Decreased mortality from brain abscesses since advent of computerized tomography

Computed tomography-guided drainage of a canine intracerebral abscess

An approximately 7-week-old female American Bulldog was presented for head injury and seizures. The dog was obtunded with absent left-sided postural reactions, absent left palpebral reflex, delayed vestibulo-ocular reflex bilaterally, and calvarial hyperesthesia. CT revealed a fragmented, depressed fracture of the right frontal bone, with an associated abscess and evidence of raised intracranial pressure. The dog initially declined on medical management. Following a CT-guided drainage procedure, the dog improved and remained clinically well twenty months later. This is the first report of minimally-invasive sequential CT allowing successful drainage and culture of a canine intracerebral abscess.

Experimental animal models for brain abscess: a systematic review

BACKGROUND

Brain abscess (BA) is a rare, but severe infection and experimental BA animal models may prove crucial for advances in treatment. This review describes the development of experimental BA models and the clinical advances obtained from these, in a historical perspective.

MATERIAL AND METHODS

Experimental BA studies from inception until June 15, 2022, were included by searching the PubMed and Embase databases. Inclusion required the use of an experimental BA animal model. Non-bacterial BA models, in vitro studies, veterinarian case-reports, and articles written in non-English language were excluded. Bias was not systematically assessed, and the review was not registered at the PROSPERO.

RESULTS

79 studies were included. The majority of animal BA models have been based on small rodents using Staphylococcus aureus. The models have delineated the natural development of BA and provided detailed descriptions of the histopathological characteristics consisting of a necrotic centre surrounded by layers of inflammatory cells and fibroblasts encapsulated by a dense collagenous layer. Radiological studies of animal BA have been shown to correlate with the corresponding stages of human BA in both computed tomography and magnetic resonance imaging and may guide diagnosis as well as the timing of neurosurgical intervention. Moreover, pharmacokinetic studies of the intracavitary penetration of various antimicrobials have helped inform medical treatment of BA. Other studies have examined the diverse effects of corticosteroids including decreased cerebral oedema, intracranial pressure, and intracavitary drug concentration, whereas concerns on decreased or weakened capsule formation could not be confirmed. Finally, studies on the immunological response to BA have highlighted potential future immunomodulatory targets.

CONCLUSIONS

Animal models have been vital for improvements in the management of BA. Experimental BA models resembling human disease including polymicrobial infection by oral cavity flora in large animals are needed.

Profiles of primary brain abscesses and their impact on survival: An international ID-IRI study

OBJECTIVES

This study of 331 primary brain abscess (PBA) patients aimed to understand infecting agents, predisposing factors, and outcomes, with a focus on factors affecting mortality.

METHODS

Data were collected from 39 centers across 16 countries between January 2010 and December 2022, and clinical, radiological, and microbiological findings, along with their impact on mortality, were analyzed.

RESULTS

The patients had a mean ± SD age of 46.8 ± 16.3 years, with a male predominance of 71.6%. Common symptoms included headache (77.9%), fever (54.4%), and focal neurological deficits (53.5%). Gram-positive cocci were the predominant pathogens, with Viridans group streptococci identified as the most frequently isolated organisms. All patients received antimicrobial therapy and 71.6% underwent interventional therapies. The 42-day and 180-day survival rates were 91.9% and 86.1%, respectively. Significant predictors of 42-day mortality included intravenous drug addiction (HR: 6.02, 95% CI: 1.38-26.26), malignancy (HR: 3.61, 95% CI: 1.23-10.58), confusion (HR: 2.65, 95% CI: 1.19-5.88), and unidentified bacteria (HR: 4.68, 95% CI: 1.76-12.43). Significant predictors of 180-day mortality included malignancy (HR: 2.70, 95% CI: 1.07-6.81), confusion (HR: 2.14, 95% CI: 1.11-4.15), temporal lobe involvement (HR: 2.10, 95% CI: 1.08-4.08), and unidentified bacteria (HR: 3.02, 95% CI: 1.49-6.15).

CONCLUSION

The risk of death in PBA extends beyond the infection phase, with different factors influencing the 42-day and 180-day mortality rates. Intravenous drug addiction was associated with early mortality, while temporal lobe involvement was associated with late mortality.

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.

Surgical aspiration versus excision for intraparenchymal abscess: a systematic review and Meta-analysis

Brain abscesses are associated with considerable morbidity and mortality, requiring timely intervention to achieve favourable outcomes. With the advent of high-resolution computed tomography (CT) imaging, mortality following both aspiration and excision of brain abscesses has improved markedly. As a result, there has been a marked shift in neurosurgical practice with aspiration eclipsing excision as the favoured first-line modality for most abscesses. However, this trend lacks sufficient supporting evidence, and this systematic review and meta-analysis seeks to compare aspiration and excision in the treatment of brain abscess. Twenty-seven studies were included in the systematic review, and seven comparative papers in meta-analysis. Aspiration was the chosen technique for 67.5% of patients. Baseline characteristics from the studies included only in the systematic review demonstrated that abscesses treated by aspiration were typically larger and in a deeper location than those excised. In the meta-analysis, we initially found no significant difference in mortality, re-operation rate, or functional outcome between the two treatment modalities. However, sensitivity analysis revealed that excision results in lower re-operation rate. On average, the included studies were of poor quality with average Methodological Index for Non-Randomized Studies (MINORS) scores of 10.3/16 and 14.43/24 for non-comparative and comparative papers respectively. Our study demonstrates that excision may offer improved re-operation rate as compared to aspiration for those abscesses where there is no prior clinical indication for either modality. However, no differences were found with respect to mortality or functional outcome. Evidence from the literature was deemed low quality, emphasizing the need for further investigation in this field, specifically in the form of large, well-controlled, comparative trials.

