The bacteriology and chemotherapy of acute pyogenic brain abscess

Brain abscess in immunocompetent adult patients

Brain abscess is a focal infection of the brain due to contiguous spread of pathogens following otitis, sinusitis, neurosurgery or traumatic brain injury or through hematogenous dissemination. Classical symptoms consisting of headache, fever, and focal signs may be absent on admission and brain MRI with contrast plays a major role in diagnosis. Initial management consists of stereotactic aspiration for microbiological documentation empirical treatment covering common pathogens, including oral streptococci, staphylococci, anaerobes, and Enterobacteriaceae. De-escalation of antimicrobials based on microbiology is safe only when samples have been processed optimally, or when primary diagnosis is endocarditis. A 6-week combination of third-generation cephalosporin and metronidazole will cure most cases of community-acquired brain abscess in immunocompetent adults. Significant advent in brain imaging, minimally invasive surgery, molecular biology, and antibacterial agents, has dramatically improved the prognosis. Main indicators of outcome include altered mental status at presentation and intraventricular rupture.

Novel approach to the treatment of a cerebral abscess using the Apollo vibration/suction device

BACKGROUND AND IMPORTANCE

Intracerebral abscess is a very serious condition associated with significant morbidity and mortality. This article describes a novel treatment for a cerebral abscess, using the Penumbra Apollo suction/vibration aspiration system (Penumbra, Almeda, CA, USA). This article represents the first reported case of the device's use for treatment of an intracerebral abscess.

CLINICAL PRESENTATION

The patient discussed presented to the emergency department in critical condition, and was found to be suffering from a right thalamic cerebral abscess. She underwent treatment with both medical management and surgical intervention with the use of the Apollo system.

CONCLUSION

This report details a novel technique for surgical abscess drainage with an excellent clinical outcome. The aim is to provide insight into the treatment of intracerebral abscesses, the utility of the Apollo system, and the device's application beyond intracerebral and intraventricular hemorrhage.

Outcome of burr-hole aspiration of brain abscess

Objective

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

Methods

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

Results

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

Conclusion

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

An update on bacterial brain abscess in immunocompetent patients

BACKGROUND

A brain abscess is a focal infection of the brain that begins as a localized area of cerebritis. In immunocompetent patients, bacteria are responsible for >95% of brain abscesses, and enter the brain either through contiguous spread following otitis, sinusitis, neurosurgery, or cranial trauma, or through haematogenous dissemination.

AIMS

To identify recent advances in the field.

SOURCES

We searched Medline and Embase for articles published during years 2012-2016, with the keywords 'brain' and 'abscess'.

CONTENT

The triad of headache, fever and focal neurological deficit is complete in ∼20% of patients on admission. Brain imaging with contrast-preferentially magnetic resonance imaging-is the reference standard for diagnosis, and should be followed by stereotactic aspiration of at least one lesion, before the start of any antimicrobials. Efforts should be made for optimal management of brain abscess samples, for reliable microbiological documentation. Empirical treatment should cover oral streptococci (including milleri group), methicillin-susceptible staphylococci, anaerobes and Enterobacteriaceae. As brain abscesses are frequently polymicrobial, de-escalation based on microbiological results is safe only when aspiration samples have been processed optimally, or when primary diagnosis is endocarditis. Otherwise, many experts advocate for anaerobes coverage even with no documentation, given the sub-optimal sensitivity of current techniques. A 6-week combination of third-generation cephalosporin and metronidazole will cure most cases of community-acquired brain abscess in immunocompetent patients.

IMPLICATIONS

Significant advances in brain imaging, minimally invasive neurosurgery, molecular biology and antibacterial agents have dramatically improved the prognosis of brain abscess in immunocompetent patients over the last decades.

Brain abscess potentially secondary to odontogenic infection: case report

Odontogenic infections are rarely implicated in the causes of brain abscess formation. As such, there are very few reports of brain abscesses secondary to odontogenic infections in the literature. This is due partly to the relative rarity of brain abscesses but also to the difficulty in matching the causative organisms of a brain abscess to an odontogenic source. The authors report a case of a 50-year-old woman whose brain abscess may potentially have been secondary to an odontogenic infection. The patient's early diagnosis, supported by imaging and microbiologic assessment, along with early minicraniotomy and extraction of infected dentition followed by a course of cephalosporins and metronidazole, contributed to a successful outcome.

Intracranial calcification caused by a brain abscess : a rare cause of intracranial calcification

Intracranial calcifications are relatively common computed tomographic findings in the field of neurosurgery, and cysticercosis, tuberculosis, HIV, and cryptococcus are acquired intracranial infections typically associated with calcifications. However, intracranial calcification caused by a bacterial brain abscess is rare. Here, we present a rare case of intracranial calcification caused by a bacterial brain abscess, from which staphylococcus hominis was isolated. To the best of our knowledge, no previous report has been published on intracranial calcification caused by bacterial brain abscess after decompressive craniectomy for traumatic brain injury. In this article, the pathophysiological mechanism of this uncommon entity is discussed and relevant literature reviewed.

