Bacterial Brain Abscess Research Articles

Serious Bacterial Infections After Endoscopic Procedures

Transient bacteremia during and after endoscopic procedures is a well- documented phenomenon, but complicated bacteremia such as endocarditis in patients at risk is considered to be extremely rare. The recommendations for prophylaxis before endoscopy in patients with valvular heart disease were recently released. We discuss 16 cases of complicated bacteremia that developed after endoscopy (eight cases previously published in the literature and eight cases we encountered). The endoscopic procedures were gastroscopy (five cases), sclerotherapy (six cases), sigmoidoscopy (three cases), and esophageal dilation (two cases). Fourteen patients had underlying disease: valvular heart disease (six patients), cirrhosis of the liver (five patients, one of whom also had a prosthetic knee), valvular heart disease and cirrhosis of the liver (two patients), and gastric carcinoma (one patient). The organisms involved were Streptococcus viridans (six cases), streptococcus group D (three cases), Streptococcus pneumoniae (two cases), Streptococcus microaerophilicus (two cases), Staphylococcus aureus (two cases), and Cardiobacterium hominis (one case). The patients presented with the following infections: endocarditis (12 patients), spontaneous bacterial peritonitis (two patients), septic arthritis (one patient), and brain abscess (one patient). The outcome was good in 15 patients; one patient died. Patients with valvular heart disease, cirrhosis of the liver, ascites, malignancies, or prosthetic joints who undergo endoscopic procedures should be considered for antibiotic prophylaxis.

Stereotactic Management of Bacterial Brain Abscesses

CT and MR guided stereotactic techniques have provided promising results in the management of brain abscesses. We reviewed our results of stereotactic management of brain abscesses in 20 consecutive patients with 28 abscesses from 1986 to 1993. 13 abscesses were in the cerebral hemispheres, 12 in the cerebellum, 2 in the pons and 1 in the thalamus. The bacterial organism was isolated in 12 of the 20 cases. All patients, except one who had a tuberculous abscess, were on antibiotics for less than 7 weeks. Although there were 3 patients in coma before surgery, the mortality rate was zero and 17 patients had an excellent recovery with 3 patients having a persistent mild neurologic disability. Stereotactic aspiration of the largest lesion in the patients with multiple brain abscesses combined with intravenous antibiotic therapy was sufficient for the resolution of all lesions. Two of our patients treated with antibiotics alone showed abscess progression with neurologic worsening. Stereotactic aspiration is safe, accurate, and when combined with the appropriate antibiotics, should be considered the procedure of choice in the management of brain abscesses.

Infections of the central nervous system

Recent clinical studies and review articles concerning the epidemiology, clinical features, and antibiotic and adjunctive therapy of bacterial meningitis and brain abscess are presented. The type and frequency of complications that may occur during the course of bacterial meningitis are reported, and their intensive care management is discussed. The role of the polymerase chain reaction in viral diseases of the central nervous system is briefly presented, and further areas of research are mentioned.

Improved management of multiple brain abscesses: a combined surgical and medical approach.

Bacterial brain abscesses occur in approximately 1500 to 2500 patients each year in the United States. Multiple abscesses have been noted in 10 to 50% of these patients. The goal of this study was to better define the roles of surgery and medical management in patients harboring multiple brain abscesses and to develop an algorithmic approach to the treatment of these complex patients. Between 1976 and 1992, 16 patients with multiple brain abscesses were treated by a single physician (M.L.R.). The ages of the patients ranged from 1.5 to 73 years (median, 47 yr). In all patients, a diagnosis of multiple abscesses was made by computed tomography (15 patients) or magnetic resonance imaging (1 patient) brain scans. The number of abscesses per patient ranged from 2 to 30, and the abscesses were located in all regions of the brain. Thirteen received a combination of antibiotics and surgical drainage, and three received antibiotics only. Surgery was performed on abscesses larger than 2.5 cm or on those situated in critical areas of the brain or causing significant mass effect. Excision and open aspiration via craniotomy and stereotactic aspiration were analyzed on the basis of the location of the lesion and infecting organism. Any abscess that enlarged after 2 weeks of antibiotics or that failed to shrink after 3 to 4 weeks of antibiotics was again aspirated or excised. Forty-three surgical procedures were performed in 13 patients, and 8 (62%) of the patients operated on required more than one surgical procedure. No significant morbidity was observed in any of the surgical procedures. Antibiotics were administered intravenously for an average of 6 to 8 weeks and were adjusted according to organism type and sensitivity to antibiotics. One patient (6%) died, and the remaining 15 patients had resolution of all abscesses and good neurological recovery within 6 months. On the basis of these results, we propose a combined surgical and medical approach to the treatment of patients with multiple brain abscesses. We recommend the aggressive surgical drainage of all abscesses larger than 2.5 cm in diameter, combined with 6 to 8 weeks of intravenous antibiotics. Biweekly computed tomography or magnetic resonance imaging is necessary to closely monitor patients for evidence of abscess growth or failure to resolve despite antibiotics, prompting another operation. The application of this combined approach should yield cure rates of more than 90% in patients with multiple brain abscesses, a result similar to that expected when treating patients with solitary lesions.