50th anniversary of computed tomography: past and future applications in clinical neuroscience

Purpose: It has been 50 years since computed tomography was introduced to the worldwide neurologic medical and surgical community. In that time, tremendous advances in computer software and hardware, as well as creative changes in computerized tomographic (CT) hardware and tube technology, have dramatically improved the temporal and spatial resolution of CT. In this paper, I address what I feel are some of the most important impacts of CT in the field of clinical neuroscience over the last 50 years, as well as potential applications of CT that are on the horizon.

Approach: I have recounted from literature, colleagues, and personal recollection the historical impact of CT on neuroradiology practice and what appear to be near-term future applications.

Conclusions: Therapeutic applications beyond diagnosis, such as image-guided procedures, radiation, and surgical planning, and development of the field of theranostics have emerged and further increased the need for faster and more precise CT imaging. The integration of machine learning into the acquisition chain and radiologist tool kit has great implications for standardization, analysis, and diagnosis worldwide.

Brain Abscess Complicating a Traumatic Intracerebral Hemorrhagic Contusion

A 63-year-old right-handed man was admitted to our hospital after sustaining a traumatic right-sided subdural hematoma, subarachnoid hemorrhage, and temporal lobe hemorrhagic contusion. He was managed non-operatively and discharged without any neurologic deficits. Two weeks later he presented with worsening headaches and altered sensorium. Imaging studies showed that the patient had developed a cerebral abscess at the site of his intracerebral hemorrhage. The abscess was surgically resected, and the patient was treated with antibiotics with complete resolution of symptoms. This case illustrates the importance of timely recognition of a rare complication of intracranial hemorrhage, and the utility of MR spectroscopy.

HIV, Tuberculosis, and Otogenic Intracranial Sepsis: A Devastating Disease With a Subtle Presentation

OBJECTIVES

To undertake a large-scale review of otogenic intracranial sepsis in an area of highly prevalent HIV and tuberculosis (TB) to re-examine and inform early diagnosis and treatment efforts.

METHODS

Seventy-seven consecutive cases of otogenic intracranial sepsis in KwaZulu-Natal, South Africa were reviewed for demographics, presentation, imaging, HIV status, culture results, and outcomes.

RESULTS

The most common intracranial complications were intracranial abscess (46.8%), hydrocephalus (31.2%), subdural empyema (28.6%), and epidural empyema (26.0%). Ear discharge (87.0%), postauricular abscess (29.9%), and hearing loss (29.9%) were notable presenting symptoms. Overall mortality was 15.6%. Of the 45.5% of patients with HIV testing, 54.2% were HIV+, Mortality among HIV+ patients was 15.8% but only 6.3% in HIV- patients (p = 0.61, OR = 2.8). Eight patients (10.4%) had culture or histological evidence of TB infection.

CONCLUSIONS

Otogenic intracranial complications continue to present late and are associated with significant mortality and morbidity, despite advances in diagnostic and treatment modalities. This study represents one of the largest case-series in the literature, and the first to specifically evaluate the effects of HIV and TB infection.Patient presentation and severity of illness varied; however, a majority of patients presented with ear discharge and no focal neurological signs. An effect size for higher mortality among HIV+ patients compared with HIV- patients was noted but was not significant. Tuberculosis infection was prevalent compared with previous studies.This study reinforces the need for enhanced screening and early treatment of ear disease to minimize associated mortality and morbidity, particularly in immunocompromised patients.

Treating Intracranial Abscesses in Rats with Stereotactic Injection of Biodegradable Vancomycin-Embedded Microparticles

Brain abscesses are emergent and life-threating despite advances in modern neurosurgical techniques and antibiotics. The present study explores the efficacy of vancomycin embedded to 50:50 poly(lactic-co-glycolide acid) (PLGA) microparticles in the treatment of brain abscess. The vancomycin embedded microparticles (VMPs) were stereotactically introduced into the cerebral parenchyma in Staphylococcus aureus bacteria- induced brain abscess-bearing rats. Experimental rats were divided into three groups: group A (n = 13; no treatment), group B (n = 14; daily vancomycin injection (5 mg intraperitoneally), and group C (n = 12; stereotactic introduction of VMPs into the abscess cavity). Group C exhibited no inflammatory response and significantly increased survival and reduced mean abscess volumes (p <0.001) at the eighth week, compared with other groups. Vancomycin delivery via a biodegradable PLGA vehicle can easily attain Area Under the Curve (AUC)/minimum inhibitory concentration (MIC) ratios of ≥400, and strengthens the therapeutic efficacy of antibiotics without provoking any potential toxicity. Biodegradable VMPs are a safe and sustainable drug delivery vehicle for the treatment of brain abscess.

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.

Prognosis of pituitary adenomas in the early 1970s and today-Is there a benefit of modern surgical techniques and treatment modalities?

OBJECTIVE

Neurosurgical techniques for the treatment of sellar pathologies have been evolving continuously over the last decades. Additionally to the innovation of approaches and surgical techniques, this progress yielded to the application of modern intraoperative surgical tools as well as peri- and intraoperative imaging. Until now, no long-term analysis of the impact of new therapy concepts on the patient's outcome exists. Aim of this study was to analyse the impact of new operative approaches on perioperative mortality and morbidity as well as the long-term outcome after pituitary surgery.

PATIENTS AND METHODS

Three groups of patients were compared in this retrospective analysis of surgically treated pituitary adenomas between the years of 1963 and 2014. Group A contains 93 patients, treated between 1963-1980 with a mean follow-up of 12.1 years (±14.3years), group B comprises 89 patients treated between 1990 and 2000 with a mean follow-up of 10.1 years (±8.1years) and group C consists of 95 patients treated between 2011-2014 with a mean follow-up of 3.4 years (±1.9years).

