Unstrange Mind

Autistic Author, Artist, Advocate, and Speaker

Tag: neuroscience

Autistic Shutdown Alters Brain Function

spanish moss

[image description: You are standing beneath a mighty live oak (Quercus virginiana) in central Florida, looking up at a heavy, gnarled tree branch dripping in Spanish Moss (Tillandsia usneoides). The sun is just hidden behind the branch and its light shines down through the limbs, illuminating the fluffy yet intricate twists of parasitic angiosperm, creating something of a magical, ethereal effect in the process. Photo copyright Sparrow Rose, 2016]


This is a re-post of a blog post that was originally posted on March 30, 2016.  Other than editing pronouns, it is identical to the original text.

Content note: descriptions of shutdown, meltdown, self-injurious activity, stress, brain function.

 


By now, pretty much everyone who knows much of anything about autism has heard of meltdowns — episodes of frustration and panic that seriously disrupt the lives of Autistic people, to varying degrees and amounts per person. But shutdowns don’t seem to get talked about as much as meltdowns and I run into people who, despite the blue-illuminated buckets of “autism awareness” out there, were completely unaware of the phenomenon of shutdown.

I had a pretty bad shutdown last week so I thought I ought to write a little bit about them. The people in my day-to-day life were unprepared to deal with a shutdown and that increased everyone’s stress levels. More education about shutdowns can’t hurt and it could help quite a bit.

Shutdowns and meltdowns are more similar than they might appear on the surface. One (somewhat simplistic but workable) way to think of shutdown is a meltdown turned inward instead of outward, much as some people describe depression as anger turned inward.

My most recent shutdown started off as a meltdown. My brain was going through all its usual short-circuits when some synaptic gap got crossed. Or something. One minute I was out of control, smacking myself in the face, as one does, and the next minute I was on the floor, unable to move. I started to get tunnel vision. My hearing began to get fuzzy. My vision closed and closed like turning off an old tube-driven television, closing down to a tiny dot of light that winked out just as my hearing entirely cut out, leaving me alone in the numbly terrifying darkness.

If you like to get your information from audio and video, you should take ten minutes to go watch Amethyst Schaber’s magnificent discussion of Autistic shutdown on their YouTube channel, “Ask an Autistic.” I’ll wait.

Shutdown is a response to overwhelm. It is a self-protective response — shutting down the circuits before they fry, to use computer/brain analogies — but it is as much a system overload as it is a system failsafe. And too much overwhelm for too long can cause some longer-term shutdown and loss of basic skills. We’re talking everything from forgetting how to tie your shoes to forgetting how to speak. And it can hit at age 14 or age 24 or age 54.

As Mel Baggs explained it: ” Most people have a level to which they are capable of functioning without burnout, a level to which they are capable of functioning for emergency purposes only, and a level to which they simply cannot function. In autistic people in current societies, that first level is much narrower. Simply functioning at a minimally acceptable level to non-autistic people or for survival, can push us into the zone that in a non-autistic person would be reserved for emergencies. Prolonged functioning in emergency mode can result in loss of skills and burnout.”

I my case, it was just a matter of hours before I started coming out of shutdown, much like an ocean creature finally creeping onto a deserted beach after a long swim across the Marianas Trench of shutdown. But I only had one, isolated shutdown. An extended amount of time living on “personal emergency reserves” due to being forced to operate at a higher clock speed than my chips are rated for, combined with a series of shutdowns would have left me pretty burned out. I’ve gone 17 days in shutdown before, unable to speak or properly care for myself. This is why shutdowns must be treated with caution and this is why going to apparent extremes to avoid shutdown is not “lazy,” “spoiled,”  “entitled,” or any other judgmental adjective anyone has ever been tempted to drop at an Autistic’s feet. Or heap on an Autistic’s head, for that matter, since it’s often on the floor alongside the feet once shutdown hits.

Miller and Loos wrote about shutdowns and stress, both in a manner accessible to laypeople and in an academic paper. Their observations were based on a case study of an Autistic six-year-old girl who was prone to shutdown under stress. The authors found that shutdown behavior gets labelled as conscious avoidance but is more likely an involuntary physiological process caused by “stress instability,” an inability to regulate the body’s overwhelming response to stressors. The authors hypothesize that shutdown begins with the basolateral amygdala (BLA) in the brain and quickly spirals into a debilitating feedback loop: the BLA is involved in experiencing emotions. When the BLA becomes overstimulated, it can become hyperreactive, leading to extreme emotionality, heightened levels of fear, and social withdrawal.

