Leading on from previous post about dyslexia, this week I’d like to discuss the phenomenon of hyperlexia and autism.
So first things first, what is hyperlexia?
Hyperlexia is a phenomenon where a child begins to read at a surprisingly early age beyond their expected ability compared with their peers. Onset is usually before 5 years of age, and the child tends to develop the skill without any training or prompting. It’s often described as a “splinter skill”- unique, but not very useful. It’s estimated that approximately 84% of those diagnosed with hyperlexia are on the autistic spectrum equating to between 6-14% of the overall autistic community.
There are 3 different types of hyperlexia:
Hyperlexia I– occurs in the neurotypical population where children learn to read at a very early age. This is usually considered temporary as their peers will eventually learn to read and catch up to hyperlexic children
Hyperlexia II– this is the form of hyperlexia that is most associated with autists. Beginning in infancy, hyperlexic autists are often obsessed with letters and numbers, tending to show a preference for books instead of other toys. Autistic hyperlexics also tend to have excellent recall for important numbers like phone numbers, dates and licence plates
Hyperlexia III– is quite similar to hyperlexia II, but the symptoms tend to decrease with time and disappear. Type III hyperlexics may have delays in verbal language and development like autists, but they tend to have remarkable skills for reading comprehension and excellent memory recall. However, unlike autists, these children generally have no issues with social interaction and anxiety
In my own experience, I’d say I probably had some mild hyperlexic tendencies as a child. I loved books- my mother couldn’t buy me enough to keep me entertained! As I’m sure I’ve told you in previous posts, my reading skills were so advanced at 6 years old in senior infants, my teacher from the previous year invited me to come and read to her junior infant class (4/5 year olds)!😂 I’ve always had an excellent memory and am pretty good at remembering dates, but as the experts say this skill isn’t the most exciting or useful- no point in donning a cape and calling myself a superhero 😛
This week I’d like to take a look at another neurological condition that can be co-morbid with autism- dyslexia.
First things first, what is dyslexia?
Dyslexia can be described as a specific type of learning disability that impacts a persons reading, writing and spelling abilities. Impacting approximately 10% of the population, dyslexia ranges from mild to severe characterized by cognitive difficulties with processing phonetics, working memory and speed of long term memory retrieval. Like autism, the exact neurological causes and mechanisms are unclear, but as dyslexia can run in families, genetic factors are largely thought to contribute.
So how is it linked to autism?
The link between autism and dyslexia has not been scientifically established, but there are some commonalities. Interestingly, dyslexia overlaps with many autistic co-morbidities such as ADHD, dysgraphia, dyspraxia (an estimated 52-53% of dyslexics are also dyspraxic), and auditory processing disorders, which would suggest that these conditions likely operate through similar neurological mechanisms and pathways.
Scientists have found it difficult to establish a direct genetic link between the two conditions, however, recent research may implicate gene deletions in CNTNAP5 (a gene involved in connecting neurons) and DOCK4 (a gene that regulates junctions between cells) in both dyslexia and autism. In addition to this, a 2015 study found that declarative memory (the type of memory that can be “declared” like names, facts, figures etc.) can be used to develop coping mechanisms for both autism and dyslexia, suggesting that perhaps there may be overlap in the brain regions associated with this type of memory formation. Other studies exploring the neural mechanisms of dyslexia indicate structural changes in such regions as the frontal lobe (memory and problem solving), cerebellum (the motor centre) and corpus callosum (the bundle of nerves that splits and connects the left and right hemispheres of the brain)- all areas that have also shown structural changes in studies of the autistic brain.
Most recently, a 2021 study exploring the co-occurrence of dyslexia and other neurodevelopmental disorders reported that many dyslexic patients in their dataset also had issues with sensory processing and other ASD traits, but concluded that the links between the two conditions are complex and hard to underpin, especially given that some autists are hyperlexic (guilty!) rather than dyslexic.
Whilst there is no definitive scientific link, the overlap cannot be denied.
Leading on from my previous post about autism and anxiety, this week I’d like to talk about the phenomenon of brain zaps which autists may experience.
So what exactly are brain zaps?
Brain zaps (also know as brain shakes/shocks/shivers/flips) are a poorly understood phenomenon where it feels as though the brain is undergoing an electrical shock or a shaking/shivering/vibrating sensation. I personally have experienced these from time to time as a vibrating sensation in my brain, where it feels like your brain is literally shaking in your skull. Others report that it feels like a zap has gone off in their head and they can hear a hissing or a ringing sound in their ears. In some cases people experience bursts of light and can feel faint and disorientated afterwards. They are not harmful to the brain but they can be distracting and uncomfortable, especially for autists who are already sensitive to sensory stimuli.
