Update and approach to patients with brain abscess

PURPOSE OF REVIEW

The epidemiology of brain abscess has changed in recent decades. Moreover, acute and long-term management remains challenging with high risks of mortality and neurological sequelae. This review describes recent advances in epidemiology, diagnosis, and treatment of brain abscess.

RECENT FINDINGS

The incidence of brain abscess is increasing, especially among elderly individuals. Important predisposing conditions include dental and ear-nose-throat infections, immuno-compromise, and previous neurosurgery. Molecular-based diagnostics have improved our understanding of the involved microorganisms and oral cavity bacteria including anaerobes are the predominant pathogens. The diagnosis relies upon a combination of magnetic resonance imaging, neurosurgical aspiration or excision, and careful microbiological examinations. Local source control by aspiration or excision of brain abscess combined with long-term antimicrobials are cornerstones of treatment. Long-term management remains important and should address neurological deficits including epilepsy, timely diagnosis and management of comorbidities, and potential affective disorders.

SUMMARY

A multidisciplinary approach to acute and long-term management of brain abscess remains crucial and source control of brain abscess by neurosurgery should be pursued whenever possible. Numerous aspects regarding diagnosis and treatment need clarification. Nonetheless, our understanding of this complicated infection is rapidly evolving.

Cerebral phaeohyphomycosis due to Cladophialophora bantiana: case report and systematic review of cases

PURPOSE

Cladophialophora bantiana is a wonted melanized fungus causing brain abscess. In past many cases were reported from Asia, particularly from India. Of late, there is a rise in cases in places besides Asia and hence a review of the cases is warranted.

METHODS

We present a case of fatal cerebral phaeohyphomycosis caused by C. bantiana and conduct a systematic review of culture confirmed brain abscess due to C. bantiana reported between 2015 and 2022.

RESULTS

Of the 39 cases found, majority (68%) were immunocompromised. The various clinical presentations were headache (53%), hemiparesis (34%), visual disturbance (25%), altered sensorium (18%), aphasia/dysarthria (12%) and seizures (9%). Isolated lesion was observed in 18 (60%) patients. In the sequence of occurrence, the lesions were in frontal (30%), temporal (27%) and parietal (20%) region. There were five cases with coinfections such as concurrent detection of Nocardia pneumonia in two cases, toxoplasma DNA in brain abscess, coexisting pulmonary Cryptococcus neoformans infection and coexisting Candida in a case of brain abscess in one case each. Surgical intervention was performed in 84% cases. Antifungal therapy included voriconazole (80%), liposomal amphotericin B (76%), 5-fluorocytosine (30%), posaconazole (10%), and amphotericin B deoxycholate (6%). The overall mortality was 50% with lower mortality (42%) in regions outside Asia compared to Asia (63.6%) though not statistically significant.

CONCLUSIONS

C. bantiana brain abscess is an emerging infection worldwide. Next generation sequencing is an upcoming promising diagnostic test. Early complete excision of the lesion with effective antifungals may improve the outcome.

Brain Abscess Caused by Oral Cavity Bacteria: A Nationwide, Population-based Cohort Study

BACKGROUND

Oral cavity bacteria are the most frequent etiology of brain abscess. Yet, data on the clinical presentation and outcome are scarce.

METHODS

We performed a nationwide, population-based study comprising all adults (aged ≥18 years) with brain abscess due to oral cavity bacteria in Denmark from 2007 through 2020. Prognostic factors for unfavorable outcome (Glasgow outcome scale, 1-4) were examined using modified Poisson regression to compute adjusted relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

Among 287 identified patients, the median age was 58 years (interquartile range, 47-66), and 96 of 287 (33%) were female. Preexisting functional impairment was absent or mild in 253 of 280 (90%), and risk factors for brain abscess included immunocompromise in 95 of 287 (33%), dental infection in 68 of 287 (24%), and ear-nose-throat infection in 33 of 287 (12%). Overall, a neurological deficit was present in 246 of 276 (86%) and in combination with headache and fever in 64 of 287 (22%). Identified microorganisms were primarily the Streptococcus anginosus group, Fusobacterium, Actinomyces, and Aggregatibacter spp., and 117 of 287 (41%) were polymicrobial. Unfavorable outcome occurred in 92 of 246 (37%) at 6 months after discharge and was associated with antibiotics before neurosurgery (RR, 3.28; 95% CI, 1.53-7.04), rupture (RR, 1.89; 95% CI, 1.34-2.65), and immunocompromise (RR, 1.80; 95% CI, 1.29-2.51), but not with specific targeted antibiotic regimens. Identified dental infection was associated with favorable prognosis (RR, 0.58; 95% CI, .36-.93).

CONCLUSIONS

Brain abscess due to oral cavity bacteria often occurred in previously healthy individuals without predisposing dental infections. Important risk factors for unfavorable outcome were rupture and immunocompromise. However, outcome was not associated with specific antibiotic regimens supporting carbapenem-sparing strategies.

Brain abscess of odontogenic origin: A case report and literature review

BACKGROUND

The objective of this study is to investigate and understand the characteristics of odontogenic brain abscess.

METHODS

A case of brain abscess suspected to be caused by odontogenic infection was documented, and a comprehensive analysis and summary of odontogenic brain abscess cases reported in various countries over the past 20 years was conducted.

RESULTS

Based on the analysis and synthesis of both the present and previous reports, we have examined and consolidated the distinctive features of odontogenic brain abscess, the potential transmission pathway of pathogenic bacteria, diagnostic assertions, verification techniques, and crucial considerations during treatment.

CONCLUSION

This investigation contributes to an enhanced comprehension and improved clinical identification of odontogenic brain abscess.

Brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum mimicking acute stroke

We described a case of a 65-year-old man with a brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum. The patient presented right central facial nerve palsy, mutism and right hemiparesis at the examination. The patient underwent a left frontal craniotomy with evacuation of the brain abscess. Specimens were collected for microbiological analysis and intravenous treatment was started with levetiracetam, dexamethasone, meropenem (1 g/8 h) and linezolid (600 mg/12 h). After identification of anaerobic bacteria the antibiotic treatment was changed to piperacillin/tazobactam (4 g/0,5 g/8 h), fulfilling 8 weeks of antibiotic with good clinical and radiological evolution.

Identification of bacterial pathogens in brain abscesses by metagenomic approach using nanopore 16S amplicon sequencing

Brain abscess is medically challenging. In this study, we applied nanopore sequencing for 16S rRNA analysis and investigated its efficacy and diagnostic value for patients with brain abscesses. Genomic DNA was extracted from the pus samples (n = 27) of brain abscess, and 16S rRNA genes were amplified by PCR. Sequencing libraries were generated using a rapid barcoding kit, and the generated reads were analyzed using the EPI2ME16S workflow. A conventional culture study was performed. More sensitive identification of pathogens was made by 16S sequencing, faster than the culture study. The proportion of anaerobic bacteria identified by 16S sequencing was higher (75%) than that obtained by culturing (32%). Polymicrobial infections were identified in 10 cases (40%) by 16S sequencing, while the culture study identified multiple bacteria in only 2 cases (8%). 16S sequencing was useful for identifying the composition of polymicrobial infections, including rare pathogens, and for the initial diagnosis of space-occupying lesions.

Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections

BACKGROUND

Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors.

METHODS

Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses.

RESULTS

From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses.

CONCLUSIONS

Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.

First case of Rhinocladiella mackenziei brain abscess in Turkey: Case report and review of the literature

Rhinocladiella mackenziei is a highly neurotropic fungus, mainly reported from the Middle East. However, in recent years, there have been some cases from outside this region. We described an additional fatal case of R. mackenziei cerebral infection for the first time from Turkey and made a literature review of all previously reported cases. During 34 years (1988-2022), there have been 42 R. mackenziei brain abscess cases. Most patients have been reported from Saudi Arabia (n = 14, 33.3%). It is noteworthy that 40.5% of patients, including our case, were immunocompetent at initial diagnosis and mostly presented with a single lesion (n = 10, 23.8%). The most frequent comorbidities were solid organ transplant (n = 9, 21.4%), diabetes mellitus (n = 6, 14.3%), malignancy (n = 6, 14.3%) and prior surgery (n = 3, 7.1%). The most commonly used initial antifungal regimen were amphotericin B together with itraconazole (n = 9, 21.4%), combinations of lipid preparations of amphotericin B, voriconazole and/or posaconazole (n = 9, 21.4%) and amphotericin B alone (n = 8, 19%). Although both surgical procedures and antifungal medication in the majority of patients were performed, mortality rates remained high (90.4%). The area at risk of R. mackenziei cerebral abscess cases extends to other countries. Clinicians should be aware of this emerging disease and take a detailed travel history in patients with atypical and undocumented brain abscesses. Our case confirms the hypothesis that this fungus might spread more widely than previously predicted regions.

Culture-Negative Fusobacterium nucleatum Brain Abscess and Pleural Empyema Cases Revealed by 16S rRNA Sequencing

BACKGROUND

We reported two Fusobacterium nucleatum cases each of brain abscesses and pleural empyema, using 16S rRNA sequencing technology.

METHODS

We reviewed clinical records and microbiological findings in four patients with F. nucleatum infection.

RESULTS

All conventional culture results from peripheral blood, cerebrospinal fluid, and pleural fluid samples were found to be negative for this pathogen. Three patients were treated with antimicrobial agents for more than a week before specimen sampling. All patients recovered from their fusobacterial infections and were discharged.

CONCLUSIONS

Molecular identification methods such as 16S rRNA sequencing should accompany conventional culture to detect obligate anaerobic bacteria in deep-seated sites and organs.

Brain abscesses caused by anaerobic bacteria

OBJECTIVES

The objective of this study was to review the characteristics, causative bacteria, treatment and outcomes of brain abscesses due to anaerobes in our health setting.

METHODS

A retrospective analysis of all brain abscesses caused by anaerobic bacteria over the period 2005-2021 was performed.

RESULTS

Out of 300 brain abscesses identified during the study period, 31 were produced by anaerobic pathogens, either alone (monomicrobial infection) or together with aerobic and/or anaerobic bacteria (polymicrobial infection). The mean age of the 31 patients was 53 years, and 61.2% were male; 51.6% of infections were polymicrobial, with only four (12.9%) caused by anaerobic bacteria alone. Forty-three anaerobic bacteria were isolated: Cutibacterium acnes in thirteen (41.9%), Parvimonas micra in eight (25.8%), and Prevotella spp. in seven (22.5%). The most frequent etiologies were local neurosurgery (13/41.9%) and contiguous otogenic, oral, or sinus foci of infection (8/28.8%). Cancer was present in eight patients (28.8%), headaches in seventeen (54.8%), and fever in nine (28.8%). All patients received both surgery and antimicrobial therapy. The abscess was in the frontal region in 12 patients (38.7%) and in the parietal region in 11 (35.4%). A good outcome was obtained in all patients.

CONCLUSIONS

Anaerobes were isolated in 10.3% of patients with brain abscesses in our health setting, similar to other reports. C. acnes was the most frequently detected anaerobe, especially in neurosurgical patients.

