Autism – Current Issues 41
This set of summaries begins with
an expression of concern about the (perceived) limitations of research with its
emphasis upon aetiology and the relative lack of ongoing information about the
effectiveness of interventions.
There is additional evidence for
the existence of a frequent pattern of regression at some point before the
second birthday among children who are diagnosed as autistic.
The question of environmental
toxins (metals) as significant in aetiology, and the benefits of supplementary
minerals and vitamins in interventions, is further explored.
The significance of
under-connectivity among brain areas is reinforced; and the final section
quotes some interview points made by Temple Grandin with particular reference
to autistic style including the issue of limited central coherence.
M.J.Connor
November 2005
Status of Research
A current survey completed by
Charman and Clare (2004) has indicated how little is really known about the
nature of autism and ASD …. especially the effectiveness of interventions.
Their study, which represented a
collaboration between The Institute of Child Health, the National Autistic
Society, and the Parents’ Autism Campaign for Education, sampled the opinions
and experiences of around 200 researchers and 130 parents of children with
autism, and examined a number of databases for evidence of current scientific
research.
The outcomes indicated that
almost 60% of UK autism research focused solely upon symptoms, with only 22%
examining causation, 8% interventions, and 5% the effects of family history and
circumstances.
Meanwhile, the majority of
families felt there should be more attention paid to environmental factors
while the researchers were more likely to favour genetic research.
A commentary from the NAS
referred to the desirability of further research across a number of areas, but
made a particular note of the under-investment in research concerning
interventions. It was stressed that
there is a need for a more consistent coordination and funding of research so
that parents can be confident in their awareness of what works for children
with autism.
(The present writer – MJC – would
highlight the parallel with research into dyslexia with its endless quest for
correlates or for what symptoms and behaviours constitute the condition. Here, too, there is a tradition of much research
into the physiology of dyslexia [ eg hemispheric functions ] or psychological
features [ eg auditory sequencing
capacities ] but not a great deal of evidence concerning the most effective
programmes of intervention [ educational features ].
It might also be speculated that
a practical problem common to both areas of research is that of identifying
sufficient numbers of participant children who are adequately matched for both
endogenous and exogenous characteristics and who can form viable experimental
and control groups. There is also the
complication whereby apparently similar interventions are actually of limited
comparability in terms of the precise methodology, intensity, etc., with the
additional risk of therapy drift coming into play over time so that there is a
failure to compare like with like.)
The plea for knowledge about the
effectiveness of interventions is well made given the ongoing quest for some
overall answer or means of recovery when, actually, the children will continue
to be autistic but can be helped by certain interventions or by shifts in the
nature of demands and expectations.
What is needed is valid and
empirical evidence by means of which to match a given child with the most
appropriate intervention as opposed to the continuing situation where
reported success for some children of some intervention may be taken as
evidence that there will be equal probability of success for any other
child, and where new treatment options emerge but then gradually fall into
disuse … such as “Holding Therapy” or
“Auditory Integration Therapy.”
One ongoing study (Millonig et al
2005) is an example of the emphasis upon physiological or genetic aetiology in
that this team have reported the identity of an autism susceptibility gene.
Their work has indicated that
there is an association between the symptoms of ASD and the expression of a
specific gene (ENGRAILED2 Gene) given that alterations in this particular
genetic marker were observed across three separate samples of families all
affected by ASD.
The lead researcher has estimated
that up to 40% of individuals with ASD would show some anomaly in the way this
gene is expressed.
Further work has highlighted a
possible mechanism by which the mal-expression of the gene can bring about
altered neuronal functioning, namely, some altered response to an environmental
toxin … supporting the view of autism as the outcome of an (innate) propensity
for the condition which is realised via some environmental trigger.
Further Evidence for Autistic Regression
The paper by Werner and Dawson
(2005) begins by citing the report that anywhere between 20% and 50% of parents
of an autistic child describe how the child appeared to be developing normally
until around 18 months to 2 years of age at which point a marked regression in
communication and social skills occurred.
The existing evidence has been
dependent upon parental memory and reporting with the attendant risk of recall
bias.
Therefore, the present
researchers obtained home videotapes of a range of children with autism or PDD,
children with ASD and regression, and typically developing children which
provided clear evidence of their behaviour at the times of their first birthday
and of their second birthday.
The children were assessed by the
confederates of the researchers who were blind to the diagnostic status of the
children, using a range of published rating scales, such as the Autism
Diagnostic Interview-Revised.
The focus was upon behavioural
variables such as language (including complexity of babbling), joint attention
(pointing), direction of gaze, orienting to the call of their name, smiling,
and repetitive behaviours.
The analysis highlighted
developmental changes between the ages of 12 months and 24 months.
At 12 months, the children with
ASD and parentally-reported subsequent regression were found to be babbling and
speaking more readily than the other children with ASD and the typically
developing group.
At 24 months, both the ASD
samples had less use of language than the latter group.
Similarly, the shared attention observed
among the ASD-regression group at 12 months was greater than in the other ASD
group; but, at 24 months, both these groups showed significantly less shared
attention than the typically developing group.