RESULTS

The surgical treatment was performed significantly earlier today on smaller tumors with less preoperative complaints (p<0.01). Panhypopituitarism was detected only in 9.5% of the cases in group C compared to 50.8% in group A (p<0.01). Also, the incidence of revision surgery (5.6 vs. 2% vs 0%), postoperative hemorrhage (10.8% vs. 3.4% vs. 1%) and diabetes insipidus (34.4% vs. 11.2% vs. 5.2%) was decreased (p<0.01). Moreover, a significant postoperative improvement of ophthalmological complaints was detected (p<0.001). The long-term follow-up showed 40% of the entire recurrence rate occurring after the ninth postoperative year. The progression-free survival time increased significantly from group A to group B (p<0.05).

CONCLUSIONS

The results demonstrate a benefit of the recent developments of pituitary surgery in the short-term results as well as in the long-term outcome. The prognosis of pituitary adenoma patients could be improved by the introduction of new surgical approaches and techniques in the last decades. Also the perioperative morbidity and mortality rate has been reduced clearly since the 1970s. Furthermore our results emphasise the necessity of lifelong follow-up of all patients with successfully treated pituitary adenomas.

Management of Brain Abscess

Despite recent advances in neuroimaging techniques, brain abscesses can be difficult to diagnose and may often require surgical intervention. The primary sources of infection are often difficult to locate; hence, even if an abscess is suspected, the organisms may remain unknown. In other patients, the location of the lesion may be in a site of the brain where surgical intervention may not be possible. The types of brain abscesses, their pathophysiology including predisposing conditions, and their characteristic radiologic features are discussed in this review, with particular emphasis on the indications and modes of medical management of brain abscesses. It discusses the use of antimicrobial agents that have the best central nervous system penetration and outlines a strategy for treatment of organisms likely to infect the brain with the different types of predisposing conditions. Also discussed are the indications for empirical therapy, and antimicrobial regimens for this purpose are suggested.

Relationship between demography, etiology, level of consciousness, and outcome of surgical intracranial suppurations of bacterial origin in a tropical tertiary center

Introduction:

Intracranial suppurations (ICS) of bacterial origin are associated with significant mortality and morbidity. This study aimed to review demography, etiology, level of consciousness, and outcome of surgical ICS in a tropical tertiary hospital.

Materials and Methods:

All patients admitted to the neurosurgical unit within the study period of 7 years that had a surgical intervention for their ICS were prospectively included in the study. In accordance with the unit protocol, all patients in whom there was clinical suspicion of ICS had a preoperative computed tomography scan and/or magnetic resonance imaging done. The following data among others were documented and recorded electronically: demography, clinical and radiological diagnosis, etiology of ICS, admission Glasgow Coma Scale (GCS) score, type of neurosurgical intervention, mode of anesthesia, and outcome.

Results:

Forty-nine patients were included in the study. There were 33 males with a male-to-female ratio of 2.1:1. All patients presented at least a week after the use of antibiotics. The most common type of ICS was cerebral abscess (33 patients, 67.3%). There was no statistical significant association between outcome and age group (P = 0.630), gender (P = 0.999), diagnosis (P = 0.464), etiology of ICS (P = 0.169), solitary or multiplicity of ICS (P = 0.485), or type of offending organism (P = 0.278).

Conclusions:

ICS usually follows otorhinological infections in our center. The surgical outcome is dependent on the admission GCS score.

Risk factors associated with poor outcomes in patients with brain abscesses

OBJECTIVE

The purpose of this study was to describe the clinical characteristics, treatment outcomes, and prognostic factors in patients with brain abscesses treated in a single institute during a recent 10-year period.

METHODS

Fifty-one patients with brain abscesses who underwent navigation-assisted abscess aspiration with antibiotic treatment were included in this study. Variable parameters were collected from the patients' medical records and radiological data. A comparison was made between patients with favorable [Glasgow Outcome Scale (GOS) ≥4] and unfavorable (GOS <4) outcomes at discharge. Additionally, we investigated the factors influencing the duration of antibiotic administration.

RESULTS

The study included 41 male and 10 female patients with a mean age of 53 years. At admission, 42 patients (82%) showed either clear or mildly disturbed consciousness (GCS ≥13) and 24 patients (47%) had predisposing factors. The offending microorganisms were identified in 25 patients (49%), and Streptococcus species were the most commonly isolated bacteria (27%). The mean duration of antibiotic administration was 42 days. At discharge, 41 patients had a favorable outcome and 10 had an unfavorable outcome including 8 deaths. The decreased level of consciousness (GCS <13) on admission was likely associated with an unfavorable outcome (p=0.052), and initial hyperglycemia (≥140 mg/dL) was an independent risk factor for prolonged antibiotic therapy (p=0.032).

CONCLUSION

We found that the level of consciousness at admission was associated with treatment outcomes in patients with brain abscesses. Furthermore, initial hyperglycemia was closely related to the long-term use of antibiotic agents.

Brainstem abscess of undetermined origin: microsurgical drainage and brief antibiotic therapy

CONTEXT

Solitary brainstem abscesses are rare and they are usually associated with other infections. They are severe conditions with high morbidity and mortality. The surgical options are stereotactic aspiration and microsurgical drainage. Systemic antibiotic therapy is used for more than six weeks.

CASE REPORT

We present the case of a young man with a solitary abscess at the pons, without other systemic infections. The patient was treated by means of microsurgical drainage and antibiotic therapy for three weeks. His postoperative recovery was good.

CONCLUSIONS

A microsurgical approach may be considered to be an important option for large abscesses that are multiloculated, close to the surface or contain thick fluid. Complete emptying of the purulent accumulation may diminish the required duration of antibiotic therapy.

Brain abscess: Current management

Brain abscess (BA) is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA.

