Intracranial dissemination of Klebsiella pneumoniae originating from pulmonary infection: a case report.

BACKGROUND: Metastatic brain abscesses caused by Klebsiella pneumoniae are extremely rare but life-threatening conditions. To depict a unique case of the middle-aged hypertensive man with an unusual presentation of metastatic brain abscesses originating from a pleural abscess caused by Klebsiella pneumoniae and subsequently leading to loss of consciousness (LOC). CASE REPORT: A 52-year-old Iranian man with a history of hypertension presented to the emergency department with a five-day history of worsening cough, high-grade fever, shortness of breath, chest pain, fatigue, and a productive cough. Laboratory tests revealed leukocytosis, elevated C-reactive protein, and respiratory alkalosis. A chest computed tomography scan confirmed pneumonia, and a brain scan revealed multiple hypodense lesions. Despite antibiotic therapy, the patient's condition worsened, leading to confusion, disorientation, and loss of consciousness. Magnetic resonance imaging revealed multiple ring-enhancing lesions, suggesting an abscess formation. Bronchial washings and BAL samples confirmed a lower respiratory tract infection. Cultures from the bronchial washings grew Klebsiella pneumoniae. CONCLUSIONS: Metastatic brain abscesses caused by Klebsiella pneumoniae are exceedingly rare but life-threatening conditions. Timely diagnosis and effective antimicrobial treatment are critical for patient outcomes. This case underscores the significance of recognizing atypical presentations of bacterial infections, as early detection and appropriate management can significantly impact patient outcomes.

Listeria brain abscess: a therapeutically challenging rare presentation of listeriosis.

We report a very rare case of Listeria multiple brain abscesses manifested as delirium, which represented diagnostic and therapeutic challenges overcome only by the close cooperation between Infectious Diseases and Neuroradiology, without which a satisfactory outcome would not be achieved.An elderly man presented with confusion and drowsiness with a background of type-II diabetes mellitus. Although computed tomography of the brain only showed frontal lobe oedema, contrast magnetic resonance (MR) imaging showed numerous irregular rim-enhancing lesions containing central diffusion restriction, suggesting multiple pyogenic cerebral abscesses of unclear aetiology. Thereafter, Listeria monocytogenes was isolated from blood cultures, suggesting this as the causative organism. Deemed unsuitable for neurosurgical drainage, the patient received medical management with a protracted course of antibiotics. This case was extremely challenging, due to 1) the impossibility of source control, 2) the small number of effective antibiotics available to treat this condition, and 3) the inevitable antibiotic side-effects, derived from long-term exposure. A successful outcome was only possible thanks to strict close multidisciplinary follow up, requiring frequent MR imaging and a judicious antibiotic choice, including monitoring of their side-effects. Due to the rarity of this condition, there is lack of guidance on its management, hence the importance of multidisciplinary involvement with very close imaging and antibiotic monitoring.

[Brain abscess due to Aggregatibacter aphrophilus]. / Absceso cerebral por Aggregatibacter aphrophilus.

Brain abscess is a focal suppurative process produced in most cases by bacterial agents. Aggregatibacter aphrophilus is a gram-negative bacteria belonging to the HACEK group, which causes infective endocarditis, liver abscesses, among others. Brain abscesses secondary to this germ are rare and, in most cases, it is associated with contact with pets, poor dental hygiene or dental procedures. Treatment consists of drainage of the abscess (greater than 2.5 cm) combined with antibiotic therapy, ideally beta-lactams. The case of a 64-year-old male patient with no relevant history is here presented. He was admitted to the emergency service due to headache, hemianopsia of a week's duration and later tonic-clonic seizures, in whom imaging studies and culture of a brain lesion subsequently revealed a brain abscess due to A. aphrophilus. This case aims to illustrate about the rarity of this infection, because A. aphrophilus is a normal part of the oropharyngeal flora and respiratory tract, in which it rarely causes invasive bacteremia.