The researchers held that these
findings provided validation for the phenomenon of regression in a subgroup of
children with ASD … although this should not be taken as evidence that such
children had entirely ordinary development until that regression point. On the contrary, the children were reported
by parents to have shown a range of behavioural anomalies such as sleep
disorders, and sensory hypersensitivity.
The authors describe the need for
continuing investigation of the trajectory of the ASD signs and symptoms in the
children with regression ASD and early onset ASD, but they report currently no
available evidence of significant differences between the two groups when
assessed for the level and nature of behaviours at 48 months.
Toxin Effects :
Essential Mineral/Vitamin Effects
One major environmental factor is
the nature of what substances are ingested either through the air breathed or
the foods eaten.
The study by Adams et al (2003)
recognises the range of factors that could underlie the psychological disorders
observed in an estimated 25% of children and young people but makes particular
reference to either excessive levels of toxic metals or deficiencies in
essential minerals as significant influences upon day to day functioning.
The example is given of low
levels of calcium, as assessed via analysis of hair samples, as possibly
significant in the (partial) aetiology of difficult and distractible
behaviours.
The authors also acknowledge that
the precise cause or causes of autism and ASD are not clear, but there are
indications that mercury or other toxic metals may play a role. For example, Bernard et al (2000) refer to a
large number of similarities between autism and the kinds of effects observed
in prenatal or infantile exposure to mercury. Such similarities include the
greater prevalence or sensitivity to autistic problems among males than among
females, inhibited language and communication skills, decreased social
relatedness, repetitive behaviours, and gastrointestinal problems.
The study by Adams et al (op.
cit) compared a sample of children with ASD (N=51) with a sample of
neuro-typical children, and the focus of the study was an analysis of hair
samples completed by specialists blind to the group to which the samples
related.
The results perceived as most
important were as follows …..
(thimerasol in vaccines, maternal
seafood consumption, and maternal dental
amalgams).
The
authors concluded that all of the above results should be treated with some
caution until they were replicated in a study involving much larger
samples. Nevertheless, it was held that
these findings could prove significant in terms of highlighting nutritional
problems as a contributory factor in the aetiology of autism. It may also be found that dietary
supplementation such as enhanced lithium ingestion, including prenatal
intervention, can be effective in treating some of the symptoms of ASD in at
least some of the children.
A
subsequent study by Adams and Holloway (2003) examined the use of multi-vitamin
and mineral supplements for children with ASD, and the author introduced the
report by describing the lack of previous studies of the effectiveness of such
interventions despite their relatively common use. It was also held that there are few existing data concerning the
nutritional status of children with autism, despite the growing belief that
nutritional deficiencies may well be significant in the expression of ASD and
that, correspondingly, food supplementation could prove a beneficial
intervention.
Adams and
Holloway go on to cite the awareness of widespread nutritional deficiencies in
the USA including the estimated 30% of the general population with inadequate
vitamin C status, or the even greater estimated of insufficient intake of folic acid and magnesium.
Given
this, it is held to be unsurprising that there is growing evidence for the
benefits of targeted vitamin and mineral supplementation in enhancing cognitive
performance, achievement, and behaviour among children with certain learning
disadvantages.
It is
further suggested that the low levels of nutrients such as zinc or magnesium or
calcium, and of vitamins, among individuals with ASD may be explicable on three
counts ….
·
The frequency of intestinal problems among individuals with
autism, including chronic diarrhea.
·
Gastro-intestinal inflammation and general problems with
the digestive tract in the absorption of nutrients.
·
Inadequate diets as a result of the limited choice of foods
- akin to the autistic characteristic of restricted interests and behaviours -
with the probability of a loss of essential nutrients.
The study completed by these
researchers involved a sample of participants diagnosed with ASD, aged between
3 and 8 years; and set out to determine the level of vitamin absorption among
these children and whether supplements are effective in (partially) reducing
some of the observable symptoms … acknowledging all the while the limitations
of the study in terms of the size of the experimental sample (N=25) and the
dependence upon parental assessments and reports concerning the behaviours of
the children.
With the above caveats, it was
reported that a 3-month treatment with a multi-vitamin and essential mineral
supplement did produce significant improvements in sleep and in
gastro-intestinal functioning in the children.
The results were seen as very
encouraging and as justifying a larger study with more participants and more
targeted pre- and post-intervention assessments.
One would interpret the
conclusions not as suggesting that dietary intervention can prevent or
remediate ASD, but as intimating that, in a multi-causal and multi-symptomatic
condition such as autistic spectrum disorder, there is logic in the use of
relatively non-intrusive interventions as part of any overall package.
More Evidence for
Central Coherence Deficiencies in ASD
Ongoing studies by Just et al
(2004) have shown how individuals with autism, in contrast to those who do not
show autistic traits, remember letters of the alphabet in a part of the brain
that usually serves to process shapes.
This finding is interpreted as
support for the theory which regards autism as a matter of failure of
coordinated working of different brain areas.
