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Urgent Neuroimaging In
Children With First Nonfebrile Seizures
.........................................................................................................................
Hussein I Alawneh
MD,
Hussein A Bataineh MD
Royal Medical Services, Pediatric Department
Correspondence:
Dr: Hussein I Alawneh
Email: hualawneh2000@yahoo.com
Prince Rashed Hospital
Post Office: Irbid Aidoun
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ABSTRACT
Objective:
to determine the risk factors mandatory
for urgent neuroimaging study in children
with first nonfebrile seizures.
Methods:
We reviewed medical charts of 105 children
who were admitted with a new-onset nonfebrile
seizure to the Pediatric Ward of Prince
Rashed Hospital and underwent brain CT
scan. Neuroimaging was performed for 95%
(100/105) of these children over the first
few hours of their arrival to the Emergency
Department.
Results:
In 90% (90/100) of them, the result was
normal. There was a significant relationship
between abnormal neuroimaging and focal
seizure (P < 0.001), history of head
trauma, and with age under 2 years (P
< 0.002).
Conclusion:
we recommended that urgent brain CT scan
to be performed in children with first
nonfebrile seizure who present with focal
seizures, abnormal neurological findings,
head trauma, and age less than 2 years.
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Key
words: Computed tomography scan, seizure,
nonfebrile, focal
..........................................................................................................................
Seizures
are common neurological disorders in the pediatric
age group and occur in 3-5% of children1; five
percent of all medical attendances to accident
and emergency departments are related to seizures.
The role of emergent neuroimaging for those
children with first nonfebrile seizure is, however,
not well-defined..
The purpose of performing
an emergent neuroimaging study in a child with
first nonfebrile seizure is to detect a serious
condition that may require immediate intervention.
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.2 Guide-lines
for obtaining emergent neuroimaging in adult
patients presenting with seizures have recently
been published.3 It is recommended that emergent
brain computed tomography (CT) scan should be
performed for most adults with a new-onset seizure,
because of the large proportion of the structural
lesions such as stroke or neoplasm in the adult
population.4 The prevalence of abnormal neuroimaging
in an adult with a new-onset seizure is 34%
to 45%.4,5 However, the role of emergent neuroimaging
in children presenting with first nonfebrile
seizure is still not well-defined. Based on
several studies, the prevalence of abnormal
neuroimagings in pediatric patients with a new-
onset nonfebrile seizure is estimated to be
0% to 21%.6, 7
Nevertheless, the
American Academy of Neurology8 states that these
evidences are not sufficient to make a recommendation
at the level of guideline for the use of routine
neuroimaging in children with a new-onset seizure.
The objective of this study was to determine
those children with a new-onset nonfebrile seizure
who were more likely to have abnormal neuroimaging
findings.
Study
design/patients
In this study, medical charts of 100 children
aged between one month and 14 years, with a
new-onset nonfebrile seizure, admitted to the
Pediatric Ward of Prince Rashed Hospital, Irbid,
north of Jordan between 2000 and 2005, were
reviewed. We excluded neonatal seizures (before
28 days of life), first seizures lasting 30
minutes or more (status epilepticus), and febrile
seizures, because these disorders are diagnostically
and therapeutically different. Patients with
their first nonfebrile seizure and absence of
any laboratory abnormalities were included in
the study.
Historical
and clinical data included patient's age, sex,
and the presence of any predisposing conditions,
generalized or focal type of seizure, temperature,
focal neurological signs, and any other abnormal
findings in the neurological examination.
The
reports of CT scans performed over the first
few hours of arrival to hospital were studied.
All the emergent neuroimaging studies were conducted
without the injection of contrast medium.
Laboratory
data included serum electrolytes, calcium, and
blood sugar.
Statistical
analysis was conducted using SPSS software.
Variables were reported as mean ± SD.
?2 analysis was performed to determine the correlation
between age of the patients and type of seizure
with abnormal findings on neuroimaging.
A
P value of <0.05 was considered statistically
significant.
There were 520 patients
admitted with the diagnosis of seizure over
this five-year period. One hundred and five
(20%) of these patients had new-onset nonfebrile
seizures; neuroimagings were obtained in 100
(95%) patients, by emergent CT scan and formed
our study group. There were 54 (54%) females
and 46 (46%) males. The mean ± SD age
of patients was 52 ± 48 months (range:
one month - 14 years).
Neuroimaging results
were normal in 90 (90%) patients. Clinically-significant
neuroimaging results were reported in 10 (10%)
patients (Table 1).
CNS hemorrhage is the
most common neuroimaging finding in those patients
who presented with first attack of nonfebrile
seizures.
One of five patients
with brain hemorrhage had bleeding disorder
due to thrombocytopenia, the other four had
a history of head trauma, and one of them was
due to child abuse.
Cyanotic heart disease
with right to left shunt resulted in brain ischemia
in one patient. Brain tumor, tuberous sclerosis,
systemic lupus erythematosus, and arachnoid
cyst were among the other predisposing factors
for nonfebrile seizures. Seven of ten patients
had abnormal findings on neurological examination.
Twelve (12%) patients
were under two years of age, of whom 5 (41.6%)
had abnormal neuroimaging findings. Based on
the Chi-square test, there was a significant
relationship (P < 0.002) between the age
of patients and neuroimaging abnormalities.