Nocardial Brain Abscess

The successful management of nocardial brain abscess remains problematic. The authors report 11 cases of nocardial brain abscess treated between 1971 and 1993 and review 120 cases reported since 1950. The clinical findings included focal deficits in 55 patients (42%), nonfocal findings in 36 (27%), and seizures in 39 (30%). Extraneural nocardiae were present in 66% of the cases; pulmonary (38%) and cutaneous/subcutaneous (20%) locations were the most frequent. The abscesses were single in 54% of the patients, multiple in 38%, and of unknown number in 8%. Forty-four of 131 patients (34%) were immunocompromised; since 1975, 18 of 40 immunocompromised patients (45%) were transplant recipients and six (15%) had human immunodeficiency virus. The mortality rate was 24% after initial craniotomy and excision (11/45), 50% after aspiration/drainage (17/34), and 30% after nonoperative therapy (7/23); 29 cases (22%) were diagnosed at autopsy. The mortality rate was 33% in patients with single abscesses and 66% in those with multiple abscesses (P < 0.0003). There was no difference in the mortality rates of immunocompromised and nonimmunocompromised patients treated before computed tomography (CT) was available; since the advent of CT, however, the mortality rate has been significantly higher in immunocompromised patients (55% vs. 20%, P < 0.05). Although the mortality rate for nocardial brain abscesses has dropped almost 50% since the advent of CT, it has remained virtually unchanged in immunocompromised patients and is three times higher than that of other bacterial brain abscesses (30% vs. 10%). The authors recommend image-directed stereotactic aspiration for diagnosis; however, craniotomy and total excision are necessary in most cases, because nocardial abscesses are usually multiloculated. Patients with minimal neurological deficits or small abscesses may be treated initially with antibiotics alone. Sulfonamides, alone or in combination with trimethoprim, are most effective and should be continued for at least 1 year. Minocycline, imipenem, or aminoglycoside in combination with a third-generation cephalosporin may be used with reasonably good success as second-line agents in cases of allergy or nonresponsiveness to sulfa agents.

Multiple Brain Abscesses at King Khalid University Hospital

The authors reviewed six cases of multiple brain abscesses that were treated at King Khalid University Hospital (KKUH) over an eight year period. This represented 22% of the total brain abscesses treated during the same period. The series is unusual in that the infective pathogens were fungi (Fonsecaea pedrosoi) in two patients (33%) and an aerobic actinomycete (Nocardia asteroides) in one patient (16%). Two patients treated elsewhere with antibiotics empirically for one month died at three and 28 days following admission. The poor outcome was probably related t the delay in obtaining a microbiological diagnosis and commencing the appropriate antimicrobial therapy. The importance of early identification of the pathogen in patients with multiple brain abscesses is stressed.

Bacterial brain abscesses: factors influencing mortality and sequelae.

Thirty-nine cases of brain abscess diagnosed since the advent of the computed tomographic (CT) scan were analyzed for factors influencing the outcome. The mortality rate was 13%, and severe sequelae were present in 22% of the survivors. The mean delay between occurrence of the first symptoms and hospitalization was significantly shorter for the 12 patients with poor outcome (death or severe sequelae) than for the 25 who recovered (fully or with moderate sequelae). Moreover, severely impaired mental status and neurological impairment at admission were associated with a poor outcome in terms of both mortality and sequelae. In all cases with fatal outcome or severe sequelae, the diagnosis was made and treatment was initiated within 24 hours of admission. There was no apparent correlation between the outcome and the presence or type of predisposing factors, the radiological, biological, or microbiological findings, or the treatment modalities. Thus, with the advent of the CT scan and the possibility of early diagnosis and treatment, the prognosis of brain abscess appears to be mainly determined by the rapidity of progression of the disease before hospitalization and the patient's mental status on admission.