Culture on Selective Media and Amplicon-Based Sequencing of 16S rRNA from Spontaneous Brain Abscess-the View from the Diagnostic Laboratory

Forty-one stored samples from cases of spontaneous brain abscess were investigated to gain insight into the natural history, causative agents, and relevant laboratory diagnostics of a rare infection. Samples from a larger collection were selected based on retrospective analysis of patient records. All samples were subjected to amplicon sequencing of 16S rRNA gene fragments. Supplementary culture on selected media was performed as suggested by bioinformatics analysis. For three cases, no microorganism was disclosed, while Toxoplasma gondii, Aspergillus fumigatus, and various bacteria were the cause of 1, 2, and 35 cases, respectively. Bacterial infections were monomicrobial in 20 cases and polymicrobial in 15; the microorganisms of the latter cases were restricted to residents of cavum oris. Amplicon sequencing did not further enhance the importance of the Streptococcus anginosus group, which was involved in 17 cases, and the single primer set used may be suboptimal for amplification of Actinomyces and Nocardia. But, amplicon-based sequencing unquestionably expanded the number of polybacterial infections, with focus on the Fusobacterium nucleatum group, Parvimonas, and Porphyromonas. Culture on selective media confirmed the presence of F. nucleatum group bacteria, which attained a prominence in spontaneous brain abscess similar to the S. anginosus group. Metagenomics is a powerful tool to disclose the spectrum of agents in polymicrobial infections, but a reliable cutoff value for substantial detection is complex. Commercial media for isolation of F. nucleatum group bacteria from mixed infections are available, and these pathogens should be carefully characterized. Isolation of Parvimonas and Porphyromonas in polymicrobial infections has not been resolved. IMPORTANCE Polymicrobial brain abscess is a challenge to the clinical microbiology laboratory due to the aggregative nature of the dental and oral microbiota. Because polymicrobial infections may escape detection by conventional culture methods, directed therapy toward a single detected bacterium is problematic. Amplicon-based sequencing provides important clues to these infections, but only cultured microorganisms can be fully characterized, subjected to antimicrobial susceptibility testing, and formally named. By use of specific selective culture plates, we successfully isolated bacteria of the Fusobacterium nucleatum group, and these bacteria rose to the same prominence as the widely recognized pathogen, the Streptococcus anginosus group. Named and unnamed members of the Fusobacterium nucleatum group must be further investigated to gain insight into a rare but grave disease.

Observational study of the clinical utility of sulfamethoxazole serum level monitoring in the treatment of brain abscesses due to Nocardia species

Although there is a lack of data in trimethoprim-sulfamethoxazole (TMP-SMX) serum monitoring utility for invasive nocardial infections, therapeutic drug monitoring is widely used to optimize dosing and avoid adverse reactions that may cause treatment interruption.We retrospectively reviewed all adults who received TMP-SMX to treat nocardial brain abscess and had SMX serum level testing from 2010 to 2020.Twenty-two patients received treatment with TMP-SMX for Nocardia species brain abscess and 16 (72.7%) had a reported SMX level, with a median patient age of 65.5 years (interquartile range, IQR 59.5-72.5). Compared to those who did not have a documented SMX serum level, patients with SMX levels had a shorter median course of TMP-SMX treatment (322 days [IQR 188-365] vs. 365 [IQR 224-365]; P = .31) and higher therapeutic induction dose (10 [62.5%] vs. 3 [50%]; P = .92). Similarly, they were more frequently on hemodialysis (3 [13.6%] vs. 1 [4.5%]; P = > .99). The median peak level was 158.5 (IQR 120-218) μg/mL, collected at 2 hours (75%) post-administration in the induction phase (81.3%). Patients with documented SMX levels had fewer reported drug toxicity (5 [31.3%] vs. 4 [66.7%]; P = .1) than those without SMX levels. Among the five patients who reported TMP-SMX-related toxicity, 4 (80%) had an SMX peak level >150 μg/mL. There was no difference in the cure, relapse, and death rates among the two groups.While SMX level was not associated with Nocardia species brain abscess cure rates and mortality, most patients with SMX peak >150 μg/mL experienced drug toxicity.

Klebsiella pneumoniae-related brain abscess and meningitis in adults: Case report

INTRODUCTION

Klebsiella pneumoniae is once thought to be a less common cause of brain abscess in adults and is mainly hospital-acquired. Community-acquired CNS infection (brain abscess and meningitis) caused by K pneumoniae without other metastatic septic abscesses is exceedingly rare. Therefore, we present a rare adult patient with invasive cerebral abscess and meningitis without other invasive abscesses related to K pneumoniae.

PATIENT CONCERNS

A 64-year-old woman experienced a sudden onset of severe continuous headache accompanied by intermittent nausea, vomiting, and fever. Meanwhile, she experienced tinnitus and had a feeling of swelling in the right ear.

DIAGNOSIS

Cranial magnetic resonance imaging revealed abnormal hyperintensity signals in the left head of the caudate nucleus. The next generation sequencing of cerebral spinal fluid showed infection with K pneumoniae. The patient was diagnosed with K pneumoniae-related brain abscesses and meningitis.

INTERVENTIONS

Antibacterial treatment was carried out for 2 months.

OUTCOMES

The patient recovered well.

CONCLUSION

Despite the progress of modern neurosurgical techniques, new antibiotics, and modern imaging techniques, brain abscesses are still a potentially fatal infection. Streptococci are common organisms that result in brain abscesses. Nevertheless, Klebsiella species, once thought to be a less common cause of brain abscess in adults, has become an increasingly important cause of brain abscess, especially in Asia.

Bacterial Brain Abscess: An Outline for Diagnosis and Management

Despite advances in the diagnosis and management of brain abscess, significant associated morbidity and mortality remain high. We retrospectively reviewed adults who presented with pyogenic brain abscess from January 1, 2009, through June 30, 2020. Overall, 247 patients were identified. The median age was 59 years, and 33.6% had a history of head and neck surgery or traumatic brain injury. Diagnostic brain magnetic resonance imaging (MRI) was performed in the bulk (93.1%) of patients. A total of 205 patients (83%) were managed with medical and surgical treatment. The most common definitive antibiotic regimen was monotherapy (48.2%). The median duration of antimicrobial therapy was 42 days. Compared with those who received combined therapy, patients with medical therapy alone had a higher mortality rate (21.4% vs 6%; P =. 003) with more neurologic sequelae (31% vs 27.1%; P = .5). Most patients with brain abscesses are older with multiple underlying comorbidities, and one-third had antecedent head and neck surgery. A prompt combined surgical and medical approach with prolonged antimicrobial therapy may cure the infection with avoidance of permanent residual neurologic deficits.