The BLA can quickly become hyperreactive when exposed for too long to corticotropin releasing factor (CRF), a “stress-mediating neurotransmitter.” In other words, stress gives the BLA a hair trigger and the resulting explosions feed more CRF to the BLA, ramping the overload up in a ratcheting cascade of intense panic that finally flips all the breaker switches, resulting in shutdown. This is probably why my own meltdown tipped over into shutdown: I had been stressed for days with multiple meltdowns and my system just couldn’t handle any more stimulation so it shut off to prevent my brain from frying itself. My brain crawled up inside its own virtual Faraday cage to wait things out.

In the case of “the SD child,” Miller and Loos observed that one shutdown would make her extra vulnerable to more shutdowns during the following three weeks. It takes that long for the BLA to “come back down” from its hyperaroused state. It’s pretty easy to see how quickly things can take a bad turn if the brain is not given time to heal. This is the low-detail version of why I have a medical discharge from the Navy and why I was able to hold a series of minimum-wage jobs before the military but unable to get a job at all afterwards. When I signed up for the Navy, I didn’t understand my neurology. It was a devastating blow to not only fail at boot camp but come out of it so debilitated I couldn’t even keep a roof over my head any more.

This is why I speak so strongly about helping Autistic children to build low-stress environments that nurture rather than damage their neurology. This is why I warn so often against shaming Autistics for not “pushing the envelope” the way you think they ought to instead of the way that protects them from damage. Of course it’s healthy to step out of one’s comfort zone from time to time. What you need to remember is that the entire world is outside of an Autistic’s comfort zone. We live our whole lives outside that zone. Please recognize and honor that. I just can’t say that enough: we are trying and the obstacles can be as massive for us as they are invisible to you.

Treat shutdown  as the medical situation it truly is. Help us get away from bright lights and loud noises. Help us find a quiet space to re-regulate our nervous system. And be gentle with us as we recover from a neurological episode, understanding how delicately balanced our brains are after marinating in the biochemicals of stress. We need support, not blame. We need peace and stress-relief, not punishment. And, always, we need love, understanding, and acceptance.

Autistics Are at Greater Risk of Trauma

Wolf Lake

[image description: a photo of Wolf Lake in Sebring, Florida, taken by Sparrow Rose Jones. It has nothing to do with either autism or trauma, but it’s pretty and the author enjoys including an image with their writing.]


I am at the 2016 Association for Autistic Community (AAC) conference. During Kit Mead’s excellent presentation, Autism, Awareness Campaigns, and the Mental Health System (slides), several people mentioned the need for research supporting the idea that Autistics might be more easily traumatized. I mentioned that there has been a small amount of research in that area and others were eager to know more. Since multiple people wanted that information, I decided to make a brief annotated bibliography in a blog post to more easily share it with as many people as would like to see.

As you might imagine, the bulk of the available research (and there isn’t a lot of it yet — I definitely agree that we need more research into multiple aspects of autism and trauma) focuses on the role of the amygdala in stress and trauma imprinting. There are two main aspects of showing an autistic predisposition for trauma: showing the role of the amygdala in sustaining trauma, and showing the ways that the autistic amygdala is different in structure and/or function, thus exacerbating that brain structure’s role in trauma. Some of the following research is of one type or the other, much addresses both halves of the equation.

-=-

Some assessments of the amygdala role in suprahypothalamic neuroendocrine regulation: a minireview

This article has little to do with autism specifically. I am including it in this annotated bibliography because it does a good job of explaining the role of the amygdala for those who don’t have a neuroscience background and thus may not instantly know why the amygdala is important in considering the autistic risk for trauma. As the abstract says, “The amygdala plays a key role in what has been called the “general-purpose defense response control network” and reacts in response to unpleasant sights, sensations, or smells. Anger, avoidance, and defensiveness are emotions activated largely by the amygdala.”

The Basolateral Amygdala c-Aminobutyric Acidergic System in Health and Disease

This research review article from 2016 is the main “smoking gun” I was referring to when I mentioned that there has been some research already that has found a higher risk of trauma among Autistics.

