00:01
Now, let's move to some of the
important symptomatic epilepsies.
00:04
Symptomatic epilepsy
or secondary epilepsies.
00:07
It's epilepsy secondary
to some type of problem.
00:11
And there are a few
really important conditions
that you should know.
00:15
The first is West syndrome.
00:16
This is a combination of epilepsy
in someone
in a patient who has other
neurodevelopmental abnormalities.
00:24
The classic triad is
infantile spasms,
hyparrhythmia on the EEG,
and psychomotor delay
on clinical exam.
00:32
So what is West syndrome?
What do we see?
The peak onset is early in life.
00:37
Within the first 4 to 7 months,
patients begin to develop seizures.
00:41
That characteristic seizure
is an epileptic spasm.
00:45
We also call that
an infantile spasm.
00:47
And those cluster
during sleep transitions.
00:50
So typically,
when a patient is waking up,
we can see
a number of seizures,
or sometimes
when a patient is going to sleep.
00:56
Epileptic spasms have a very
characteristic clinical appearance.
01:00
The patient's arms
extend out.
01:03
Their head often
can go down,
and then the arms and head
go back to the normal posture.
01:08
And that brief episode is a seizure,
with the arms extended head down,
and then slowly returning back
to normal posture.
01:15
And seeing that in a child
should raise suspicion
for a possible epileptic phenomenon,
which would be confirmed by EEG.
01:22
In addition, the EEG also shows
an important interictal abnormality.
01:26
And abnormality that's there
at all times.
01:29
And this is called hypsarrhythmia,
which we'll look at
on a subsequent slide.
01:33
We see both the
hypsarrhythmia interictally,
and an electrodecrement ictally.
01:40
So that clinical epileptic spasm
is associated with a spike.
01:43
And then as the spasm is
resolving, we see a decrement
where the EEG resolves down
and is suppressed
for a short period of time.
01:51
And that discharge tips us off
that we may be dealing with
West syndrome or infantile spasms.
01:57
This is a secondary epilepsy.
01:59
It's caused by
some type of problem
and there are numerous etiologies,
or insults that can lead to this.
02:06
Perinatal hypoxic-ischemic injury,
brain malformations,
tuberous sclerosis,
Down syndrome,
and other metabolic disorders
are inherited
and genetic
metabolic disorders,
all can result in the presentation
of West syndrome.
02:20
So many different
underlying pathologies
or problems with the brain
can present with a
common epileptic syndrome.
02:27
The prognosis depends
on the underlying etiology,
upwards of 75
or more percent of patients
will be severely delayed
with neurodevelopmental
abnormalities and dysfunction.
02:40
What is the EEG look like
in West syndrome?
Well, here again,
we're looking at a normal EEG
from front to back
and left to right,
odd numbers indicate
the left side of the brain,
and even numbers
the right side of the brain.
02:53
When we look at an EEG for someone
who has an infantile spasm,
this is what we tend to see.
02:58
You can see on the
left side of the tracing,
we see a chaotic rhythm.
03:03
There is no organization.
03:04
It looks dramatically different
from the normal EEG,
which has some
characteristic waves
in the back part of the brain
that's called an alpha rhythm,
and otherwise, is a low amplitude
and irregular tracing.
03:17
This is irregular and chaotic.
It's also disorganized.
03:20
We can't pick out individual lines
or individual waves.
03:24
And in the middle of this tracing,
we see that
all that disorganization
calms into a smooth line
that comes back down
to the baseline
and that is called
an electrodecrement.
03:37
And in some cases can be associated
with an infantile spasm or seizure.
03:42
This disorganized
and chaotic pattern
is characteristic
of a hypsarrhythmia.
03:47
Again, we see chaos, irregularity,
and disorganization of the EEG.
03:51
And this is an
interictal pattern that occurs
without any
clinical seizure activity.
03:58
The second very important
symptomatic generalized epilepsy
is Lennox-Gastaut syndrome.
04:03
There are a lot of similar features
to West syndrome to Lennox-Gastaut,
but some important differences.
04:09
The first is its age of onset.
04:11
West syndrome begins very early.
04:14
A perinatal or early injury
to the brain or neurodevelopment
results in early onset
West syndrome.
04:22
Lennox-Gastaut patients
tend to present a little bit later,
in the first
2 to 8 years of life.
04:28
We see multiple seizure types:
tonic, atonic, absence
or a typical absences
is a myoclonic seizures.
04:36
All of these are
generalized onset seizures,
and most patients
have multiple seizure types.
04:42
The EEG shows a 1.5 to 2.5 hertz,
polyspike and wave discharge,
which we call a slow spike
and wave discharge.
04:51
What that looks like
is not as important
as the name
slow spiking wave discharge.
04:56
And that's characteristic
of a diagnosis of
Lennox-Gastaut syndrome.
05:00
There are multiple etiologies,
multiple underlying insults
that can contribute to the
development of Lennox-Gastaut.
05:07
Two-thirds of patients
are symptomatic,
and 1/3 have a history
of infantile spasms.
05:12
Early in life that then develops
into full blown
Lennox-Gastaut syndrome.
05:17
Patients frequently have
medically refractory seizures
for their lifetime,
and severe developmental delay.
05:23
Some being nonverbal
and fully dependent on others
for complete care.
05:28
In Lennox-Gastaut
as well as West syndrome
underscores the way
that we make a diagnosis
of a symptomatic epilepsy.