Central Nervous System Infections in Cancer Patients

In the immunocompromised patient, even mild forms of any combination of headache, meningismus, altered mental status, or focal neurologic signs should initiate an evaluation for possible CNS infection. The limited signs and symptoms of acute CNS infection are not due to specific organisms but to pathologic changes at the neuroanatomic site of infection. The initial clinical history, examination, laboratory, and neuroradiographic data will narrow the problem to one of several groups of agents, although it may not be possible to specify a single causative agent. It should be remembered that several concurrent infections (i.e., CMV and toxoplasmosis, aspergillosis, and bacterial sepsis) may be present. Thus, the clinician should rely on broad antibiotic coverage appropriate to the suspected causative agent or agents at the site of infection. It may be necessary to offer broad-spectrum antibiotic coverage for a CSF presentation that is subsequently found to result from a viral illness or from a noninfectious cause. However, one should avoid undertreating those infections for which specific therapy can be offered, and broad-spectrum treatment usually will not be regretted. Uncertainty in diagnosis following noninvasive procedures should lead to a brain biopsy. Although many of the infections discussed in this article have a poor prognosis, some of the most common pathogens, such as Cryptococcus, Listeria, and Toxoplasma, have effective specific therapies to which the patient should have access as rapidly as possible. The clinician who has successfully treated a patient with CNS infection should remain vigilant for late sequelae or recurrence of infection. Chronic treatment of some infections, such as toxoplasmosis or aspergillosis, may be necessary. The reintroduction of steroids for the treatment of an underlying cancer may reactivate previously treated disease, such as cryptococcosis, and periodic CSF surveillance is appropriate under these circumstances. Recurrence of the symptoms should raise the suspicion of recurrent or new infection, and the patient also should be evaluated with CT or MRI for the development of hydrocephalus or for new metastatic disease. In patients who have had varicella-zoster infection, postherpetic neuralgia and delayed arteritis may develop. Seizures, hearing loss, and neuropsychologic sequelae may follow any meningoencephalitis. The patient should always be reevaluated for the possibility of infection with a different opportunistic organism. CNS infections remain a major cause of morbidity and mortality in immunosuppressed patients with malignancies. In one series, 60% of such patients died as a result of their CNS infection, many at a time when the underlying disease had an otherwise good prognosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Use of Antibacterial Agents in Infections of the Central Nervous System

The movement of drugs from the systemic circulation into the central nervous system is restricted by several factors, including the blood-brain and blood-CSF barriers, an active transport system that affects primarily the beta-lactam antibiotics, and the high degree of serum protein binding of certain agents. The functions of the blood-brain and blood-CSF barriers and of the active transport system are reduced but not abolished by inflammation. For most antimicrobial agents, the major determinant of passage aside from serum protein binding is the degree of lipid-solubility of the drug. The beta-lactam and aminoglycoside antibiotics and vancomycin penetrate the central nervous system relatively poorly, whereas chloramphenicol, metronidazole, the fluoroquinolones and trimethoprim-sulfamethoxazole fare better. Knowledge of the relative capacity of various drugs to penetrate the central nervous system after systemic administration may help the physician to choose an optimum regimen for the treatment of bacterial meningitis and brain abscess.

Trends in the management of bacterial brain abscesses: a review of 102 cases over 17 years.

The records of 102 patients with brain abscesses treated over 17 years were analyzed. In recent years, cardiac and pulmonary causes were less frequent, the abscesses were smaller, and fewer patients were in poor neurological condition. There has been no significant change in the type or number of infective organisms or in the number of abscesses during the study period. Computed tomographic brain scanning was the most important factor in reducing the mortality rate from 41% to 4%. The patients were grouped according to the treatment received: excision (n = 46), aspiration (n = 33), or nonsurgical therapy (n = 17). Patients treated nonsurgically were more likely to have smaller abscesses and multiple lesions than were patients in the other two groups. There were no significant differences in the morbidity or mortality rates between treatment groups. Patients whose abscesses were excised had a significantly shorter course of antibiotics than the other patients. Organisms were identified in 85% of the cultures from surgical specimens. The use of preoperative antibiotics was significantly associated with sterile cultures; 30% of patients who received antibiotics preoperatively had sterile cultures, compared with only 4% of patients who did not receive such treatment. The mortality rate among all treated patients (the diagnosis of brain abscess was missed in 6 patients before computed tomographic scanning became routine) was significantly related to the initial neurological grade and the size of the lesion but not to age, sex, or the number of abscesses. Four of the 8 treated patients who died had congenital cyanotic heart disease; an aggressive surgical approach is recommended for such patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in the management of bacterial brain abscesses

Trends in the management of bacterial brain abscesses

Management of Bacterial Brain Abscesses

Management of Bacterial Brain Abscesses

Plaque and systemic disease: a reappraisal of the focal infection concept.