Brain abscess due to listeria monocytogenes: A case report and literature review

RATIONALE

Listeria monocytogenes infective encephalitis is a rare phenomenon, which is more common in people with changed eating habits and immunodeficiency. To the best of our knowledge, listeria brain abscess is even more rare. In this case report, we summarized the clinical characteristics of listeria brain abscess, in order to explore the diagnosis and treatment of Listeria brain abscess, and raise awareness and attention to the disease.

PATIENT CONCERNS

A 64-years-old female patient presented to our institution with 4 days of right arm and leg weakness, the salient past history of the patient was nephrotic syndrome, membranous nephropathy diagnosed 6 months prior, for which she was prescribed glucocorticoids and cyclophosphamide.

DIAGNOSIS

Listeria monocytogenes was cultured in the blood of the patient. Comprehensive medical history and imaging features, she was diagnosed as listeria brain abscess.

INTERVENTIONS

The patient underwent ampicillin combined with meropenem but not surgery.

OUTCOMES

The patient recovered without complications. At a 3-month follow-up visit, the condition was better than that before treatment.

LESSONS

Listeria brain abscess is an unusual form of listeriosis, its clinical manifestations lack specificity. Early accurate diagnosis and standardized treatment can effectively promote the recovery of neurological function as well as reduce the morbidity and mortality and improve the prognosis.

A Case of Brain Abscess Caused by Actinomyces Cardiffensis and Parvimonas Micra

Brain abscesses occur in 0.3-1.3 per 100,000 worldwide each year with 0.4-0.9 in Japan alone. Most of the causes are direct infection from a nearby infectious lesion and are rarely caused by an odontogenic infection. Here, we reported a case of brain abscess suspected to be associated with odontogenic infection. The patient was a 55-year-old woman. Blurred eyes and pain in the left eye noted, for which she consulted an ophthalmologist, but her eyes were normal. She was conscious and was able to converse clearly, but she could not read the letters and had difficulty in writing at the time of admission. A brain abscess was diagnosed based on the head magnetic resonance imaging (MRI) and clinical course, and a small craniotomy abscess drainage was performed. A. cardiffensis and P. micra were detected in the abscess, suggesting the involvement of periodontal disease bacteria. After the surgery, antimicrobial treatment was performed for about 2 months. At the same time, perioperative treatment was performed. On the 70^th day after the surgery, tooth extraction, which was considered as the source of infection, was performed. The patient was discharged 74 days after surgery. A good turning point was obtained without relapse of symptoms.

Brain abscess in a patient with psoriatic arthritis treated with adalimumab: A case report

RATIONALE

In patients receiving biological therapies, serious infections are a major concern. Infections associated with anti-tumor necrosis factor antibody therapy include tuberculosis, viral, fungal, and bacterial infections. Likewise, severe infections of the upper and lower respiratory tract, lung, skin and soft tissue, urinary tract, gastrointestinal tract, joint, and bone have also been reported previously. However, infections involving the central nervous system are rare, especially an intracranial infection caused by odontogenic infection. To date, only few cases have been reported of this infection. This is the first case of a patient with psoriatic arthritis receiving adalimumab and developing brain abscess of odontogenic origin.

PATIENT CONCERNS

A 39-year-old male with psoriatic arthritis receiving adalimumab treatment came to the emergency department with initial presentation of sudden onset convulsions. He had been receiving adalimumab treatment for 1 month. Two days after the third injection, the patient had an episode of sudden-onset general convulsion for nearly 5 min with the upgazing and general tonic presentation. Magnetic resonance imaging (MRI) showed left frontal lobe brain abscess. Pus culture from the brain abscess detected Streptococcus sanguinis (S. sanguinis), Fusobacterium nucleatum (F. nucleatum), and Parvimonas micra (P. micra).

DIAGNOSIS

Brain abscess with odontogenic infection.

INTERVENTIONS

The patient received left frontal craniotomy, abscess drainage and systemic empiric antibiotics treatment with vancomycin, cefepime, and metronidazole. Due to drug rash with eosinophilia and systemic symptoms during the treatment, vancomycin and metronidazole were discontinued, and systemic antibiotics were switched to teicoplanin and ceftriaxone.

OUTCOMES

A brain MRI follow-up performed after 1 month of initial treatment revealed the reduced size of the abscess lesion and minimal oedema. The patient was discharged with stable condition.

LESSONS

To the best of our knowledge, this is the first case of a patient with psoriatic arthritis receiving adalimumab and developing brain abscess of odontogenic origin. Such a rare diagnosis must be kept in mind when patients treated with adalimumab present with sudden-onset convulsions. Careful dental examination should be performed before administration of adalimumab.

[Invasive fungal brain abscess: a case report]

Mucormycsois, also known as zygomycosis, is an extremely serious acute invasive fungal infection（IFI）. The disease progresses rapidly and the mortality rate is high. Even if cured, it may leave behind serious sequelae. Immunocompromise is at high risk of mucormycosis. Rhino-orbital-cerebral mucormycosis（ROCM） is the most common type of mucormycosis. It can manifest as headache, nasal obstruction, exophthalmos, ophthalmoplegia and nerve palsy, loss of vision, arterial embolism, etc. A case of ROCM is reported in this paper. The etiology, course of development, clinical and imaging manifestations and treatment of ROCM are described in detail.

Sigmoid Sinus Thrombosis with Cerebellar Tuberculous Abscess: A Rare Case of Chronic Headache with Vision Loss

Cerebral venous sinus thrombosis (CVST) is a rare form of brain stroke which is often misdiagnosed. We present a case of CVST due to cerebellar tuberculous abscess. A 41-year female patient was admitted with chronic occipital headache, diminished vision, and fever. The initial brain CT scan was negative, but subsequent imaging (MRI with MRV) showed cerebellar abscess with sigmoid sinus thrombosis. Fundoscopy revealed bilateral optic atrophy. Marked improvement (subjective and objective) was noted after 4 weeks with anti-tuberculosis chemotherapy and anticoagulants. Vision loss was irreversible due to optic atrophy. The case is extremely rare due to the location, rare causative organism (tuberculosis) and complex clinical presentation (occipital headache with vision loss).