Citrobacter brain abscesses in neonates: early surgical intervention and review of the literature

PURPOSE

Citrobacter koseri, a facultatively anaerobic, lactose-fermenting, gram-negative bacilli, has a strong propensity to form cerebral abscesses. C. koseri brain abscesses can be a devastating disease of infancy and childhood with more than 30% succumbing to the disease and more than 50% suffering severe neurological deficits.

METHODS

This study represents a retrospective review of two cases of C. koseri brain abscesses along with a review of the literature regarding diagnosis and treatment.

RESULTS

Early aggressive surgical and medical treatment resulted in favorable outcomes for two children with C. koseri brain abscesses, one diagnosed at 6 weeks of age and the other at 2 months of age.

CONCLUSION

C. koseri brain abscesses can be devastating and have been associated historically with significant morbidity and mortality. However, favorable outcomes are possible, and aggressive surgical and medical management should be considered for patients with C. koseri abscesses.

Taming an old enemy: a profile of intracranial suppuration

Intracranial suppurative disorders (ICSDs; brain abscess, empyema, and purulent ventriculitis), have been a scourge through the ages and attempts at curative surgery, as for cranial trauma, are considered to be one of the first true neurosurgical interventions performed. ICSDs, seen initially as a consequence of poor socioeconomic conditions and neglected otorhinogenic infections, predominantly manifest today as postsurgical complications, and/or in immunocompromised patients where they continue to result in significant neurologic morbidity and death. The reduction in the incidence of "old world" classic ICSDs can be attributed to the modernization of society, driven inter alia by a shift from an agricultural to an industrial economic society. It can also be coupled with pivotal achievements in public health and the dramatic developments in medicine in the 20th century. This trend was first noted in developed countries but now, with improved socioeconomic circumstances and globalization of medical technology, it is occurring in the developing regions of the world as well. Although ICSDs have undergone a metamorphosis in their clinical profile and despite their rarity in contemporary "developed world" neurosurgical practice, they still have undoubted potential for fatal consequences and continue to pose a significant challenge to the 21st-century neurosurgeon.

The study of etiologic and demographic characteristics of intracranial brain abscess: a consecutive case series study from Pakistan

BACKGROUND

To determine the demographics, management, bacteriological spectrum, and outcome of brain abscesses of patients brought to Aga Khan University Hospital (AKUH), Karachi, with a history of neurologic symptoms and to examine the factors associated with it.

METHODS

This hospital-based descriptive study included 53 patients from both sexes who presented to the neurosurgery section at AKUH from January 1, 2000, until December 31, 2008, with neurologic symptomatology and fulfilling other inclusion criteria. Data regarding their demographic profile and other factors were collected in a well-structured proforma. Data were analyzed using frequencies, proportions, group means, and standard deviations.

RESULTS

The male-to-female ratio in our study was 3.4:1, with Staphylococcus milleri (20.7%) being the most common etiologic agent followed by anaerobic bacteria (15.1%). The triad of headache, fever, and vomiting was present in 62.7% of patients at the time of presentation. The most important factors influencing mortality was the neurologic condition of the patient at the time of admission. Chronic suppurative otitis media was the most common predisposing factor for temporal lobe infections, and the frontal lobe was the most common site of involvement in majority of the patients (67.8%). The mortality rate in our study was 11.3%.

CONCLUSION

Findings suggest that patients in the second and fourth decades of life are the most susceptible, both in terms of morbidity and mortality. Early diagnosis and appropriate management, along with rapid access to tertiary care centers, will lead to a better prognosis.

Brain Abscesses of Ear, Nose, and Throat Origin: Comparison between Otogenic and Sinogenic Etiologies

This retrospective study analyzed 29 cerebral abscesses of ear, nose, and throat (ENT) origin. The mean follow-up of patients was 37 months. ENT etiologies included 45% otitis media (n = 13), 48% sinusitis (n = 14), and 7% ethmoidal sinus tumors (n = 2). Thirty-eight percent (n = 5) of otogenic abscesses occurred within 15 days after a mastoidectomy. Sinogenic abscesses were never due to surgery but were associated in 31% of cases (n = 5) with anterior skull base defects. The main locations of otogenic abscesses were the temporal lobe (54%; n = 7) and the cerebellum (23%; n = 3), whereas sinogenic abscesses were located in the frontal lobe in 75% of cases (n = 12). Because of this location, sinogenic abscesses were less symptomatic than otogenic ones and had greater size and encapsulation at the time of diagnosis. Thus, they required longer antibiotic treatment (p = 0.05) and more numerous surgical drainages (p = 0.02). Bacteriologic abscesses samples were positive in 90% of cases. Bacteria found in brain abscesses were different from the ones found in ENT samples in 62% of cases. Thus, the results of ENT bacteriologic samples were not helpful for choosing adequate antibiotic agents in case of negative brain abscess samples. Although mortality was not significantly higher in otogenic abscesses (31%; n = 4) than in sinogenic ones (6%; n = 1, p = 0.08), otogenic abscesses appeared more threatening. Indeed, they represented 80% (n = 4) of lethal cases and encompassed more clinical or radiological prognosis pejorative factors than sinogenic ones (p = 0.006). In conclusion, higher danger of otogenic abscesses mainly resulted both from their temporal or cerebellous locations and from the bacteria that were more frequently resistant to antibiotics.

Anaerobic brain abscess following chronic suppurative otitis media in a child from Uganda

Brain abscess, while rare, confers high mortality, especially in the developing world. The case of a Ugandan child with a polymicrobial brain abscess including infection with Tissierella praeacuta/Clostridium hastiforme requiring repeated drainage and eventual surgical excision is reported. The case demonstrates the importance of considering anaerobic organisms in the treatment of children with brain abscess from the developing world.