El absceso cerebral es un proceso supurativo focal producido en la mayoría de los casos por agentes bacterianos. Aggregatibacter aphrophilus es una bacteria gram negativa perteneciente al grupo HACEK, causante de endocarditis infecciosa, abscesos hepáticos, entre otras. Los abscesos cerebrales secundarios a este germen son infrecuentes y en la mayoría de los casos asociados a contactos con animales domésticos, pobre higiene dental o procedimientos odontológicos. El tratamiento consiste en drenaje del absceso (mayores de 2.5 cm) combinado con terapia antibiótica, idealmente betalactámicos. Se presenta el caso de un paciente varón de 64 años sin antecedentes de relevancia quien ingresó al servicio de emergencias por cuadro de cefalea, hemianopsias de una semana de evolución y posteriormente crisis tónico clónicas, en quien posteriormente en estudios imagenológicos y cultivo de lesión cerebral se arribó al diagnóstico de absceso cerebral por A. aphrophilus. Este informe tiene como objetivo ilustrar al lector sobre la rareza de esta infección, debido a que A. aphrophilus forma parte normal de la flora orofaríngea y del tracto respiratorio, en los que rara vez ocasiona bacteriemias invasivas.

Esophageal Perforation Presenting Initially as Multiple Brain Abscesses Secondary to Streptococcus intermedius.

Brain abscess is a life-threatening infection that can occur secondary to contiguous or hematogenous spread. Several underlying conditions can lead to brain abscesses, such as dental infection, otitis media, sinusitis, and immunosuppression. Esophageal perforation leading to brain abscesses is extremely rare. We report a rare case of a 32-year-old man who presented to the emergency department with progressive headaches and upper-extremity weakness. Upon further evaluation, computed tomography (CT) revealed multiple brain abscesses secondary to Streptococcus intermedius infection. The patient eventually underwent esophagogastroduodenoscopy (EGD), which showed a perforation in the middle third of the esophagus. This case highlights the importance of considering esophageal perforation as a predisposing condition for brain abscesses.

Diffusion-weighted imaging-based radiomics model using automatic machine learning to differentiate cerebral cystic metastases from brain abscesses.

OBJECTIVES: To develop a radiomics model based on diffusion-weighted imaging (DWI) utilizing automated machine learning method to differentiate cerebral cystic metastases from brain abscesses. MATERIALS AND METHODS: A total of 186 patients with cerebral cystic metastases (n = 98) and brain abscesses (n = 88) from two clinical institutions were retrospectively included. The datasets (129 from institution A) were randomly portioned into separate 75% training and 25% internal testing sets. Radiomics features were extracted from DWI images using two subregions of the lesion (cystic core and solid wall). A thorough image preprocessing method was applied to DWI images to ensure the robustness of radiomics features before feature extraction. Then the Tree-based Pipeline Optimization Tool (TPOT) was utilized to search for the best optimized machine learning pipeline, using a fivefold cross-validation in the training set. The external test set (57 from institution B) was used to evaluate the model's performance. RESULTS: Seven distinct TPOT models were optimized to distinguish between cerebral cystic metastases and abscesses either based on different features combination or using wavelet transform. The optimal model demonstrated an AUC of 1.00, an accuracy of 0.97, sensitivity of 1.00, and specificity of 0.93 in the internal test set, based on the combination of cystic core and solid wall radiomics signature using wavelet transform. In the external test set, this model reached 1.00 AUC, 0.96 accuracy, 1.00 sensitivity, and 0.93 specificity. CONCLUSION: The DWI-based radiomics model established by TPOT exhibits a promising predictive capacity in distinguishing cerebral cystic metastases from abscesses.

Tetralogy of Fallot complicated by multiple cerebral abscesses in a child: a case report.

