Open craniotomy for brain abscess: A forgotten experience?

Polymicrobial brain abscesses: A complex condition with diagnostic and therapeutic challenges

Brain abscesses (BA) are focal parenchymal infections that remain life-threatening conditions. Polymicrobial BAs (PBAs) are complex coinfections of bacteria or bacterial and nonbacterial pathogens such as fungi or parasites, with diagnostic and therapeutic challenges. In this article, we comprehensively review the prevalence, pathogenesis, clinical manifestations, and microbiological, histopathological, and radiological features of PBAs, as well as treatment and prognosis. While PBAs and monomicrobial BAs have some similarities such as nonspecific clinical presentations, PBAs are more complex in their pathogenesis, pathological, and imaging presentations. The diagnostic challenges of PBAs include nonspecific imaging features at early stages and difficulties in identification of some pathogens by routine techniques without the use of molecular analysis. Imaging of late-stage PBAs demonstrates increased heterogeneity within lesions, which corresponds to variable histopathological features depending on the dominant pathogen-induced changes in different areas. This heterogeneity is particularly marked in cases of coinfections with nonbacterial pathogens such as Toxoplasma gondii. Therapeutic challenges in the management of PBAs include initial medical therapy for possibly underrecognized coinfections prior to identification of multiple pathogens and subsequent broad-spectrum antimicrobial therapy to eradicate identified pathogens. PBAs deserve more awareness to facilitate prompt and appropriate treatment.

European society of Clinical Microbiology and Infectious Diseases guidelines on diagnosis and treatment of brain abscess in children and adults

SCOPE

These European Society of Clinical Microbiology and Infectious Diseases guidelines are intended for clinicians involved in diagnosis and treatment of brain abscess in children and adults.

METHODS

Key questions were developed, and a systematic review was carried out of all studies published since 1 January 1996, using the search terms 'brain abscess' OR 'cerebral abscess' as Mesh terms or text in electronic databases of PubMed, Embase, and the Cochrane registry. The search was updated on 29 September 2022. Exclusion criteria were a sample size <10 patients or publication in non-English language. Extracted data was summarized as narrative reviews and tables. Meta-analysis was carried out using a random effects model and heterogeneity was examined by I2 tests as well as funnel and Galbraith plots. Risk of bias was assessed using Risk Of Bias in Non-randomised Studies - of Interventions (ROBINS-I) (observational studies) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) (diagnostic studies). The Grading of Recommendations Assessment, Development and Evaluation approach was applied to classify strength of recommendations (strong or conditional) and quality of evidence (high, moderate, low, or very low).

QUESTIONS ADDRESSED BY THE GUIDELINES AND RECOMMENDATIONS

Magnetic resonance imaging is recommended for diagnosis of brain abscess (strong and high). Antimicrobials may be withheld until aspiration or excision of brain abscess in patients without severe disease if neurosurgery can be carried out within reasonable time, preferably within 24 hours (conditional and low). Molecular-based diagnostics are recommended, if available, in patients with negative cultures (conditional and moderate). Aspiration or excision of brain abscess is recommended whenever feasible, except for cases with toxoplasmosis (strong and low). Recommended empirical antimicrobial treatment for community-acquired brain abscess in immuno-competent individuals is a 3rd-generation cephalosporin and metronidazole (strong and moderate) with the addition of trimethoprim-sulfamethoxazole and voriconazole in patients with severe immuno-compromise (conditional and low). Recommended empirical treatment of post-neurosurgical brain abscess is a carbapenem combined with vancomycin or linezolid (conditional and low). The recommended duration of antimicrobial treatment is 6-8 weeks (conditional and low). No recommendation is offered for early transition to oral antimicrobials because of a lack of data, and oral consolidation treatment after ≥6 weeks of intravenous antimicrobials is not routinely recommended (conditional and very low). Adjunctive glucocorticoid treatment is recommended for treatment of severe symptoms because of perifocal oedema or impending herniation (strong and low). Primary prophylaxis with antiepileptics is not recommended (conditional and very low). Research needs are addressed.

A Canadian National Survey of the Neurosurgical Management of Intracranial Abscesses

OBJECTIVE

Intracerebral abscess is a life-threatening condition for which there are no current, widely accepted neurosurgical management guidelines. The purpose of this study was to investigate Canadian practice patterns for the medical and surgical management of primary, recurrent, and multiple intracerebral abscesses.

