Tuberous Sclerosis Australia Reach Out Magazine October 2016

Information
Information
Lachlan, QLD
Oliver, NSW
Hamish
Matilda, VIC
How does knowing about these higher risk periods of
time help parents and carers?
For all the parents of small babies with TSC, I explain what a
subtle seizure or epileptic spasm looks like. Around those periods
of higher risk for the baby (see above) we go back through that
information, particularly if the EEG is starting to show some signs
of being abnormal. Parents capturing video of events of concern
is the most important thing at that time. Videos can be sent to
neurologists who can review them rapidly and provide reassurance
or arrange rapid assessment if the events are confirmed to be a
seizure. Obtaining this rapid support for events of concern is one
of the most important things for infants with TSC in these risky
time windows. While I understand the urge to put TSC in the
background and get on with life, I think that being over-anxious is
probably better than being under-anxious when it comes to these
early seizures in the life of an infant with TSC as early action is
important for the best outcome.
What are the challenges in rolling out this new
approach to all infants with TSC?
High frequency EEGs in early life for infants with TSC who have
not yet had clinical seizures is a very resource intensive process.
I can be seeing some babies every week or fortnight for an EEG.
A lot of centres would not have the ability to provide that service
given funding for EEG services. However a long term view of this
resourcing is important, as if we provide this resource intense
service early, and see these babies early on frequently, we can
potentially make an important difference to the frequency of long
term seizures and to their developmental outcome and this means
that once the infant is 3 years of age and older, that child will not
be a frequent attender in complex epilepsy clinics and requiring
heavy lifelong support from hospital and health and care services.
The trend that is emerging at our centre is that I am seeing these
babies very intensively up until the age of 2 to 3 years of age and
then only seeing them yearly after that. We’ve only been doing this
new approach of EEG surveillance since 2011 so we still have more
to learn about the approach on whether there is a long term benefit
and how great this is.
General principles from other
epilepsies are...relevant to understanding
why early treatment of an active tuber,
identified on EEG is important.
What are the implications of this approach for general
epilepsy, outside of TSC?
That’s a good question. This idea of controlling the EEG is new to
epilepsy in general. We’ve always focused on the clinical seizures.
We increasingly realise that clinical seizures are just the worst
manifestation of abnormal biology in the brain and it is this
abnormal biology that has enormous impact on quality of life,
development, behaviour and sleep. So this principle of ‘clinical
seizures are not everything’ is very important for other epilepsies.
TSC has some characteristics that are unique from other causes
of epilepsy that make this approach particularly suitable. We
know that the majority of babies with TSC will have epilepsy; we
know that the EEG will, fairly reliably, predict the onset of clinical
seizures; and we have the potential to prevent the brain developing
very complex and difficult to control epilepsy. This is in contrast
to other groups at risk of seizures, such as babies that have had a
stroke. For this group there is a smaller percentage of babies that
will go on to develop seizures, and these seizures are much more
likely to be controlled with a single medication.
General principles from other epilepsies are, however, relevant
to understanding why early treatment of an active tuber, identified
on EEG is important. There is a concept that is known from
general epilepsy, that ‘seizures beget seizures’. We’ve known for
some time that if you’ve got ongoing abnormal electricity in part of
the brain that this recruits wider and wider areas and seizures then
come from the whole brain or other areas of the brain. Once this
whole brain recruitment has occurred, it is harder to wind seizures
down again with anti-convulsant medications. The new approach
of EEG surveillance for infants with TSC is a very clear model of
managing this: essentially we catch seizure-generating tubers on
an EEG very early and treating before they start recruiting other
areas of the brain so that there is better overall epilepsy control or
remission of seizures.
What advice would you give to parents of a new baby
with TSC?
From a medical perspective, I encourage people to ensure they
have access to a paediatric neurologist with an interest in TSC.
This could be their doctor, or someone their doctor can link in
with when needed for support and advice.
There has been incredible progress in TSC in the last 20 years.
We only discovered the genetic changes that cause TSC in the 1990s
and the pathways that these influence not long after that. Our
knowledge of ways that we can positively influence the condition is
increasing rapidly. I usually highlight that most of the information
on the internet is out of date and that this can be unnecessarily
alarming. I always emphasise that TSC is a highly individual
condition and that every individual with TSC is an individual.
I try to tell my new families balanced information about
current data from our clinic, which reflects some of the newer
treatments, early access to EEG surveillance (from 2011),
early access to curative epilepsy surgery and access to mTOR
inhibitors. I give information that is balanced about current
rates of epilepsy and intellectual disability in our modern TSC
cohort. I have teenagers in our clinic who are school captains
and some have high IQs, and will transition to university. It has
a very diverse impact but in our clinic at this time, the rate of
intractable epilepsy is low (14% of our cohort currently) and
this likely reflects better and more intense therapy in early life.
The best information is therefore obtained from people who are
familiar with TSC and this often helps allay anxiety that can
escalate when the internet is accessed.
Editor’s note - This approach to treating epilepsy in TSC is available
at many centres around Australia. The availability of EEG testing,
particularly in regional areas, is one barrier to more widespread use of
this intensive monitoring protocol. For help finding a neurologist with
experience treating TSC you can contact the TSC Information Service
by emailing info@tsa.org.au or calling 1300 733 435.
1. Jozwiak, S., et al., Antiepileptic treatment before the onset of
seizures reduces epilepsy severity and risk of mental retardation
in infants with tuberous sclerosis complex. Eur J Paediatr Neurol,
2011. 15(5): p. 424-31.
2. Wu, J.Y., et al., Clinical Electroencephalographic Biomarker for
Impending Epilepsy in Asymptomatic Tuberous Sclerosis Complex
Infants. Pediatr Neurol, 2016. 54: p. 29-34.
3. Muzykewicz, D.A., et al., Infantile spasms in tuberous sclerosis
complex: prognostic utility of EEG. Epilepsia, 2009. 50(2):
p. 290-6.
4. Domanska-Pakiela, D., et al., EEG abnormalities preceding the
epilepsy onset in tuberous sclerosis complex patients - a prospective
study of 5 patients. Eur J Paediatr Neurol, 2014. 18(4): p. 458-68.
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