Role of CT Scan in Diagnosis and Management of Otogenic Intracranial Abscess

The existence of complications of suppurative otitis media and efforts to control it go far back into history. Early diagnosis and management have been greatly modified by the extensive use of CT scan and higher antibiotics. Despite an overall decline in the incidence of complications of otitis media, severe complications still exist with high mortality. Suggested reasons are decrease in physician's experience and changing of the virulence and susceptibility of causative organism. This series is a prospective study of 18 cases of otogenic brain abscess, carried out in Department of ENT and Head & Neck Surgery, SSG Hospital, Baroda from June 2005 to June 2008. We emphasize on confirmation of resolution of brain abscess by CT scan. This will eliminate recurrent/residual abscess and help in reduced overall mortality and morbidity.

The role of f-fluorodeoxyglucose positron emission tomography in the treatment of brain abscess

OBJECTIVE

The purpose of this study was to evaluate whether (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) can be used to assess the therapeutic response of brain abscess.

METHODS

A study was conducted on 10 consecutive patients with brain abscess. Magnetic resonance imaging (MRI) with diffuse-weighted imaging (DWI) was performed at 3 and 6 weeks after surgical treatment and intravenous antibiotics therapy and FDG-PET at 6 weeks after treatment. The extent of the abscess, signal changes on MRI, and FDG-PET standardized uptake values were analyzed and correlated with the response to therapy.

RESULTS

Aspiration or craniotomy with excision of the abscess followed by intravenous antibiotics for 6-8 weeks resulted in good recovery with no recurrence. In 10 patients, two had low signal intensity on the DWI; one had no uptake on FDG-PET imaging after 6 weeks antibiotics and discontinued intravenous treatment, but the other patient had diffuse, increased uptake on FDG-PET imaging after 6 weeks antibiotics and underwent an additional 2 weeks of intravenous antibiotics. The remaining eight patients had high signals on the DWI. Four had no uptake on FDG-PET imaging and the treatment period varied from 6 to 8 weeks (mean, 6.75 weeks). Among the other four patients, FDG was accumulated in a diffuse or local area corresponding to a high signal area within the DWI and 2 weeks of intravenous antibiotics was added.

CONCLUSION

MRI plus FDG-PET improved the accuracy of assessing therapeutic responses to antibiotics treatment of brain abscess and aided in optimizing therapy.

Gas-forming brain abscess caused by Klebsiella pneumoniae

Gas forming brain abscess is a rare disease caused by Klebsiella pneumoniae occurring in patients with impaired host defense mechanism such as diabetes mellitus or liver cirrhosis. A 59-year-old man with 2-year history of diabetes mellitus and 20-year history of liver cirrhosis presented to the hospital with headache. On the day after admission, severe headache was developed and he deteriorated rapidly. Brain CT showed a non-enhanced mass including multiple air density as well as surrounding edema seen in the right occipital lobe, and isodensity air-fluid level seen in the right lateral ventricle. Despite emergent ventricular drainage and intraventricular and intravenous administration of antibiotics, his condition progressively worsened to sepsis and to death after 5 days. Bacterial culture of blood and ventricular fluids disclosed a Gram (-) rod, Klebsiella pneumoniae. In this report we review the pathogenic mechanism and its management.

Management of brain abscesses in children

Brain abscesses occur infrequently but continue to be problematic for the pediatric neurosurgical community. The incidence of brain abscesses in children has not changed much, although individual reports may show an increase or decrease in the number of reported cases depending on the patient population studied. An increase could be attributed to earlier detection due to advancements in imaging modalities and/or to an increase in the number of children with immunodeficient states caused by AIDS, chemotherapy for malignant lesions, and immunosuppressive therapy for organ transplantation. A decrease in the incidence of brain abscesses could be attributed to practices such as antibiotic treatment for otitis media, sinusitis, and/or prophylactic antimicrobial treatment for congenital heart disease in children. The morbidity and mortality rates associated with brain abscesses have not changed dramatically in the antibiotic and imaging era, and their preferred management can vary among healthcare providers. These lesions have been successfully treated by neurosurgeons. The causes of brain abscesses are highly variable in children, which is also the case in adults, but the predisposing factors in the pediatric population differ in prevalence. Cyanotic congenital heart disease, hematogenous dissemination, contiguous infection, and penetrating traumatic injuries are the most common causes of brain abscesses in children. In this review, the authors discuss the causes and medical and surgical management of brain abscesses in children.

Efficacy of stereotactic aspiration in deep-seated and eloquent-region intracranial pyogenic abscesses

Object

Intracranial abscesses located deep in the cerebral parenchyma and in eloquent regions are often difficult to manage surgically. The authors have attempted to analyze the efficacy of stereotactic aspiration in the management of these abscesses.

Methods

Cases involving 22 patients (including 9 children) with deep-seated and/or eloquent-region intracranial abscesses who underwent CT- or MR imaging–guided stereotactic aspiration between January 1995 and July 2001 were analyzed.

Results

A definite source of infection could be identified only in 9 of the cases. In 18 patients, the abscess was deep seated, whereas in the rest it was located in the eloquent cortex. Five patients had abscesses located in multiple sites. In 17 patients only 1 aspiration was required; in 5 others subsequent procedures were required. In the initial postaspiration CT, minor hemorrhage was noted in 3 patients not requiring further intervention. Antibiotics were administered for a period varying from 4 to 8 weeks following aspiration. An early recurrence (within 2 weeks of initial aspiration) was evident in 5 patients. All recurrent abscesses were reaspirated. In 2 patients new abscesses developed while the patients were still receiving antibiotic therapy. There were no late recurrences. In 1 patient ventriculitis developed, with subsequent hydrocephalus requiring a shunt insertion. Follow-up CT scans showed complete resolution of the abscess in all patients. There were no deaths.

Conclusions

Stereotactic aspiration is a useful management option for abscesses located in eloquent or inaccessible regions. Repeated aspiration should be considered in patients in whom the initial aspiration proves ineffective or partially effective. Complete resolution may require repeated stereotactic aspirations and continued antibiotic therapy.