METHODS

A self-administered, cross-sectional, electronic survey was distributed to active staff and resident members of the Canadian Neurosurgical Society and Canadian Neurosurgery Research Collaborative. Responses between subgroups were analyzed using the Chi-square test.

RESULTS

In total, 101 respondents (57.7%) completed the survey. The majority (60.0%) were staff neurosurgeons working in an academic, adult care setting (80%). We identified a consensus that abscesses >2.5 cm in diameter should be considered for surgical intervention. The majority of respondents were in favor of excising an intracerebral abscess over performing aspiration if located superficially in non-eloquent cortex (60.4%), located in the posterior fossa (65.4%), or causing mass effect leading to herniation (75.3%). The majority of respondents were in favor of reoperation for recurrent abscesses if measuring greater than 2.5 cm, associated with progressive neurological deterioration, the index operation was an aspiration and did not include resection of the abscess capsule, and if the recurrence occurred despite prior surgery combined with maximal antibiotic therapy. There was no consensus on the use of topical intraoperative antibiotics.

CONCLUSION

This survey demonstrated heterogeneity in the medical and surgical management of primary, recurrent, and multiple brain abscesses among Canadian neurosurgery attending staff and residents.

Retrospective Review of the Clinical Outcomes of Surgically Managed Patients with Intracranial Abscesses: A Single-Center Review

OBJECTIVE

This study analyzed patient, radiologic, and clinical factors associated with operative brain abscesses and patients' functional outcomes.

METHODS

A retrospective analysis was conducted of neurosurgical cases of brain abscesses from 2009 to 2019 at a Canadian center. Functional outcome was recorded as Modified Rankin Scale score and Extended Glasgow Outcome Scale score. Multivariate analysis was conducted to identify relevant prognostic factors.

RESULTS

We identified 139 patients managed surgically for brain abscesses. Resection alone was performed in 64% of patients, whereas 26.6% underwent aspiration alone. Most were adults (93.2%) and male (68.3%). Immunocompromise risk factors included diabetes (24.5%), cancer (23.7%), and immunosuppressive therapy (11.5%). Likely sources were postoperative (17.3%), systemic spread (16.5%), and poor dentition (12.9%). Microorganisms cultured from abscess samples were mixed growth (28%), Streptococcus anginosus (24.5%), and Staphylococcus aureus (7.9%). Disposition was home (42.4%) or repatriation to a home hospital (50.4%). By Extended Glasgow Outcome Scale, 25.2% had an unfavorable outcome including a mortality of 11.5%. Factors on multivariate analysis associated with poor outcome included diabetes (odds ratio, 2.8; 95% confidence interval [CI], 1.2-5.0) and ventricular rupture (odds ratio, 5.0; 95% CI, 1.7-13.5; hazard ratio, 12; 95% CI, 3.9-37.0). Supratentorial superficial eloquently located abscess was also associated with poor outcome (hazard ratio, 5.5; 95% CI, 1.8-16.7). Outcomes were similar with surgical excision and aspiration.

CONCLUSIONS

Ventricular rupture and diabetes are significant risk factors for poor outcomes in intraparenchymal brain abscesses. No clear difference in outcomes was found between surgical excision or aspiration in our retrospective cohort.

Aspiration Surgery with Appropriate Antibiotic Treatment Yields Favorable Outcomes for Bacterial Brain Abscess

BACKGROUND

Even in the era of advanced medical treatment, brain abscess still has a high mortality rate. At our institution, brain abscess has been treated mainly using stereotactic or echo-guided aspiration followed by relatively long-term antibiotic treatment, achieving favorable outcomes. To evaluate the efficacy of our strategy involving less-invasive aspiration surgery and long-term selective antibiotic administration for brain abscess, a single-institution series of cases was investigated.

METHODS

We retrospectively reviewed and analyzed the medical records of 25 cases of brain abscess treated at Saitama Medical University Hospital between 2008 and 2021. The patients comprised 16 men and 9 women aged between 39 and 85 years (median 62 years). Neurosurgical intervention was performed for 23 (92.0%) of the patients and the remaining 2 received antibiotics alone.