INTRODUCTION: Brain abscesses are rare but potentially fatal condition and can be associated with cyanotic congenital heart disease of which 5-18.7% of these patients that develop cerebral abscess commonly have tetralogy of Fallot (TOF). CASE PRESENTATION: We report a case of 3-year-old Muganda male that presented with convulsions, cyanosis and difficulty in breathing. The patient had a combination intervention of medical treatment and surgical drainage of the abscess. Post-operative Computerized tomography scan images and pre-operative brain Computerized tomography scans were compared. The multiple rings enhancing lesions were reduced in number and sizes. The largest measured ring was 44 × 22.5×16mm compared to the previous; 42 × 41×36mm. The mass effect had reduced from 16 mm to 7.5 mm. The periventricular hypodensities persisted. Findings showed radiological improvement with residual abscesses, subacute subdural hematoma and pneumocranium. The patient was treated with intravenous ceftriaxone 1 g OD for six weeks and he showed marked improvement and was discharged home after 3 months. CONCLUSION: A comprehensive strategy involving medications, surgical drainage, and early neurosurgical consultation is vital in treating brain abscesses in uncorrected TOF. Early identification of the pathogen, appropriate antibiotic therapy, and vigilant follow-up through clinical assessments and imaging are crucial, potentially spanning a 4-8-week treatment.

Endoscopic Access to Brain Abscess Due to Sinonasal Infection.

BACKGROUND: Brain abscesses caused by sinonasal infections have become more common during the coronavirus pandemic, particularly due to the increase in sinonasal mucormycosis. This study aimed to evaluate the efficacy and safety of endoscopic endonasal brain abscess drainage as a therapeutic technique for these cases. METHODS: Clinical outcomes and retrospective evaluations were performed in patients who underwent endoscopic endonasal brain abscess drainage between May 2019 and August 2022. A total of 7 patients diagnosed with 9 brain abscesses caused by sinonasal infections were included in the study. The main outcome of this study was to evaluate the success and safety of this technique. RESULTS: The average age of the patients was 40.71 ± 14.17 years. The most common symptom observed in these patients was nasal discharge, and the frontal lobe was the most common site of abscess. Notably, the majority of cases were associated with COVID-19. CONCLUSIONS: Based on the results of this study, endoscopic endonasal brain abscess drainage is considered a viable treatment option for skull base brain abscesses caused by sinonasal infections. Further research in this field can help establish this technique as a mainstay approach for managing brain abscesses at the skull base.

Brain abscess - A rare confounding factor for diagnosis of post-traumatic epilepsy after lateral fluid-percussion injury.

OBJECTIVE: To assess the prevalence of brain abscesses as a confounding factor for the diagnosis of post-traumatic epilepsy (PTE) in a rat model of lateral fluid-percussion-induced (FPI) traumatic brain injury (TBI). METHODS: This retrospective study included 583 rats from 3 study cohorts collected over 2009-2022 in a single laboratory. The rats had undergone sham-operation or TBI using lateral FPI. Rats were implanted with epidural and/or intracerebral electrodes for electroencephalogram recordings. Brains were processed for histology to screen for abscess(es). In abscess cases, (a) unfolded cortical maps were constructed to assess the cortical location and area of the abscess, (b) the abscess tissue was Gram stained to determine the presence of gram-positive and gram-negative bacteria, and (c) immunostaining was performed to detect infiltrating neutrophils, T-lymphocytes, and glial cells as tissue biomarkers of inflammation. In vivo and/or ex vivo magnetic resonance images available from a subcohort of animals were reviewed to evaluate the presence of abscesses. Plasma samples available from a subcohort of rats were used for enzyme-linked immunosorbent assays to determine the levels of lipopolysaccharide (LPS) as a circulating biomarker for gram-negative bacteria. RESULTS: Brain abscesses were detected in 2.6% (15/583) of the rats (6 sham, 9 TBI). In histology, brain abscesses were characterized as vascularized encapsulated lesions filled with neutrophils and surrounded by microglia/macrophages and astrocytes. The abscesses were mainly located under the screw electrodes, support screws, or craniectomy. Epilepsy was diagnosed in 60% (9/15) of rats with an abscess (4 sham, 5 TBI). Of these, 67% (6/9) had seizure clusters. The average seizure frequency in abscess cases was 0.436 ± 0.281 seizures/d. Plasma LPS levels were comparable between rats with and without abscesses (p > 0.05). SIGNIFICANCE: Although rare, a brain abscess is a potential confounding factor for epilepsy diagnosis in animal models of structural epilepsies following brain surgery and electrode implantation, particularly if seizures occur in sham-operated experimental controls and/or in clusters.