Management of bacterial brain abscesses

✓ Brain abscesses are well-known lesions that have been reported from the beginning of the Hippocratic era. They continue, however, to be characterized by problematic and fatal features, even though there have been enormous developments in treatment and diagnostic technologies—especially in the areas of computed tomography (CT), surgery, anesthesia, bacterial isolation techniques, and new antibiotics. The predisposing factors may change according to patient age, geographic location, and socioeconomic conditions of the community, but patients frequently have a contiguous infection such as otitis or mastoiditis. The clinical signs and symptoms of brain abscesses are nonspecific. Patients typically present with signs and symptoms due to mass effects, accompanied by high fever and seizure. The main treatment is surgical, although medical therapy can be used for selected cases. The treatment of choice is aspiration, which may be performed with the aid of an endoscope or free hand, with or without stereotactic or intraoperative ultrasound guidance. Excision is valuable in some cases. The success of the treatment, whether surgical or medical, mostly depends on the success of isolation of the causative organism, which provides essential data for accurate medical treatment. Third-generation cephalosporins and metronidazole are the most commonly used antimicrobial agents in the treatment of brain abscesses. Use of corticosteroids may be acceptable when lesions are accompanied by edema. Prophylactic antiepileptic therapy is strongly recommended. The patient's Glasgow Coma Scale score at presentation is one of the most important factors predicting outcome.

Retrospective analysis of 49 cases of brain abscess and review of the literature

The case records of 49 patients discharged from St George's Hospital, London, between December 2000 and March 2004 with the diagnosis of brain abscess were reviewed in order to document the epidemiology, causes, treatment, and prognostic factors associated with brain abscess. Brain abscess occurred at all ages, more frequently in men than in women. Headache and altered mental status were common presenting symptoms. The frontal lobe was the most common site. Streptococcal infection was seen most commonly, but staphylococcal infection predominated in cases following neurosurgery. Computed tomography provided sufficient diagnostic information in most cases. All but five patients had early surgical drainage. Cefotaxime and metronidazole were used most often for empirical therapy. Thirty-nine patients recovered fully or had minimal incapacity. Five patients died. Patients with underlying cranial neoplasms or medical conditions had a worse outcome than those with a contiguous focus of infection or post-traumatic abscess. Changes in disease pattern were determined by comparison to a literature review. A PubMed search of the literature using the keywords "brain abscess" was undertaken, and identified papers and relevant citations were reviewed. Compared to earlier series, there was a marked decrease in the number of cases of brain abscess secondary to otitis media and congenital heart disease. There was an increase in the number of cases of brain abscess secondary to neurosurgery and trauma. Changes in the epidemiology of predisposing conditions for brain abscess are associated with changes in the patient population and causative organisms. Though still a potentially fatal infection, there have been recent improvements in diagnosis, treatment, and outcome.

Pulmonary Arteriovenous Malformations, Hereditary Hemorrhagic Telangiectasia, and Brain Abscess

Hereditary hemorrhagic telangiectasia (HHT) is a systemic angiodysplasia inherited as an autosomal dominant disease. Patients with HHT and pulmonary arteriovenous malformations (PAVMs) are at increased risk for brain abscess (BA), a potentially preventable condition as effective treatment for PAVMs is available. In a center dedicated to HHT, a history of BA was found in 6 out of 128 patients with a definite diagnosis: herewith, their histories are reported focusing on mistakes in the diagnosis and management of the disease. Patients with PAVMs and BA had a higher mean hemoglobin concentration (15.1 g/dl vs. 12.2 g/dl, p < 0.006 by Student's t test) compared to patients with PAVMs alone. Other clinical features (genetics, bacteriology, types of PAVMs, treatments, outcomes) are also discussed. Prompt diagnosis and screening for visceral involvement is pivotal for HHT patients and their relatives.

Pyogenic infections of the central nervous system secondary to dental affections--a report of six cases

Pyogenic infections of the central nervous system of dental origin are quite uncommon in industrialized countries. We report six cases with intracerebral (n = 4) and intraspinal (n = 2) infections treated in our hospital. The microbial pathogen was successfully isolated in all patients. Fusobacterium nucleatum as well as Streptococcus species were found in three cases. Bacillus species were identified in two patients. Actinomyces was the etiologic agent in one case. All patients suffered from dental pathologies, so that after clinical and radiological exclusion of other sources an oral focus was presumed. Therapeutic management consisted of an operative procedure in order to obtain decompression, as well as evacuation of the pus on the one hand, followed by targeted antibiotics on the other. Clinical improvement was achieved in all patients, with one patient lost to follow-up. On magnetic resonance tomography, the inflammatory changes also disappeared in all cases. We recommend that oral infection with recurrent bacteraemia should always be considered in the pathogenesis of the so-called "cryptic" intracerebral and intraspinal infections.

Hyperbaric oxygen therapy for the treatment of brain abscess in children

INTRODUCTION

The treatment of brain abscess remains a challenging topic usually involving a multimodal concept.

METHODS

We report our experience with hyperbaric oxygen (HBO) therapy in five children presenting with brain abscesses between 1995 and 2002 at the Department of Neurosurgery, Graz. Mean age was 14.8 (range 11-17 years). All abscesses were located supratentorially. One child had a single abscess and one had multilocated abscesses. Two other patients presented with both subdural empyema and brain abscess, one of them showing an epidural empyema as well. In another child, the brain abscess was associated with meningoencephalitis and subdural empyema. In all of them the underlying condition was spread of infection from the paranasal sinuses, except for one, who was immunocompromised due to cytotoxic chemotherapy for acute lymphocytic leukaemia.

