00:01
So let's talk more about
status epilepticus
and the evaluation of breakthrough
seizures and continuous seizures.
00:08
When we're dealing with recurrence
of a breakthrough seizure,
a patient with epilepsy
or with multiple seizures,
who has a breakthrough seizure.
00:16
The first thing
we need to think about is
compliance, compliance, compliance.
00:21
The most common cause
of a breakthrough seizure
and that's a seizure that occurs
in someone with known epilepsy
is medication non-adherence.
00:28
There's many reasons
not to be able to adhere
to a medication.
00:31
It may have
not been called in.
00:33
Patients may not be able
to afford it.
00:35
They may be experiencing
side effects.
00:37
And non-adherence inability
to take the medication
is the most common reason
for a breakthrough seizure.
00:44
We also want to think for other
potential exacerbating features.
00:48
Electrolyte abnormalities.
00:49
Infections can lower
the seizure threshold
and make it more likely for
an epileptic patient to seize.
00:55
New medications that lower
the seizure threshold
like fluoroquinolones.
00:59
Sleep deprivation is
one of the most common
exacerbating conditions
or other things that lower
the seizure threshold.
01:08
We typically perform labs
to evaluate for those
electrolyte abnormalities
or other potential causes
of exacerbation of seizures.
01:15
But a CT of the head
is not indicated
unless the exam suggests
or support some reason,
some new focal neurologic deficit
that indicates that we need imaging.
01:27
We typically think about
titrating medications first
and then think about
changing additional agents.
01:32
So in epileptic patients
who are on a seizure medicine,
like the patient in our case,
who was taking levetiracetam,
we would increase the levetiracetam
before adding additional medications
when treating that patient
for a breakthrough seizure.
01:48
The patient in our case was
suffering from status epilepticus.
01:52
So let's spend some time
learning about status.
01:55
And let's start with
definitions and semiology.
01:58
The official definition of
status epilepticus
has been for years
prolonged or recurrent seizures
lasting at least 30 minutes.
02:07
That may be one seizure
lasting at least 30 minutes,
or multiple seizures
without return to baseline
lasting at least
a 30 minute period of time.
02:15
But operationally,
we know that epileptic seizures
are rarely longer
than five minutes.
02:21
And a seizure or multiple seizures
lasting more than five minutes
should raise early concern
that we're dealing with
status epilepticus.
02:30
We can classify status
by the semiology.
02:33
Just like we do
each individual seizure.
02:36
Convulsive status and that status
then involves convulsion of the body
tonic-clonic activity
accounts for 77%,
the majority of patients who
suffer from status epilepticus.
02:48
We also see non-convulsive status.
02:50
That's continuous seizure activity
without the motor convulsions.
02:54
This can be hard to diagnose,
and more difficult to evaluate,
and sometimes treat.
02:59
There are two types
of non-convulsive status:
Complex partial status.
03:04
And that status
that hasn't evolved
into that secondary generalized
tonic-clonic seizure,
but it is continuous.
03:09
And absence status,
which is again a
primary generalized epilepsy
and multiple seizures
without return to baseline
would be consistent with
absence status epilepticus.
03:21
And then lastly, we can see
simple partial status epilepticus.
03:24
Those are those
simple partial seizures
that just continue
repetitively.
03:29
Another name for this
in the literature has been
epilepsia partialis continua
or continuous partial seizures.
03:36
This is rare in accounts for
less than 10% of patients
who present with
status epilepticus.
03:44
In terms of
some other information.
03:46
Etiology of seizures.
03:48
1 to 8 hospital admissions
for epilepsy
will be for status epilepticus,
so we see it, it's rare,
but it is an emergency.
03:56
Four to 16% of patients
with epilepsy
will have one episode
of status epilepticus.
04:01
So up to 10% of our patients,
one in 10 epileptic patients
will develop status.
04:08
In children status epilepticus
is most common
in those that are younger
than two years of age.
04:13
80% will present
with febrile
or acute symptomatic
status epilepticus.
04:18
And so in these patients,
we need to look for
an underlying etiology.
04:22
And some of the things
we think about
would be fever or
systemic infection
that's causing status
in a patient with
underlying epilepsy.
04:29
A change in medication can result
in the development of status
and someone who previously
had well controlled seizures.
04:35
Sometimes
we don't find a cause.
04:37
Metabolic derangements,
congenital abnormalities, anoxia.
04:42
CNS infections, trauma, strokes.
04:45
Other CNS insults,
alcohol or drug intoxication,
or new tumors can cause the
development of status epilepticus
in someone who previously
had a diagnosis of epilepsy.
04:58
What about the prognosis?
Convulsive status is
a medical emergency.
05:03
This is one of the
conditions in neurology,
where we don't wait and watch.
We intervene abruptly.