So what causes them?
Like many neurological sensations, they are somewhat of a mystery, but they generally tend to occur in response to withdrawal or missed doses of certain drugs such as anti-depressants, ecstasy and MDMA, and medications for anxiety and ADHD – many of which are prescribed for co-morbid mental health conditions in autists. As these drugs alter levels of key calming inhibitory neurotransmitters such as serotonin and GABA (levels which are naturally dysregulated in the autistic brain), it is thought that low levels of these neurotransmitters may cause over-excitement in the brain, leading to abnormal firing between the neurons causing localized minor seizures i.e. brain zaps.
Don’t be alarmed by the term seizure here- this theory has not yet been confirmed and there is no evidence that brain zaps have a negative impact on our health.
On the other hand, brain zaps can also occur in response to high stress and anxiety. When you experience chronic stress, the brain is hyperstimulated as your worries swirl round and around in your restless mind. Completely overworked and overexcited from stress, your neurotransmitter levels fluctuate causing lower levels of calming GABA and higher levels of glutamate- the primary excitatory neurotransmitter. Such changes may over-excite the brain resulting in a localised seizure/brain zap as described above. Autists may be particularly susceptible to brain zaps in this manner as we experience higher levels of biological stress than our neurotypical peers, not to mention that our neurons are naturally hyper-connected, our neurotransmitters dysregulated and our brains hyperstimulated as a result.
Interestingly, a recent study has suggested that lateral eye movement may be a triggering factor for brain zaps. This is particularly intriguing for autists as evidence suggests that we process most visual information in our periphery, so our natural inclination to avoid direct eye contact could trigger brain zaps.
There are no treatments for brain zaps, but while they may not be the most pleasant sensation, they are generally nothing to be worried about and can be mitigated with proper management of stress and your prescribed medications.
This week I’d like to have a discussion about a somewhat polarizing topic- the internet and autism.
The internet is without a doubt one of the most powerful tools in the world- it connects us, shops for us, provides us with data instantly and is a vital tool in both school and the workplace. But as with most tools, it has many sharp and dangerous edges. As such, we need to be quite cognizant of both sides of the coin for vulnerable autists.
The internet often feels like a Godsend to an autist- it educates us about our condition, keeps those of us with ADHD stimulated (so many hours of online content to shut my brain up! 😛 ) and it removes the physical barriers of socializing, allowing us to make friends in a seemingly less threatening environment. Online support groups, vlogs and blogs can be immensely beneficial for autists, giving information, advice and a sense of community, knowing there are people out there dealing with the same struggles as you.
It can also really help mitigate some of the anxiety associated with in person or phone interactions. I’ve always hated shopping, so the rise in online retail during the pandemic has been very convenient for me, allowing me to offset some of the awkwardness and anxiety I would normally feel when dealing with retail workers (not to mention it’s keeping my habit of dropping/knocking things over in shops from poor coordination at bay! 😛 ). Even little things like being able to book appointments and restaurants over the internet can have a huge impact for an autist- the smallest of things can make our lives so much less stressful.
Perhaps one of the biggest benefits of the internet to emerge from the pandemic for autists is how it enables us to work remotely. With just a couple of clicks, we can work away as if we were in a physical office, safe in the comfort of our home, free from many of the stresses of workplace life.
But as useful as the internet is, it can also be a very dangerous place for autists.
The internet provides us with a vast network of information, but a large percentage of it goes un-monitored which could be dangerous in the hands of vulnerable autists. We can be quite innocent and trusting, our struggles with social cues often making it difficult to discern what is truly ingenuous. The internet is filled with harmful pages about “curing” autism which a desperate and struggling autist could take at face value. The threat of cyber bullying is a serious issue for today’s youth (I was blessed this was only taking off as I was leaving school), but autists are especially vulnerable given our social struggles. An even bigger danger may arise from these struggles as online predators may target autists, many of whom may be innocently oblivious to their potential danger.
Furthermore, there are an increasing number of studies which have identified a trend of internet addiction among autists, as we can often be vulnerable to addictive behaviours. Researchers feel that the internet allows us to compensate for our social difficulties in the offline world through online activity. The list of perceived advantages of the internet is endless to an autist, and so it can very quickly become a crutch.
Whilst we can put up filters and blocks to mitigate some of these risks, there is a real need to properly educate growing autists about the internet and the potential threats that are out there. Not just from others, but autists also need to be educated about the danger they pose to themselves with what they post on the internet. With our mimetic and impulsive nature, internet behaviours can often be monkey see-monkey do, and so we may post inappropriate content without properly realizing the potential consequences.