RESULTS

One single brain abscess and one of the multiple abscesses were drained. All subdural/epidural empyemas were treated surgically. Antibiotics were administered intravenously for 13 to 22 days (mean 22 days). All patients underwent HBO therapy; the number of treatments ranged from 26 to 45 "dives" (mean 30). Treatments were given once daily at 2.2 atmosphere absolutes for 60 min at 12 m. During the hospital stay all improved their clinical condition, with continued regression of abnormalities on magnetic resonance imaging (MRI). In the following weeks, other interventions were performed to treat the origin of the infections. At 6 months follow-up they were all in good clinical condition, either symptom free or with minor residual symptoms. MRI at this time showed no evidence of disease in three, a residual dural enhancement in one and a residual shrunken collection in the child with multilocated abscesses. No recurrence was observed during a mean follow-up of 21 months (range from 7 to 72 months).

CONCLUSION

HBO therapy in children with brain abscesses seems to be safe and effective, even when they are associated with subdural or epidural empyemas. It provides a helpful adjuvant tool in the usual multimodal treatment of cerebral infections and may reduce the intravenous course of antibiotics and, consequently, the duration of hospitalization. Multidisciplinary management is recommended to optimize care for these critically ill children.

Stereotactic Aspiration and Antibiotic Treatment Combined with Hyperbaric Oxygen Therapy in the Management of Bacterial Brain Abscesses

OBJECTIVE:

Despite advances in surgical techniques in the management of the brain abscess, long-term antibiotics are as crucial to cure as the initial surgical procedure itself. This study was designed to evaluate the effect of adjuvant hyperbaric oxygen (HBO) therapy on the duration of antibiotic treatment.

METHODS:

Between 1999 and 2004, 13 patients with bacterial brain abscesses treated with stereotactic aspiration combined with HBO and systemic antibiotic therapy. Patients younger than 18 years of age were excluded from this study. Postoperatively, all patients were given a 4-week course of intravenous antibiotics. Additionally, patients received hyperbaric oxygen (HBO, 100% O2 at 2.5 ATA for 60 min) twice daily for five consecutive days, and an additional treatment (100% O2 at 2.5 ATA for 60 min daily) was given for 25 days.

RESULTS:

There were eight male and five female patients. Their ages ranged between 18 and 71 years, with a mean of 43.9 years. The average duration of follow-up was 9.5 months (range, 8–13 mo). This treatment modality allowed infection control and healing for all 13 patients with 0% recurrence rate. HBO treatment was tolerated well, and there were no adverse effects of pressurization. At the end of the follow-up period, 12 patients had a good outcome: nine are without sequelae, and three have a mild hemiparesis but are capable of self-care. One patient has a moderate hemiparesis.

CONCLUSION:

Although the number of patients is small, this series represents the largest reported group of brain abscess patients treated with stereotactic aspiration combined with antibiotic and HBO therapy. Our preliminary results indicate that the length of time on antibiotics can be shortened with the use of HBO as an adjunctive treatment.

Brain abscess: clinical experience and analysis of prognostic factors

BACKGROUND

Over the past 2 decades, the diagnosis and treatment of brain abscess have been facilitated by a number of technological advancements, which have resulted in a significant improvement of outcome. The aim of this manuscript is to review our experience, to determine the factors related to the outcome, and to improve the therapeutic strategy for this disease.

METHODS

From 1986 to 2002, 178 consecutive patients with bacterial brain abscess were treated at the National Taiwan University Hospital, Taipei, Taiwan. We reviewed their clinical presentation, bacteriology, treatment, and outcome retrospectively. Groups were compared by chi2 test, Fisher exact test, or t test as appropriate. Multivariate logistic regression with backward selection was used to select the set of covariates that were independently associated with outcome.

RESULTS

One hundred eleven patients (62%) had favorable outcome, 14 patients (8%) had severe disability, 9 patients (5%) became vegetative, and 44 (25%) died during hospitalization. Patients with better Glasgow Coma Scale (GCS) on admission, no underlying disease, positive culture, or surgical treatment were more likely to have a good outcome. Patients with nasopharyngeal carcinoma, acquired immunodeficiency syndrome, hematologic disease, deep-seated abscess, or medical treatment alone were more likely to have a poor outcome. Multivariate analysis revealed that only GCS, immunodeficiency, and presence of underlying disease related with outcome.

CONCLUSIONS

The poor prognostic factors of brain abscess are poor GCS, immunodeficiency, and presence of underlying disease. Aggressive treatment with surgery when indicated and careful management of specimen for culture might improve outcome.

Prognosis of gliomas in the 1970s and today

The benefit of the current strategy for diagnosis (magnetic resonance, [MR] imaging) and treatment (surgery, chemotherapy, radiotherapy) of gliomas, in contrast to the standard treatment in use before MR imaging and the microsurgical era, has not yet been determined. A retrospective statistical analysis was performed for all patients with glioma who underwent surgery at a single institution between 1965 and 1974 (Group I, 88 patients) or 1986 and 1995 (Group II, 249 patients). There were no major differences in symptomatology, tumor localization, and number of surgical procedures. The mean time until tumor diagnosis was significantly shorter in Group II (Group I, 48 weeks; Group II, 19.5 weeks). Also, the mean time from initial symptoms to surgery was significantly shorter for high-grade gliomas in Group II (Group I, 16.3 weeks; Group II, 11.7 weeks). For high- as well as low-grade gliomas, there was a clear reduction of the perioperative morbidity and mortality rates in Group II. Nevertheless, for the postoperative duration of survival, no significant differences were demonstrated for high- or low-grade gliomas. Based on the results of this study, the perioperative morbidity and mortality rate as well as the time from diagnosis to treatment have been remarkably reduced within the last 30 years. Nevertheless, the overall prognosis for patients with gliomas has not changed from the 1970s until today. Thus, the introduction of modern diagnostic modalities and surgical procedures has not improved the outcome in patients with glioma. Further research to improve the treatment of this disease is urgently needed.

