Introduction
Sinusitis is a common medical condition from which most patients can recover with
proper treatment. However, in rare cases, there are potentially lethal intracranial
complications, such as subdural empyema, meningitis, venous sinus thrombosis, intracerebral
and epidural abscesses, which develop as a result of the inflammation of frontal,
ethmoidal, sphenoidal, and maxillary sinuses.[1]
[2]
[3]
[4]
[5]
Subdural empyema is the most common complication, and it can be defined as an infection
with its purulent collection located between the inner surface of the dura mater and
the outer surface of the cerebral arachnoid. Moreover, it should be noted that it
is more frequent among male patients younger than 20 years of age.[2]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
The mortality rate can be significantly reduced with antibiotics, and it varies from
4 up to 15%, while morbidity in survivors can reach up to 50% for residual neurological
deficits, 15 to 35% for hemiparesis, and 12 to 37,5% for persistent seizures.[2]
[4]
[5]
[6]
[12]
It is widely known that subdural empyema is overlooked by physicians due to its low
incidence. However, despite its rarity, this pathology is a serious condition and
requires early diagnosis and therapeutic management, as sequelae are reported in up
to 40% of cases and onset is related to late treatment and the duration of the symptoms
prior to diagnosis.[11]
[13]
Still, delays in diagnosis occur due to the absence of specific signs. Therefore,
in cases with clinical suspicion, patients must be evaluated via computerized tomography
(CT) or magnetic resonance imaging (MRI) to rule out intracranial infection. Empyema
is considered a neurosurgical emergency due to the increase in intracranial pressure
in the first 24 to 48 hours, which may lead to coma and death. Thus, physicians must
be aware of its risks.[2]
[5]
[6]
In summary, this study aims to reaffirm sinusitis as the primary focus of subdural
empyema and the importance of its eradication for treatment.
Materials and Methods
A systematic literature review was conducted. Articles were selected from the PubMed,
SciELO, and BVS platforms, using the descriptors sinusitis, subdural empyema, and intracranial complication, followed by the Boolean operators “AND” and “OR” to combine keywords. All the references
from the eligible studies were also reviewed in search of additional articles.
The inclusion criteria were case reports and retrospective studies from the past 15
years (2008–2023), available in full, were included in this study. We excluded unrelated
articles, reviews, meta-analyses, and those without full text available. Following
the criteria application, 16 articles remained.
Results
Out of the 16 selected articles ([Fig. 1]), 5 are retrospective studies, and the other 11 are case reports, which reinforce
subdural empyema as a complication of sinusitis. Moreover, they highlight this condition
as a neurosurgical emergency and highlight symptoms that raise clinical suspicion
of related intracranial complications. Some studies also provide evidence for the
recommendation of otolaryngological procedures, since sinusitis is the main focus
and must be treated to eradicate the infection ([Table 1]).
Fig. 1 Study methodology.
Table 1
Summary of selected articles
|
Author (year)
|
Title
|
Type of study
|
Sample
|
Points relevant to each study
|
|
Aljonas and Watanabe (2018)[6]
|
Subdural empyema following rhinosinusitis condition – case report
|
Case report
|
It reports a case regarding a 17-year-old male patient, diagnosed with rhinosinusitis.
It evolved, however, to an SDE. The patient received antibiotic therapy treatment,
but his condition ultimately led to death.
|
Complications of rhinosinusitis may come from acute or chronic infections. Although
they occur more frequently in children, these infections may also impair adult patients.
Among those of nasosinusal origin, SDE, cerebral, and extradural abscesses, as well
as meningitis are mentioned as the most common. Treatment for empyemas is a neurosurgical
emergency (burr holes or craniotomy) due to how quickly it can lead to coma or death
as a consequence of the increase in intracranial pressure in the first 24 to 48 hours.
|
|
Sung et al. (2018)[1]
|
Bilateral subdural empyemas with meningitis secondary to acute barosinusitis
|
Case report
|
Healthy, immunocompetent 30-year-old man developed bilateral SDEs secondary to barosinusitis
succeeding a plane trip abroad.
|
Intracranial complications of acute rhinosinusitis are not common, but may lead to
extreme consequences, such as neurological morbidity or death.
|
|
Rasul et al. (2022)[12]
|
The Case for Early Antibiotic Commencement and Source Control in Pediatric Subdural
Empyema: A Single-Centre Retrospective Case Series
|
Retrospective cohort study
|
Every patient admitted to their unit with a diagnosis of SDE over an 11-year period.
