TITLE:
Practice parameter: Evaluating a first
nonfebrile seizure in children. Report of the Quality Standards Subcommittee of
the American Academy of Neurology, the Child Neurology Society, and the
American Epilepsy Society.
SOURCE(S):
Neurology 2000 Sep 12;55(5):616-23 [66 references]
ADAPTATION:
Not applicable: Guideline was not adapted from another source.
RELEASE
DATE:
2000 Sep
MAJOR
RECOMMENDATIONS:
Each clinical practice recommendation is stratified by type of procedure, based
on the strength of the evidence. Definitions of the strength of the
recommendations (Standards, Guidelines, Practice Options, Practice Parameters)
and classification of the evidence (Class I through Class III) are provided at
the end of the Major Recommendations field.
Summary
In the child with a
first nonfebrile seizure, diagnostic evaluations influence therapeutic
decisions, how families are counseled, and the need for hospital admission
and/or specific follow-up plans. This practice parameter has reviewed the
published literature concerning the usefulness of studies following a first
nonfebrile seizure in children, and has classified the strength of the
available evidence. There is sufficient Class I evidence, which involves a
well-executed prospective study, to provide a recommendation with the highest
degree of clinical certainty--i.e., a Standard , that
an electroencephalogram be obtained in all children in whom a nonfebrile
seizure has been diagnosed--to predict the risk of recurrence and to classify
the seizure type and epilepsy syndrome. The decision to perform other studies,
including lumbar puncture, laboratory tests, and neuroimaging, for the purpose
of determining the cause of the seizure and detecting potentially treatable
abnormalities, will depend on the age of the patient and the specific clinical
circumstances. Children of different ages may require different management
strategies.
Laboratory
Studies
The fact that a
first nonfebrile seizure occurred in the absence of any suggestive history or
symptoms in a child who is older than age 6 months and has returned to baseline
has not been shown to be sufficient reason to perform routine laboratory
testing in the child with a first nonfebrile seizure. However, the number of
children reported is too small to be confident that in rare circumstances,
routine laboratory screening such as blood glucose determination might not
provide important information, even without specific clinical indications.
There were only two reports of positive toxicology screens, but no studies that
systematically evaluated the yield from doing routine toxicology screening in
children with first seizures. If no cause for the seizure has been identified,
it is important to ask questions regarding possible toxic ingestions or
exposures.
Recommendations:
·
Laboratory tests should
be ordered based on individual clinical circumstances that include suggestive
historic or clinical findings such as vomiting, diarrhea, dehydration, or
failure to return to baseline alertness (Option).
·
Toxicology screening
should be considered across the entire pediatric age range if there is any
question of drug exposure or substance abuse (Option).
Lumbar
Puncture
There is no evidence
regarding the yield of routine lumbar puncture following a first nonfebrile
seizure. The one study available (Class II) is limited in size and age range.
Recommendations based on age and clinical symptoms are available for Class III
publications. In the very young child (<6 months), in the child of any age
with persistent (cause unknown) alteration of mental status or failure to
return to baseline, or in any child with meningeal signs, lumbar puncture
should be performed. If increased intracranial pressure is suspected, the
lumbar puncture should be preceded by an imaging study of the head.
Recommendations:
·
In the child with a first
nonfebrile seizure, lumbar puncture is of limited value and should be used
primarily when there is concern about possible meningitis or encephalitis (Option).
Electroencephalogram
The majority of
evidence from Class I and Class II studies confirms that an
electroencephalogram helps in determination of seizure type, epilepsy syndrome,
and risk for recurrence, and therefore may affect further management decisions.
Experts commonly recommend that an electroencephalogram be performed after all
first nonfebrile seizures. It is not clear what the optimal timing should be
for obtaining an electroencephalogram. Although an electroencephalogram done
within 24 hours of the seizure is most likely to show abnormalities, physicians
should be aware that some abnormalities such as postictal slowing that can be
seen on electroencephalogram done within 24 to 48 hours of a seizure may be
transient and must be interpreted with caution.
There is no evidence
that the electroencephalogram must be done before discharge from the emergency
department; the study may be arranged on an outpatient basis. Epileptiform
electroencephalogram abnormalities may be useful in confirming that the event
was a seizure; however, an electroencephalogram abnormality by itself is not
sufficient to make a diagnosis that an epileptic seizure occurred, nor can its
absence rule out a seizure. The electroencephalogram is necessary to determine
the epilepsy syndrome and the diagnosis of an epilepsy syndrome may be helpful
in determining the need for imaging studies. The electroencephalogram is also
useful in predicting the prognosis for recurrences.
It is not clear what
the optimal timing should be for obtaining an electroencephalogram. Although an
electroencephalogram done within 24 hours of the seizure is most likely to show
abnormalities, physicians should be aware that some abnormalities such as
postictal slowing that can be seen on electroencephalogram done within 24 to 48
hours of a seizure may be transient and must be interpreted with caution.
Recommendations:
·
The electroencephalogram
is recommended as part of the neurodiagnostic evaluation of the child with an
apparent first unprovoked seizure (Standard)
Neuroimaging
Studies
Although
abnormalities on neuroimaging are seen in up to one third of children with a
first seizure, most of these abnormalities do not influence treatment or
management decisions such as the need for hospitalization or further studies.
Of available reported imaging results, from Class I and Class II studies of
children, an average of about 2% revealed clinically significant findings that
contributed to further clinical management, the majority of which were
performed because the seizure was focal or there were specific clinical
findings beyond the fact that a seizure had occurred (see the table in the
guideline document).