Pediatric intracranial empyema complicating otogenic and sinogenic infection.

OBJECTIVE: To describe and compare clinical and microbiological features, surgical and medical management, and outcomes of children with otogenic and sinogenic intracranial empyema (IE) in an institution with an established multidisciplinary protocol. To use the study findings to inform and update the institutional algorithm. METHODS: Retrospective analysis was carried out on the electronic healthcare records of all children with oto-sinogenic IE admitted in a 5-year period. RESULTS: A total of 76 patients were identified and treated according to an institutional protocol. Two distinct groups were identified: intracranial empyema related to otogenic infection (OI-IE, n = 36) or sinogenic infection (SI-IE, n = 40). SI-IE was seen in older children and had a significantly higher morbidity. Sub-dural IE was seen in a minority (n = 16) and only in SI-IE and required urgent collaborative ENT-neurosurgery. Extra-dural IE occurred more frequently and was seen in both SI-IE and OI-IE. No death and overall low morbidity were observed. Particularities found in SI-IE and OI-IE groups (as thrombosis, microbiology, antibiotic treatment, duration and outcome) permitted the delineation of these groups in our updated algorithm. CONCLUSION: The presence of a collaborative multidisciplinary protocol permits the step-wise co-ordination of care for these complex patients in our institution. All patients received prompt imaging, urgent surgical intervention, and antibiotic treatment. Microbiological identification was possible for each patient and antibiotic rationalization was permitted through use of Polymerase chain reaction (PCR) testing in cases of sterile cultures. Of note, intracranial empyema related to sinogenic infection is shown to have significantly more severe clinical presentation, a higher morbidity, and a longer duration of antibiotic therapy than that related to otogenic infection. Study findings allowed for the update and clarification of the institutional protocol, which now clearly demarcates the clinical presentation, biological evidence, radiology, surgical and medical treatments in children with oto-sinogenic IE.

[Brain abscess as a complication of pulmonary manifestation of HHT]. / Hirnabszess als Komplikation bei pulmonaler Manifestation einer HHT.

A 43-year-old female patient with a brain abscess and a complicated clinical course was diagnosed with hereditary haemorrhagic telangiectasia (HHT) at the Martin Zeitz Centre for Rare Diseases in Hamburg, Germany. The brain abscess was caused by pulmonary arteriovenous malformations (AVM), a typical finding in HHT. Patients with cryptogenic brain abscess should be screened for pulmonary AVM and HHT. This case report illustrates the importance of patient history and interdisciplinary exchange in patients with a broad clinical spectrum as well as interdisciplinary treatment in the case of complications of rare diseases.

Endoscopic Ultrasonic Aspiration of Brain Abscess.

Brain abscess is a focal infection occurring within the brain parenchyma consisting of a pus collection surrounded by a vascularized capsule and a fibrinous-caseous layer between the pus and capsule. Surgery is indicated for lesions with a diameter >25 mm. Different surgical approaches have been described, including puncturing of the abscess (under neuronavigation, stereotactic or echographic guidance) with aspiration of the purulent fluid through a catheter and craniotomy with microsurgical removal of the purulent material and surrounding capsule. In recent years, the endoscopic approach has become more frequently used to treat brain abscesses. The theoretical advantages are visual awareness of the completeness of pus removal and the possibility of also removing the more solid fibrinoid component, which could be the source of recurrence. Craniotomy is likewise avoided. We present the case of an 11-year-old boy affected by a parieto-occipital brain abscess and initial ventriculitis who underwent endoscopic surgery. An ultrasonic aspirator was used to wash and suck the purulent material and fragment and remove the more solid fibrinoid component. The occipital horn of the lateral ventricle was also entered, and pus was removed. At the end of the procedure, a ventricular drainage tube was left in the surgical cavity. It was removed 1 day later, because the cavity had completely collapsed. The key surgical steps are presented in Video 1.1-9 The procedure was uneventful, with very good clinical and radiological results. The endoscopic technique has been shown to be a safe and effective treatment option for intracranial abscess. In the case of large superficial lesions, the surgical risks appear similar to those of simple drainage through catheters, with a possible reduction of the 20% reported recurrence rate. The use of an ultrasonic aspirator could facilitate complete and faster pus removal, increasing the efficacy of the procedure. The patient and his parents consented to the procedure and the report of the patient's case details and imaging studies. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Clinicopathologic characteristics of Nocardia brain abscesses: Necrotic and non-necrotic foci of various stages.