05:09
About 4% to 11% of children will die
because of status epilepticus,
And somewhere
between
4 to up to 37% of adults
in some reports
will suffer death from
status epilepticus.
05:21
What are the risk factors for death
in status epilepticus?
The underlying etiology
is important
and patients who suffer status
from anoxia, cerebral anoxia,
are at increased
risk of death.
05:32
Patients at the
extremities of age.
05:34
Very young neonates
or the severe elderly
are at higher risk of death
from status epilepticus.
05:41
The duration of time is important.
05:43
Patients whose seizures
are longer than an hour
have a 32% risk of mortality
compared to 2.7%,
who seizures are stopped
within an hour of their onset.
05:54
And inadequate treatment
is important.
05:57
And this is why as you'll see,
when we talk about treatment,
we talked about early and acute
quick intervention
to stop the status
or stop the seizure
from where it started.
06:07
What do we see in the brain?
Well, brain compensatory
mechanisms
begin to fail at about
30 minutes after continuous seizure.
06:16
And this is why that
30 minute mark is very important.
06:18
We want seizures to stop
and we treat them to stop well
before that period of time.
06:23
We see excitotoxicity with
neural injury and cell death,
especially in the
hippocampus and amygdala
for prolonged seizures
greater than 30 minutes in duration.
06:35
Decreased brain oxygen tension,
there can be a fall
in cerebral blood flow,
and depletion of brain glucose
can all occur with
prolonged seizure activity.
06:45
This is why we really treat
these seizures aggressively
and are looking to stop the status
about as soon as it starts.
06:53
So in terms of classification,
we can classify status epilepticus,
both based
on its initial presentation
the semiology
as well as response
to treatment.
07:03
In terms of
initial presentation,
we can classify status
as convulsive status,
nonconvulsive status
and simple partial status.
07:11
And in general,
convulsive status is easier to treat
than nonconvulsive status.
07:17
It's also easier to recognize.
07:19
patients who have
motor jerking activity,
we can recognize that
as can caregivers.
07:24
Nonconvulsive status
often has a delay
to presentation or recognition.
07:29
Simple partial status epilepticus
can be particularly
difficult to treat.
07:33
And oftentimes,
treating the underlying lesion
finding a nidus,
and treating that lesion
can be important.
07:41
So for example,
if the simple partial status
is coming from a tumor,
we need to diagnose the tumor
and surgically remove it,
and that can be
much more effective
than additional
anti-epileptic drugs.
07:51
In addition, we can also categorize
status epilepticus
based on its
response to treatment.
07:56
We'll talk about the
treatment algorithm for status
and it starts with initial
anti-epileptic drugs.
08:03
Status that fails to respond
to those initial interventions
we call
refractory status epilepticus.
08:09
Those patients are typically
put in the ICU,
and treated with a
medically induced coma,
to shut the brain down,
turn the brain off,
restart the brain
to try and treat the status
and prevent
that seizure activity.
08:23
Patients who fail that
intensive intravenous therapy
are considered or
categorized as having
super-refractory
status epilepticus.
08:32
And with each failed
attempt at treatment,
the status becomes
more difficult to control.
08:38
So, this classification helps
to orient us
to the prognosis
of the patient
and how difficult
their situation and condition
may be to treat.
08:47
Looking at that
classification system
algorithmically,
we see that convulsive status
can be categorized
as well as
non-convulsive status.
08:56
For convulsive status
it can be categorized as
tonic clonic, or myoclonic.
09:01
And with non-convulsive status,
it may be simple partial,
complex partial,
or absence status epilepticus.
09:08
The simple partial status
manifests with
based on the part of the brain
that's involved.
09:13
So if the status is coming from
the somatosensory cortex,
it's a somatic sensory,
simple partial status,
or motor simple partial status,
or in aphasic
simple partial status.
09:25
What about convulsive
versus non-convulsive status.
09:27
This is an
important differentiator.
09:30
Convulsive status is more common.
09:31
It makes up 80 to 95% of patients
with status epilepticus
compared to nonconvulsive status
around five to 20% of cases.
09:41
We can see varying degrees
of convulsions.
09:43
And so some patients start
with convulsive status,
and then become
subclinical status epilepticus.
09:49
They lose the motor activity.
09:51
We don't see
clinical signs of status
even though that EEG discharge
has continued.
09:56
We can also see
subtle motor findings
myoclonic subtle myoclonus,
or other subtle status epilepticus
presentations.
10:04
Nonconvulsive status epilepticus
can be categorized as
absence status,
which is a confusional state.
10:10
Often with eyelid myoclonus, or
myoclonus of the face, or nystagmus,
which we are clues
to this diagnosis,
or complex partial
status epilepticus.
10:19
Again a confusional state
that can wax and wane
with motor automatisms
and varying degrees of level
of interactivity and awareness.