Brain abscess in Korean children: A 15-year single center study.

Abstract

A brain abscess is a serious disease of the central nerve system. We conducted this study to summarize the clinical manifestations and outcomes of brain abscesses.
A retrospective chart review of pediatric patients diagnosed with brain abscesses from November 1994 to June 2009 was performed at Samsung Medical Center, Seoul, Korea.
Twenty-five patients were included in this study. On average, 1.67 cases per year were identified and the median age was 4.3 years. The common presenting clinical manifestations were fever (18/25, 72%), seizure (12/25, 48%), altered mental status (11/25, 44%), and signs of increased intracranial pressure (9/25, 36%). A total of 14 (56%) patients had underlying illnesses, with congenital heart disease (8/25, 32%) as the most common cause. Predisposing factors were identified in 15 patients (60%). The common predisposing factors were otogenic infection (3/25, 12%) and penetrating head trauma (3/25, 12%). Causative organisms were identified in 64% of patients (16/25). The causative agents were S. intermedius (n=3), S. aureus (n=3), S. pneumoniae (n=1), Group B streptococcus (n=2), E. coli (n=1), P. aeruginosa (n=1), and suspected fungal infection (n=5). Seven patients received medical treatment only while the other 18 patients also required surgical intervention. The overall fatality rate was 16% and 20% of patients had neurologic sequelae. There was no statistical association between outcomes and the factors studied.
Although uncommon, a brain abscess is a serious disease. A high level of suspicion is very important for early diagnosis and to prevent serious consequences.

Full text

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DOI: 10.3345/kjp.2010.53.5.648
Korean J Pediatr 2010;53(5):648-652
Original article
648
Brain abscess in Korean children: A 15-year single
center study
Received: 15 September 2009, Revised: 2 November 2009
Accepted: 1 December 2009
Corresponding Author: Yae-Jean Kim, M.D.
Department of Pediatrics, School of Medicine, Sungkyunkwan
University, Samsung Medical Center, 50 Irwon-dong, Gangnam-
Gu, Seoul 135-710, Korea
Tel: +82.2-3410-3539, Fax: +82.2-3410-0043
E-mail: aejeankim@skku.edu
Copyright © 2010 by The Korean Pediatric Society
Purpose: A brain abscess is a serious disease of the central nerve
system. We conducted this study to summarize the clinical
manifestations and outcomes of brain abscesses.
Methods: A retrospective chart review of pediatric patients
diagnosed with brain abscesses from November 1994 to June 2009
was performed at Samsung Medical Center, Seoul, Korea.
Results: Twenty-five patients were included in this study. On
average, 1.67 cases per year were identified and the median age
was 4.3 years. The common presenting clinical manifestations
were fever (18/25, 72%), seizure (12/25, 48%), altered mental status
(11/25, 44%), and signs of increased intracranial pressure (9/25,
36%). A total of 14 (56%) patients had underlying illnesses, with
congenital heart disease (8/25, 32%) as the most common cause.
Predisposing factors were identified in 15 patients (60%). The
common predisposing factors were otogenic infection (3/25, 12%)
and penetrating head trauma (3/25, 12%). Causative organisms were
identified in 64% of patients (16/25). The causative agents were S.
intermedius (n=3), S. aureus (n=3), S. pneumoniae (n=1), Group B
streptococcus (n=2), E. coli (n=1), P. aeruginosa (n=1), and suspected
fungal infection (n=5). Seven patients received medical treatment
only while the other 18 patients also required surgical intervention.
The overall fatality rate was 16% and 20% of patients had
neurologic sequelae. There was no statistical association between
outcomes and the factors studied.
Conclusion: Although uncommon, a brain abscess is a serious
disease. A high level of suspicion is very important for early
diagnosis and to prevent serious consequences.