Brain abscess of odontogenic origin

Brain abscess is a rare and threatening infection, which is in a suppuration area, caused either by trauma, neurosurgical complication, or by a secondary infection of dental origin complication. The infectious process spread from the start focus can occur in 2 ways: hematogenous or by contiguity. The treatment should ideally be based on the etiological factor excision, combined with drainage and antibiotics as adjuvant; this philosophy is not observed in the reports described in the 1960s, 1970s, and 1980s. This study's goal was to report a case of brain abscess consequent of an odontogenic outbreak, where an adequate treatment was set up, but it was already in advanced stages and had as a result the lethal outcome. Complications from the odontogenic infections have a low incidence, but should never be disregarded, because they can lead to death, as described in this manuscript.

Pyogenic brain abscess

✓ Brain abscesses have been one of the most challenging lesions, both for surgeons and internists. From the beginning of the computed tomography (CT) era, the diagnosis and treatment of these entities have become easier and less invasive. The outcomes have become better with the improvement of diagnostic techniques, neurosurgery, and broad-spectrum antibiotics. Atypical bacterial abscesses are more often due to chemotherapy usage in oncology, long life expectancy in patients with human immunodeficiency virus (HIV) infection, and immunosuppression in conjunction with organ transplantation. Surgical treatment options showed no significant difference with respect to mortality levels, but lower morbidity rates were achieved with stereotactically guided aspiration. Decompression with stereotactically guided aspiration, antibiotic therapy based on results of pus culture, and repeated aspirations if indicated from results of periodic CT follow-up scans seem to be the most appropriate treatment modality for brain abscesses. Immunosuppression and comorbidities, initial neurological status, and intraventricular rupture were significant factors influencing the outcomes of patients. The pitfalls and evolution in the diagnosis and treatment of brain abscesses are discussed in this study.

Cerebral abscess of odontogenic origin

INTRODUCTION

Cerebral abscess is a rare but serious and life-threatening infection. Dental infections have occasionally been reported as the source of bacteria for such an abcess.

PATIENT AND METHODS

A 54-year-old man was admitted with a right hemiparesis and epileptic fits. After clinical, laboratory and imaging examination, the diagnosis of a cerebral abscess of the left parietal lobe was made. The intraoral clinical examination as well as a panoramic radiograph confirmed the presence of generalized periodontal disease, multiple dental caries, and periapical pathology. The treatment included: (i) Immediate administration of high-dose intravenous antibiotics and (ii) surgical procedures consisting of craniotomy and resection of the abscess cavity first, and secondly removal of the periodontal, decayed and periapically involved teeth of the patient, in an effort to eradicate all the possible septic foci, presuming the cerebral abscess to be of odontogenic infection.

RESULTS

The patient made an uneventful recovery, and 29 months postoperatively he had completely recovered from the hemiparesis.

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.

Are dental infections a cause of brain abscess? Case report and review of the literature

Dental pathology and/or treatment have been linked to a small number of brain abscesses as possible sources of infection. A further case is presented, in which a dental site is implicated. A review of the evidence was undertaken. A wide range of dental procedures had been implicated. In some cases the brain isolate was not of dental origin. In many, the diagnosis was one of exclusion. In order to confirm the role of odontogenic infection in the pathogenesis of brain abscess, modern sampling techniques should be used to precisely identify the isolates. The causal organism should be identified in both oral and cranial sites.

Factors that enhance the likelihood of successful stereotactic treatment of brain abscesses

Successful clinical outcomes are not achieved in all patients who undergo image-guided stereotactic surgery as the initial procedure in the management of brain abscess. We sought to define those factors related to management failure, so that the initial surgical approach could be selected using preoperative clinical or imaging criteria. We reviewed our twelve-year experience in 29 consecutive patients. Twenty-two (76%) patients had drainage of abscesses with purulent centers. Seven (24%) underwent lesion biopsy for diagnosis. Twelve patients (with abscesses > 3 cm in average diameter) underwent stereotactic insertion of drainage catheters. Ten patients (34%) had adverse risk factors including immunologic suppression after prior organ transplantation, chronic steroid therapy, prior antineoplastic chemotherapy, or retained foreign body. Microbiological identification of the causative organism was obtained in 22 patients; 6 patients had positive Gram stains without growth in culture (bacteriological diagnosis = 97%). Long-term clinical evaluation (up to 8.5 years, median 3 years) confirmed disease resolution after initial single-procedure stereotactic management in 21 patients (72%). Eventual abscess resolution occurred in an additional 6 patients (21%), all of whom required multiple procedures. Five patients died of complications of their systemic disease during the follow-up period. Fifteen of the 18 (83%) surviving patients who had no associated risk factors returned to their premorbid functional capacity. Factors associated with initial treatment failure included inadequate aspiration, lack of catheter drainage of larger abscesses, chronic immunosuppression, and insufficient antibiotic therapy.

