DEE-SWAS (Night Terrors, Sleep EEG Abnormalities etc.) masquerading as Regressive Autism

  

 

One of the key points in understanding "autism" is that it is not a single biological condition. It is just a behavioral diagnosis based on observed developmental patterns involving language, social communication, repetitive behaviors and sensory differences.

That means very different biological conditions can produce children/adults who all outwardly appear some version of “autistic.”

A striking example of this was recently shared with me by one of our readers.

 

A Child Diagnosed with "autism"

The parents noted severe developmental regression accompanied by unusual sleep disturbances and night terrors. Over time they also observed something very interesting, that changes in valproic acid (VPA) dosing appeared to significantly affect symptoms.

Their neurologist had performed EEGs which reportedly showed abnormalities and yet despite this, no further major investigations were ordered:

• no epilepsy-protocol MRI
• no prolonged 24-hour EEG
• and no comprehensive workup for epileptic encephalopathy.

Meanwhile, the family pursued extensive genetic testing searching for answers.

This is unfortunately an increasingly familiar story in developmental medicine, a child receives a behavioral autism diagnosis, and the diagnostic process effectively stops there.

 

Seeking a second opinion

The family eventually attended a specialized pediatric neurology clinic at a major children’s hospital.

The difference was immediate.

After reviewing EEGs, videos before regression, videos after regression and recordings of the child’s sleep terrors, the specialists concluded that the child fit the modern framework of:

DEE-SWAS
(Developmental and Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep)

The older terms for overlapping conditions include:

• ESES (Electrical Status Epilepticus in Sleep)
• CSWS (Continuous Spike-Wave During Sleep)
• Landau-Kleffner syndrome

The clinic immediately ordered:

• epilepsy-protocol MRI
• prolonged 24-hour EEG
• metabolic investigations
• ophthalmologic evaluation
• orthopedic assessment

Most strikingly, they reportedly stated that this looked like:

“DEE-SWAS masquerading as autism.”

 

What Is DEE-SWAS?

DEE-SWAS is increasingly understood as a disorder of abnormal brain network synchronization during sleep.

The key issue is not simply seizures. Some children have obvious seizures, others do not.

In many children, pathological spike-wave activity during deep non-REM sleep may interfere with:

• language development
• memory consolidation
• emotional regulation
• cognition
• attention
• and developmental plasticity itself.

Some primarily present with:

• regression
• loss of speech
• autistic behaviors
• sensory abnormalities
• emotional dysregulation
• fluctuating cognition
• sleep disturbance
• night terrors.

In many cases, the child outwardly appears to have classic regressive autism.

 

Why night terrors matter

Night terrors are usually benign in ordinary children.

However, in the context of

• developmental regression
• abnormal EEGs
• fluctuating cognition
• or epileptiform activity

they become much more significant.

DEE-SWAS specifically affects deep slow-wave sleep — the same sleep stage associated with night terrors and abnormal arousal phenomena.

This does not mean every child with night terrors has epileptic encephalopathy.

But regression plus unusual sleep phenomena should raise suspicion that a prolonged sleep EEG may be warranted.

 

Treating the EEG to treat the child

One of the most interesting concepts in modern DEE-SWAS research is:

“Treating the EEG to treat the patient.”

The concern is that the abnormal sleep spike-wave activity itself may drive the developmental deterioration.

Treatments used include:

• valproic acid
• clobazam
• clonazepam
• steroids
• ketogenic diet
• acetazolamide (Diamox)
• ethosuximide
• and in some cases surgery.

Ethosuximide is particularly interesting because it is a T-type calcium channel blocker that affects thalamocortical spike-wave synchronization.

The thalamus appears to play a major role in generating these pathological sleep oscillations.

Ketogenic therapies and ketone esters are also fascinating because they may:

• stabilize neuronal metabolism
• reduce hyperexcitability
• alter glutamate/GABA balance
• and improve network stability during sleep.

 

For more information on treatment:

Treatment of Developmental/Epileptic Encephalopathy With Spike-Wave Activation in Sleep

Is DEE-SWAS Rare?

Officially, yes. But many experts suspect it is significantly under-recognized.

Why? Because many children with:

• regression
• autism
• language loss
• or sleep problems

never receive a prolonged sleep EEG monitoring.

A short daytime EEG may miss much of the pathology.

This is especially important because some children may improve substantially when the abnormal sleep-related epileptiform activity is treated.