The upshot is that the individuals concerned cannot produce an overview
of a task or cope with complex information, but the independent working of the
various brain areas leads to a focus upon details.
For example, there can be
excellent performance at spelling even if the meaning of a sentence or story
containing the words in question is not fully grasped. Similarly, there may be great difficulty in
organising and interpreting the considerable information, verbal and
non-verbal, that emerges in interpersonal encounters.
The implication is for the
provision of a series of tasks which gradually increase in complexity and which
activate several brain areas simultaneously.
Language skill is seen as a
microcosm of the disorder in that the person with autism can manage lower
levels of interaction but show increasing deficits as the interchange becomes
more subtle and complex.
In their own study, the present
authors assessed the data from MRI patterns of brain functioning as the
participants performed a simple memory task involving letters.
Typically, the participant would
be shown a sequence of letters and asked to name the letter that came before
the current letter, or the one before last.
Differences were observed between
the brain activation patterns revealed by the autistic participants and the
control group.
The autistic pattern emphasised
activation in the right hemisphere which is heavily involved in processing
shapes and visual information, and less activation in the left hemisphere which
is usually involved in processing letters, words, and sentences.
In other words, the autistic
pattern involved spatial recognition - the letters present as shapes rather
than as linguistic elements.
Similarly, the autistic brain
activation was greater in the posterior areas of the brain, with implications
for an attention to detail, and less evident in the anterior areas associated
with reasoning and higher-order thinking.
The issue of non-synchrony of
brain working was highlighted.
In sum, the findings were seen as
support for the theory of “Underconnectivity” in autism …. a failure of the
wiring of the brain and a lack of inter-connections such that different brain
areas can only work independently with implications for an excellent focus on
component parts of a task but problems in integrating those different parts
into a coherent whole.
Self-Report (Temple
Grandin)
An interview with Temple Grandin
appeared in the national press (Guardian 25-10-05) in which she described the
idiosyncratic pattern of thinking that she regards as part of her autistic
style and condition.
Reinforcing the comments set out
in the above section, Grandin describes how she thinks in images – words are
seen only as a second language. Ideas
are illustrated by pictures as opposed to being set out verbally.
She goes on to acknowledge the
characteristically profound difficulties among autistic individuals in respect
of communication and imagination … a detachment from the immediate world around
… and an indifference to social cues.
Reference is made to the
un-connectedness of autistic brains with implications for a potential for
specialised knowledge and expertise in contrast to limited capacities in many
or most other areas.
One plus factor perceived by
Grandin (whose qualifications and career are in the realm of animal welfare and
humane handling) is the ability to empathise with infra-human organisms whose
cognitions are largely in the form of images; and she argues that the
well-developed and well-connected frontal lobes of normally-functioning
individuals means that people are usually too verbal to perceive how the world
appears to organisms who lack the capacity for verbal and abstract thought.
Reference is made to the growing
belief that certain eminent scientists (including Einstein and Newton) could
well have been identified as autistic given their ability to focus upon almost
obsessive details and to persevere in some very narrow academic field. It is further speculated that Einstein might
not have the (social or practical) skills necessary to apply for and gain a
place at a university in today’s world !
Grandin holds that she was
fortunate to have been a child during the 50’s when many social skills were
taught and practised by rote so that children, including children with higher
functioning ASD, were “moulded into shape”.
It was also the case at that time, she believes, that the curricula were
a little more varied and that children and young people with ASD had more
access to the practical (and less verbal-dependent) skills where they could
perform well.
The implication is for
recognising and seeking to understand the nature of the style and cognitive
preferences and perceptions of individuals with autism, and to beware of the
assumption that adequate cognitive ability will ensure a successful and happy
experience of mainstream schooling when actually such an assumption could not
only be unrealistic but also insensitive and even damaging.
* * * * *
M.J.Connor November 2005
Adams J. and Holloway C. 2003 Pilot study of a multi-vitamin/mineral supplement for children with ASD. Tempe, Arizona : Arizona State University.
Adams J., Holloway C., George F., and Quig D. 2003
Toxic metals and essential minerals in the hair of children with autism
and their mothers. Tempe, Arizona :
Arizona State University
Bernard S., Enayati A., Roger H., et al 2000
Autism : a unique type of lead poisoning. ARC Research Report
Charman A. and Clare P. 2004 The Causes and Treatment of Autism London : Institute of Child Health
Grandin T. 2005 “I’m an anthropologist from Mars” Interview recorded in The Guardian (25th October). By-Line : David Cohen
Just M., Minshew N., et al 2004 Autistic recall of letters of the alphabet. Washington : National Institute of Child Health (Article published in the July 2004 edition of Brain)
Millonig J., DiCicco-Bloom E.,
and Brzustowicz L. 2005 Autism susceptibility gene. New Jersey : National Alliance for Autism
Research (Paper to be published in the
November issue of the American Journal of Human Genetics)
Werner E. and Dawson G. 2005
Validation of the phenomenon of autistic regression using home
videotapes. Archives of General
Psychiatry 62(8) 889-895
© Mike Connor 2005.
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