The review presented here covers metastatic local and systemic disease secondary to the accumulation of plaque or the formation of other pathogenic microbial depots in the mouth. At least 3 pathways may link oral infection to secondary disease, to wit metastatic infection due to transient bacteremia, metastatic immunological injury, and metastatic toxic injury. The available evidence is presented and examples are provided. They concern among others such divergent diseases as acute bacterial myocarditis, infective endocarditis, brain abscess, uveitis and iridocyclitis, trigeminal and atypical facial neuralgia, unilateral facial paralysis, fever of "unknown' origin, and neutrophil dysfunction.

Current concepts of bacterial infections of the central nervous system

Investigative work continues to provide guidance toward more rational management of bacterial meningitis and bacterial brain abscess. An increased understanding of the host's response in cases of bacterial meningitis has established that diffusibility of an antibiotic into the cerebrospinal fluid (CSF) is necessary, but is not sufficient for microbial cure. The antibiotic must also have a bactericidal effect on the pathogen. Meningitis after neurosurgery may be caused by Gram-negative aerobic bacilli. In some of these cases the newer cephalosporin antibiotics may be a useful advance. Meningitis complicating ventricular CSF shunts presents a paradigm for the problem of eradicating foreign body-related infections. Studies of the interaction of the host, the organism, and the shunt material offer some explanation for the limited efficacy of antibiotics observed in this setting. There have been advances in microbial definition of bacterial brain abscess. The identification of Bacteroides fragilis as a pathogen in certain brain abscesses has established a role for a newly available antibiotic, metronidazole. The study of the pathological distinction between cerebritis and frank abscess is clarifying two clinical characteristics of brain abscess: the limited success of antibiotic treatment and the increase in intracranial pressure. Computerized tomography has offered a valuable clinical "look" at brain abscesses; however, there are still problems in correlating the scan images with the evolving pathological process.

Glutamic acid decarboxylase in cerebrospinal fluid in infancy and childhood part II. Glutamic acid decarboxylase activity in cerebrospinal fluid of children with neurological diseases

Glutamic acid decarboxylase (GAD) activity in cerebrospinal fluid (CSF) was determined in 53 patients with neurological diseases as follows: Epilepsy (n:17), febrile convulsions (n:3), meningoencephalitis (n:17), encephalopathies (n:10), CNS leukemia (n:3), congenital hydrocephalus (n:2) and pseudoileus neonatorum (n:1). Compared with the mean normal value (5.2 +/- 2.5 pmol CO2 formed/hr/ml) reported in Part I, a significant increase of GAD activity in CSF was demonstrated in patients with uncontrolled epileptic seizures (11.4 +/- 3.9 pmol CO2 formed/hr/ml), febrile convulsions (13.5 +/- 8.7), viral meningitis with or without encephalitis (20.3 +/- 13.6), encephalopathies (30.0 +/- 25.9), CNS leukemia (11.1 +/- 5.0), congenital hydrocephalus (20.5 +/- 7.3) and pseudoileus neonatorum (28.6). Markedly high GAD activity was found in patients with CNS leukemia several days after intrathecal injection of methotrexate (39.8 +/- 18.0). On the other hand, significantly low GAD activity was shown in patients with bacterial meningitis or brain abscess (1.3 +/- 1.2). This suggests that some bacterial factors may be inhibitory toward GAD activity in CSF. High GAD activity in CSF may be useful as an indicator of aseptic brain dysfunction, although it was not always correlated with the severity of symptoms.

Congenital cardiac disease: a review of 357 cases studied pathologically.

The purpose of this work is limited, but it is most effectively served. A catalogue of the autopsy experience of the Mayo Clinic with congenital heart disease is analyzed, compared with other large pathologic series, and discussed from the point of view of possible functional characteristics affecting length of survival. It provides a ready source of information as to incidence of individual malformations and combinations of malformations, and states age at death, sex, incidence of bacterial endocarditis and brain abscess. The bibliography—50 pages of fine print carefully arranged by subject—is of great value in the light of the burgeoning literature in this field. In this list are well over 20 of Dr. Edwards' own works, usually written in collaboration with one or more clinicians. He is well recognized among pediatric cardiologists as a pathologist who is sincerely interested in clinical problems. The comments upon pathologic physiology which make the book