Twenty two (22%) patients
presented with focal and seventy eight (78%)
with generalized seizures (Table 2). Out of
22 patients with focal seizures, seven (31.8%)
and out of 78 with generalized seizures, only
four (5%) had abnormal neuroimaging results
(P < 0.001).
A significant relationship
was also found between the focality of seizure
and abnormal findings in neuroimaging (Chi-square
test, P < 0.001) (Table
2).
After
stabilization of the child, a physician must
determine if a seizure has occurred, and if
so, if it is the child's first episode. It
is critical to obtain as detailed a history
as possible at the time of presentation. The
determination that a seizure has occurred
is typically based on a detailed history provided
by a reliable observer. A careful history
and neurological examination may allow a diagnosis
without need for further evaluation. Children
can present with seizure-like symptoms that
may not in fact represent actual seizures,
but rather breath-holding spells, syncope,
gastro-esophageal reflux, pseudoseizures (psychogenic),
and other nonepileptic events8
The
next goal of assessment is to determine the
cause of the seizure. In many children, the
history and physical examination alone will
provide adequate information regarding probable
cause of the seizure or the need for other
tests including neuroimaging. The etiology
of the seizure may necessitate prompt treatment
or provide important prognostic information.
Provoked seizures are the result of an acute
condition such as hypoglycemia, toxic ingestion,
intracranial infection, trauma, or other precipitating
factors. Unprovoked seizures occur in the
absence of such factors; their etiology may
be cryptogenic (no known cause), remote symptomatic
(pre-existing brain abnormality or insult),
or idiopathic (genetic) 8.
Approximately
4 - 6% of children are expected to have a
seizure by the age of 16 years. About 70%
of these children are admitted and undergo
different investigations.9 The role of emergent
neuroimaging for children with a new-onset
nonfebrile seizure is not well-understood.
This is because the prevalence of neuroimaging
abnormalities in this group has yet not been
determined. However, regarding the results
reported in the literature for adults, there
has been a relatively high prevalence (between
34 - 45%) of CT scan abnormalities in adults
with a new seizure. As a result, a recommendation
has been published to perform emergent neuroimaging
in large populations of adults having their
first seizure.3
So
far, several studies have reported the prevalence
of abnormal neuroimaging in children with
new-onset seizures. The prevalence of abnormal
neuroimaging in these studies ranged between
0 -21%. The proportion of children with febrile
seizures ranged between 17% and 71%.6,7 It
is important to note that children with febrile
seizures, either simple or complex, are at
low risk of neuroimaging abnormalities.8 Our
study reviewed 100 patients with their first
nonfebrile seizure. All patients with febrile
seizures, as well as those with recurrent
seizures were excluded. Neuroimaging was performed
in 95 patients and abnormalities were found
in only 10% of cases. The results showed that
there was a significant relationship (P <
0.001) between focality of the seizure and
abnormal neuroimaging. In addition, a significant
relationship (P < 0.002) was found between
an age of less than 2 years and abnormal findings
in neuroimaging. The high-risk age was reported
to be less than 24 months by Adamsbaum et
al11 and less than 33 months by Sharma et
al.10
Seven (70%) out of 10 children with abnormal
neuroimaging in our study had grossly abnormal
findings on physical examination (coma, papilledema,
focal neurological deficits, unilateral pupil
dilation, etc), while five (50%) had history
of head trauma.
Practice
parameters, which have been recently published,8
recommend emergent neuroimaging to be performed
in a child of any age, who exhibits a postictal
focal deficit (Todd's paresis) not quickly
resolving, or who is not recovered to the
preictal state within several hours after
the seizure.
Based
on our study, a relatively small number of
children (10%) suffering from their first
nonfebrile seizure had abnormal neuroimagings
and the majority of this group also had abnormal
neurological examinations.
Although
CT scan is more available in the emergency
departments, MRI is accepted as a more sensitive
neuroimaging modality for children presenting
with seizure12, unfortunately MRI study is
not available in our hospital.
Urgent
brain CT scanning is rarely necessary in children
after a first seizure. Based on our findings,
we recommend that emergent neuroimaging should
be performed in children with their first
nonfebrile seizure, if there are abnormal
neurological findings, the child presented
with focal seizures, there is history of head
trauma, and if the age is less than two years.
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Table
1. Neuroimaging
abnormalities.
|
|
Abnormal findings
|
Frequency
|
Hemorrhage
Epidural (1)
Parenchymal (3)
Subdural (1) |
5
|
|
Brain tumor
(Medulloblastoma)
|
1
|
|
Calcification
(Tuberous sclerosis)
|
1
|
|
SLE+
|
1
|
|
Brain ischemia
|
1
|
|
Arachenoid cyst
|
1
|
|
Total
|
10
|
|
+= systemic
lupus erythematosus
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Table
2.
Correlation between type of seizure
and abnormal neuroimaging.
|
| |
Seizure
|
|
Neuroimaging
|
Focal
|
General
|
Total
|
|
Abnormal
|
7
(7%)
|
5
(5%)
|
12
(12%)
|
|
Normal
|
15 (15%)
|
73 (73%)
|
88 (88%)
|
|
Total
|
22 (22%)
|
78 (78%)
|
100 (100%)
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<<
back to text
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