RESULTS

Among the neurosurgery patients, 22 (95.7%) underwent echo-guided or stereotactic aspiration, and only 1 underwent craniotomy. Anaerobic bacteria were detected in 11 patients. In the surgical and conservative groups, the median duration of antibiotic treatment was 16 weeks and 23 weeks, respectively. Since 2014 when metronidazole first became available, it has replaced meropenem to cover anaerobic bacteria. The overall mortality rate was 4.0% and a favorable outcome (Glasgow Outcome Scale 4 or 5) was achieved in 76% of the patients. There was no surgical mortality or morbidity.

CONCLUSIONS

Most patients underwent aspiration surgery and achieved favorable outcomes. Along with antibiotic treatment for a sufficiently long period to cover anaerobes, this approach can be expected to yield good results.

Diagnosis and Neurosurgical Management of Cerebral Nocardiosis

Primary Nocardia infections are uncommon gram-positive bacterial infections caused by aerobic actinomycetes and are typically regarded as opportunistic infections (only one-third of infected patients are immunocompetent). Risk factors include: glucocorticoid therapy, malignancy, organ transplant recipients, human immunodeficiency virus infections, tumor necrosis factor-α inhibitor therapy, diabetes mellitus, alcoholism, inflammatory bowel disease, chronic obstructive pulmonary disease, chronic granulomatous disease, and tuberculosis. The organism has a predisposition to disseminate to the central nervous system and can relapse or progress despite appropriate therapy. Treatment ranges from oral antibiotic management to multiple intravenous antibiotic therapy, with surgical intervention required for severe cases. The surgical options include aspiration or complete excision of abscess contents and capsule. In the present case, we describe the use of bilateral craniotomy with assisted image guidance and multiple abscess excision in an immunocompetent patient with systemic nocardiosis.

Treatment of Nocardial Brain Abscess in a Patient With Systemic Lupus Erythematosus and Idiopathic Thrombocytopenic Purpura: Case Report and a Review of the Literature

Brain abscesses due to Nocardia species account for 1-2% of all cerebral abscesses, often in immunosuppressed individuals, with a mortality three times higher than other cerebral abscesses. Early diagnosis and management are vital for good outcomes. We report a case of a right frontal Nocardia brain abscess in an immunosuppressed 38-year-old female. She presented with headaches, confusion, memory deficits, and personality change. She remained systemically well, with normal inflammatory markers. She underwent two open surgical drainages, with excision of the abscess wall. She made an excellent recovery with minimal edema and no contrast enhancement on imaging at eight weeks postoperatively. Management of Nocardia brain abscess includes a prompt diagnosis with direct microscopic examination and initiation of correct antibiotic therapy for good outcomes. We recommend open surgical resection, including excision of the abscess wall, followed by long-term antimicrobial therapy, to enhance the rate of recovery.

Parenchymal Brain Abscess as an Intracranial Complication After Sinusitis

Brain abscesses caused by sinusitis are rare in the antibiotic era. The purpose of the current manuscript was to report a rare case of a brain abscess located mainly in the frontal lobe after sinusitis, which was initially thought to be meningitis or encephalitis. A 39-year-old man was transferred to our hospital from another neighbouring hospital with tonic-clonic seizures, severe headache, and purulent nasal secretions. For one week, he was taking antibiotics for sinusitis. The computed tomography indicated lesions in the right sinuses but not in the parenchymal brain and thus antibiotics along with antiepileptic drugs were given. However, due to the deterioration of symptoms, magnetic resonance imaging was executed, which revealed an abscess in the frontal lobe. Afterward, an anterior ethmoidectomy and middle maxillary antrostomy were performed in order to drain the purulent content from the right sinuses. Ten days later, the patient presented disorientation and thus an open craniotomy for successful removal of the parenchymal abscess was performed. One month later, the patient was discharged with mild irritability, which was eliminated gradually over the next two months. Conclusively, brain abscesses can be caused by local spread from an infection of the paranasal sinus. The contribution of imaging modality is very significant not only for the early diagnosis but also for the therapeutic management of such cases. Frequently antibiotic treatment is insufficient and surgery may be required.

