Vol.2, No.5, 294-297 (2013) Case Reports in Clinical Medicine
http://dx.doi.org/10.4236/crcm.2013.25079
Nonsurgical treatment of infratentorial subdural
empyema: A case report
Y. Sogoba1*, D. Kanikomo1, O. Coulibaly1, K. Singaré2, Y. Maiga3, D. Samaké2, S. K. Timbo2
1Department of Neurosurgery, Gabriel TOURE Hospital, Bamako, Mali; *Corresponding Author: [e-mail]
2Department of Ear, Nose and Throat, Gabriel TOURE Hospital, Bamako, Mali
3Department of Neurology, Gabriel TOURE Hospital, Bamako, Mali
Received 26 June 2013; revised 10 July 2013; accepted 19 July 2013
Copyright © 2013 Y. Sogoba et al. This is an open access article distributed under the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Infratentorial subdural empyemas are rare. It is
an import ant neurological infection r e quiring im-
mediate neurosurgical treatment. The nonsur-
gical treatment of subdural empyema has been
reported sporadically. In this paper the authors
report the nonsurgical treatment of a case of in-
fratentorial subdural empyema. The patient with
left recurrent otitis was hospitalized with symp-
toms of headache and fev er of 3 weeks duration.
Examination revealed that the patient had Glas-
gow Coma Scale score of 15, fever, mild cere-
bellar signs, no focal deficit, and abundant sup-
puration from the left ear. A contrast-enhanced
CT scan showed an infratentorial supracerebel-
lar hypodense fluid collection with the periph-
eral rim enhancement to the left of the midline
that mimicked a subdural empyema. Routine he-
matological investigation revealed polymorphic
leukocytosis and elevated erythrocyte sedimen-
tation rate. After the left mastoidectomy and an-
tibiotic treatment, the patient recovered with com-
plete resolution of the subdural empyema on CT
scan.
Keywords: Subdural Empyema; Otitis;
Infratentorial Lesion; Antibiotic Therapy
1. INTRODUCTION
Subdural empyema is defined as a collection of pus in
the preformed space between the cranial dura mater and
arachnoid mater [1]. It is a serious intracranial infection,
and in most cases prompt evacuation of the pus collec-
tion is required. Infratentorial subdural empyemas (IS-
DEs) are rare, constituting only 0.6% of all cases of in-
tracranial suppurative disorders [2]. In this paper, the
authors report a case of ISDE successfully treated with
antibiotic therapy only after the left mastoidectomy had
been performed.
2. CASE REPORT
This 24-year-old woman had been treated for left re-
current chronic otitis for years. She was hospitalized in
the Ear, Nose, and Throat Department (ENT) of Gabriel
TOURE Hospital with symptoms of headache and fever
of 3 weeks duration. Examination revealed that the pa-
tient had a Glasgow Coma Scale (GCS) score of 15, fe-
ver, mild cerebellar signs, no focal deficit, and abundant
suppuration from the left ear. A contrast-enhanced CT
scan (Figure 1) showed an infratentorial supracerebellar
hypodense fluid collection with peripheral rim enhance-
ment to the left of the midline that mimicked a subdural
empyema. Routine hematological investigation revealed
polymorphic leukocytosis and elevated erythrocyte sedi-
mentation rate. A left mastoidectomy was performed and
culture of pus was sterile and the patient was then trans-
ferred to the department of Neurosurgery. As the lesion
was thought small enough to be amenable to medical
(a) (b)
Figure 1. Coronal (a) and sagittal (b) contrast-enhanced CT
scans showing the infratentorial subdural empyema.

Y. Sogoba et al. / Case Reports in Clinica l Me dicine 2 (2013) 294-297 295
therapy, the patient was started on a 4-week course of
empirical intravenous antibiotics including third genera-
tion of cephalosporin, metronidazole and ciprofloxacin.
By the end of this course he r neurological symptoms h ad
recurred. The second CT scan (Figure 2) showed a par-
tial resolution of the empyema and the hematological
investigation became normal. The patient was then con-
tinued on a 6-week course of oral antibiotics followed by
an uneventful recovery and the third CT scan (Figure 3)
showed a complete resolution of the empyema. The pa-
tient was discharged home asymptomati c .
(a) (b)
(c)
Figure 2. Coronal (a), sagittal (b) and axial (c) contrast-en-
hanced CT scans showing the partial resolution of the infraten-
torial subdural empyema after 4-week course of intravenous
antibiotics treatment.
(a) (b)
Figure 3. Axial CT scans (a) and (b) showing the complete re-
solution of infratentorial subdural empyema after 10 weeks of
antibiotics treatment.