Primary pituitary abscess case series and a review of the literature

OBJECTIVE

Pituitary abscess is a rare condition, with approximately 300 cases reported in the literature. Primary pituitary abscess, the most common type, occurs in previously healthy normal glands. Secondary pituitary abscess is secondary to pre-existing lesions in the pituitary region, such as pituitary adenoma, Rathke's cleft cysts, or craniopharyngioma and infections.

MATERIAL AND METHODS

A total of 2281 patients underwent pituitary surgery via endoscopic transsphenoidal approach in Kocaeli University Pituitary Gland Research Center between 1997 and 2018. Among this cohort 9 patients (4 female and 5 male) were diagnosed with primary pituitary abscess based on both intraoperative findings and postoperative histopathological evidence.

RESULTS

Primary pituitary abscess incidence was obtained 0.39% in our center. Mean age of the patients was 50 years old. There was no history of pituitary surgery, radiotherapy and infection diseases in our patients. Visual symptoms were prominent in two patients, hypopituitarism was found in 5 out of the 9 patients. All patients have typical pituitary lesion on pituitary magnetic resonance imaging. Staphylococcus species were the most commonly isolated organisms in the culture. A few weeks of antibiotic therapy were administered after surgery.

CONCLUSION

Presentation of fever, headache, diabetes insipidus, hypopituitarism and a sellar cystic mass with an enhanced rim after gadolinium contrast on pituitary magnetic resonance imaging may be suggestive of a pituitary abscess. Transsphenoidal endoscopic surgery, proper antibiotics and appropriate hormone replacement therapy when necessary are the keys of pituitary abscess treatment.

ANTIBACTERIAL THERAPY FOR PURULENT-SEPTIC COMPLICATIONS IN PATIENTS WITH COMBAT RELATED PENETRATING CRANIOCEREBRAL GUNSHOT WOUNDS

Aim - to evaluate pathogens and their susceptibility to antibiotic therapy (ABT) in combat-related penetrating craniocerebral gunshot wound (PCGW) patients and develop recommendations for treatment of post-traumatic meningoencephalitis. We conducted a prospective analysis of examination and treatment results of 121 patients who were admitted to the Public Institution, Mechnikov Dnipropetrovsk Regional Clinical Hospital, Dnipro, Ukraine, from 25 May 2014, to 31 December 2017, and were successively enrolled in the study. Intracranial purulent-septic complications were diagnosed in 14 (11.6%) patients including eight cases of isolated meningoencephalitis, three cases of meningoencephalitis combined with ventriculitis, two cases of meningoencephalitis combined with ventriculitis and subdural empyema and one case of multiple brain abscesses. In most cases of combat-related craniocerebral wounds, infections are considered nosocomial and typically related to medical procedures and devices. In most cases, the effectiveness of first-line antibiotics was low, and it was often necessary to prescribe broad-spectrum ABT, including those related to second-line antibiotics and reserve drugs, according to the World Health Organisation classification. The use of initial de-escalation of empiric ABT with the broadest-spectrum drugs, mainly as a part of combination therapy for expected gram-positive and gram-negative aerobic and anaerobic infection pathogens, is recommended.

Polymicrobial Cerebral Abscess in a Child with Uncorrected Tetralogy of Fallot

Aggregatibacter aphrophilus and Beta haemolytic Streptococci Lancefield group F are part of the normal oral flora and are known to cause endocarditis, sinusitis, empyema, meningitis and septic arthritis. They are now emerging as a cause of brain abscess particularly in patients with congenital heart diseases. We report a case of a 10-year-old boy with Tetralogy of Fallot (TOF), who presented with fever, headache and drowsiness. Culture yielded the growth of Aggregatibacter aphrophilus and Beta hemolytic streptococci Lancefield group F. He became clinically stable after treatment with ceftriaxone.

The bacterial aetiology of pleural empyema. A descriptive and comparative metagenomic study

OBJECTIVES

The view of pleural empyema as a complication of bacterial pneumonia is changing because many patients lack evidence of underlying pneumonia. To further our understanding of pathophysiological mechanisms, we conducted in-depth microbiological characterization of empyemas in clinically well-characterized patients and investigated observed microbial parallels between pleural empyemas and brain abscesses.

METHODS

Culture-positive and/or 16S rRNA gene PCR-positive pleural fluids were analysed using massive parallel sequencing of the 16S rRNA and rpoB genes. Clinical details were evaluated by medical record review. Comparative analysis with brain abscesses was performed using metagenomic data from a national Norwegian study.

RESULTS

Sixty-four individuals with empyema were included. Thirty-seven had a well-defined microbial aetiology, while 27, all of whom had community-acquired infections, did not. In the latter subset, Fusobacterium nucleatum and/or Streptococcus intermedius was detected in 26 patients, of which 18 had additional facultative and/or anaerobic species in various combinations. For this group, there was 65.5% species overlap with brain abscesses; predisposing factors included dental infection, minor chest trauma, chronic obstructive pulmonary disease, drug abuse, alcoholism and diabetes mellitus. Altogether, massive parallel sequencing yielded 385 bacterial detections, whereas culture detected 38 (10%) and 16S rRNA gene PCR/Sanger-based sequencing detected 87 (23%).

CONCLUSIONS

A subgroup of pleural empyema appears to be caused by a set of bacteria not normally considered to be involved in pneumonia. Such empyemas appear to have a similar microbial profile to oral/sinus-derived brain abscesses, supporting spread from the oral cavity, potentially haematogenously. We suggest reserving the term 'primary empyema' for these infections.

