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Page 6 of 8 Kafle et al. Neuroimmunol Neuroinflammation 2018;5:24 I http://dx.doi.org/10.20517/2347-8659.2018.10

initiation of antibiotics. However, surgery is imperative for the identification of the causative pathogen
and for the purpose of reducing the size of the abscess. With the use of modern stereotactic neurosurgical
techniques, almost any brain abscess that measures at least 1 cm in diameter is amenable to stereotactic
aspiration, regardless of location. Stereotactic navigation systems can be used for abscess drainage . Non-
[8]
operative management of small abscess with broad spectrum antibiotics is also common. In the present study
we managed the cases with burr hole and abscess aspiration. Abscess wall excision was done in cases which
required additional procedures, like evacuation of subdural or epidural pathology. It was also indicated that
following multiple aspirations fail to result in abscess resolution.

Another important aspect of care is managing the primary source. A number of studies have shown good
results with concurrent abscess drainage and mastoidectomy in the same setting without added morbidity
in cases with CSOM. They have shown low recurrence rate, though not statistically significant . Other
[9]
procedures being carried out include transmastoid approaches for abscess .
[10]
Brain abscess is seen in 5%-18% cyanotic congenital heart diseases and these individuals are 10 times
more prone to develop brain abscess then those without cyanotic heart disease. Tetralogy of Fallot is the
most common cardiac condition associated with brain abscess. Right-to-left shunt, hypoxia, acidosis, and
increased viscosity decrease the perfusion in the brain resulting in micro infarcts, which provide the milieu
for organisms to form abscesses. The 2 mortalities in this study were associated with cardiogenic brain
abscesses.

Important criteria for evaluating treatment are the neurologic condition of the patient and abscess size
on imaging. Cranial imaging should be performed immediately if there is clinical deterioration; after 1 to
2 weeks if there is no improvement; and on a biweekly basis for up to 3 months until clinical recovery is
evident . Culture positivity is low in cases of brain abscess. In the present study, organism growth is seen
[11]
only in 19.6% cases. In a study done in India, only 20% culture growth was noted whereas in China only 13%
showed organism growth . Lack of anaerobic culture and use of antibiotics before samples are drawn may
[12]
be the reasons behind the higher number of negative culture reports. However, metagenomics analysis and
nucleotide sequence analysis are being used in some centers to identify the responsible organism and they
have been able to identify bacteria that have never been incriminated as a cause for brain abscess .
[13]
Tract hematoma, abscess cavity hematoma, extension of abscess into the ventricles, surgical site infection,
meningitis, sinus thrombosis and mortality are known complications of brain abscess management. Apart
from this, drug-related complications including minor rashes (potentially due to phenytoin use) are common
side effects. We commonly use anti-epileptics at least for 1 month and continue if seizure is present. Cerebral
hemisphere was the most common site (84.32%) of abscess in the present study, which was similar to the
previous study done by Sharma in the same institute. One patient developed hematoma adjacent to the
[14]
aspiration site, which can be explained either by direct injury to the vessel during aspiration or reactive
hemorrhage due to rapid decompression of the abscess. In the pre-CT era, mortality rate was about 40%-60%.
This has decreased to 6%-17% currently [15,16] . Preoperative GCS remains the best prognostic factor .
[16]

There were two deaths during this study (3.92%). The first mortality was a case of cyanotic congenital heart
disease with brain abscess that died due to cardiac causes during hospital stay. The second mortality was also
a child with large abscess with intraventricular rupture. Patients with intraventricular extension of abscess
carry higher mortality rates of up to 48%, even in this modern era .
[17]
In conclusion, with the advent of modern technology in radio imaging, mortality rates of brain abscess have
improved over the decades as compared in the past. Outcomes may be dismal if not treated early which is
particularly challenging given non-specific presentation of many patients with brain abscess. Thus, a high