Brain Abscess, Subdural Empyema, and Intracranial Epidural Abscess

Methicillin-resistant Staphylococcus aureus intracranial abscess: An analytical series and review on molecular, surgical and medical aspects

Purpose

Intracranial abscess caused by methicillin-resistant Staphylococcus aureus (MRSA) is rare and unexplored. The aim of the present study is to examine the prevalence, clinical and molecular characteristics, treatment options and outcome of MRSA intracranial abscess over a period of 6 years.

Patientsand Methods

A total of 21 patients were included in this retrospective study. The demographic and clinical details of all the patients were collected. Molecular typing including staphylococcal cassette chromosome mec typing, spa typing and polymerase chain reaction of Panton-Valentine leucocidin toxin (PVL) gene for the latter 6 isolates was performed.

Results

The paediatric population was the most affected group (33.3%). The primary route of infection was post-operative/trauma in 7 (33.3%) cases. All the patients were treated surgically either by aspiration or excision. Fifteen (71%) patients received anti-MRSA treatment with vancomycin or linezolid, where linezolid-treated patients showed better prognosis. Of the 11 patients who were on follow-up, unfavourable outcome was observed in 3 (27.3%) cases and 8 (72.7%) cases improved. The molecular typing of six isolates revealed four community-associated (CA) MRSA, one each of livestock-associated (LA) and healthcare-associated MRSA with PVL gene noted in all.

Conclusion

We propose that timely diagnosis, surgical intervention and appropriate anti-MRSA treatment would contribute to better outcome. The occurrence of CA-MRSA and LA-MRSA infection in the central nervous system signifies the threat from the community and livestock reservoir, thus drawing attention towards surveillance and tracking to understand the epidemiology and implement infection control measures.

Pediatric infratentorial subdural empyema: A case report

BACKGROUND

Infratentorial subdural empyemas in children are extremely rare and potentially lethal intracranial infections. Delay in diagnosis and therapy is associated with increased morbidity and mortality.

CASE DESCRIPTION

A 4-year-old boy presented with cerebellar signs following a failed treatment of otitis media. Imaging studies revealed a subdural empyema and left transverse and sigmoid sinus thrombosis. The empyema was evacuated operatively and antibiotic treatment was initiated and administered for 6 weeks. The patient recovered fully and was discharged 4 weeks following the evacuation of the empyema.

CONCLUSION

While prompt identification and treatment of subdural infratentorial empyemas are crucial for favorable outcomes, their diagnosis in children might be initially missed. This is, in part because they are so rare and in part, because imaging artifacts arising from the complex posterior fossa anatomy may obscure their presence in the computer tomography (CT) scan. Therefore, high level of suspicion is necessary, given the appropriate history and clinical presentation. In children, this is a recent history of protracted otitis media and central nervous system symptomatology-cerebellar or other.

Intracranial abscess due to Mycobacterium avium complex in an immunocompetent host: a case report

Background

Mycobacterium avium complex (MAC) is a ubiquitous pathogen, widely distributed in the environment including water, soil and animals. It is an uncommonly encountered clinical pathogen; primarily causing pulmonary infections in patients with underlying lung disease or disseminated disease in immunocompromised hosts. Sporadically, extra-pulmonary infections have been documented including involvement of the liver, spleen, skin, soft tissue and lymph nodes. Central nervous system (CNS) infections due to MAC are exceedingly rare and carry a poor prognosis. Additionally, such infections are largely reported in patients infected with HIV. Herein we report the first case of intracranial abscess due to MAC in an immunocompetent man with a normal CD4 count and negative HIV status.

Case presentation

A previously healthy 40-year-old male presented to us with progressively worsening CNS symptoms. The patient’s presentation was uncharacteristic of MAC infection in immunocompetent hosts, as he developed subacute, progressive symptoms that included severe frontal headaches, left eyelid swelling, blurry vision, and diplopia, without any pulmonary or systemic manifestations. Neuroimaging revealed multiple ring-enhancing lesions, which required neurosurgical intervention. MAC was the only pathogen that grew from intraoperative tissue cultures. The patient was subsequently treated with a 12-month regimen consisting of Clarithromycin, Ethambutol, and Rifampin, with successful clinical resolution.

Conclusion

Our findings indicate that it is important to consider rare infections such as MAC in immunocompetent patients, regardless of atypical symptoms. Despite the severity of this infection, with timely diagnosis effective treatment is available.

Intracranial epidural abscess of odontogenic origin

Dental infection as a cause of epidural abscess is rare compared with other forms of intracranial suppurations. A 10-year-old boy was seen because of headaches and fever. There was no history of otitis media or sinusitis, but he had sought care for dental complaints. The patient was from an upper-middle-class family, was not immunocompromised, and had no other risk factor for a major infection. A CT brain scan confirmed a frontal epidural abscess. The patient underwent emergency surgery for evacuation of the epidural abscess, followed by antimicrobial therapy. His condition improved remarkably following surgery, with complete resolution of symptoms. He subsequently underwent extraction of 2 teeth following dental review. Dental infection as a cause of intracranial epidural abscess is rare, but should be considered when evaluating patients for intracranial infections. A review of the literature sheds light on the causal relationship and possible pathogenesis of this condition.

Use of permeability surface area-product to differentiate intracranial tumours from abscess

Background and Purpose

Clinical and radiological findings of intracranial abscesses may mimic the findings of brain tumours and vice versa. However, the discrimination is of great clinical importance in planning treatment and in following prognosis and response to therapy. This study evaluates the Computed Tomography (CT) perfusion parameters, especially the permeability index, with the aim of evaluating the usefulness of dynamic CT perfusion imaging as an alternative tool to differentiate necrotic brain tumours and intracerebral abscesses.

Materials and Methods

A total of 21 patients underwent perfusion CT study and were divided into 2 groups: Group 1, patients with necrotic brain tumours (n=13); and Group 2, patients with cerebral abscesses (n=8). The mean perfusion parameters were obtained from the enhancing part of the lesion. The relative ratios were then calculated by using the results from mirrored regions within the contralateral hemisphere as reference.

Results

The results of this study showed that there was significant difference in the relative permeability surface values between necrotic brain tumours and cerebral abscesses (p=0.005). By applying the ROC curve, a value of 25.1 for rPS was found to be the best estimate to distinguish necrotic brain tumours from cerebral abscesses with a specificity of 88 % and sensitivity of 70 %.

Conclusion

CT perfusion, especially permeability surface, may allow for better differentiation of cerebral abscesses from brain tumours, making it a strong additional imaging modality in the early diagnosis of these two entities.