Secondary pituitary abscess following transsphenoidal surgery with recurrent meningitis: A case report

RATIONALE

The transsphenoidal surgical (TS) approach to sellar masses is the preferred surgical route in most cases. Secondary pituitary abscess (PA) following TS is an extremely rare but serious postoperative complication with potentially high disability and mortality.

PATIENT CONCERNS

We describe an uncommon case of secondary PA in a 42-year-old woman, who underwent uncomplicated transsphenoidal procedures without cerebrospinal fluid leak, to treat primary Rathke cleft cyst. Without obvious cause, the patient suffered recurrent meningitis with complaints of headache, hyperpyrexia, and chills from 1 month after the operation.

DIAGNOSIS

There were no significant imaging findings until a new rim-enhancement lesion was seen in the sellar region on magnetic resonance imaging during the 6th episode of meningitis 11 months after the initial surgery. A diagnosis of secondary PA was considered; INTERVENTIONS:: Therefore, she underwent a 2nd TS with pus evacuation and antibiotic treatment.

OUTCOMES

She improved remarkably and had no recurrence of symptoms during the 9-month follow-up.

LESSONS

Our aim was to present this rare case and discuss the most likely etiologies and preventive measures for this condition. In patients with recurrent meningitis but dormant imaging manifestations after TS, the possibility of secondary PA should considered. Adequate surgical drainage with microbiology-guided antibiotic therapy is the 1st choice for treatment.

Successful surgical excision of cerebral abscess caused by Fonsecaea monophora in an immunocompetent patient and review of literature

Cerebral abscesses caused by dark-pigmented Fonsecaea fungi are rare, especially in otherwise healthy individuals. In this case report, we present a 61-year-old man from Moldova, living in the Czech Republic, who had worked as a locksmith on oil platforms in Turkmenistan, Kazakhstan, Sudan, and Iraq since 1999, and was admitted to a neurology ward for a sudden motion disorder of the right leg, dysarthria, and hypomimia. Imaging revealed presence of expansive focus around the left lateral ventricle of the brain and a pronounced peripheral edema. The intracranial infectious focus was excised under intraoperative SonoWand guidance. Tissue samples were histologically positive for dark-pigmented hyphae, suggesting dematiaceous fungi. Therefore, liposomal amphotericin B therapy was initiated immediately. Fonsecaea monophora was provisionally identified using ITS rDNA region sequencing directly from brain tissue. The identification was subsequently confirmed by cultivation and DNA sequencing from culture. The strain exhibited in vitro sensitive to voriconazole (MIC = 0.016 μg/mL) and resistance to amphotericin B (MIC = 4 μg/mL); therefore, the amphotericin B was replaced with voriconazole. Postoperatively, a significant clinical improvement was observed and no additional surgery was required. Based on the literature review, this is the third documented case of cerebral infection due to this pathogen in patients without underlying conditions and the first such case in Europe.

The Tunnel Sign Revisited: A Novel Observation of Cerebral Melioidosis Mimicking Sparganosis

The tunnel sign has been described as a specific feature of cerebral sparganosis. We present a case of a 55-year-old gentleman found to have cerebral melioidosis and with initial imaging mimicking the appearance of sparganosis. This suggests that the tunnel sign in brain abscesses may be specific for infection by Burkholderia Pseudomallei, Spirometra Mansoni or Listeria Monocytogenes.

Brain abscess caused by chronic invasive actinomycosis in the nasopharynx: A case report and literature review

RATIONALE

Actinomycosis is a rare anaerobic, gram-positive bacterial infection caused by Actinomyces, which is part of the normal flora in the oral cavity and respiratory and female genitourinary tracts. The cervicofacial area is the most common site of involvement, and involvement of the central nervous system is rare.

PATIENT CONCERNS

We report a case involving a 51-year-old woman who developed an actinomycotic brain abscess 15 months after the treatment of noninvasive nasopharyngeal actinomycosis, which recurred as an invasive form.

DIAGNOSES

Histopathological examination of the surgical specimens revealed actinomycosis.

INTERVENTIONS

The patient was treated by surgical drainage of the brain abscess and long-term antibiotic treatment.

OUTCOMES

Follow-up brain imaging performed 12 months after surgery showed complete resolution of the brain abscess, and there were no further signs or symptoms of infection.

LESSONS

Physicians should be aware of the typical clinical presentations of cervicofacial actinomycosis. Moreover, they should know that actinomycosis may mimic the process of malignancy at various anatomical locations.

Unusual synchronous liver and brain abscesses infected by rare Aerococcus viridians in a patient with pulmonary arteriovenous malformations on FDG PET/CT: A case report and literature review

RATIONALE

Pulmonary arteriovenous malformations (PAVMs) complicated with multiple organ abscesses is an uncommon manifestation. Because of the low incidence of the disease, F-18 fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG PET/CT) imaging studies for PAVMs complicated with multiple organ abscesses are scarce.

PATIENT CONCERNS

We report a case of a 54-year-old man presenting with PAVMs complicated with synchronous multiple organ abscesses founded by F-FDG PET/CT. F-FDG PET/CT revealed tortuous stripes and mass opacities with no significant FDG uptake in the left upper lung lobe. However, hypermetabolic lesions located in the anterior inferior segment of right hepatic lobe [with maximum standardized uptake value (SUVmax) of 10.7], and in the right basal ganglia with SUVmax of 14.1 were found by F-FDG PET/CT.

DIAGNOSES

A diagnosis of synchronous liver and brain abscesses infected by rare Aerococcus viridans was determined by tissue culture.

INTERVENTIONS

Vancomycin was provided intravenously, and oral linezolidate tablets were prescribed for anti-inflammatory treatment for 1 month. Liver and head magnetic resonance imaging was performed during the follow-up.

OUTCOMES

The lesion in the right basal ganglia was reduced, and the lesion in the right liver had disappeared, indicating the lesions were abscesses.