Key words: Brain, Abscess, Child, Korea
Cha Gon Lee, M.D.1, Seong Hun Kang, M.D.1,
Yae Jean Kim, M.D.1, Hyung Jin Shin, M.D.2,
Hyun Shin Choi, M.D.1, Jee Hun Lee, M.D.1
and Mun Hyang Lee, M.D.1
Department of Pediatrics1, Department of Neurosurgery2,
School of Medicine, Sungkyunkwan University,
Samsung Medical Center, Seoul, Korea
Introduction
A brain abscess is a focal collection of infectious material within
the brain, which can arise as a complication from a variety of
causes including infection, trauma, and surgery. A wide variety of
organisms (bacteria, fungi, protozoa, and parasites) can cause abscess
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-
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Korean J Pediatr 2010;53(5):648-652 • DOI: 10.3345/kjp.2010.53.5.648
649
formation. Brain abscesses occur relatively infrequently because of
the abundant blood supply to the brain and the protection of the
brain by the blood-brain barrier. In the pre-antibiotics era when
medicines with good central nervous system (CNS) penetration
were not available, brain abscesses were almost uniformly lethal1).
Despite the major advances in neuroimaging and the increased
availability of potent antibiotics and neurosurgical intervention, the
incidence of brain abscesses has not changed much. Brain abscesses
still have high rates of neurologic impairment and fatality2).
While a number of reports have reviewed brain abscesses in adult
populations, only a few comprehensive reports on long follow-ups of
pediatric cases are available2-8). In this study, we analyzed data from
25 patients with brain abscesses and we describe the clinical features
of these brain abscesses.
Materials and methods
Pediatric patients less than 19 years old who were diagnosed
with a brain abscess at Samsung Medical Center, Seoul, Korea
from November 1994 through June 2009 were included. We
searched all the patients whose diagnosis at discharge was brain
abscess(es) using Samsung Medical Information System (SMIS)
and only included cases with radiological evidence; 21 patients had
brain parenchymal abscesses, 3 patients had a subdural abscess,
and 1 patient had an epidural abscess. Clinical data (clinical
manifestations, initial laboratory findings, causative organisms,
characteristics of abscesses, treatment modalities, and outcomes)
were collected based on retrospective chart reviews. Statistical
analysis, such as univariate analysis, Mann-Whitney test, Fisher’s
exact test, was performed to evaluate association between outcomes
and the factors studied.
Results
1. Patient characteristics
A total of 25 pediatric patients were diagnosed with one or more
brain abscesses during 14.7 consecutive years, an average of 1.67
cases per year. Fourteen patients were male and 11 patients were
female (ratio 1.3:1). The median age was 4.3 years (range, 0.1-18.9
years), and the abscesses occurred most commonly in patients
younger than 2 years of age, including 1 neonate (11/25, 44%).
Five of these 11 patients (45%) were born prematurely (< 37 weeks
gestational age).
Underlying diseases and predisposing factors are listed
in Table 1. Fourteen patients (56%) presented with known
underlying medical conditions: congenital heart disease (CHD,
n=8), immunodeficiency (n=3) due to acute myeloblastic
leukemia (AML), myelodysplastic syndrome (MDS) and
agammaglobulinaemia, and suspected arterial venous
malformation (n=1). In patients younger than 2 years old (n=11),
prematurity was also considered to be an underlying medical
condition (n=5). Two patients had both prematurity and CHD
and one patient had MDS and CHD. Predisposing factors were
identified in 15 patients (15/25, 60%). The common predisposing
factors were otogenic infection (n=3) and penetrating head trauma
(n=3) followed by preceding meningitis (n=2), neurosurgical
procedures (n=2), endocarditis (n=2), ventriculoperitoneal shunts
(n=2), and poor oral hygiene with lymphangioma at the tongue
base (n=1).
2. Clinical presentation
The most common presenting symptom was fever (17/25, 68%).