Thus, there is
insufficient evidence to support a recommendation at the level of standard or
guideline for the use of routine neuroimaging, i.e., imaging performed for
which having had a seizure is the sole indication, after a first nonfebrile
seizure in children. However, neuroimaging may be indicated under some
circumstances either as an emergent or nonurgent procedure.
The purpose of performing
an emergent neuroimaging study in the context of a child's
first seizure is to detect a serious condition that may require immediate
intervention. The possible effects of emergency medication used to treat the
seizure must be taken into consideration.
The purpose of
performing a nonurgent neuroimaging study, which can be deferred to the next
several days or later, is to detect abnormalities that may affect prognosis and
therefore have an impact on long-term treatment and management. Factors to be
considered include the age of the child, the need for sedation to perform the
study, the electroencephalogram results, a history of head trauma, and other
clinical circumstances such as a family history of epilepsy.
Recommendations:
·
If a neuroimaging study is
obtained, magnetic resonance imaging is the preferred modality (Guideline).
Emergent
neuroimaging should be performed in a child of any age who exhibits a postictal
focal deficit (Todd's paresis) not quickly resolving, or who has not returned
to baseline within several hours after the seizure (Option).
·
Nonurgent imaging studies
with magnetic resonance imaging should be seriously considered in any child
with a significant cognitive or motor impairment of unknown etiology,
unexplained abnormalities on neurologic examination, a seizure of partial
(focal) onset with or without secondary generalization, an electroencephalogram
that does not represent a benign partial epilepsy of childhood or primary
generalized epilepsy, or in children under 1 year of age (Option)
Definitions:
Classification
of Evidence:
Class I. Must have
all (a through d):
a.
Prospective study of a
well defined cohort which includes a description of the nature of the
population, the inclusion/exclusion criteria, demographic characteristics such
as age and sex, and seizure type.
b.
The sample size must be
adequate with enough statistical power to justify a conclusion or for
identification of subgroups for whom testing does or does not yield significant
information.
c.
The interpretation of
evaluations performed must be done blinded to outcome.
d.
There must be a
satisfactory description of the technology used for evaluations (e.g.,
electroencephalogram, magnetic resonance imaging).
Class
II. Must have a or b:
a.
A retrospective study of
a well-defined cohort which otherwise meets criteria for Class 1a, 1b, and 1d.
b.
A prospective or
retrospective study which lacks any of the following: adequate sample size,
adequate methodology, a description of inclusion/exclusion criteria, and
information such as age, sex, and characteristics of the seizure.
Class
III. Must have a or b:
a.
A small cohort or case
report.
b.
Relevant expert opinion,
consensus, or survey.
A cost-benefit
analysis or a meta-analysis may be Class I, II, or III, depending on the
strength of the data upon which the analysis is based.
Strength
of Recommendations:
Standards. Generally
accepted principles for patient management that reflect a high degree of
clinical certainty (i.e., based on Class I evidence or, when circumstances
preclude randomized clinical trials, overwhelming evidence from Class II
evidence that directly addresses the issue, decision analysis that directly
addresses the issue, or strong consensus of Class III evidence).
Guidelines. Recommendations
for patient management that may identify a particular strategy or range of
management strategies and that reflect moderate clinical certainty (i.e., based
on Class II evidence that directly addresses the issue, decision analysis that
directly addresses the issue, or strong consensus of Class III evidence).
Practice
options. Other strategies for patient
management for which the clinical utility is uncertain (i.e., based on
inconclusive or conflicting evidence or opinion).
Practice
parameters. Results, in the form of one or more
specific recommendations, from a scientifically based analysis of a specific
clinical problem.
CLINICAL
ALGORITHM(S):
None provided
DEVELOPER(S):
American Academy of Neurology - Medical Specialty Society
Child Neurology Society - Medical Specialty Society
American Epilepsy Society - Disease Specific Society
COMMITTEE:
Quality Standards Subcommittee
GROUP
COMPOSITION:
Subcommittee Members: Gary Franklin, MD, MPH (Co-Chair);
Catherine Zahn, MD (Co-Chair); Milton Alter, MD, PhD; Stephen Ashwal, MD; John
Calverley, MD; Richard Dubinsky, MD; Jacqueline French, MD; Gary Gronseth, MD;
Deborah Hirtz, MD; Robert Miller, MD; James Stevens, MD; and William Weiner,
MD.
ENDORSER(S):
American Academy of Pediatrics - Medical Specialty Society
GUIDELINE
STATUS:
This is the current release of the guideline.
An update is not in
progress at this time.
GUIDELINE
AVAILABILITY:
Electronic copies: A list of American Academy of Neurology (AAN) guidelines,
along with a link to a Portable Document Format (PDF) file for this guideline,
is available at the AAN Web site.
Print copies:
Available from the AAN Member Services Center, (800) 879-1960, or from AAN,
1080 Montreal Avenue, St. Paul, MN 55116.
COMPANION
DOCUMENTS:
The following are available:
·
Practice statement
definitions. St. Paul (MN): American Academy of Neurology. Available from the American
Academy of Neurology (AAN) Web site.
·
Practice statement
development. St. Paul (MN): American Academy of Neurology. Available from the AAN Web site.
Edward E.
Rylander, M.D.
Diplomat American
Board of Family Practice.
Diplomat American
Board of Palliative Medicine.