DEE-SWAS is likely a spectrum from mild to severe. The underlying cause varies, but often is thought to be an anomaly in an ion channel (calcium, sodium, potassium).  

Autism is just a behavioral phenotype

Cases like this reinforce an increasingly important idea.

“Autism” represents a common behavioral phenotype arising from many different biological mechanisms.

For one child:

• synaptic dysfunction may dominate.

For another:

• mitochondrial dysfunction.

For another:

• immune dysregulation.

And for another:

• sleep-activated epileptiform encephalopathy.

The behavioral presentation may look similar, while the biology underneath is profoundly different. The treatment will also be different, although there are surprising overlaps.

 

Conclusion

DEE-SWAS is not just a case of a bad night’s sleep.

The concern is months or years of abnormal electrical activity repeatedly disrupting the brain during one of its most critical developmental states.

In DEE-SWAS the brain spends large portions of deep sleep in a pathological synchronized firing mode instead of normal developmental processing.

Over time this may interfere with language acquisition, cognition, emotional regulation and developmental plasticity itself, potentially leading to developmental regression and a child who outwardly appears to have regressive autism.

This post is not suggesting that most regressive autism is actually DEE-SWAS, but some clearly is.

However, children with:

• clear regression
• fluctuating abilities
• sleep deterioration
• night terrors
• language loss
• episodic worsening
• or unusual EEG findings

deserve more extensive neurological investigation than they often receive.

The father who contacted me persisted despite initial dismissal and eventually reached a centre experienced in developmental epileptic encephalopathies.

That persistence may prove extremely important for their child’s future outcome.

Sensory Gating in Autism, Particularly Asperger's

Sensory gating is an issue in autism, schizophrenia and ADHD.   It is the neurological process of filtering out redundant or unnecessary stimuli in the brain; like the child who sits in his classroom and gets bothered by the noise of the clock on the wall.  He is unable to filter out and ignore this sound. He becomes preoccupied by the sound and cannot concentrate on his work.

There are also sometimes advantages to not filtering out environmental stimuli, because you would have more situational awareness and notice things that others miss.

An example of sensory gating is the fact that young children are not waken by smoke detectors that have high pitched siren, but are waken by a recorded human voice telling them there is a fire and to wake up.

There may be times when sensory overload in autism is not a case of too much volume from each of the senses, but rather too many inputs being processed by the brain, instead of some just being ignored.  It is more a case of information overload.

Note that this blog has already covered hypokalemic sensory overload in some depth, which is treatable.

Much is known about sensory gating because it has long been known to be a problem in schizophrenia.

An EEG (Electroencephalography) test measures your brain waves / neural oscillations. Many people with autism have EEGs, but mainly those in which epilepsy is a consideration.

In the world of the EEG, the P50 is an event occurring approximately 50 millisecond after the presentation of an auditory click.  The P50 response is used to measure sensory gating, or the reduced neurophysiological response to redundant stimuli.

Abnormal P50 suppression is a biomarker of schizophrenia, but is present in other disorders, including Asperger’s, post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI).

In more severe autism abnormal P50 suppression was found not to be present in one study.  This might be because cognition and the senses are dimmed by the excitatory-inhibitory imbalance.

More broadly, sensory gating is seen as an issue in wider autism and ADHD.

Correcting P50 gating

It is known that α7 nicotinic acetylcholine receptor (α7 nAChR) agonists can correct the impaired P50 gating. It is also known that people with schizophrenia have less expression of this receptor in their brains than typical people.

One short term such agonist is the nicotine released from smoking.  This likely contributes to why people with schizophrenia can be heavy smokers.  The effect is thought to last for about 30 minutes.

Clinical trials using Tropisetron, a drug that is a α7 nAChR agonist and used off-label to treat fibromyalgia, have shown that it can correct defective P50 gating and improve cognitive function in schizophrenia.

An alternative α7 nAChR agonist that is widely available is varenicline, a drug approved to help people stop smoking.

So you might expect varenicline to improve P50 gating and improve cognition. You might also expect it to help people with fibromyalgia and indeed some other people with chronic inflammation, as shown by elevated inflammatory cytokines.

You may recall that the α7 nAChR is the key to stimulating the vagus nerve and this should be beneficial to many people with inflammatory conditions (from arthritis to fibromyalgia).