“This Review discusses the anatomy, development, and physiology of the GABAergic system in the BLA and circuits that modulate GABAergic inhibition, including the dopaminergic, serotonergic, noradrenergic, and cholinergic systems.” That’s a lot for those of us who are not biochemists, but I’m going to try to boil it down a little bit. The article says that Autistics, along with a few other categories of neurodivergents (Alzheimer’s, TBI, epilepsy) have hyperexcitability in our amygdala. That means the neurons in our amygdalas are firing much more often than neurons in the amygdalas of the general population and that this increased amygdala function leads to anxiety and “the development of neurological and/or neuropsychiatric diseases.”

In Autistics, GABA metabolism is reduced and certain GABA receptors are delayed in their maturation. The authors point out that a reduction in GABA-mediated synaptic inhibition (a reduction in ‘less neurons firing because GABA “calms them down”‘) is linked to an increase in anxiety. The hyperactivity of the amygdala not only increases anxiety but greatly increases the risk of developing PTSD. The review goes on to say that benzodiazepines (which are commonly given to people experiencing anxiety and/or PTSD) may not be effective in Autistics because their mode of action relies on the same GABA receptors that take longer to develop in Autistic people than in the general population.

The authors are careful to point out that they are not arguing that hyperactivity in the amygdala results in PTSD but simply to point out the role of GABA in PTSD and the action (or lower action, as it were) of GABA in the autistic brain creates an environment more likely to result in PTSD and other anxiety disorders. They suggest the need for research into deeper understanding of the role of GABA and the possibility of developing therapies that increase the growth of interneurons that could reduce the excitation of neurons in the amygdala.

The Result of Traumatizing Events on a Child With Autism

Although the 2016 GABA review is new, knowledge of the role of the amygdala in autistic trauma has been around for a while. This is a 2008 statement by Dr. David Larson Holmes who, unfortunately, does not include citations when he writes, “Recent studies have confirmed that children with autism have very active Amygdalas; the center of the brain that stores traumatic events. This center is directly connected to the brain stem [reticular formation] which is the area of the brain stimulated during potentially threatening conditions and places the child in a ‘fight or flight’ condition. […] Upon further analysis of the brain activity of children with autism it has been found that the Hippocampus, the center of the brain which stores pleasant experiences, is actually much less active than the children’s Amygdalas. This has resulted in a supposition that children with autism are affected more from traumatizing events than pleasant events and that the traumatizing events have greater robustness; thereby maintaining a greater degree of panic and fear in the child than what would be found in typically developing children.”

Amygdala and Hippocampus Enlargement During Adolescence in Autism

Strictly speaking, this 2010 study doesn’t indicate anything about increased risk of trauma. I’m including it because it’s an example of a structural difference in the amygdala between Autistics and the general population. The authors are unsure whether the increase in the size of brain structures causes emotional differences or whether the “increased emotional learning” Autistics go through when compared to the general population is the cause of the structural changes.

Amygdala Subregional Structure and Intrinsic Functional Connectivity Predicts Individual Differences in Anxiety During Early Childhood

This article is not about autism or Autistics, although the lead researcher, Vinod Menon, has conducted other research that does focus on Autistics. This 2013 paper ties in with the uncited claims above of Dr. Holmes, as well as the 2010 study directly above about amygdala size increases in Autistics during adolescence (an emotionally difficult time for nearly anyone of any neurological profile.)

The study found that the larger the amygdala, and the more connectivity between the amygdala and other neurological structures, the higher the anxiety rate in children and the greater the risk of anxiety disorders developing later. In addition to the human study upon which this article was based, “Studies of laboratory animals placed in an environment causing chronic stress have determined that the animals’ amygdalae grew additional synapses and that synaptic connectivity increased in response to the resulting persistent anxiety.” This suggests that what the authors of the 2010 study were calling “increased emotional learning” in adolescence was actually a burden of chronic stress and anxiety, causing the amygdala to grow larger than non-autistic controls.

-=-

All of this information is pieced together and none of it is so clear cut as the 2016 GABA minireview, but taken together, they paint a strong portrait of the greater trauma risk Autistics face and the great need for further research into the nature and causes of trauma in Autistics.

© 2017 Unstrange Mind

Theme by Anders NorenUp ↑