The median body temperature at diagnosis was 38.5˚C (range,
36.3-41˚C). Twelve patients (48%) had seizures (generalized or
partial). Altered mental status (ranging from drowsy to coma) was
observed in 12 patients (48%): 7 patients were drowsy, 2 were in
a stupor, and 3 were in a semicoma. One patient’s mental status
could not be assessed due to deep sedation. The median interval
between symptom onset and diagnosis by imaging studies was 11
days in 23 patients (range, 1-119 days). Two patients did not have
any symptoms. One patient had the longest time delay of 119 days
until diagnosis. This patient was a 9 month-old female who had
been born prematurely (gestational age 30+1/7 weeks) at an outside
hospital and was transferred to our hospital under the diagnosis
of cystic encephalomalacia, ventriculitis, and parenchymal abscess
with shunt infection.
The Glasgow coma scale was only evaluated in six patients
(24%) at diagnosis; severe brain injury (GCS ≤8) was diagnosed in
two, moderate brain injury (GCS 9-12) in one, and minor brain
injury (GCS ≥13) in three patients. Focal neurologic deficits were
observed in seven patients (28%). Signs of increased intracranial
pressure (IICP) such as vomiting, neck stiffness, or bulged
fontanelle were observed in nine patients (36%).
3. Laboratory data
The median WBC count at diagnosis (n=24 patients) was
11,740/μL (range, 580-43,660/μL), the median level of C-reactive
protein (n=24) was 1.69 mg/dL (range, 0.06-29.06 mg/dL), and
the median erythrocyte sedimentation rate (n=18) was 23 mm/
hr (range, 8-105 mm/hr). Lumbar puncture was performed in
14 patients (56%); the median CSF WBC was 206/μL (range, 0-
15,700/μL); the median protein level was 158 mg/dL (range, 10-

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CG Lee, et al. • Brain abscesses in children
1,502), and the median glucose level was 53 mg/dL (range, 2-85
mg/dL).
4. Microbiological study
Microbiological diagnosis was confirmed in 64% of patients
(16/25 patients) based on abscess cultures (n=5/13), blood
cultures (n=6/21), CSF cultures (n=4/12), vegetation culture
by open-heart surgery (n=1/2), or pathology reports (n=2/2).
Streptococcus intermedius (n=3), Staphylococcus aureus (n=3),
Group B Streptococcus (n=2), Streptococcus pneumoniae (n=1),
Escherichia coli (n=1), Pseudomonas aeruginosa (n=1), Aspergillus
spp. (Aspergillus flavus, Aspergillus spp.) (n=2), Candidia albicans
(n=2), and a suspected fungal infection (n=1) were detected.
Two patients had the same pathogens in both blood and CSF
cultures: Streptococcus pneumonia and Pseudomonas aeruginosa.
Staphylococcus intermedius (n=3), Staphylococcus aureus (n=1),
and Aspergillus flavus (n=1) were present in abscess cultures.
Candia albicans was identified in a vegetation culture of one
patient. The organisms present in two patients were confirmed by
abscess pathology reports only; an Aspergillus species in one patient
and a suspected fungal infection (no species identification) in the
other patient.
5. Radiologic study
For radiologic diagnosis, computer tomography (CT, n=17),
magnetic resonance (MRI, n= 5), or ultrasonography (US, n=3)
images were obtained. Twenty-one patients were diagnosed with a
brain parenchymal abscess, 3 patients with a subdural abscess, and
1 patient with an epidural abscess. Among 21 patients with brain
parenchymal abscess, a single lesion was observed in 9 patients
(43%) and multiple lesions were observed in 12 patients (57%).
The distribution of single lesions was similar in both sides of the
brain; five patients had abscesses in the right hemisphere and four
had abscesses in the left hemisphere. The most common location
of single abscesses was the temporal lobe (3/9, 33%) followed by
the parietal lobe (2/9, 22%), frontoparietal lobe (1/9, 11%), basal
ganglia (1/9, 11%), cerebellum (1/9, 11%), and occipital lobe (1/9,
11%).
