Efficacy of cannabidiol in convulsive and nonconvulsive seizure types associated with treatment-resistant epilepsies in the Expanded Access Program.

The cannabidiol (CBD) Expanded Access Program (EAP), initiated in 2014, provided CBD (Epidiolex) to patients with treatment-resistant epilepsy (TRE). In the final pooled analysis of 892 patients treated through January 2019 (median exposure = 694 days), CBD treatment was associated with a 46%-66% reduction in median monthly total (convulsive plus nonconvulsive) seizure frequency. CBD was well tolerated, and adverse events were consistent with previous findings. We used pooled EAP data to investigate the effectiveness of add-on CBD therapy for individual convulsive seizure types (clonic, tonic, tonic-clonic, atonic, focal to bilateral tonic-clonic), nonconvulsive seizure types (focal with and without impaired consciousness, absence [typical and atypical], myoclonic, myoclonic absence), and epileptic spasms. CBD treatment was associated with a reduction in the frequency of convulsive seizure types (median percentage reduction = 47%-100%), and nonconvulsive seizure types and epileptic spasms (median percentage reduction = 50%-100%) across visit intervals through 144 weeks of treatment. Approximately 50% of patients had ≥50% reduction in convulsive and nonconvulsive seizure types and epileptic spasms at nearly all intervals. These results show a favorable effect of long-term CBD use in patients with TRE, who may experience various convulsive and nonconvulsive seizure types. Future controlled trials are needed to confirm these findings.

Arginine vasopressin in cerebrospinal fluid is a marker of sociality in nonhuman primates.

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by core social impairments. ASD remains poorly understood because of the difficulty in studying disease biology directly in patients and the reliance on mouse models that lack clinically relevant, complex social cognition abilities. We use ethological observations in rhesus macaques to identify male monkeys with naturally occurring low sociality. These monkeys showed differences in specific neuropeptide and kinase signaling pathways compared to socially competent male monkeys. Using a discovery and replication design, we identified arginine vasopressin (AVP) in cerebrospinal fluid (CSF) as a key marker of group differences in monkey sociality; we replicated these findings in an independent monkey cohort. We also confirmed in an additional monkey cohort that AVP concentration in CSF is a stable trait-like measure. Next, we showed in a small pediatric cohort that CSF AVP concentrations were lower in male children with ASD compared to age-matched male children without ASD (but with other medical conditions). We demonstrated that CSF AVP concentration was sufficient to accurately distinguish ASD cases from medical controls. These data suggest that AVP and its signaling pathway warrant consideration in future research studies investigating new targets for diagnostics and drug development in ASD.

Memantine as adjunctive therapy in children diagnosed with autistic spectrum disorders: an observation of initial clinical response and maintenance tolerability.

Autism and Pervasive Developmental Disorder Not Otherwise Specified are common developmental problems often seen by child neurologists. There are currently no cures for these lifelong and socially impairing conditions that affect core domains of human behavior such as language, social interaction, and social awareness. The etiology may be multifactorial and may include autoimmune, genetic, neuroanatomic, and possibly excessive glutaminergic mechanisms. Because memantine is a moderate affinity antagonist of the N-methylD-aspartic acid (NMDA) glutamate receptor, this drug was hypothesized to potentially modulate learning, block excessive glutamate effects that can include neuroinflammatory activity, and influence neuroglial activity in autism and Pervasive Developmental Disorder Not Otherwise Specified. Open-label add-on therapy was offered to 151 patients with prior diagnoses of autism or Pervasive Developmental Disorder Not Otherwise Specified over a 21-month period. To generate a clinician-derived Clinical Global Impression Improvement score for language, behavior, and self-stimulatory behaviors, the primary author observed the subjects and questioned their caretakers within 4 to 8 weeks of the initiation of therapy. Chronic maintenance therapy with the drug was continued if there were no negative side effects. Results showed significant improvements in open-label use for language function, social behavior, and self-stimulatory behaviors, although self-stimulatory behaviors comparatively improved to a lesser degree. Chronic use so far appears to have no serious side effects.