Ciliated respiratory epithelium encapsulating Pseudomonas brain abscess due to prior trauma

Bacterial brain abscesses are typically spread through a haematogenous route. Open head wounds and neurosurgical interventions are uncommon aetiologies. Ectopic tissue found in the cerebral cortex is usually ascribed almost entirely from carcinomas. Here, we describe a 57-year-old gentleman who, 22 years after a fireworks related traumatic injury to the left orbit, presented with headaches and altered behaviour. Imaging revealed an abscess immediately superior to the orbit, whose bacterial aetiology was identified to be Pseudomonas aeruginosa, encapsulated by ciliated respiratory epithelium. This represents a case in which tissue was displaced during the initial trauma or craniofacial reconstructive surgery from the frontal sinus.

Intracranial infections: lessons learned from 52 surgically treated cases

OBJECTIVE

Intracranial infections are serious and life-threatening health problems. They may present as subdural empyemas or intracerebral abscesses. Surgical drainage and subsequent antibiotic treatment is the main technique for a satisfactory clinical outcome. The aims of this study were to present a 10-year intracranial infection series and discuss the surgical characteristics in the light of literature.

METHODS

Fifty-two patients with intracranial infection underwent surgical treatment between 2008 and 2018. Eleven patients were female and 41 patients were male. The mean age was 40.46 years (range 10-75 years). Eighteen patients had intracerebral abscesses, and 34 had subdural empyemas. All patients underwent surgical treatment as well as an antibiotic regimen.

RESULTS

No etiological agent was isolated in 29 (56%) cases. Bacterial agents were detected in 20 cases, while fungi were observed in 3 cases. Staphylococci species were the most common agents and were isolated in 8 (15%) cases. Endoscopic aspiration was performed in 3 cases, while surgical drainage and capsule resection via craniotomy was performed in 49 cases. An associated intracranial tumor was diagnosed in 2 patients with brain abscesses. Four (8%) patients died despite surgical and medical treatments.

CONCLUSIONS

Surgical treatment via craniotomy is an older method, but it is still the best to treat the intracranial infections not only for decompression of the brain but also to attain an accurate diagnosis. The abscess wall should always be histologically examined after surgery to rule out any intracranial tumor.

Endoscopic Evacuation of a Panhemispheric Subdural Empyema

BACKGROUND

Subdural empyema (SDE) is a well-known entity in pediatric populations and is associated with a high rate of morbidity and mortality. Large scale evacuation of empyema, although effective, places the bone flap at risk of failure when replaced.

CASE DESCRIPTION

We report the case of a 19-year-old man with a history of a shunted left middle fossa cyst presenting with a panhemispheric SDE after removal of his cystoperitoneal shunt by an outside facility. Extensive evacuation was performed via the patients prior parietal shunt incision after expansion of the preexisting burr hole. Cultures grew methicillin-sensitive Staphylococcus aureus and Propionibacterium acnes, and he was treated with long-term antibiotics. The patient had a complete recovery with persistent empyema resolution on 6-month follow-up.

CONCLUSIONS

Endoscopic-assisted burr hole evacuation of large panhemispheric and loculated SDE is feasible, effective, and safe. The primary advantage over conventional open evacuations is that it negates the need for a bone flap and its potential complications related to a secondary infection.

Brain abscess in pediatric age: a review

OBJECTIVE

The purpose of the paper is to examine the current state of the art about epidemiology, diagnosis, and treatment of this infection.

METHODS

A review of the literature was performed through a PubMed search of original articles, case reports, and reviews using the key words "brain abscess," "cerebral abscess," "brain infection," "intracranial suppuration," "otogenic brain abscess," "otitis complications," and "sinusitis complications."

RESULTS

Pediatric brain abscess is a rare but serious infection, often involving patients with specific risk factors and burdened by a high risk of morbidity and mortality. Brain abscess incidence and mortality decreased over the years, thanks to improved antibiotic therapy, new neurosurgical techniques, and the wide spread of vaccinations. There are no guidelines for the adequate diagnostic-therapeutic pathway in the management of brain abscesses; therefore, conflicting data emerge from the literature. In the future, multicentric prospective studies should be performed in order to obtain stronger evidences about brain abscesses management. Over the next few years, changes in epidemiology could be observed because of risk factors changes.

Management of brain abscesses: where are we now?

INTRODUCTION

Brain abscesses affect all age groups and are not peculiar to a particular country, race, or geographical location. It is a disease that, in the past, carried a high morbidity and mortality. With improvements in medical technology and expertise, outcomes have improved tremendously. The causative organisms vary vastly and have evolved with time. Treatment of brain abscesses is primarily with antimicrobial therapy but surgery plays a vital role in achieving better outcomes.