Nocardia brain abscesses are rare bacterial infections associated with a high mortality rate, and their preoperative diagnosis can be difficult for various reasons including a nonspecific clinical presentation. While late-stage nocardial brain abscesses may be radiologically characteristic, early-stage lesions are nonspecific and indistinguishable from another inflammatory/infectious process and other mimics. Despite the paucity of previous histopathological descriptions, histopathological examination is critical for the identification of the pathogen, lesion stage(s), and possible coexisting pathology. In this study, we examined the clinical, radiological and histopathological features of 10 patients with brain nocardiosis. Microscopic findings were analysed in correlation with clinical and radiological features in 9 patients, which revealed that brain nocardiosis was characterized by numerous necrotic and non-necrotic foci of various stages (I-IV) along with Nocardia identification, as well as the leptomeningeal involvement in most cases, and co-infection of brain nocardiosis with toxoplasmosis in 2 patients. The imaging features were characteristic with a multilobulated/bilobed ring-enhancing appearance in 8 patients including 2 patients with multiple lobulated and non-lobulated lesions and 1 patient showing the progression from a non-lobulated to lobulated lesion. These findings suggest that nocardial brain abscesses particularly at late-stages share common characteristics. Nevertheless, given the complex pathologic features, including possible co-infection by other pathogens, nocardial brain abscesses remain a therapeutic challenge.

Abiotrophia defectiva triple threat: A rare case of infective spondylodiscitis, endocarditis, and brain abscess.

Abiotrophia defectiva is a pathogen of the oral, gastrointestinal, and urinary tracts that can cause significant systemic disease with uniquely negative blood cultures depending on the growth medium. Prior cases note possible seeding from relatively common procedures such as routine dental work and prostate biopsies, however case literature describes prior infectious complications to include infective endocarditis, brain abscess formation, and spondylodiscitis. While prior cases describe some aspects of these presentations, we highlight a case of a 64-year-old male who presented to the emergency department (ED) f5or acute onset of low back pain with fever symptoms four days after an outpatient transrectal ultrasound-guided needle biopsy of the prostate, with a prior dental extraction described four weeks prior to arrival. Findings on initial ED presentation and subsequent hospitalization revealed infective spondylodiscitis, endocarditis, and brain abscess formation. This is the only cases noted in literature with all three infection locations with dual risk factors of dental and prostate procedures prior to symptom onset. This case highlights the multifocal illness that can complicate Abiotrophia defectiva infections, and the importance of thorough ED evaluation and multiservice approach for consultation and treatment.

Coronavirus disease 2019 (COVID-19)-associated brain abscesses caused by Pseudomonas aeruginosa and Aspergillus fumigatus: two case and a review of the literature.