3. DISCUSSION
Subdural empyema is defined as a collection of pus in
the preformed space between the cranial dura mater and
arachnoid mater [1]. It is rare in the developed world due
to early and judicious use o f antibiotics. It remains; how-
ever, a relatively common disease entity in developing
countries [3-6]. Subdural empyema represents approxi-
mately 20% of all intracranial suppurations [7]. Although
pus may localize anywhere in the subdural space follow-
ing ear infection or paranasal sinusitis, there is a paucity
of literature regarding the infratentorial localization of
pus. Morgan and Williams [8] reported a series of seven
cases of posterior fossa subdural empyema that occurred
during a 30-year p eriod, and Borovich and associates [9]
identified three cases of infratentorial subdural e mpyema
over 10 years. The tendency for a greater incidence of in-
fratentorial empyema among male patients was observed
by several authors [2,6,8,9]. The reason for this prepon-
derance among male patients is not known. That ten-
dency was not noted in our case. Clinical manifestations
are due to increases in intracranial pressure, focal distur-
bances of brain function, and constitutional symptoms
due to infection [1,6]. Th e illness is usu ally characterized
by fever, headache, vomiting, and meningism [2,8,9]. As
noted by Borovich and associates [9], in cases of ISDE,
the patient’s clinical condition may deteriorate rapidly,
and the duration of symptoms is usually shorter than in
cases of supratentorial empyema. Our patient was in
good neurological condition with GCS score of 15. In the
vast majority of patients with ISDE, the lesion develops
as a result of chronic suppurative otitis media. Therefore
the history of otorrhea should prompt further investiga-
tion even when the patient presents with nonspecific
symptoms. All three patients in the series reported by
Borovich and associates [9] and 71.4% in the series re-
ported by Morgan and Williams [8] had ISDE secondary
to chronic otogenic sepsis. Our patient had left recurrent
chronic otitis for years leading to ISDE. Extension of
infection from the ear into the infratentorial compartment
may be direct or indirect. Direct extension of infection
by erosion of the bone typically causes epidural abscess-
es and bone infections, whereas indirect extension via
progressive thrombophlebitis of the perforating blood
vessels from the middle ear mucosa would typically lead
to subdural empyemas and cerebellar abscesses. Apart
from the otic source, other sources are well described in
the literature [7,10-13], these include trauma and para-
nasal sinusitis. CT scan may be the most cost-effective
imaging modality in subdural empyema because of its
accessibility and sensitivity [3,14]. Magnetic resonance
imaging, if availab le in the acute setting, may be the im-
aging modality of choice as it provides a better anatomi-
cal delineation of any collections present than does CT

Y. Sogoba et al. / Case Reports in Clinica l Me dicine 2 (2013) 294-297
296
scanning, and it can adequately display areas of localized
meningeal infection [14,15].
Historically, the most significant determinants of out-
come in patients with subdural empyema have been ag-
gressive early removal of the source of infection, drain-
age of the pus and treatment of the infection with the
appropriate antibiotic medications [7,16-19].
The purpose of neurosurgical treatment is to decrease
the toxic and inflammatory influences on the brain and
its blood supply and to diminish the mass effect of the
subdural pus and ob tain pus for isolation of the causative
organism and identification of its antibiotic sensitivity.
Surgical treatment can involve drainage via either burr
holes or craniotomy [20]. The choice of procedure has
been the subject of much debate. The advantages of as-
piration via burr holes are that it is simple, and it h as less
potential morbidity than surgical trauma. On the other
hand, several reports have advocated craniotomy as the
procedure of choice because it is often followed by a
lower incidence of recurr ence and shorter hospitalization
[16,19]. Nonsurgical treatment is contrary to the accept-
ed rule that a subdural empyema should be operated as
soon as the diagnosis is made. Two main factors prom-
pted us to withhold neurosurgical treatment from this
patient. First, he was in good neurosurgical condition
with a GCS score of 15 and limited collection of pus on
CT scans. Second, our patient’s rapid clinical and radio-
logical improve ment prov id ed a strong argument for con-
tinuing medical treatment. The patient must be followed
up closely clinically and radiologically when a subdural
empyema is managed medically. The nonsurgical treat-
ment of subdural empyema has been reported sporadi-
cally [21,22]. Early mastoidectomy will prevent recur-
rence of the empyema and development of other em-
pyemas [13]. Therefore consultation with otorhinolaryn-
gological colleagues is recommended as soon as possible
in the course of the disease.
4. CONCLUSION
Although surgery with antibiotic therapy constitutes
the mainstay of treatment of infratentorial subdural em-
pyema, the nonsurgical treatment may be considered in
patients in good neurosurgical condition with a GCS
score of 15 and limited collection of pus on CT scans.
Immediate neurosurgical treatment is still indicated in
those with impaired consciousness, major focal deficits,
or marked mass effect on CT scans.
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