Hi, my name is Stephanie, and today I want to talk to you about non-verbal
learning disorder, which is abbreviated as either NLD or NVLD.
It was actually introduced to me by one of my viewers
and they asked me to look into it as they have it.
And I had no idea quite what
I was getting myself into when I started searching about this.
So, to begin with, NVLD, or non-verbal learning disorder,
is not an official diagnosis in the ICD-10
or the DSM-5, which are the major diagnostic manuals.
However, the ICD-10 does have a diagnostic code that people might put this under,
just kind of like an unspecified learning disorder kind of grouping.
And within those codes, there's also something for visuo-spatial deficits,
which is a core symptom or core part of NVLD.
Something else to note before we get any further
is that despite being called non-verbal learning disorder,
it's not
that the person themselves is non-verbal, but rather
they have difficulty with things that aren't verbal, if that makes sense.
So like nonverbal body language, for example, is difficult for people
with NVLD.
Now, despite not being technically included in the ICD-10
or the DSM-5, a lot of people have been diagnosed with this.
Additionally, one source estimates that about 5% to
10% of clinical populations present with NVLD.
The earliest description and use of the term non-verbal
learning disabilities actually dates back to 1975.
This condition has struggled to be properly defined and arguably often
gets mistaken for other diagnoses because of the symptom overlap.
Additionally, there are arguments
of whether NVLD is a thing or not, or if it's its own thing or not.
So, let's look at the common
symptoms or traits of NVLD to make clear
why we are talking about this on a channel about autism related topics.
According to an article hosted on ADDitude or A-D-D-itude,
the following are commonly reported symptoms of NVLD: trouble recognizing
nonverbal cues, facial expressions, body language,
early speech and language acquisition, talks like an adult from a young age.
Poor coordination, seen as clumsy or always getting in the way,
poor fine motor skills.
Difficulty using scissors, tying shoes, etc.
Always asking questions to the point
of being repetitive or interrupting the regular flow of conversation,
needs to verbally label information in order to understand it.
Difficulty comprehending unsaid or spatial information.
Visual spatial difficulties; discrimination of differences of objects,
visualization of images determining one's location of body in space.
Extremely literal; struggles with sarcasm, innuendo or other linguistic nuances.
Naive or overly trusting, difficulty coping with change.
Trouble following multi-step directions,
difficulty making generalizations or seeing the big picture.
Overall challenges
often masked by highly advanced verbal skills.
Now, a great many of those can be considered traits of autism and before
the change in the DSM-5, specifically, traits of Asperger's syndrome.
And some of these traits also do overlap with ADHD.
Thus, the research
on NVLD has a lot to do with comparing
what they see as NVLD with ADHD
and specifically Asperger's or high-functioning autism.
The articles that I ran across did not ever really include anyone on
the autism spectrum who was not considered to the research team to be considered
either meeting Asperger's criteria or high functioning autism.
I do imagine that this is due to the verbal component of NVLD.
This research is partially hindered by the fact that there's no universally
agreed upon definition of NVLD, so different people might see
NVLD criteria differently, according to different research papers.
However, one of the main factors that everyone does
seem to agree on is the deficit and visuospatial abilities.
A paper evaluating the research done on NVLD actually mentions this confusion
and the research that is involved in the field: Taken
as a whole, this body of work has yielded considerable confusion.
For example, some have found that the NLD profile
is consistent with Asperger's syndrome and high functioning autism,
while others have suggested that the profiles are distinguishable.
Many children diagnosed with NLD eventually meet
criteria for attention deficit hyperactivity disorder.
Additionally, the paper discusses the researcher
who is kind of the pioneer in the field, Byron Rourke, and his work,
which has explored NVLD features in many different conditions.
Rourke has characterized children with NLD as having strong verbal skills
and tactile visual deficits that subsequently affect attention,
memory, problem solving and social competence.
He developed a neurological hypothesis for NLD known as the white matter model.
Rourke widened his research to include subsets of children
with genetic and medical conditions to provide validation of the hypothesis
that disturbances in the integrity of the myelinated fibers of the brain
might be related to symptoms of NLD.
Rourke and colleagues have identified neurological syndromes such as fetal
alcohol syndrome, traumatic brain injury, and Asperger's and Turner syndromes
as disorders for which the phenotype is likely to include features of NLD.
Rourke (2002) and others have also used the NLD syndrome to describe children
with no apparent congenital or acquired neurological disease.
So, while Rourke has kind of sketched out a profile for NLD or NVLD as people
having strong verbal skills but tactile visual deficits
that basically affected executive functioning and social competence,
he also kind of identified a bunch of other conditions that
have these traits, too.
Additionally, he and others have described children as having NVLD
who don't have already existing conditions that they're aware of.
As mentioned, he did hypothesize an idea called the white matter model,
where issues with the myelin that's on the neurons might lead to NVLD.
Others have also suggested that there might be issues
in the right hemisphere of the brain because of the type
of deficits and strengths they're seeing in those with NVLD.
I wasn't finding a lot of useful follow up information on this particular theory
until I came across an article that was published in 2017,
in which they actually used MRI and did find evidence
that the white matter, which is the myelinated part,
does seem to have some dysfunction in the right hemisphere,
and there might also be issues in some of the gray matter as well.
However, beyond that particular one, I'm not seeing a whole lot that delve deeper
into actually verifying the white matter model, although it is
mentioned as a hypothesis or a theory in quite a few papers.
Now, with all these overlaps and symptoms, again, people aren't sure.
Is this Aspergers?
Is this a part of the autism spectrum?
Is this actually part of ADHD?
Or is this its own thing?
So, people have turned to neuro imaging, and a lot of the research
that I found involving
NVLD had to do with brain scans.