CONTENT

In this article, we review the literature to find out how the epidemiology of this disease has changed through the years and re-visit the basic pathological process of abscess evolution and highlight the new research in the biochemical pathways that initiate and regulate this process. We also highlight how magnetic resonance imaging and its various modalities have improved diagnostic accuracy. Finally, we discuss the pros and cons of traditional open surgery versus newer minimally invasive methods.

Outcome of burr-hole aspiration of brain abscess

Objective

To determine the clinical outcome of burr-hole aspiration of brain abscess.

Methods

We analyzed 100 cases of intracranial abscess, treated surgically from January 2015 and October 2016 at Jinnah Postgraduate Medical Centre (JPMC). All patients were treated with burr hole aspiration. Medical records were analyzed for demographics, clinical presentation, predisposing factors, abscess location on imaging and clinical outcomes were charted.

Results

The study included 100 patients with 73 (73%) males and 27 (27%) females with a mean age of 36.69±10.96 years. Mean duration of signs and symptoms was 8.50±4.2 days. The most common presenting complaint was altered sensorium in 70 (70%) patients and commonest source of infection was otitis media seen in 27 patients (27%). The GCS on presentation was 13 in 57 (57%) cases. The parietal region was the most common site in 43 patients (43%), followed by frontal region in 33 patients (33%). Complete resolution of abscess with recovery of preoperative neuro-deficit was seen in 77 (77%) patients and recovery with major neuro-deficit was observed in 10 (10%) cases while 13 (13%) patients expired.

Conclusion

Early diagnosis, optimum follow-up and timely burr-hole aspiration are the keys in the proper management of brain abscess.

Evaluation of Continuous Irrigation and Drainage with a Double-Cavity Sleeve Tube to Treat Brain Abscess

BACKGROUND

Brain abscesses carries a high morbidity and mortality, and despite medical advances, it continues to pose diagnostic and therapeutic challenges worldwide. The traditional surgical approaches to treating brain abscess (burr hole aspiration and craniotomy) have both advantages and disadvantages and remain controversial. Here we report a single institution's experience with a new surgical approach for brain abscess.

METHODS

We retrospectively analyzed 46 patients with intracranial abscess who underwent continuous irrigation and drainage through a double-cavity sleeve tube placed surgically in conjunction with a 4-week course of intravenous cefotaxime and metronidazole at Renmin Hospital of Wuhan University between January 2008 and December 2016. The patients' medical records were analyzed for demographic data, clinical presentation, predisposing factors, imaging findings, microbiological test results, treatments, surgical techniques, and outcomes.

RESULTS

The 46 patients included 29 males and 17 females, ranging in age from 22 to 74 years. A single abscess was detected in 34 patients, whereas 12 patients had multiple abscesses. The average duration of hospitalization was 12.6 days. After treatment, 38 of the 46 patients resumed a normal life despite minor deficits (Glasgow Outcome Score [GOS] 5), 6 patients exhibited slight neurologic deficits (GOS 4), and 2 patients died of severe systemic infection and multiorgan failure. In particular, a patient with a brain abscess broken into the ventricle recovered well (GOS 5). No patient required repeat aspiration or surgical excision.

CONCLUSIONS

Continuous brain abscess cavity irrigation and drainage with a double-cavity sleeve tube is an effective treatment for brain abscess and produces excellent results, especially for an abscess broken into the ventricle. It combines the advantages of burr hole aspiration and open craniotomy excision. It is easy to perform and reduces costs and damage to the patient, and also shortens hospitalization time and antibiotic treatment time, greatly reducing the likelihood of reoperation. This approach may be the optimal choice to treat brain abscess.

Expressive aphasia caused by Streptococcus intermedius brain abscess in an immunocompetent patient

Background

Brain abscess is an uncommon but life-threatening infection. It involves a focal, intracerebral infection that begins in a localized area of cerebritis and develops into a collection of pus, surrounded by a well-vascularized capsule. Brain abscess still poses a significant problem in developing countries but rarely in developed countries. Predisposing factors vary in different parts of the world. With the introduction of antibiotics and imaging studies, the mortality rate has decreased between 5% and 15%. If left untreated it may lead to serious neurologic sequelae. The temporal lobe abscess can be caused by conditions like sinusitis, otitis media, dental infections, and mastoiditis if left untreated or partially treated. Additionally, in neurosurgical procedures like craniotomy, the external ventricular drain can get infected, leading to abscess formation.