A total of 36 patients received medical treatment throughout the inclusion period.
|
The contemporary series highlights some of the important changes regarding presentation
and management of SDE over time. First, bimodal age distribution is in accordance
with prior observations, with peaks in infancy, secondary to meningitis, and in older
children, secondary to sinusitis or otitis media.
|
|
Belentani et al. (2008)[7]
|
Subdural Empyema: Complication of Acute Rhinosinusitis
|
Case report
|
13-year-old male patient.
|
SDE as an intracranial complication due to sinus disease, despite being infrequent,
is still a reality. It is more common among male patients under 20-years-old, and
presents considerable morbidity and lethality. It must be faced as a matter of urgency.
|
|
Barroso et al. (2019)[2]
|
Recurrent subdural empyema secondary to bacterial frontal sinusitis in an immunocompetent
teenager: case report
|
Case report
|
16-year-old immunocompetent patient, with no associated comorbidities, who suffered
an aggressive evolution to SDE from acute sinusitis. Urgent clinical-surgical approach
was necessary.
|
Morbidity in SDE may reach 50% of the cases for residual neurological deficits, 15
to 35% for hemiparesis, and 12 to 37,5% for persistent seizures. In this case, the
clinical picture had a satisfactory evolution, with no sequelae.
|
|
Hicks et al. (2011)[14]
|
Identifying and managing intracranial complications of sinusitis in children: a retrospective
series
|
Retrospective cohort study
|
Every underage patient admitted to the Children's Hospital between January 1st, 2001, and December 31, 2009, with a diagnosis of sinusitis and intracranial suppuration
or CVST.
|
Findings suggest that acute sinusitis, in combination with severe intractable headache,
various degrees of altered level of consciousness, focal neurological deficits, and/or
meningeal irritation signs, should raise clinical suspicion for potential sinusitis
intracranial complications.
|
|
Pereira et al. (2018)[8]
|
Subdural empyema as a consequence of sinus diseases: considerations on 11 cases
|
Retrospective cohort study
|
11 cases of sinogenic SDE treated from January 1994 to August 1995 at the Department
of Neurosurgery and Infectology from João Alves Filho Hospital (Aracaju, SE, Brazil)
were studied.
|
It is worth noting the importance of conducting the specific procedure for the paranasal
sinuses simultaneously to the SDE treatment. This approach aims to eradicate the infection's
primary focus during the same surgical procedure, reducing the mortality rate.
|
|
Nicoli et al. (2016)[15]
|
Intracranial Suppurative Complications of Sinusitis
|
Retrospective cohort study
|
6 patients diagnosed with intracranial infection related to sinusitis;
4 patients with epidural abscess;
1 patient with both epidural abscess and SDE;
1 patient with SDE.
|
This study highlights the important clinical finding that patients with epidural abscess
or SDE related to sinusitis usually present signs of elevated intracranial pressure
instead of ordinary signs of sinusitis.
|
|
Gorman et al. (2018)[16]
|
Subdural empyema
|
Case report
|
69-year-old female patient on long-term immunosuppressive therapy for liver transplantation.
|
SDE is typically caused by prior neurosurgical procedure, sinusitis, otitis media,
mastoiditis or meningitis. Its imaging characteristics may look subtle compared with
its clinical severity. Thus, a high index of suspicion for diagnosis is required.
|
|
de Albuquerque Freitas et al. (2010)[9]
|
Intracranial complications of rhinosinusitis
|
Case report
|
15-year-old male patient, previously healthy, admitted to Risoleta Tolentino Neves
Hospital in Belo Horizonte, MG, Brazil.
|
IEA and SDE are rare but highly lethal intracranial complications of sinusitis. They
must be faced as a matter of urgency. In cases with clinical suspicion, CT is still
the first exam in diagnostic investigation.
|
|
Mathon & Korinek (2018)[13]
|
Subdural empyema: an underestimated neurosurgical emergency
|
Case report
|
The study describes the clinical cases of three patients, aged 17, 21, and a 16-years.
|
SDE is an absolute neurosurgical emergency. Any delay in diagnostic and/or therapeutic
management exposes the patient to a higher risk of death or neurological sequelae.
|
|
Szyfter et al. (2018)[3]
|
Simultaneous treatment of intracranial complications of paranasal sinusitis
|
Retrospective cohort
|
51 patients with intracranial complications of sinusitis, treated in the Department
of Otorhinolaryngology and Laryngeal Oncology at the Poznán University of Medical
Sciences from 1964 to 2016.
|
The most common intracranial complications of sinusitis develop as a result of inflammation
of the frontal sinuses, ethmoid cells, sphenoid sinus and, less frequently, the maxillary
sinuses.