6. Treatment and outcomes
All patients received combination antimicrobial therapy. Seven
Table 1. Characteristics and Outcomes of Brain Abscesses in 25 Pediatric Patients
PatientsSexAge (years)Underlying diseases/predisposing factors
Outcome
Mortality Neurologic impairment
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
F
M
F
M
F
F
F
F
M
M
M
M
M
M
F
M
F
M
F
M
M
M
F
M
F
0.8
1.3
1.3
3.2
4.8
5.0
5.0
5.3
7.7
7.9
8.4
15.5
17.2
17.6
18.9
0.8
13.1
0.1
0.1
1.7
4.3
0.1
1.3
0.1
1.0
Preterm(GA 30+1/7 wks), VP shunt infection
Preterm (GA 35+2/7 wks), poor oral hygiene due to tongue base lymphangioma
Preterm (36 wks), bicuspid aortic valve with aortic regurgitation, pneumonia sepsis with
DIC and ICH
Tricuspid atresia
Head trauma
Ventricular septal defect
Medulloblastoma, neurosurgery
R/O AVM, ICH, neurosurgery
Pulmonary atresia
MDS , patent foramen ovale,
Pulmonary stenosis with atrial septal defect
Preceding dental procedure, endocarditis
Lt COM with cholesteatoma
No underlying disease or predisposing factor
Rt COM with cholesteatoma
Agammaglobulinema
Head trauma
Patent foramen ovale, fungal endocarditis
Preceding meningitis
AML
AOM
Preterm (GA 25+3/7 wks), patent ductus arteriosus, ICH
Head trauma
Preceding meningitis
Preterm (GA 28 wks), VP shunt infection
Dead
Alive
Alive
Alive
Alive
Alive
Dead
Alive
Dead
Alive
Alive
Alive
Alive
Alive
Alive
Alive
NA
Alive
Alive
Alive
Alive
Dead
Alive
Alive
Alive
NA
None
None
None
Dysarthria, limping gait
None
NA
Right hemiplegia
NA
None
None
None
None
Hemianopsia
None
None
NA (lost to follow- up)
None
Cerebral palsy
None
None
NA
Epilepsy
None
None
Abbreviations: MDS, myelodysplastic syndrome; AOM, acute otitis media; DIC, disseminated intravascular coagulation syndrome; AML, acute myeloblastic
leukemia; COM, chronic otitis media; AVM; arterio-venous malformation; ICH, intra-cerebral hemorrhage; VP shunt, ventriculoperitoneal shunt; NA, not
applicable

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651
patients received medical treatment only and 18 patients received
additional surgical interventions (17 neurosurgeries and 2 open-
heart surgeries for vegetation removal). One patient had two
neurosurgeries. Commonly performed neurosurgical procedures
were bur hole drainage (n=9), surgical excision with open
craniotomy (n=4), and image-guided stereotactic aspiration (n=3).
The median duration of antimicrobial therapy was 42 days (range,
12-108 days). Commonly used antimicrobials were vancomycin
(23/24, 96%), third-generation cephalosporin (19/24, 76%),
metronidazole (13/24, 52%), and amphotericin B (5/24, 21%).
Four patients died and the overall fatality rate was 16% (4/25
patients). One patient was lost to follow-up. The median follow-
up duration was 3.1 years in the remaining 20 patients (range,
0.2-13.2). Neurological impairments such as epilepsy, motor
impairment (limping gait, hemiplegia), cerebral palsy, visual field
defect (hemianopsia), were observed in 5 of 20 survivors (Table 1).
There was no statistical association between outcomes (fatality
and neurological impairments) and the factors studied; age, sex,
days from symptom onset to diagnosis, presence of congenital
heart diseases, initial mental status, seizure at diagnosis, IICP
at diagnosis, focal neurologic defect at diagnosis, initial body
temperature, WBC counts, level of CRP, diagnostic images used
(CT vs US vs MRI), and treatments used (medical treatment only
vs surgery combined).
Discussion
Brain abscesses are serious and life-threatening lesions of the
CNS. They are uncommon in pediatric patients and most of the
published literature comprises case reports. This study is one of the
few to report comprehensive data on brain abscesses collected from
25 pediatric patients at a single tertiary center during a period of
14.7 years.