It’s easy to demonize it, but we cannot deny that the internet truly has provided a platform to increase visibility for the autistic community in recent years. It’s given so many of us a voice that we never knew we could have. The internet is on the whole primarily a good thing for autists, but we should always be wary of the dangers and advocate for proper education around internet usage.
In continuation from a previous post exploring coordination issues and autism, I’d like to dedicate a specific post to the often co-morbid issue of dyspraxia.
So what exactly is dyspraxia?
Dyspraxia, like autism, is a neurodevelopmental disorder that impacts a person’s ability to plan and process motor movements. It may also be known as motor learning difficulties, perceptuo-motor dysfunction, developmental coordination disorder (DCD).
Some of the general symptoms of dyspraxia include issues with balance and hand-eye coordination, poor posture, problems with fine motor skills (like picking up and holding items like a pencil or tying shoelaces), clumsiness and issues with spatial awareness and perception. It can also cause learning difficulties, but it generally does not impact intelligence.
So how are autism and dyspraxia linked?
Dyspraxia is caused by errors in the transmission of motor messages from the brain to the body. The neurological basis for the coordination issues associated with autism is poorly understood, however, it’s believed that they occur through a similar pathway to dyspraxia. The synapse (or connecting junction point between two neurons) is thought to play a major role in motor coordination. Autist’s have an overabundance of synapses compared to their normally developing peers, so with a greater number of brain connections comes the greater potential for signals to get lost en route to their destination.
Motor learning and control is influenced by a specific group of neurons known as purkinje cells. Purkinje cells, (located in the cerebellum- an area heavily involved in motor control), receive signals from climbing fibers- a type of neuron which carries information from the body to the brain. These climbing fibers detect changes or disturbances in our environment, such as changes in space or the position of nearby objects, and relay this information to the purkinje cells. Purkinje cells then emit inhibitory signals at synapses so to modify motor movements accordingly. In autism however, the efficacy of purkinje cells to influence motor change is greatly reduced.
Normally, each purkinje cell receives input from a single climbing fiber. As autists have too many synapses connecting the brain, the purkinje cell receives signals from multiple climbing fibers. This confuses the purkinje cell, which in turn alters the efficacy of corrective signals and motor movements veer off course.
In addition to this, dopamine deficiency is thought to disrupt motor learning at the synapses, which as I’ve discussed in many previous posts, is dysregulated in the autistic brain.
Roughly 80% of autists have issues with motor coordination, but not all will also have dyspraxia. It can be difficult to differentiate between the two conditions due to the high level of overlap in symptoms.
This week I’d like to talk about the role that hormones (or horror-mones as my younger cousin used to call them) and fluctuations in hormone levels may play in autism.
So first off the basics, what exactly is a hormone?
We’ve all heard of them, but not all of us are aware of how they work.
Hormones are powerful biochemical messengers that travel through the blood in the body influencing a number of bodily changes and functions such as growth, mood, metabolism, puberty and reproduction to name but a few. Secreted by the endocrine glands of the body (e.g. adrenal glands, thyroid, pancreas etc.), it only takes a small amount of hormone to trigger large changes in the body, so fluctuations in normal hormone levels can have serious consequences for bodily functions.
So what impact do hormone changes have for autists?
Research suggests that a number of hormonal imbalances can contribute to autistic behaviours. The primary hormones thought to contribute to autism are oxytocin and vasopressin- also referred to as the “love” or “social” hormones. These hormones are involved in social bonding, trust, sexual behaviours and processing of sensory information. Studies have revealed that autists have lower levels of both of these hormones, and that treatments designed to increase these hormones may help improve social behaviours.
Most recently, new evidence suggests that growth hormone and the digestive hormone ghrelin may contribute to autism. A recent study showed that children with autism have lower levels of these hormones compared with their neurotypical peers. Ghrelin has a wide range of physiological functions such as stimulating the release of growth hormone, memory and learning, the formation of new brain synapses between neurons (i.e biochemical junctions joining one brain cell to the next) and it is involved in triggering satiety after meals (guess that explains why I’m always hungry 😛 ).
As many of these functions are disrupted in autism, low levels of these hormones likely contribute to their pathology. Moreover, ghrelin is thought to have a protective effect against reactive oxygen species in the brain which are also thought to contribute to autism (as I’ve discussed in previous posts) so reduced ghrelin levels could reduce the brains protection against these chemicals.