05:35
And the things
we're looking at clinically
and in vignettes
with these patients.
05:38
Were characterizing
the seizures
And with Lennox-Gastaut,
30% of patients
have infantile spasms,
and will progress on to
Lennox-Gastaut syndrome.
05:47
That seizure type is important
in making this epilepsy diagnosis.
05:51
We're also evaluating the
neurologic status of the patient.
05:54
And 80% of patients
with Lennox-Gastaut
will have cognitive dysfunction,
the second key pillar of this triad.
06:02
And the last we're
incorporating EEG findings.
06:05
And with Lennox-Gastaut,
we see that
slow spike and wave activity.
06:08
And that triad
of infantile spasms,
cognitive dysfunction or
neurodevelopmental delay,
and slow spike and wave
is what establishes
this diagnosis of
Lennox-Gastaut syndrome.
06:19
There are specific medications
that are approved
to treat Lennox-Gastaut
vaigabatrin is one of those
as well as others.
06:26
And we can use this information
to prognosticate for patients
and Lennox-Gastaut
is associated with
long-term
difficult to treat epilepsy
and significant
neurodevelopmental delay.
06:38
This is an example of an EEG
for a patient with Lennox-Gastaut.
06:42
We see it's quite different
from that hypsarrhythmia pattern
for West syndrome.
06:46
We see spike and wave.
And this is very slow.
06:49
The hertz is about 1.5 to 2.5 hertz.
06:52
That's how many bumps,
spikes, and waves you see
each second of this tracing.
06:57
And this slow spike
and wave activity,
which we see generalized
throughout the entire brain
is characteristic of Lennox-Gestaut.
07:06
And last,
let's finish by talking about
temporal lobe epilepsy.
07:09
This is one of the most common forms
of symptomatic focal onset epilepsy.
07:14
It's one of those epilepsies
we see in adults
and a diagnosis that sometimes
we make in adults.
07:20
The onset can be between
10 and 20 years.
07:23
That we can see patients that
present even after the age of 20
with their first time seizure.
07:29
This is the most common form
of focal onset or partial epilepsy.
07:34
Patients have that
typical description
of a focal onset epilepsy
coming from the temporal lobe.
07:39
The aura often begins with
déjà vu, or a rising nausea,
or other temporal lobe
localization symptoms.
07:48
This progresses
to alteration and awareness.
07:51
During that altered awareness
patients may have
automatisms,
motor automatisms,
like lip smacking or chewing,
or other automatisms
in their behavior.
08:01
And this ultimately will progress
to generalize convulsions
and postictal confusion.
08:06
The EEG shows
temporal lobe spikes interictally
or sharp waves interictally,
and we can see a seizures arising
out of the temporal lobe, ictally.
08:16
And the treatment begins with
antiepileptic medications.
08:20
Typically, we start
with one medication
and titrate
to the maximum dose.
08:24
If the patient fails, we would
consider a second medication.
08:28
In this syndrome is important
for understanding the definition of
medically refractory epilepsy.
08:34
Treatment refractory epilepsy,
or medically refractory epilepsy
is a patient with epilepsy
who has failed
two medications
at maximum doses.
08:43
And in those patients
they should be considered
for a surgical evaluation.
08:47
One of the reasons to consider that
is temporal lobe epilepsy.
08:50
This can be highly amenable
to temporal lobe resection.
08:54
Removing that epileptic nidus
Some patients will be able
to reduce their medicines
and others may be able to come off
of all antiepileptic medications
as a result of that surgery.
09:05
Importantly, seizure surgery
must happen early
before one epileptic focus
co ops another.
09:11
and a patient develops
multi-focal epilepsy
that would not be
amenable to surgery.
09:16
And that's why
we think about this
at the time of failing
two medications
at maximum doses
or medically
refractory epilepsy.
09:26
Here we see the characteristic
imaging of a patient
with temporal lobe epilepsy.
09:30
This is associated with
scarring of the temporal lobe,
which we call
mesial temporal sclerosis.
09:37
We're looking at a
coronal picture at T2
looking back through
a patient's eyes.
09:42
And again, the patient is flipped
as we look at this image.
09:46
The left temporal lobe is over
on the right side of the screen
and the right temporal lobe
is on the left side of the screen.
09:54
The green arrow is pointing
to the temporal lobe.
09:57
We can see it's smaller
than the right side.
09:59
The left hippocampus is smaller.
10:02
It's a little bit
brighter and scarred
compared to the right side.
10:05
And this is a good example
of mesial temporal sclerosis,
which is a cause of
temporal lobe epilepsy.
10:12
This underscores that the
symptomatic epilepsies have a cause
we need to go looking for them.
10:17
And a high resolution
MRI is important
for looking at
temporal lobe sclerosis,
a cortical dysplasia,
or some other underlying
nidus and cause
of the patient's epilepsy.
10:28
Surgically,
we would target this
and by removing that scar,
we're removing
the nidus for epilepsy
and can cure
the patient's seizures.
The lecture Symptomatic Epilepsies by Roy Strowd, MD is from the course Seizures and Epilepsy.
Which statement is the most accurate regarding epilepsy syndromes?
Which statement is the most accurate regarding West syndrome?
Which finding is the most accurate in Lennox-Gastaut syndrome?
Which of the options is most accurate regarding temporal lobe epilepsy?
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