We want to see, are these brains looking different than these other conditions?
One study found that those considered
to have Asperger syndrome had a larger hippocampal and amygdala
volume compared it to the NVLD and control groups.
Additionally, both the Asperger's group and the NVLD group had a significantly
smaller anterior cingulate cortex when compared to controls.
While the study wasn't exactly huge, about 26 people per group,
it still gave an interesting insight to differences in the brains of people
in each category, especially in regard to the amygdala and hippocampus.
The researchers also noted that those with NVLD don't seem to have
the same level of anxiety that those with Asperger's do.
In regard to the anterior cingulate cortex, or the ACC, ADHD is also known
to have a smaller ACC, such as was found in those with Asperger's and NVLD.
Another note they made was that they didn't see a significant difference
in caudate volume, which they found surprising because all but one child
technically would meet the criteria for having ADHD in the NVLD group.
I'm going to assume here that those with ADHD typically are considered
to have a difference in their caudate size,
considering the researchers were surprised by this information.
Other studies found differences in visual spatial skills in children with NVLD
while not finding a difference in the Asperger's, ADHD or control groups.
This is suggested as a possible differentiation
between Asperger's and NVLD,
and they do mention this is a hotly debated topic in their field.
Yet another MRI based study found that children with NVLD
had a smaller splenium than did so-called high functioning autism and ADHD.
The splenium is a part of the corpus callosum
that helps connect the two sides of the brain together.
Overall, however, they didn't really note any difference
in the size of the corpus callosum as a whole
between any of the different groups, which included NVLD,
high-functioning autism, ADHD prominently inattentive type,
ADHD combined type, and a control group of typically developing children.
They also noted that those with high functioning autism
had a larger mid body than those with NVLD.
Now, I know that's a lot of information, and a lot of that
might be pretty much meaningless to you if you're not really sure
what those things are about or not really familiar with the brain.
But basically what I want you to take away from that is
they did a bunch of brain scans and were looking for differences
in the types of brains of conditions that have very big symptom overlap.
And they were seeing some differences between the groups.
Basically, they're trying to distinguish the difference based on neuroimaging
instead of just symptomatology, because clearly there's such an overlap,
it gets very confusing.
So they wanted to see, is there actually a difference going on in the brain?
And they were seeing some differences.
And it does lend support to the concept that NVLD might be its own thing.
A group called the NVLD Project supports the idea of NVLD as separate from autism.
They addressed this in their FAQ page on their website, but
the people who responded to that particular question gave
kind of a less than satisfactory reasoning in their reply.
Addressing the question of if they feel that NVLD is distinct from autism
and how to try to demonstrate this to those who think it's an autism spectrum
disorder, they essentially say that it can be distinct, even though they have
similar social issues and difficulty with cognitive flexibility.
They then go on to say that the old Asperger's diagnosis had noted issues
with visual spatial problems and that they feel it's a loss
to those who felt the Asperger's profile fit them because they lost a community
they could relate to.
Kind of a weird deviation from the topic, but OK.
Then they conclude that although there's no good
data on the subject, they find that those with NVLD tend
to at least express more desires to have social relationships
than those in the Asperger's or now high functioning autism groups.
That's a really
terrible way of trying to differentiate the two, in my opinion.
It's based off of anecdotal evidence ,suggests that high functioning autism
is a diagnosis in the DSM-5,
which it's not, and overall, it's kind of insulting.
I'm not really a fan of the reasoning, well, they can be distinct
and Asperger's mentioned visuospatial issues.
Isn't it sad that Asperger's is no longer considered distinct?
Also, people with NVLD just seem to express that they want to connect more.
That's just . . .
I'm sorry. That's just not great reasoning.
Now, on a different part of the NLVD Project's website,
they mention a much more useful difference to point out, noting that NVLD doesn't
include deficits in verbal expression and involves motor
difficulties and challenges reading body language
rather than stereotyped or repetitive movements.
Now, to be fair, autism also involves motor difficulties.
But this particular distinction here interests me because I have had people
reach out to me and ask me, Can you have autism and like,
have all these traits of autism, but not have stimming behaviors,
not really have stereotyped behaviors that fall under stims
that aren't just everyday everyone does this kind of stims.
With NVLD appearing so ridiculously similar,
and if it is indeed its own condition,
this could be an answer to why some people are experiencing this.
Now, this area really needs more research.
There are cases where people with NVLD are diagnosed with ADHD,
like that one study where every single one of them,
except for one, met criteria to be diagnosed with ADHD.
They could be prescribed medication that's supposed to help them,
but doesn't because they don't have the thing that's causing ADHD.
Larger studies would also really help with the concept of neuro imaging.
I think that they should include autistic people who don't meet
the old criteria for Asperger's as well.
In these studies, I get that they were curious about the overlap,
but I think there's value into broadening this look, especially if you're
trying to argue that NVLD isn't just a part of the autism spectrum.
And then in the case that NVLD gets recognized,
then treatment options or support options,
or whatever else can be looked into to help these individuals.
Apparently, some with NVLD complain that programs
that were supposed to help them were more geared toward autistic people.
I'm actually quite interested in what the difference is.
Like, what exactly about the therapy that was supposed to help them as well
wasn't meeting their needs because they're not autistic?
And I'm just curious how that works.
And I think that would actually help not only for therapies to improve,
to be distinguish between NVLD and autism, but for us to understand
the differences between the two.
If someone is experiencing things that aren't being catered to them properly,
maybe that is going to reveal a difference that we're not maybe aware of right now.
So, have you heard of NVLD before?
Do you think that this is something
that should be included in the spectrum of autism spectrum disorders?
Or do you think that this is its own thing?
Let me know your thoughts in the comments below.
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