At the University of Virginia Children’s Hospital between
2000-2007, an average of 1.5 children per year were admitted to
the inpatient pediatric service with a primary diagnosis of brain
abscess4). Lee et al24) reported 27 pediatric cases of Korean children
over 10 years, an average of 2.7 cases per year. In our study, an
average of 1.67 pediatric patients per year were identified during
14.7 consecutive years. In terms of age distribution, brain abscesses
occurred most commonly in patients younger than 2 years of age.
The clinical manifestations of brain abscesses initially tend to
be nonspecific and there are no typical laboratory or CSF study
results, which often causes a delay in diagnosis9, 10). The median
interval from symptom onset to diagnosis was 11 days in our study,
similar to another report (13 days)11). Previously, headache was
reported as the most common symptom of a brain abscess in non-
pediatric patients12-14). In our study, fever was the most common
presenting symptom. However, it should also be emphasized that
fever is a common symptom of many other childhood illnesses15),
and as many as 32% of children did not have high fever. Therefore,
fever is not always a reliable indicator of a brain abscess in children.
Seydoux et al16) observed focal neurologic deficits in 50% of
their patients; these deficits generally occurred days to weeks
after the onset of headache. They also reported that 25% of
patients developed seizures and that having a seizure was the first
manifestation of a brain abscess16). Lee et al24) reported that 38%
of their survivors had neurological sequlae. In our study, seizure
was present in 48% of cases and focal neurologic deficits in 28% of
cases. Neurological impairment was observed in 5 of 20 survivors
with available follow-up data. However, not all patients had follow-
up visits to our institution or long-term follow-ups of the same
duration, and some patients’ neurological conditions were not
described in detail. Therefore, it is possible that the actual rate of
neurological impairment in our study population could have been
higher than what was observed.
In non-pediatric patients, the most commonly underlying
diseases are diabetes mellitus and/or liver cirrhosis12). In pediatric
patients, congenital heart disease has been reported to be the
leading condition2). In our study, congenital heart disease was
also the leading condition. Among 11 babies less than 2 years old,
prematurity was the most common underlying condition (n=5) and
congenital heart disease was the second most common underlying
condition (n=3). Two patients were premature babies and also had
congenital heart disease and intra-cerebral hemorrhage.
Radiology tests (CT or MRI) are tests of choice for the diagnosis
and monitoring of brain abscesses14). In particular, MRI is more
sensitive for detecting early cerebritis and estimates the extent of
central necrosis more accurately than the other test modalities.
CT scanning is not as sensitive as MRI for the diagnosis of brain
abscesses, but is more easily performed in an emergency-room
setting14). Ultrasongraphy is also a possible neuroimaging modality
in infants who have an open fontanelle and sutures17). In addition,
ultrasonography is a readily accessible and portable neuroimaging
modality. Therefore, ultrasonography is very useful in pediatric
patients. In our study, all three types of radiologic tests were used
to diagnose brain abscesses. CT was the most commonly-used
imaging modality (68% of patients) followed by MRI (16%) and
ultrasonography (12%). Because most of patients were evaluated
in the emergency room or the patient’s condition was critical at the
time of work-up for brain abscesses, CT was more frequently used
than MRI in our study population.

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CG Lee, et al. • Brain abscesses in children
Published fatality rates for brain abscesses range from 0 to 30%
10, 16, 18-20, 24, 25). In this study, the overall fatality was 16%. Several
studies have failed to find an association between outcomes and
the factors studied such as age, focal neurologic deficits, seizures,
laboratory findings, causative organisms, characteristics of
abscesses, and treatment modalities1, 14, 21-23). In this study, there was
no statistical association between outcomes and the factors studied.
Brain abscesses result in significant morbidity and high fatality.
Because brain abscesses can have subtle initial presentations, a
high level of suspicion is very important for early diagnosis in
pediatric patients, particularly those with underlying conditions
such as congenital heart disease or prematurity with a complicated
postnatal course.
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