LESSONS

The present case indicated that the possibility of abscesses should be considered with patients with PAVMs, and whole-body F-FDG PET/CT is suggested to identify possible accompanying abscesses in multiple organs for PAVMs patients.

Multiple brain abscesses caused by Rhinocladiella mackenziei in an immunocompetent patient: a case report and literature review

Primary cerebral phaeohyphomycosis due to Rhinocladiella mackenziei is an extremely rare infection carrying more than 80% mortality, with most cases reported from the Middle East region. This darkly pigmented black yeast is highly neurotropic, aggressive and refractory to most antifungal agents. Here we present an immunocompetent elderly male, presenting with multiple brain abscesses, with R. mackenziei confirmed by nuclear ribosomal repeat region sequencing, who was successfully treated by surgical debridement and intravenous voriconazole. To our knowledge this is the first case reported from the United Kingdom. We also present a review of all such cases so far reported in the English literature world-wide, which we believe is a step further to understanding the pathogenesis and establishing effective treatment of this rare, yet often fatal disease.

Burr Hole Aspiration of Brain Abscess in Children with Cyanotic Heart Disease

OBJECTIVE

To determine the efficacy of burr hole aspiration of brain abscess in children with cyanotic heart disease in terms of number of aspirations and residual abscess.

STUDY DESIGN

Experimental study.

PLACE AND DURATION OF STUDY

Department of Pediatric Neurosurgery at The Children's Hospital and The Institute of Child Health, Multan, from July 2010 to June 2014.

METHODOLOGY

Pediatric patients of cyanotic heart disease with brain abscess were admitted. After taking history, clinical examination and necessary investigation, aspiration of abscess through a burr hole was performed. Data was collected through pre-designed proforma. Analysis of results was performed and comparison was made through statistical package for social sciences (SPSS-20).

RESULTS

Total number of patients were 50 with 31 (62%) male and 19 (38%) female children. Patients' age ranged from 5-10 years with mean age of 7.44 ±1.11 years. Single abscess in supra tentorial was commonly found in 44 (88%) patients. Multiple abscesses were present in 4 (8%) patients. Cerebellum was involved in 2 (4%) patients. Abscess was completely aspirated in single attempt in 37 (74%) patients, two attempts in 9 (18%) patients, and three attempts in 4 (8%) patients. No bacterial growth on culture was reported in 32 (64%) patients. Culture was positive in 18 (36%) patients. Postoperative hematoma developed in 2 (4%) patients. No mortality was reported in early postoperative period.

CONCLUSION

Aspiration of brain abscess in children with cyanotic heart disease through a burr hole is safe and successful.

[Disseminated nocardiosis caused by Nocardia nova with brain abscesses and osteomyelitis in an immunocompetent patient]

INTRODUCTION

Nocardia is an opportunist bacteria involved in patients with cellular immunodepression or chronic lung disease. The most frequent portals of entry are the respiratory tract by inhalation or direct inoculation through a cutaneous effraction. Nocardiosis may be localised or disseminated.

CASE REPORT

We report a rare case of disseminated nocardiosis to Nocardia nova with pulmonary, cutaneous, cerebral attacks and femoral osteomyelitis. The diagnosis was confirmed by prolonged cultures of the bronchoalveolar fluid and the pus extracted from a cutaneous lesion. The outcome was favorable under adapted and prolonged antibiotherapy with imipenem and amikacine and then cotrimoxazole.

CONCLUSION

This observation is original because it involves a immunocompetent patient with an association of two exceptional locations for N. nova: brain abscesses and femoral osteomyelitis. Screening for cerebral involvement should be systematic, even in the lack of neurological signs. An adapted and prolonged antibiotherapy must be conducted.

[Brain abcesses associated with a systemic infection by Nocardia Farcinica]

The prevalence of nocardia infections is increasing because of both improved detection laboratory techniques and a higher number of immunosuppressed patients. We report the case of a patient with brain abcesses resulting from nocardia farcinica cerebral dissemination associated with lung infection, endocarditis and ocular lesions for which we suspected a similar origin. This case gives the opportunity to discuss the main issues of these infections and the current therapeutic guidelines.

[Brain abscesses caused by Nocardia farcinica in a kidney transplanted man]

Nocardiosis is primarily an opportunistic infection caused by aerobic Gram-positive bacteria of the genus Nocardia. In this case report we describe a male patient who previously received a kidney transplant and was admitted to hospital with chills, headache and pain in the neck and left eye, tremor and coordination problems. A magnetic resonance scan of the brain showed multiple abscesses, and blood culture was positive for Nocardia farcinica. Nocardiosis of the central nervous system is a rare, but serious differential diagnosis in immunosuppressed patients with signs of high intracranial pressure.

Prevalence of hereditary hemorrhagic telangiectasia in patients operated for cerebral abscess: a retrospective cohort analysis

It is well described that patients with pulmonary arteriovenous malformations (PAVMs) and Hereditary Hemorrhagic Telangiectasia (HHT) have an increased risk of cerebral abscess (CA). However, as both CA and HHT are rare, the proportion of patients with CA who are diagnosed with HHT has not been previously described. A retrospective study was carried out of all patients treated surgically for CA between January 1995 and September 2014 at the Department of Neurosurgery, Odense University Hospital. The cases were then cross-referenced with the Danish HHT database. Eighty patients aged 5-79 years were included. The incidence of CA was 0.33/100,000/year. Two patients (2.5%) were registered as having HHT. Bacterial pathogens were identified in 70% of all cases, most frequently streptococci species (46.3%). The most common predisposing condition was odontogenic infection (20%), followed by post-operative infection (13.8%) and post-trauma (6.3%). Patients undergoing a full diagnostic program to determine predisposing conditions causing CA increased over the 20-year period from 11.8% to 65.2%. The 3-month and 1-year mortality rates were 7.5% and 11.25%, respectively. There is an overrepresentation of HHT patients in a cohort of patients with CA, and HHT should be investigated as the cause of the CA if no other apparent cause can be identified.