Hormone fluctuations are also thought to cause sleep issues for autists. The amino acid tryptophan is needed for the body to produce melatonin (aka the hormone that controls sleep and wakefulness), an amino acid which research has shown can be either higher or lower than normal in people with autism. Ordinarily melatonin is released in response to darkness (to induce sleep) with levels dropping during daylight hours (to keep us awake). However, studies have shown the opposite in some autists, where higher levels of melatonin are released during the daytime and lower levels at night- which certainly explains why I often have the urge to nap throughout the day 😛
In addition to these, higher stress hormone levels are thought to be the driving force behind a number of autistic behaviours such as meltdowns, shutdowns and issues with anxiety. As I’ve discussed in a number of previous posts, stress hormones such as cortisol and adrenaline are released in response to stressful situations from the hypothalamic–pituitary–adrenal axis or HPA axis. This is a complex interconnecting network that comprises the hypothalamus, the pituitary gland andthe adrenal gland (i.e. HPA) to control our response to stress- a network that is hyperactive in autists. Following exposure to a stressful situation, stress hormone levels should return to normal, however, research has shown that stress hormone levels tend to persist in autists, which can make us more susceptible to stress related outbursts and meltdowns. In other words, we’re constantly living in a state of fight or flight. Long term activation of the stress system can lead to a number of health problems such as poor mental health, weight gain, sleep issues, digestive and cardiovascular problems to name but a few- many of which are regularly comorbid with autism.
Sex hormones are also thought to contribute to the development of autism. Research in recent years has indicated that exposure to higher levels of testosterone and/or oestrogen in the womb may predispose developing babies to autism- this is known as the sex-steroid theory of autism. It’s thought that these elevated hormone levels likely interact with genetic factors that may affect the developing brain. There is a particular trend among women who suffer from polycystic ovarian syndrome (PCOS) as the ovaries produce abnormal amounts of testosterone.
Moreover as I’ve discussed in previous posts, hormone imbalances are also thought to contribute to changes in behaviour in autistic women due to fluctuating hormone levels at different points in their menstrual cycle. In addition, behavioural changes are also associated with autistic women going through the menopause.
With the interplay of all these different hormone fluctuations, it’s no wonder our brains are a little muddled trying to cope with the constant change (as if we don’t find change hard enough! 😛 )
Sorry I’ve been away for so long- you wouldn’t believe how hectic these past few weeks have been!
This week I’d like to ease back in by talking about the topic of autism and space!
No- not that kind of space (we’ll leave that one to the billionaires); personal space!
Personal space is an interesting subject for autists. As we’ve discussed at length, social norms can be difficult to navigate, so our sense of personal space in company can be a little unusual. Some may stand on the sidelines away from the crowd, whereas other autists can be right in your personal bubble, and perhaps even a little too close for comfort. Sometimes you just don’t know how to judge how close is too close! From a meltdown perspective, most autists tend to seek out small, enclosed spaces away from crowds when the flight response is triggered.
For me personally, I do have a tendency to seek out smaller spaces when I’m feeling overwhelmed. I have lingered for many hours in many bathrooms and stalls across Ireland during my lifetime. The comfort of the enclosed and locked space is soothing, kind of like my environment is giving me a socially distanced hug. On the other hand, I’ve equally embraced wide open spaces when my flight response get’s triggered during a meltdown. Sometimes the best thing is to just sit down in the middle of a wide open field to help you can breathe again.
So is there any research behind personal space and autism?
An interesting study from 2015 found that autists have a tendency towards shorter distances in personal space compared with neurotypicals, not just between people, but also a shorter personal space between themselves and objects. In other words, most autists may be inches from your face and will not become uncomfortable! It’s thought that this occurs due to alterations in the regulator of personal space- the amygdala in the brain, a structure that has been implicated in many autistic symptoms.
In addition to this, it’s thought that personal space is related to our propricoceptive system- the neurological feedback system in our muscles responsible for our sense of space and pressure detection. As discussed in previous posts, alterations in this neural system can lead to dysfunction and difficulties in spacial awareness. The interesting thing about this system however, is that many autists stimulate it for relief of sensory issues through stimming and deep pressure. As pressure and space are both detected through this system, it’s thought that autists may seek out enclosed spaces as a means of stimulating it for sensory relief.
So while we might seem a little bit odd hiding under the table, there is method in the madness! 😉
This week I’d like to discuss another comorbidity that is being increasingly associated with autism- addiction issues and substance abuse disorders.