Elevation of tumor necrosis factor-alpha in cerebrospinal fluid of autistic children.

Recent reports implicating elevated cytokines in the central nervous system in a small number of patients studied with autism have reported clinical regression. These studies have not focused on tumor necrosis factor-alpha as a possible marker for inflammatory damage. A series of 10 children with autism had clinical evaluation of their serum and spinal fluid for inflammatory changes and possible metabolic disease as part of their neurological evaluation. Elevation of cerebrospinal fluid levels of tumor necrosis factor-alpha was significantly higher (mean = 104.10 pg/mL) than concurrent serum levels (mean = 2.78 pg/mL) in all of the patients studied. The ratio of the cerebrospinal fluid levels to serum levels averaged 53.7:1. This ratio is significantly higher than the elevations reported for other pathological states for which cerebrospinal fluid and serum tumor necrosis factor-alpha levels have been simultaneously measured. This observation may offer a unique insight into central nervous system inflammatory mechanisms that may contribute to the onset of autism and may serve as a potential clinical marker. More controlled study of this potentially important observation may prove valuable.

Treating autistic spectrum disorders in children: utility of the cholinesterase inhibitor rivastigmine tartrate.

Rivastigmine tartrate is a dual-action cholinesterase inhibitor shown to improve language, cognition, and global functioning in patients with Alzheimer's disease, likely via increased availability of cerebral acetylcholine. Because cholinergic receptor abnormalities can contribute to the neuropathology of autistic spectrum disorders, rivastigmine tartrate could prove to be an effective therapy for affected children. Observations of improved behavior and language output from prior open-label and double-blind treatment of autistic children with donepezil, another cholinesterase inhibitor, prompted this 12-week open-label study with rivastigmine tartrate of 32 autistic patients. Therapeutic indices were the Childhood Autistic Rating Scale, Gardner's Expressive and Receptive One-Word Picture Vocabulary tests, and the Conners' Parent Rating Scale. Testing administered at baseline, 6 weeks, and 12 weeks showed gains in both expressive speech and overall autistic behavior over baseline. These improvements were statistically significant and supported the hypothesis that treatment with cholinergic enhancing drugs in autistic spectrum disorders yields positive therapeutic effects.

Double-blind, placebo-controlled study of L-carnosine supplementation in children with autistic spectrum disorders.

L-Carnosine, a dipeptide, can enhance frontal lobe function or be neuroprotective. It can also correlate with gamma-aminobutyric acid (GABA)-homocarnosine interaction, with possible anticonvulsive effects. We investigated 31 children with autistic spectrum disorders in an 8-week, double-blinded study to determine if 800 mg L-carnosine daily would result in observable changes versus placebo. Outcome measures were the Childhood Autism Rating Scale, the Gilliam Autism Rating Scale, the Expressive and Receptive One-Word Picture Vocabulary tests, and Clinical Global Impressions of Change. Children on placebo did not show statistically significant changes. After 8 weeks on L-carnosine, children showed statistically significant improvements on the Gilliam Autism Rating Scale (total score and the Behavior, Socialization, and Communication subscales) and the Receptive One-Word Picture Vocabulary test (all P < .05). Improved trends were noted on other outcome measures. Although the mechanism of action of L-carnosine is not well understood, it may enhance neurologic function, perhaps in the enterorhinal or temporal cortex.

Immunizations, immunology, and autism.

Public fears of rising rates of children being diagnosed with autistic spectrum disorders has led to a fear that immunizations, specifically the measles-mumps-varicella vaccine (MMR), may trigger autism. This article reviews theories of immunization as a risk factor for autism, including thimerosal exposure. We also review theories of autoimmunity as a predisposing genetic risk in autistic patients. We summarize from multiple population-based studies and extensive review committee reports that neither immunization nor thimerosal exposure has been conclusively linked to autism. Current treatments for autoimmunity in autism are reviewed and summarized as being only anecdotally effective, with no controlled studies to conclusively determine effectiveness. The goal of this article is to allow child neurologists to effectively counsel parents of autistic patients about vaccination risks and treatment options in presumed cases of autoimmune dysfunction.