|
|
Shen et al. (2018)[10]
|
Interhemispheric Subdural Empyema Secondary to Sinusitis in an Adolescent Girl
|
Case report
|
13-year-old female patient.
|
The most common cause of SDE is sinusitis, which represents 15% of hospitalized patients.
|
|
Varas et al. (2011)[11]
|
Subdural empyema secondary to sinusitis. A pediatric case report
|
Case report
|
9-year-old male patient.
|
For early diagnosis, it is important to search for any neurological complications
in sinusitis cases with a negative clinical course. In view of clinical suspicion,
imaging diagnosis is necessary to rule out complications.
|
|
Waseem et al. (2008)[4]
|
Subdural empyema complicating sinusitis
|
Case report
|
A case of sinusitis causing SDE in an immunocompetent, healthy teenage patient.
|
Despite improvements in antibiotic therapies, sinusitis still carries a risk of serious
and potentially fatal complications. Physicians must consider SDE or brain abscess
when evaluating a patient with severe headaches, especially if there is a recent history
of sinusitis or ear infection.
|
|
Bruner (2012)[5]
|
Subdural empyema presenting with seizure, confusion, and focal weakness
|
Case report
|
16-year-old male patient.
|
Emergency neurosurgical consultation is essential, because surgical intervention (burr
hole or craniotomy) is necessary in most cases to provide the best opportunity for
neurological recovery. Similarly, otorhinolaryngological consultations are recommended
because FESS can assist with drainage and recovery.
|
Abbreviations: CT, computed tomography, CVST, cerebral venous sinus thrombosis; FESS, functional
endoscopic sinus surgery; IEA, intracranial epidural abscess; SDE, subdural empyema.
Discussion
Sung et al.[1] and Belentani et al.[7] argued that intracranial complications in consequence of rhinosinusitis conditions
occur through direct extension due to a defect in the anterior cranial base, or hematogenously
through retrograde thrombophlebitis of veins which interlink face and skull sinuses.[1]
[7]
Aljonas and Watanabe[6] reported a clinical case regarding a 17-year-old male patient diagnosed with rinosinusitis
who underwent outpatient, antibiotic treatment. His symptoms regressed temporarily
but evolved again after discontinuing medication. Thus, the patient underwent outpatient
treatment again. Subsequently, the patient had changes to his clinical condition,
such as seizures and decreased levels of consciousness. An MRI scan was performed,
leading to clinical suspicion of subdural empyema. However, his condition ultimately
led to brain death.[6]
The authors note that the most common symptoms are headaches, altered mental status,
seizures, focal deficits, vomit, orbital swelling, fever, rhinorrhea, nasal obstruction,
neck stiffness, and Kerning's sign. Moreover, they insist on the need for imaging
exams in any case of sinusitis with neurological signs, failure from a previous treatment,
or associated orbital cellulitis, to ensure rapid diagnosis and avoid outcomes such
as the reported one.[6]
Barroso et al.[2] state that imaging exams are mandatory for patients diagnosed with frontal sinusitis
who persistently demonstrate fever, frontal edema, or failure to resolve symptoms,
even if their condition lacks neurological signs.[2]
Belentani et al.[7] and Pereira et al.[8] emphasize that subdural empyema diagnosis is based on clinical suspicion. Therefore,
physicians must be vigilant in cases that show a symptom evolution with fever, headaches,
or neurological manifestations. Lastly, these authors highlight the importance of
specific procedures for paranasal sinuses, along with the endoscopic submucosal dissection
(ESD), to eradicate the primary focus infection during the same surgical procedure.
This also brings the advantage of reducing mortality rates. Similarly, antibiotic
treatment associated with otorhinolaryngological, and neurological surgical approaches
result in good prognosis.[8]
Rasul et al.[12] conducted a retrospective study regarding 36 patients and demonstrated an increase
in the occurrence of sinusitis and related intracranial complications. The cause of
this increase, however, remained unclear. Furthermore, in their study, none of the
patients who underwent simultaneous otorhinolaryngological procedures needed repeated
surgery, emphasizing the importance of controlling the primary focus infection.[12]
According to Hicks et al.,[14] laboratory data such as leukocytosis, polymerase chain reaction (PCR), and elevated
sedimentation levels in a sinusitis scenario can be used to raise suspicion of possible
intracranial complications. Even though those are nonspecific markers of infection
and inflammation, a comparison among 12 patients suggests that individuals diagnosed
with uncomplicated sinusitis have lower PCR and sedimentation levels than those with
intracranial abscesses. However, the small sample size is one of the study's limitations.[14]
Pereira et al.[8] concluded that sinusitis, when it is not adequately treated, may lead to intracranial
complications such as subdural empyema. They also observed that headaches and fever
are often found prior to more specific symptoms, such as neck stiffness, dizziness,
vomit, seizures, altered consciousness, and focal neurological signs.