Brief Report: Initial Trial of Alpha7-Nicotinic Receptor Stimulation in Two Adult Patients with Autism Spectrum Disorder

Abnormalities in CHRNA7, the alpha7-nicotinic receptor gene, have been reported in autism spectrum disorder. These genetic abnormalities potentially decrease the receptor’s expression and diminish its functional role. This double-blind, placebo-controlled crossover study in two adult patients investigated whether an investigational receptor-specific partial agonist drug would increase the inhibitory functions of the gene and thereby increase patients’ attention. An electrophysiological biomarker, P50 inhibition, verified the intended neurobiological effect of the agonist, and neuropsychological testing verified a primary cognitive effect. Both patients perceived increased attention in their self-ratings. Alpha7-nicotinic receptor agonists, currently the target of drug development in schizophrenia and Alzheimer Disease, may also have positive clinical effects in autism spectrum disorder.

α7-nicotinic acetylcholine receptor agonists for cognitive enhancement in schizophrenia

A role for H3 and HI histamine receptors

It has also been suggested that histamine plays a role in sensory gating via the H1 and H3 receptors.

It had also been thought H3 receptors could be targeted to improve cognition in schizophrenia, but that research really did not go anywhere.

Meclizine enhancement of sensorimotor gating in healthy male subjects with high startle responses and low prepulse inhibition.

Histamine H₁ receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H₁-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H₁ effects on sensorimotor gating to human studies. The effects of the histamine H₁ antagonist meclizine on the startle response and PPI were investigated in healthy male subjects with high baseline startle responses and low PPI levels. Meclizine was administered to participants (n=24) using a within-subjects design with each participant receiving 0, 12.5, and 25 mg of meclizine in a counterbalanced order. Startle response, PPI, heart rate response, galvanic skin response, and changes in self-report ratings of alertness levels and affective states (arousal and valence) were assessed. When compared with the control (placebo) condition, the two doses of meclizine analyzed (12.5 and 25 mg) produced significant increases in PPI without affecting the magnitude of the startle response or other physiological variables. Meclizine also caused a significant increase in overall self-reported arousal levels, which was not correlated with the observed increase in PPI. These results are in agreement with previous reports in the animal literature and suggest that H₁ antagonists may have beneficial effects in the treatment of subjects with compromised sensorimotor gating and enhanced motor responses to sensory stimuli.

Histamine and acetylcholine receptor involvement in sensorimotor gating: an autoradiography study

The aim of this study was to investigate an established rat model of decreased PPI induced by administration of the NMDA antagonist, dizocilpine and the reversal of this PPI impairment by the histaminergic H1-antagonist, pyrilamine. H1-antagonism is a potential mechanism of the therapeutic effects of the atypical antipsychotic, clozapine, which improves PPI following dizocilpine administration in rats as well as in patients with schizophrenia. In the present study we show that chronic pyrilamine administration prevents the PPI impairment induced by chronic dizocilpine administration, an effect that is correlated with a reduction in ligand-binding potential of H1 receptors in the anterior cingulate and an increase in nicotinic receptor α7 subunit binding in the insular cortex. In light of the functional anatomical connectivity of the anterior cingulate and insular cortex, both of which interact extensively with the core PPI network, our findings support the inclusion of both cortical areas in an expanded network capable of regulating sensorimotor gating.

Histamine H3 Receptor Regulates Sensorimotor Gating and Dopaminergic Signaling in the Striatum.

The brain histamine system has been implicated in regulation of sensorimotor gating deficits and in Gilles de la Tourette syndrome. Histamine also regulates alcohol reward and consumption via H3 receptor (H3R), possibly through an interaction with the brain dopaminergic system. Here, we identified the histaminergic mechanism of sensorimotor gating and the role of histamine H3R in the regulation of dopaminergic signaling. We found that H3R knockout mice displayed impaired prepulse inhibition (PPI), indicating deficiency in sensorimotor gating. Histamine H1 receptor knockout and histidine decarboxylase knockout mice had similar PPI as their controls. Dopaminergic drugs increased PPI of H3R knockout mice to the same level as in control mice, suggesting that changes in dopamine receptors might underlie deficient PPI response when H3R is lacking. Striatal dopamine D1 receptor mRNA level was lower, and D1 and D2 receptor-mediated activation of extracellular signal-regulated kinase 1/2 was absent in the striatum of H3R knockout mice, suggesting that H3R is essential for the dopamine receptor-mediated signaling. In conclusion, these findings demonstrate that H3R is an important regulator of sensorimotor gating, and the lack of H3R significantly modifies striatal dopaminergic signaling. These data support the usefulness of H3R ligands in neuropsychiatric disorders with preattentional deficits and disturbances in dopaminergic signaling.