Clostridial brain abscesses

Ten patients with clostridial abscesses of the brain are presented. Despite the presence of gas within the cerebral hemispheres and Clostridium welchii cultured from the pus obtained, the outcome of all patients managed with burrhole aspiration of the abscess was good. There were no deaths and eight of the ten patients had no residual deficit. Clostridial infections of the brain, unlike those of the soft tissues of the body, have a good outcome with conservative surgery and appropriate antibiotics.

Penetration of intravenous antibiotics into brain abscesses

INTRA-ABSCESS CONCENTRATIONS OF the intravenously administered latamoxef (LMOX, moxalactam in the United States) and cefotetan (CTT), were studied in 11 patients with intracranial abscess. None of these patients underwent surgical ablation of the abscess. In all cases, the abscess was aspirated, and multiple aspirations were required in five patients. Antibiotic concentrations in 18 aspirates were, therefore, determined by the agar well method. LMOX concentrations in 16 aspirates drawn from nine brain abscess cases ranged from 0 to 10.9 micrograms/ml, with a mean (standard deviation) of 4.18 (3.04) micrograms/ml. The CTT concentration in one patient with a brain abscess was 8.51 micrograms/ml, and the LMOX concentration in the one remaining patient with subdural empyema was 5.20 micrograms/ml. In one patient, the serum-to-pus penetration rate of LMOX was estimated to be 0.11 against the peak value of the concentration in serum or 0.44 against the simultaneously obtained level in serum. Significantly higher concentrations of LMOX were produced in abscess cavities with multiple-dose administration or by prior drainage of pus. More-advanced stages of local inflammation, as demonstrated by computed tomography, correlated with higher concentrations. However, the routine indexes of systemic inflammation, such as body temperature, white blood cell count, and level of C-reactive protein in serum, cannot be used to predict the concentration present in intracerebral pus. A tendency for LMOX concentrations in pus obtained after single dose-administration to decrease with increasing duration from symptom onset to sampling was observed but was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial suppuration caused by Micrococcus luteus

Micrococcus spp. are commensal organisms colonizing the body surfaces of humans. In a few instances these organisms have been reported to colonize ventricular shunts. We report a patient, with no overt evidence of immunosuppression, in whom Micrococcus luteus was responsible for intracranial suppuration at multiple sites.

Cerebral abscess on Merseyside 1980-1988

We report a retrospective study of 62 patients presenting to The Walton Centre for Neurology and Neurosurgery with cerebral abscess in the 8-year period between 1980 and 1988. The study shows that while the incidence of cerebral abscess has not altered from the previous decade, aetiological factors have changed and major developments in the diagnosis and management of the condition have resulted in a marked reduction in the morbidity and mortality associated with brain abscess.

Multiple brain abscess: a review of fourteen cases

The case notes of 14 consecutive patients with multiple brain abscesses presenting over a 14 year period were studied with respect to the incidence and presentation, the source of infection, the investigations, microbiology and the treatment and outcome. The incidence of multiple brain abscesses in non-immunocompromised patients is 13% of all intracranial abscesses. Computerized tomographic scanning is vital both in the detection of multiple abscesses and in the subsequent assessment of therapy. The source of infection in half of our patients was the teeth or the paranasal sinuses. Streptococci were isolated in 63% of the patients; staphylococci in 21%. This has obvious implications for the antibiotic policy. Intracranial surgery, with few exceptions, had a diagnostic and management role rather than a curative one; identification of the causative organism was its prime purpose. CSF, obtained by lumbar punctures, did not provide any positive cultures and should not be contemplated in view of the inherent hazards. The elimination of the primary focus of infection was a most important step in the management of this condition. Multiple brain abscesses represent a potentially curable condition, provided appropriate antibiotics are used, the primary septic focus is eliminated and the intracranial complications are anticipated by the use of frequently repeated CT scans.

Multiple brain abscesses secondary to bronchiectasis. A case of 34 discrete abscesses in one brain

Multiple brain abscesses are a rare complication which may occur in a number of conditions including intra-thoracic sepsis. Computerized tomography has had an advantageous impact on the management of this condition by facilitating earlier diagnosis. However, the treatment modalities are inadequate and mortality remains high. A case of multiple brain abscesses in a patient with bronchiectasis is reported which exemplifies this often fatal condition. The management of multiple brain abscesses is discussed.

CT scanning in the management of intracranial abscess: a review of 100 cases

One hundred cases of brain abscess presenting between 1974 and 1984 are reviewed. The overall mortality was 20%, 98 cases were actively treated with a peroperative mortality of 14%. The results are compared to Garfield's 1969 series, drawn from similar clinical material. Changes in presentation and outcome are described. A significant improvement in survival (p less than 0.001) has occurred following the introduction of computerised tomography (CT Scan) which permits the rapid diagnosis and accurate localisation of intracranial sepsis. As the basic therapeutic regime remains unchanged (burr hole aspiration and appropriate antibiotic treatment), other aspects of management have been examined, leading to the suggestion that CT Scanning has made a major contribution to the reduction in mortality.