Neurologic treatment strategies in autism: an overview of medical intervention strategies.

Child neurologists are likely to be caring for an increasing number of patients with autistic spectrum disorder (ASD). ASD may occur in as many as 1/100 to 1/200 births. It appears to be a multifactorial disease, with many phenotypes or subgroups. No simple treatment is currently approved for curing or managing core symptoms of autism. We rationally propose a symptom-based review of what treatments may offer relief to specific subtypes of clinical behaviors seen in autism. There is a lack of clinically based evidence on which to universally recommend a rational clinical algorithm for treatment; we suggest that rational pharmacotherapy may offer symptomatic relief to core areas of dysfunction in the autistic population. Future research into rational medical treatment options is desperately needed.

Immune therapy in autism: historical experience and future directions with immunomodulatory therapy.

Autism affects 1 in 110 new births, and it has no single etiology with uniform agreement. This has a significant impact on the quality of life for individuals who have been diagnosed with autism. Although autism has a spectrum quality with a shared diagnosis, it presents a uniquely different clinical appearance in each individual. Recent research of suspected immunological factors have provided more support for a probable immunological process or for processes that may play a role in the acquisition of an autistic condition. These factors include prenatal, genetic, and postnatal findings, as well as the discovery of a dysfunctional chronic pro-inflammatory state in brain tissue and cerebrospinal fluid in subsets of autistic patients. These findings offer new theories that may lead to the development of disease modification or preventative therapeutic options in the near future. This article reviews prenatal, genetic, and observed immune aspects of the autism condition that may be risk factors in the presentation of the autistic clinical phenotype. Historical immune interventions in autism are reviewed and potential new therapies and interventions are discussed.

Frequency of epileptiform EEG abnormalities in a sequential screening of autistic patients with no known clinical epilepsy from 1996 to 2005.

Autism spectrum disorders (ASDs) affect 1 in 166 births. Although electroencephalogram (EEG) abnormalities and clinical seizures may play a role in ASDs, the exact frequency of EEG abnormalities in an ASD population that has not had clinical seizures or prior abnormal EEGs is unknown. There is no current consensus on whether treatment of EEG abnormalities may influence development. This retrospective review of 24-hour ambulatory digital EEG data collected from 889 ASD patients presenting between 1996 and 2005 (with no known genetic conditions, brain malformations, prior medications, or clinical seizures) shows that 540 of 889 (60.7%) subjects had abnormal EEG epileptiform activity in sleep with no difference based on clinical regression. The most frequent sites of epileptiform abnormalities were localized over the right temporal region. Of 176 patients treated with valproic acid, 80 normalized on EEG and 30 more showed EEG improvement compared with the first EEG (average of 10.1 months to repeat EEG).

Frequency of EEG abnormalities in age-matched siblings of autistic children with abnormal sleep EEG patterns.

Epileptiform activity in sleep has been described even in the absence of clinical seizures in 43-68% of patients with autistic spectrum disorders (ASDs). Genetic factors may play a significant role in the frequency of epilepsy, yet the frequency in normal age-matched controls is unknown. We studied overnight ambulatory electroencephalograms (EEGs) in 12 nonepileptic, nonautistic children with a sibling with both ASDs and an abnormal EEG. EEG studies were read and described independently by two pediatric epileptologists; 10 were normal studies and 2 were abnormal. The occurrence of abnormal EEGs in our sample (16.6%) was lower than the reported occurrence in children with ASDs. Further, the two abnormal EEGs were of types typically found in childhood and were different from those found in the ASD-affected siblings. The lack of similarity between sibling EEGs suggests that genetic factors alone do not explain the higher frequency of EEG abnormalities reported in ASDs.