11 yo male with a 2 years history of staring and
unresponsiveness episodes noted several times
daily. These are now somewhat more frequent than they had been in the past. A student. EEG shows a typical absence seizure, provoked
by hyperventilation. The remainder of the EEG is unremarkable. I am confident
that I can eliminate the seizures and, probably, normalize the EEG with
medication. What benefit will accrue to this patient from my doing so?
Correspondent A: Medication
intervention may very possibly promote vigilance along with increased
attention, focusing and concentration especially at school where cognitive
stress can provoke episodes. Headaches can be a difficult comorbidity. Given
gender and age this is likely Juvenile Absence. No paroxysms during flash
stimulation ? (best seen following sleep-deprivation). Would also be on alert
for early presenting JME (Any AM jerks,e.g.?)
Correspondent B: I am
generally in agreement with Correspondent A’s answer. However, if the EEG is
classic 3Hz without any polyspike features, this young man could certainly be
classic childhood absence. The age criteria developed by Panayiotopoulos and
others suit this child (cutoff for onset 10yo) and a long line of other
excellent and meticulous electroencephalographers (Gibberd, Sato, Louiseau,
etc.) have confirmed onset of the classic "childhood" pattern of
absence rather than juvenile absence at even later ages, with the tendency to
greater risk for prolonged persistence and for the occurrence of generalized
consulsive seizures, hence some of the risks seen in juvenile absence may of
course be present. Apropos of that one must weigh treatment against the risks
of absence not only on vigilance in school, but in using a bicycle, later an
automobile, playing sports, swimming and bathing, etc.
My response: The EEG
does seem to be that of childhood absence. The only EEG abnormalities, 3HZ
S&W, are present during hyperventilation. Although the patient is 11 at
presentation, the onset of his epilepsy seems to have been 2 years earlier. For
2 years, by the history given, he has gotten along just fine, albeit his
observed seizures may be somewhat more frequent at the present. Would increased
attention, focusing and concentration make him an A+ student, instead of an A
student? His classmates have wondered why he might inexplicably halt during a
dodge ball game. Perhaps his dodge ball performance could be improved. He has
probably been riding a bicycle without mishaps, although who knows what might
occur tomorrow. By the way, does anyone have additional information on the
incidence of accidents in children with absence epilepsy specifically?
Correspondent C: Any
studies on
1. The Iikelihood of development of grand mal seizures
without treatment?
2. The Iikelihood of outgrowing seizures treated v. non treated?
Correspondent A: If
"TA" w/ onset age 5-early childhood, female, the risk is very low for
subsequent GTC. Later age onset absence is associated with much greater
likelihood for GTC and lifelong therapy.
In JA the hv-induced SW tends to be longer than 3 Hz (3.5-4)
and as Rob stated any clear multispike form presence is not
"absence". While EEG is helpful and supportive of "absence"
the clinical picture rules. Excellent history taking is a must. As we all know,
epilepsy is a clinical diagnosis.
Me again: A 2 yrs 4
mos girl was evaluated for staring episodes. An EEG showed 3HZ S&W
associated with behavioral change. She was treated with ethosuximide.
An EEG on therapy 4 1/2 years later was normal. The last
observed absence seizures had been 14 mos earlier. Ethosuximide therapy was
tapered and discontinued. An EEG subsequent to ethosuximide discontinuation
showed re-emergence of 3 Hz S&W with clinical change. The parents reported
observing only one episode; none had been seen by her teachers. At 7 yrs of age
she was doing superlative work in school and generally seemed brighter off
pharmacotherapy. Medication was not restarted. On one occasion subsequently,
she was observed to have 5 absence episodes at a time when she was tired. The
parents preferred to try to keep her from getting unduly tired. She continues
off pharmacotherapy at present and she was last reported as doing well.
Correspondent D: i
think you discontinued the drug early.
In absence seizure not only the clinical seizure must be
controlled ,but the EEC must be normal And after the clinical seizure control
led ,the patient must be evaluate in every visit with
hyperventilation test and every 3 mo with EEG.
after the drug discontinued, the patient must be followed
with EEG and if the EEG was abnormal the AED must be restarted ,even if the patient
is clinically seizure free.
My response: My usual
protocol for childhood absence which has been consistently successful (one
instance of relapse requiring reinstitution of medication; the patient
described above did not follow this protocol) has been to start an appropriate
medication and then, when medication is at a reasonable dosage and no seizures
are being observed, to obtain a repeat EEG, which generally is entirely normal.
Presuming so, and presuming no one is observing seizures, the patient is
maintained on medication for a minimum of 2 years. When a decision is made to
taper and discontinue medication, presuming no observation of seizures, an EEG
is repeated when the patient is medication free, which is generally normal.