BACKGROUND: Bacterial and fungal superinfections are commonly reported in patients with coronavirus disease 2019. CASE PRESENTATION: We report the first case of brain and intramedullary abscesses caused by Pseudomonas aeruginosa and a rare case of brain abscesses caused by Aspergillus fumigatus in two post-coronavirus disease 2019 patients. The first patient-34-year-old Iranian woman-presented with weakness of the left upper limb, headaches, and lower limb paresthesia. She had a history of undiagnosed diabetes and had received corticosteroid therapy. The second patient-45-year-old Iranian man-presented with right-sided weakness and had a history of intensive care unit admission. Both patients passed away despite appropriate medical therapy. CONCLUSION: The immune dysregulation induced by coronavirus disease 2019 and its' treatments can predispose patients, especially immunosuppressed ones, to bacterial and fungal infections with unusual and opportunistic pathogens in the central nervous system. Pseudomonas aeruginosa and Aspergillus fumigatus should be considered as potential causes of brain infection in any coronavirus disease 2019 patient presenting with neurological symptoms and evidence of brain abscess in imaging, regardless of sinonasal involvement. These patients should get started on appropriate antimicrobial therapy as soon as possible, as any delay in diagnosis or treatment can be associated with adverse outcomes.

Actinomyces meyeri-induced brain abscess in pregnancy: a case report.

BACKGROUND: Brain abscesses can occur when suppurative, bacterial or protozoan infections spread to the brain. Here, we report a rare case of Actinomyces meyeri-induced brain abscess in a pregnant woman. CASE PRESENTATION: We present the case of a 38-years-old primipara admitted to the emergency department at our hospital with a 4-day history of fever and vomiting. The symptoms worsened rapidly during the 8 h prior to admission, and the patient experienced a sudden loss of consciousness 4 h before arrival to the unit. Brain magnetic resonance imaging revealed abnormal signals in the right parietal-temporal lobe, suggesting the possibility of abscess rupture into the ventricle and sulcus. Right lateral ventricle compression and midline structure deviation to the left were noted. A right temporal-occipital mass with midline shift was detected. Emergency procedures were promptly performed, including craniotomy, removal of the right temporal-occipital mass, decompressive craniectomy, implantation of an intracranial pressure monitoring device, and external ventricular drainage. Cerebrospinal fluid culture indicated infection with Actinomyces meyeri. After administration of antibiotics, including linezolid and meropenem injections, along with treatments to decrease intracranial pressure, the patient's vital signs stabilized. However, the patient developed hydrocephalus, requiring placement of a hydrocephalus shunt several months later. Throughout this period, the patient remained in a coma vigil state, and labor was induced for the fetus. CONCLUSIONS: Although the patient did not present with any apparent predisposing causes for brain abscess, a scout view of CT revealed dental caries. In addition, the occurrence of the brain abscess may have been influenced by the hormonal changes during pregnancy, including increased secretion of estrogen and progesterone, as well as decreased immune function. Early diagnosis and intervention are crucial in such cases. Therefore, it is recommended to seek early medical attention if symptoms such as fever, vomiting, and changes in mental state occur during pregnancy, as the prognosis for both the mother and infant is poor once the abscess ruptures.

Pediatric headache patient with cerebral abscesses: a brief review of the literature and case report.

BACKGROUND: Pediatric headache is a common cause of pediatric emergency department (ED) visits, and 8.8% of cases require imaging. Alarmingly, 12.5% of imaged cases have a pathologic cause. A pediatric patient with a complicated medical history presented to the pediatric ED with multiple cerebral abscesses. The possible causes and contributors to this rare cause of pediatric headache and a review of pediatric headache emergency management are presented.Case Presentation: A 12-year-old male patient with a complex medical and surgical history, including post-repair pulmonary valve stenosis, visited the pediatric ED for intractable and worsening left frontoparietal headache, refractory to ibuprofen, for 6 days. A physical examination revealed severe photophobia and restlessness secondary to severe head pain. Non-contrast brain computed tomography demonstrated two round, bilateral, parietal hypodense lesions with surrounding vasogenic edema. The lesions were consistent with abscesses on magnetic resonance imaging. Eventually, the patient underwent successful surgical abscess drainage and made a full recovery. The patient was lost to follow-up; therefore, no causative bacterial species was determined. CONCLUSION: Managing pediatric headache in emergency settings requires a robust history and physical examination. Cerebral abscesses are an infrequent but fatal cause of pediatric headache and therefore should be considered among the differential diagnoses.