrial dysfunction (145 of 153, 95%) and toxicant exposures (170 of 190, 89%). Second, the strength of evidence for publications in each area was computed using a validated scale. The strongest evidence was for immune dysregulation/inflammation and oxidative stress, followed by toxicant exposures and mitochondrial dysfunction. In all areas, at least 45% of the publications were rated as providing strong evidence for an association between the physiological abnormalities and ASD. Third, the time trends in the four major areas were compared with trends in neuroimaging, neuropathology, theory of mind and genetics ('four comparison areas'). The number of publications per 5-year block in all eight areas was calculated in order to identify significant changes in trends. Prior to 1986, only 12 publications were identified in the four major areas and 51 in the four comparison areas (42 for genetics). For each 5-year period, the total number of publications in the eight combined areas increased progressively. Most publications (552 of 895, 62%) in the four major areas were published in the last 5 years (2006-2010). Evaluation of trends between the four major areas and the four comparison areas demonstrated that the largest relative growth was in immune dysregulation/inflammation, oxidative stress, toxicant exposures, genetics and neuroimaging. Research on mitochondrial dysfunction started growing in the last 5 years. Theory of mind and neuropathology research has declined in recent years. Although most publications implicated an association between the four major areas and ASD, publication bias may have led to an overestimation of this association. Further research into these physiological areas may provide insight into general or subset-specific processes that could contribute to the development of ASD and other psychiatric disorders.

Hyperbaric oxygen treatment for inflammatory bowel disease: a systematic review and analysis

Background

Traditionally, hyperbaric oxygen treatment (HBOT) has been used to treat a limited repertoire of disease, including decompression sickness and healing of problem wounds. However, some investigators have used HBOT to treat inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.

Methods

Comprehensive searches were conducted in 8 scientific databases through 2011 to identify publications using HBOT in IBD. Human studies and animal models were collated separately.

Results

Thirteen studies of HBOT in Crohn's disease and 6 studies in ulcerative colitis were identified. In all studies, participants had severe disease refractory to standard medical treatments, including corticosteroids, immunomodulators and anti-inflammatory medications. In patients with Crohn's disease, 31/40 (78%) had clinical improvements with HBOT, while all 39 patients with ulcerative colitis improved. One study in Crohn's disease reported a significant decrease in proinflammatory cytokines (IL-1, IL-6 and TNF-alpha) and one study in ulcerative colitis reported a decrease in IL-6 with HBOT. Adverse events were minimal. Twelve publications reported using HBOT in animal models of experimentally-induced IBD, including several studies reporting decreased markers of inflammation or immune dysregulation, including TNF-alpha (3 studies), IL-1beta (2 studies), neopterin (1 study) and myeloperoxidase activity (5 studies). HBOT also decreased oxidative stress markers including malondialdehyde (3 studies) and plasma carbonyl content (2 studies), except for one study that reported increased plasma carbonyl content. Several studies reported HBOT lowered nitric oxide (3 studies) and nitric oxide synthase (3 studies) and one study reported a decrease in prostaglandin E₂ levels. Four animal studies reported decreased edema or colonic tissue weight with HBOT, and 8 studies reported microscopic improvements on histopathological examination. Although most publications reported improvements with HBOT, some studies suffered from limitations, including possible publication and referral biases, the lack of a control group, the retrospective nature and a small number of participants.

Conclusions

HBOT lowered markers of inflammation and oxidative stress and ameliorated IBD in both human and animal studies. Most treated patients were refractory to standard medical treatments. Additional studies are warranted to investigate the effects of HBOT on biomarkers of oxidative stress and inflammation as well as clinical outcomes in individuals with IBD.

Controlled evaluation of the effects of hyperbaric oxygen therapy on the behavior of 16 children with autism spectrum disorders

Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total of 16 participants with autism spectrum disorders. No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study. This study represents the first relatively large-scale controlled study evaluating the effects of HBOT at the level of the individual participant, on a wide array of behaviors.

Improvement of attention span and reaction time with hyperbaric oxygen treatment in patients with toxic injury due to mold exposure

It is, by now, well established that mold toxins (mycotoxins) can cause significant adverse health effects. In this study, 15 subjects who developed an attention deficit disorder (ADD) and slowing of reaction time at the time of exposure to mold toxins were identified. Deficits in attention span and reaction time were documented not only by taking a careful history, but also by performing a Test of Variables of Attention (TOVA). The TOVA test provides an objective measure of these two variables. It was found that mold-exposed subjects show statistically significant decreases in attention span and significant increases in reaction time to stimuli compared to controls. After ten sessions of hyperbaric oxygen treatment (HBOT), a statistically significant improvement was seen in both measures. This preliminary study suggests promising outcomes in treating mold-exposed patients with hyperbaric oxygen.

Oxidative pathways as a drug target for the treatment of autism

IMPORTANCE OF THE FIELD

Autism is a severe, pervasive developmental disorder, the aetiology of which is poorly understood. Current pharmacological treatment options for autism are often focused on addressing comorbid behavioural problems, rather than core features of the disorder. Investigation of a new treatment approach is needed.

AREAS COVERED IN THIS REVIEW

Recent research has indicated a possible role of abnormalities in oxidative homeostasis in the pathophysiology of autism, based on reports that a range of oxidative biomarkers are significantly altered in people with autism. This article reviews the current findings on oxidative stress in autism, including genetic links to oxidative pathways, changes in antioxidant levels and other oxidative stress markers. We conducted a search of the literature up to June 2010, using Medline, Pubmed, PsycINFO, CINAHL PLUS and BIOSIS Previews.

WHAT THE READER WILL GAIN

This review provides an overview of the current understanding of the role of oxidative stress in autism. This will assist in highlighting areas of future therapeutic targets and potential underlying pathophysiology of this disorder.

TAKE HOME MESSAGE

Abnormalities in oxidative homeostasis may play a role in the pathophysiology of autism. Antioxidant treatment may form a potential therapeutic pathway for this complex disorder.

Autism spectrum disorders

Pervasive developmental disorders are a group of neurodevelopmental disorders characterized by impairments in communication, reciprocal social interaction and restricted repetitive behaviors or interests. The term autism spectrum disorders (ASD) has been used to describe their variable presentation. Although the cause of these disorders is not yet known, studies strongly suggest a genetic basis with a complex mode of inheritance. More research is needed to explore environmental factors that could be contributing to the cause of these disorders. The occurrence of ASD has been increasing worldwide, with the most recent prevalence studies indicating that they are present in 6 per 1000 children. The objectives of this article are to provide physicians with relevant information needed to identify and refer children presenting with symptoms suggestive of ASDs to specialized centers early, and to make them feel comfortable in dealing with public concerns regarding controversial issues about the etiology and management of these disorders.

Complementary and alternative medicine in autism: an evidence-based approach to negotiating safe and efficacious interventions with families

This review focuses on helping clinicians identify resources and develop strategies they may use to effectively negotiate safe and effective use of complementary and alternative medicine (CAM) treatments with families of children with autism spectrum disorders (ASD), as well as other neurodevelopmental disorders. Since new types of CAM continue to be introduced into the autism community, emphasis is placed on providing clinicians with tools to help families negotiate the myriad of available treatments and make decisions based on current safety and efficacy data, while remaining mindful of the reasons families may be considering these treatments. We familiarize readers with high-quality, evidence-based resources that providers and families may use to ascertain current information about specific types of CAM, verify the content of biologically-based treatments, identify ongoing CAM research and obtain toolkits designed to help healthcare providers raise the topic of CAM usage and facilitate disclosure and discussion of CAM use with patients and their families.