Case presentation

We present the case study of an elderly female patient who presented with expressive aphasia caused by brain abscess, secondary to Streptococcus intermedius infection. The 72-year-old female with a medical history of hypertension came to hospital for evaluation with word-finding difficulty, an expressive aphasia that began a few days prior to presentation. Computed tomography of the head showed a left temporal lobe mass-like lesion, with surrounding vasogenic edema. The patient was empirically started on courses of antibiotics. The next day, she was subjected to magnetic resonance imaging of the brain, which showed a left temporal lobe septated rim-enhancing mass lesion, with bright restricted diffusion and diffuse surrounding vasogenic edema consistent with abscess. The patient was also seen by the neurosurgery department and underwent stereotactic, left temporal craniotomy, with drainage, and resection of abscess. Tissue culture grew S. intermedius sensitive to ampicillin sulbactam. Subsequently her expressive aphasia improved.

Conclusion

Brain abscess has a high mortality, however a significant proportion of patients with appropriately treated abscess recover completely and can survive without significant neurologic damage. Advanced imaging modalities may yield more accurate methods of differentiation of mass lesions in the brain. Biopsy of brain lesion with early initiation of appropriate antibiotics will change the outcome.

Retrospective analysis of 620 cases of brain abscess in Chinese patients in a single center over a 62-year period

BACKGROUND

Despite advances in laboratory diagnostics, antibiotic regimens, and neurosurgical techniques, brain abscess (BA) remains a potentially fatal infectious disease. This study analyzed clinical and epidemiological aspects of BA in Chinese patients treated at a single center during a 62-year period.

METHOD

We retrospectively analyzed 620 BA patients treated at Tianjin Medical University General Hospital, Tianjin, PR China from 1952 to 2014. Because of the initiation of imaging technology use in 1992, and other specific changes, we analyzed data over three study periods: 1952-1972, 1980-1991, and 2002-2014. Information including incidence, sex, age, community distribution, BA size and location, therapeutic method, prognosis and outcome of BA patients was collected and evaluated.

RESULTS

Our study included 620 BA patients. The percentage mortality significantly decreased from 22.8 % in 1952 to 6.3 % in 2014 (p < 0.001). Although the incidence of BA was higher in males than females, there was no significant change in the male/female incidence ratio over time: 2.5 in 1952-1972, 2.6 in 1980-1991, and 2.2 in 2002-2014. The cryptogenic infection incidence significantly increased over time (p < 0.001). The number of positive bacterial cultures significantly decreased over the three study periods (p < 0.01).

CONCLUSIONS

The prognosis of patients with BA has gradually improved over the past 62 years in Tianjin, China. This may be because improvements in neurosurgical techniques, cranial imaging, and antimicrobial regimens have facilitated less invasive and more precise neurosurgical procedures.

Bacterial brain abscess

Significant advances in the diagnosis and management of bacterial brain abscess over the past several decades have improved the expected outcome of a disease once regarded as invariably fatal. Despite this, intraparenchymal abscess continues to present a serious and potentially life-threatening condition. Brain abscess may result from traumatic brain injury, prior neurosurgical procedure, contiguous spread from a local source, or hematogenous spread of a systemic infection. In a significant proportion of cases, an etiology cannot be identified. Clinical presentation is highly variable and routine laboratory testing lacks sensitivity. As such, a high degree of clinical suspicion is necessary for prompt diagnosis and intervention. Computed tomography and magnetic resonance imaging offer a timely and sensitive method of assessing for abscess. Appearance of abscess on routine imaging lacks specificity and will not spare biopsy in cases where the clinical context does not unequivocally indicate infectious etiology. Current work with advanced imaging modalities may yield more accurate methods of differentiation of mass lesions in the brain. Management of abscess demands a multimodal approach. Surgical intervention and medical therapy are necessary in most cases. Prognosis of brain abscess has improved significantly in the recent decades although close follow-up is required, given the potential for long-term sequelae and a risk of recurrence.