Mathon and Korinek[13] emphasize the delay in therapy as the main factor for bad subdural empyema prognosis.
They also bring attention to the importance of entry point surgical treatment, especially
when draining sinusitis, to increase bacterial isolation and improve the effectiveness
of antibiotic therapy.[13]
According to Szyfter et al.,[3] neurological signs associated with intracranial complications have been less frequent
in recent years, when compared with the usual symptoms of paranasal sinusitis. They
further emphasize that simultaneous treatment of inflammation along with intracranial
complications is quite effective.[3]
Similarly, Herrero et al.[11] describe that the therapeutic approach includes not only surgical intervention of
empyema but also drainage of the original focus.[11]
Building on other studies, Waseem et al.[4] suggest that subdural empyema is one of the most common complications of sinusitis
and that the similarity of its symptoms with those of sinusitis can make it difficult
to differentiate. The authors also noted that acute or progressive headaches are the
most important indicator of intracranial complications. They further report that,
despite antibiotic treatment, infections can still progress rapidly and might require
surgical drainage, which is the most important factor in determining a favorable outcome.[4]
Contrary to other studies, Nicoli et al.[15] say that patients with intracranial complications related to sinusitis often present
signs of elevated intracranial pressure rather than usual sinusitis signs. Moreover,
in accordance with other studies, they advise drainage of both the source of infection
and the intracranial suppuration, in combination with antibiotic therapy, to limit
morbidity, mortality, and recurrence. In addition, these authors emphasize the need
for multidisciplinary management by neurosurgeons and otorhinolaryngologists.[15]
According to Bruner et al.,[5] complications historically occurred secondary to middle ear infection, but currently
are more frequent as a consequence of bacterial sinusitis. The authors also highlight
that otolaryngological and emergency neurosurgical consultations are essential, since
a functional endoscopic sinus surgery (FESS) can assist in drainage and recovery.[5]
In summary, sinusitis is the most common cause of subdural empyema, and the aforementioned
articles reinforce the need to raise suspicion for intracranial complications whenever
there is a poor clinical course, to obtain better therapeutic response and to reduce
the risk of morbidity and mortality.
Additionally, sinus disease ought not to be underestimated, and physicians should
pay attention to clinical signs suggestive of intracranial infections, as subdural
empyema is a neurosurgical emergency that requires rapid recognition for appropriate
intervention. With the analyzed data, it becomes evident there is a great diversity
of symptoms, so imaging tests should be performed in cases with headaches, fever,
or if the treatment fails, even if they show no neurological signs.
Furthermore, it has been observed that antibiotic therapy shows better results and
prognosis when associated with otorhinolaryngological and neurological surgical approach,
since these contribute to the eradication of the primary focus. For this reason, Rasul
et al.[12] reported no repeated surgeries among their 36 patients, all of whom underwent these
simultaneous procedures. Therefore, we emphasize the importance of further research
addressing this topic and thoroughly examining the relationship between both interventions.
This work presents some limitations, as it did not address empyema treatment, except
for surgical intervention simultaneous to otorhinolaryngological treatment to eradicate
the primary focus. Furthermore, there were few studies on the relationship between
both interventions. Finally, most of the included studies are case reports, so the
final sample size is considerably small. There is a scarcity of studies measuring
the neglect from both doctors and patients regarding sinusitis.
Despite this limitation, the present study reinforced sinusitis as the primary focus
of empyema to raise awareness regarding this matter and highlighted the main symptoms
that lead to early diagnosis. Finally, we discussed otorhinolaryngological treatments
aimed at eradicating sinusitis being managed simultaneously to surgical intervention.
Conclusion
In light of this discussion, we can conclude that sinusitis is indeed one of the primaries
focuses of subdural empyema. However, its treatment is still neglected. Despite being
infrequent, subdural empyema resulting from sinusitis complications is a neurosurgical
emergency with significant morbidity and mortality rates. This should be enough to
encourage careful monitoring of patients diagnosed with sinusitis.
Additionally, we discussed how otorhinolaryngological procedures can eradicate the
primary focus, and neurosurgical interventions may be conducted to resolve subdural
empyema. However, there is limited data regarding these approaches, preventing a comprehensive
and widespread understanding of the subject. Thus, a larger sample of patients would
provide more precise information on how to prevent and treat this condition.
Furthermore, the importance of new studies providing a clear analysis of these issues
cannot be denied.