In recent years, researchers have estimated that autists may be twice as likely to suffer from addiction to drugs or alcohol than their neurotypical peers, with even higher rates in those who also suffer from ADHD. Interestingly, researchers held the belief for years that addiction was rare among autists due to our stern rigidity in following the rules and our difficulties with social interaction isolating us from potential peer pressure (but there was no real evidence to back up this view). As increasing numbers of adults are being diagnosed with autism every year, the data pool of autistic addicts could be much higher than we realize.
Addiction issues are not purely related to substance abuse for autists. Autists can suffer from a number of behavioral addictions such as gambling or shopping- there are even studies focusing on the impact of internet and video game addiction in the autistic community (may have been guilty of those at different times in my life😂).
So is there any scientific reason that autists are more prone to addiction issues?
There are very few studies that have explored the prevalence of addiction among autists so there is limited data available. However, there are several theories. One theory suggests that motor circuits in the brain play an important role in modifying our behaviours, so if there are issues in the motor system of the brain (as there are in autism), this may have a knock effect on our tendency towards addictive behaviours. Autists also have a tendency towards impulsivity, compulsivity and repetitive behaviours, which research suggests may predispose us to addiction as addictive behaviours are linked to the same brain regions involved in these types of behaviours. The link between these behaviours may even be genetic, as some studies indicate that candidate genes that are thought to cause autism, such as NLGN3 and CNTNAP4, are highly active in brain regions that are associated with addictive behaviours such as the striatum and the nucleus accumbens.
Leading on from my previous post about autism and sexuality, this week I’d like to discuss an emerging area of research interest- autism and gender dysphoria.
In recent years, research is mounting that suggests that there is a higher prevalence of gender dysphoria and diversity among autists compared with the neurotypical population i.e. they don’t identify as the sex they were assigned at birth. It has even been estimated that transgender individuals could be 3-6 times more likely to be diagnosed as autistic! 😱
As a cis-gendered woman I cannot personally comment on this issue (apart from thinking it would be a great idea to switch gender at will to avoid dealing with womanhood as a preteen 😛 ), but based on these statistics I would just like to draw some awareness. Life can be hard enough as an autist or an individual with gender dysphoria alone, but when you marry the two, rates of depression and anxiety are reported to be much higher.
While the reasons for gender dysphoria are wide and varied, for autists, there may be a larger biological component as to why many may feel they have been born into the wrong bodies.
As I have discussed previously, MRI scans of autists brains have shown that men with autism have anatomically similar brains to neurotypical women, and women with autism have anatomically similar brains to neurotypical men which could lead to gender confusion. In addition to this, high levels of foetal testosterone in utereo have been linked to the development of autism in recent years. This exposure has been proposed as a possible reason that autistic women may suffer from gender dysphoria, but this does not explain why autistic men may wish to transition. Interestingly the current evidence does indeed support a prevalence of autistic traits among trans-men vs. trans-women. Research is ongoing to investigate the link between gender dysphoria and autism.
Whilst the current evidence suggests that gender dysphoria and autism may be linked, it is important to remember that they are not mutually exclusive. It is useful to know that there may be a link, but bear this in mind when seeking support.
Following on from my recent post about diet and autism, this week I’d like to discuss a biomolecule that is not often talked about in the literature about autism- cholesterol.
When it comes to cholesterol, we usually think of it as a bad thing- that fatty yellow stuff that clogs up our arteries when we eat too much of the wrong foods. But there is so much more to cholesterol than most people realize. Cholesterol is an essential biomolecule involved in the synthesis of numerous other bodily substances such as steroid hormones, vitamin D and bile. It’s also an essential component of our cell membranes.
There are 2 types of cholesterol- LDL and HDL. LDL (low-density lipoprotein) makes up most of the cholesterol in the body. This is often referred to as the bad type of cholesterol as a build up of this can clog the arteries. HDL (high-density lipoprotein) on the other hand, is considered the good kind of cholesterol as it absorbs waste cholesterol and shuttles it to the liver for removal from the body.
So what has cholesterol got to do with autism?
Here’s where things get interesting. Cholesterol is involved in modulating the oxytocin receptor and the serotonin 1-A receptor- neurotransmitters that are dysregulated in the autistic brain which contribute to a number of autistic symptoms. Multiple studies have reported that some autists have hypocholesterolemia (i.e low cholesterol levels). Cholesterol deficits could interfere with the functioning of the oxytocin and serotonin receptors and contribute to autistic symptoms. Recent research has identified mutations in a cluster of genes involved in cholesterol metabolism in certain forms of autism which likely causes these lowered cholesterol levels. Cholesterol and omega fish oil supplementation may be useful to help counter the impact of low cholesterol on the brain.