A rare case of methicillin resistant Staphylococcus aureus (MRSA) cerebral abscess secondary to conjunctivitis

This case report discusses the rare association of cerebral abscess related to conjunctivitis in an otherwise healthy child. A 6 year old boy presented with conjunctivitis was treated with topical antibiotics and resolved after a week. Conjunctival swab cultures grew MRSA. A month later he developed status epileptics and CT scans revealed a large cerebral abscess. He was treated with intravenous antibiotics which covered for MRSA, along with an incision and drainage for the cerebral abscess. Pus cultures grew MRSA. The patient recovered well with no disturbance in visual acuity or visual field. On post-operative follow ups, he had no other neurological deficit apart from a slight limp.

Meningitis and Ventriculitis due to Nocardia araoensis Infection

A 73-year-old man was admitted to our hospital with disturbance of consciousness, fever and headache. Cerebrospinal fluid (CSF) analysis revealed pleocytosis with neutrophil predominance, increased protein and low glucose. CSF and blood cultures yielded negative results. Antibiotics and antituberculous drugs were started for meningitis. An antimycotic was also added. The patient died from transtentorial hernia 99 days after admission. Autopsy revealed meningitis, ventriculitis and brain abscess, and Nocardia araoensis was detected in pus from the left lateral ventricle. This appears to represent the first report of N. araoensis meningitis complicated by ventriculitis and brain abscess.

[Actinomycotic brain abscess in immunocompetent patient]

BACKGROUND

The actinomyces is germ commonly found in the normal flora of the oral cavity and gastro-intestinal and uro-genital tracts. Involvement in other locations is a very uncommon event.

OBJECTIVES

To describe a patient with an actinomicotyc brain abscess CLINICAL CASE: We report the case of a patient who suffered a seizure and decreased level of consciousness. Imaging tests revealed the presence of lesions both in the lung and in the brain. An urgent craniotomy was performed and the diagnosis of actinomicotyc abscess was obtained.

CONCLUSION

We describe the differential characteristics of this type of infection, discussing the diagnostic process and management in detail.

NOCARDIA BEIJINGENSIS BRAIN ABSCESS IN AN HIV INFECTED PATIENT: A FIRST CASE REPORT AND LITERATURE REVIEW

We report here brain abscesses caused by Nocardia beijingensis in a 59-year-old-Thai male with human immunodeficiency virus (HIV) infection presenting with progressive right sided hemiparesis. A computed tomography scan of the brain showed multiple brain abscesses. A stereotactic brain biopsy and 16S rRNA sequencing showed Nocardia beijingensis. The patient was treated with trimethoprim-sulfamethoxazole and recovered completely. As far as we are aware, this is the first reported case of a brain abscess in an HIV infected patient due to Nocardia beijingensis.

A CLADOPHIALOPHORA BRAIN ABSCESS IN A RENAL TRANSPLANT RECIPIENT

Cladophialophora bantiana is a dematiceous fungus with neurotrophic propensity for which therapy is not standardized and mortality is high. We report here a 49 year old non-diabetic renal transplant patient on triple immunosuppressant therapy who presented with a history of falls, weakness and headaches. A computed tomography scan of the brain revealed a 30 mm diameter abscess in the brain which was removed surgically and diagnosed on culture as C. bantiana. The patient was successfully treated medically post-operatively with chronic posaconazole. We review the literature regarding central nervous system infections due to C. bantiana.

Genomic Analyses of Cladophialophora bantiana, a Major Cause of Cerebral Phaeohyphomycosis Provides Insight into Its Lifestyle, Virulence and Adaption in Host

Cladophialophora bantiana is a dematiaceous fungus with a predilection for causing central nervous system (CNS) infection manifesting as brain abscess in both immunocompetent and immunocompromised patients. In this paper, we report comprehensive genomic analyses of C. bantiana isolated from the brain abscess of an immunocompetent man, the first reported case in Malaysia and Southeast Asia. The identity of the fungus was determined using combined morphological analysis and multilocus phylogeny. The draft genome sequence of a neurotrophic fungus, C. bantiana UM 956 was generated using Illumina sequencing technology to dissect its genetic fundamental and basic biology. The assembled 37.1 Mb genome encodes 12,155 putative coding genes, of which, 1.01% are predicted transposable elements. Its genomic features support its saprophytic lifestyle, renowned for its versatility in decomposing hemicellulose and pectin components. The C. bantiana UM 956 was also found to carry some important putative genes that engaged in pathogenicity, iron uptake and homeostasis as well as adaptation to various stresses to enable the organism to survive in hostile microenvironment. This wealth of resource will further catalyse more downstream functional studies to provide better understanding on how this fungus can be a successful and persistent pathogen in human.

Serial magnetic resonance imaging findings of intracerebral spread of listeria utilising subcortical U-fibres and the extreme capsule

We present a case of Listeria monocytogenes cerebral abscess with axonal spread via the subcortical U-fibres and extreme capsule on magnetic resonance imaging, with follow-up studies demonstrating serial reduction in oedema and enhancement pattern of the white-matter fibre tracts following antimicrobial treatment. We discuss the microbiological mechanism of bacterial mobility to account for these unique imaging features. Recognition of this distinct pattern of spread of L. monocytogenes cerebral abscess may aid in diagnosis and enable early microbiological culture and treatment.

Aggregatibacter aphrophilus misidentified as Brucella spp. in an immunocompetent patient with brain abscess

Aggregatibacter aphrophilus rarely causes brain abscesses. Here we report a case of the brain abscess caused by Aggregatibacter aphrophilus. Cultivated gram negative coccobacilli from cerebral abscess were initially misidentified as Brucella spp. because it gave false positive agglutination with anti-Brucella sera. Definite identification was made with MALDI-TOF assay. Right to left shunt through the pulmonary arteriovenous malformation was speculated to be the underlying cause for the brain abscess. The patient was treated successfully with ampicillin-sulbactam after failing ceftriaxone treatment.