Conclusion

Other than nicotine, varenicline would seem a good potential therapy for sensory gating.  There are α7-nicotinic acetylcholine receptor agonists in development.

There are many H1 histamine antagonists.  Histamine release in the brain triggers secondary release of excitatory neurotransmitters such as glutamate and acetylcholine via stimulation of H₁ receptors. Centrally acting H1 antihistamines are sedating.

H3 antagonists have stimulant and nootropic effects. Betahistine is an approved drug in this class, there are many research drugs.

The role of histamine dysfunction in sensory and cognitive deficits in schizophrenia

The aim of this study is to investigate the role of the neurotransmitter histamine in sensory and cognitive deficits as they often occur in schizophrenia patients (e.g. hearing voices, planning and memory problems). The ideal location to conduct the study and to obtain a unique learning experience is at the Institute of Psychiatry, London, United Kingdom, where staff comprises of leading experts in the field of schizophrenia and Magnetic Resonance Imaging of pharmacological effects. Current pharmacological treatment of psychotic symptoms including sensory and cognitive deficits remains partially unsuccessful due to side effects and treatment resistance. The neurotransmitter histamine seems to be a very promising target for new treatments. It has been found that histamine neurotransmission is altered in brains of schizophrenics, which may contribute to both the hallucinatory and cognitive symptoms. However, this specific role of histamine has not been investigated before. I will assess the effects of increased histaminergic activity, by administration of betahistine to healthy volunteers, on performance (sensory gating, executive functioning or planning and memory) and associated brain activity using fMRI. Altered performance and brain activity would support the importance of histamine in schizophrenia and would provide a research model and target for new treatments.

Epilepsy, Autism & EEGs

It is widely known that autism and epilepsy are comorbid with each other. Statistics are not very consistent, but it appears that up to 35% of people with autism will develop epilepsy and something like 30% of people with epilepsy already have autism.

My interest in epilepsy is currently just as a comorbidity, since Monty, aged 10 with ASD, has not exhibited any signs of it.  I will refer back to epilepsy in later posts when I attempt to “validate” potential autism interventions.  My logic is that if something has a positive effect across the majority of comorbidities, then I may be on to something.  For example, I found it insightful to read in a small study that nicotine patches reduced the incidence of epileptic attacks by 50%.

I recently came across an excellent, highly readable, paper that I think all parents interested in ASD should read.  It is written by an Israeli lady who is also doing some other very thoughtful research into treating autism.  The research itself is a retrospective study of EEG (Electroencephalography) tests on 56 children done in the US.

Autism and epilepsy: Cause,consequence, comorbidity, or coincidence?

EEG testing is known to be very insightful, but due to cost and availability, is rarely used in autism.  Some children, diagnosed with autism, turn out to have something different.

 Here are some highlights:

·        About 10% of children given a diagnosis of autism are found to have either a paroxysmal EEG pattern, as seen in acquired epileptic aphasia (Landau–Kleffner syndrome), or electrical status epilepticus during sleep, as seen in some children with childhood disintegrative disorder. 

·        None of the children who presented with ‘‘unlikely symptoms,’’ such as febrile convulsions, breath holding spells, and rage episodes, were diagnosed with epilepsy  

·        As many as 40% of the total group with autism had epilepsy, which was symptomatic in most children. Half of the children presented with convulsions, and they all had abnormal electroencephalograms (EEG) and were diagnosed with epilepsy.  

·        About one-quarter of the children presented with staring episodes, half of whom had epilepsy. 

·        None of the children with episodes of rage or breath holding spells had epilepsy 

o   This is the opposite of what many experts assume 

·       Our results, which indicate that clinical suspicion for epilepsy should be high if there is a history of convulsion and staring episodes, are in agreement with other studies showing that nearly all autistic children with seizures also exhibit epileptiform activity on electroencephalograms

 

A short film

Here is a parent-made film, showing the EEG procedure.

Conclusion

If you live in an area where EEGs are on offer, (California seems to be one good place to live) then it looks like a very smart test to have done.  If you were thinking your child’s tantrums and raging were indicative of future epilepsy, you can breathe again.