Diagnosis and management of brain abscess and subdural empyema

Advances in the diagnosis and treatment of brain abscess and subdural empyema with neuroimaging techniques such as computerized tomography, magnetic resonance imaging, magnetic resonance spectroscopy, the availability of new antimicrobials, and the development of novel surgical techniques have significantly contributed to the decreased morbidity and mortality associated these infections. Determination of point of entry and source of infection is paramount to adequate treatment. A high index of suspicion along with typical clinical presentation of headache, seizures, or focal neurologic signs can lead to early diagnosis so that effective therapy can be instituted as soon as possible. This review discusses etiology and pathology of brain abscess and subdural empyema, neuroimaging techniques useful in the diagnosis, and optimal treatment, including use of antimicrobials and surgical procedures.

A twelve-year review of central nervous system bacterial abscesses; presentation and aetiology

OBJECTIVES

To review and document the changing patterns in diagnosis, causes and treatment of bacterial infections of the central nervous system (CNS) in a national neurosurgical unit only in patients from whom a specimen was obtained for culture.

METHODS

The case notes, radiological results and laboratory records of all 163 patients in our institution who underwent a neurosurgical procedure between 1988 and 2000 for a CNS abscess in a national center were reviewed retrospectively. Those patients from whom there were no operative specimens (i.e. neurosurgical intervention was not performed) and who were treated empirically were excluded, as were patients with mycobacterial infection.

RESULTS

The mean age of the 163 patients was 35.2 years. Headache, pyrexia and an altered mental state were the commonest presentations. The frontal lobe was the commonest anatomical site (62 patients, 38%) and the majority of abscesses occurred following community infections such as sinusitis and mastoiditis; no primary source could be identified in 32 (20%) patients. Bacteria were isolated from 73% of patients and polymicrobial infections occurred in 29 (17.7%) patients. Anaerobes accounted for only 13.6% of isolates and methicillin-resistant Staphylococcus aureus (MRSA) was isolated on five occasions, all in the last five years of this review. Sixteen (9.8%) patients died prior to discharge or transfer back to the original referring hospital and 18 (11%) patients developed epilepsy.

CONCLUSION

There was a relatively high incidence of polymicrobial infection but the number of specimens with anaerobes was small, which may be because of the use of empiric metronidazole before surgical intervention. Most infections were community-acquired and responded well to a combination of surgical drainage and antibiotic therapy. The emergence of MRSA in this group of patients is, however, worrying.

[Intracranial purulent collections. Review of 34 surgically treated cases in 12 years (1989-2000)]

We made a revision of 34 cases of intracerebral supurations (31 brain abscesses and 3 subdural empyemas) treated at our department of neurosurgery of "Mutua de Terrassa" during the period of 1989-2000. Treatment used was tapping of the abscess and aspiration in 28 cases and craneotomy and resection in only two cases. Three subdural empyemas were treated with burr-holes and aspiration. Results were evaluated using the Glasgow Outcome Scale at 6 months after discharge, resulting in 7 deaths (20.6%), 17 fully recovered patients (50%) and 10 with minor deficits (29.4%). Glasgow Coma Score at admission and the age were the unique variables significantly correlated with the final outcome. After analyzing the cost of treatment in our patients we suggest using antibiotic ambulatory treatment when the disease shows an adequate clinical and radiological response, thus permitting to shorten the usually long period of hospitalization of patients with intracerebral supurative diseases.

Intracranial complications of acute frontal sinusitis

Despite advances in the diagnosis and treatment of acute frontal sinusitis, there is still significant occurrence of intracranial complications. Urgent surgical evacuation of any intracranial collection is required; however, the surgical management of the associated sinusitis remains controversial. Ten patients presented to this department over a 12-month period with subdural empyema secondary to acute frontal sinusitis. Four patients had a coexisting Pott's puffy tumour and one patient had a periorbital abscess. Each patient was managed using a multidisciplinary approach. A frontal sinus trephine/drain +/- antral washout was performed at the same time as craniotomy with evacuation of the empyema. With this approach only two patients suffered long-term morbidity in our series, in the form of persistent neurological or cognitive deficit. No patient required a definitive sinus procedure. This study emphasizes the need for the early assessment and intervention of patients with an intracranial complication secondary to acute frontal sinusitis. Further assessment of the underlying sinus disease is indicated during outpatient follow up after the acute episode.

Streptococcal brain abscess: analysis of clinical features in 20 patients

BACKGROUND

To assess the clinical features and therapeutic outcomes of brain abscess caused by streptococci.

METHODS

Twenty patients, 18 males and 2 females, aged 3 to 76 years, collected over a 14-year period, have been identified at Kaohsiung Chang Gung Memorial Hospital.

RESULTS

Among these 20 patients, 13 had viridans streptococci infection alone, one had non-A, non-B, and non-D streptococci infection alone, and the other 6 had mixed infections each including streptococci. The locations of all of the abscesses were supratentorial. Among these patients, 18 had a single abscess and 2 had multiple abscesses. Underlying conditions were common in our patients, including head trauma, heart disease, otopharyngeal infection, and medical procedures. Nineteen patients were treated surgically and 1 was treated with antibiotics alone. Nineteen survived and 1 died, with an overall mortality rate of 5%.

CONCLUSION

The clinical presentations and underlying conditions varied according to the different streptococcal species. Streptococcal brain abscesses accounted for 17% of our cases with brain abscesses, and 30% of our streptococcal infections had polymicrobial infections. Although streptococcal brain abscesses were commonly associated with otopharyngeal infections or infectious endocarditis, they also appeared to be often related to neurosurgical events or medical procedures in recent years. Based on our study, prognosis is favorable with early diagnosis and prompt treatment.