The patient is then discharged from ongoing pediatric
neurology care.
I would certainly be interested in others' thoughts, but the
protocol described by Correspondent D seems to me quite excessive. In general,
childhood absence has seemed to be a disorder which is easy to treat. I still
struggle, in certain instance, with what I am accomplishing by the treatment.
Correspondent E: I
use roughly the same protocol as you, but generally if things are going really
well don't bother with the EEG when seizures aren’t being seen.
Correspondent E: I am
sure that most of us are aware of the fairly recent paper by Glauser et al in
the New England Journal of Medicine (NEJM, 362(9), 03/04/2010, Ethosuximide,
Valproic Acid, and Lamotrigine in Childhood Absence Epilepsy). The result of
this large double blinded case controlled study showed that VPA and
ethosuximide were as efficacious (about 50%) but ethosuximide was better
tolerated, while lamotrigine had — 70% failure rate. One of the criteria for
failure rate was the presence of a clinical electrographic seizure, defined as
a spike and wave burst lasting more than 3 seconds.
Me again: A girl with
childhood absence was started on pharmacotherapy. Although pharmacotherapy was
effective in eliminating observed seizures, she seemed to have noteworthy
difficulties with medication toleration. She was then seen by an esteemed
general pediatrician at a renowned medical institution. He obtained an EEG on
the patient, while she was on therapy, which was normal. This being done, he
contemptuously asserted that the diagnosis of absence epilepsy was erroneous
from the start, and discontinued the patient's medication.
Correspondent C: What
happened?
My response: The
mother was extremely upset at the pediatric neurologist (me)who had
"erroneously" diagnosed her daughter and subjected her to the noxious
medications. No further follow-up information is available.
Correspondent F: Wow!
That story leaves me sputtering with disbelief and rage.
My response: My
letter to the mother in response to her irate phone call (this was better than
22 years ago) indicated: "The normalization of the EEG in a patient with
absence epilepsy is deemed by many authorities a criterion of adequate
treatment. Therefore, the normalcy of an EEG obtained on therapy is expected,
not unusual. Whether your daughter continues to have a paroxysmal EEG will only
be known when her EEG is repeated after discontinuation of her medication. It
is possible that her generalized paroxysmal discharges are no longer present.
However, it is likely that this is not the case."
Correspondent G: This
is an excellent example of what motivates non- compliance. Patients and
families have reasons to be afraid or concerned or annoyed by taking pills
regularly, growing pimples, spending so much money or whatnot. They may feel
useless to try to get a hearing having tried before. Or they know their
objections are unreasonable, or will be treated as such. It is a shady world of
emotions hard to describe or sometimes to take seriously but a key to non-
compliance despite rational choice and appropriate explanations on that choice.
My update regarding the 2yrs 4 mos girl described above:
Parents continue to report patient as doing very well. They have no concerns.
Off ethosuximide for 5 months.
Correspondent H: With
reference to absence seizures the worry is this. Is the child having more
seizures than what we are observing? I have had "day dreamers" who
were in absence status whose performance improved after treatment. It is of
course an informed choice.
Me again: This is one
that I've heard more than once. I was speaking to the mother of a young boy
seen in another state by another practitioner. Following the diagnosis of
absence epilepsy brand-name Zarontin was started with excellent results.
Insurance then dictated use of generic ethosuximide.
There was a rapid reemergence of absence, despite blood
levels, dosage adjustment, etc. Resuming brand-name Zarontin did not resolve
the problem. Valproate was then utilized, evidently without excellent results
and complicated by a remarkable increase in appetite and weight gain.
Currently, levetiracetam is being utilized, not
surprisingly, with lack of effect and, possibly, emerging behavioral issues.
When I inquired regarding academic performance, I was told that he is a
superlative student, as he always has been.
My most recent update regarding the 2 yrs 4 mos girl, 22 months after the prior update:
My most recent update regarding the 2 yrs 4 mos girl, 22 months after the prior update:
The patient's mother
called to indicate that she was seeing seizures once again. I then recommended
that ethosuximide be restarted and that arrangements be made for a follow-up
evaluation. Later, the patient's mother reported that she was not really sure
that she had observed seizures and, in any event, no further episodes of
concern were observed, leading to neither ethosuximide nor follow-up
evaluation. Yet later, the patient's mother observed two unambiguous seizures,
with a protracted interval of confusion accompanying these. The patient was
brought to an emergency department, at which time she was behaving normally.
Once again, there was a recommendation that ethosuximide be restarted with
arrangements for follow up. Before departing the emergency department, she had
another evident seizure, again followed by protracted confusion. The patient
was then given a loading dose of intravenous valproate and started on valproate
maintenance. Despite the prolonged interval of non-treatment, the patient
continues to be described as doing very well academically.
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