The Study of Etiologic and Demographic Characteristics of Intracranial Brain Abscess: A Consecutive Case Series Study from Pakistan

Background

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

Methods

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

Results

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

Conclusion

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

Introduction

Intracranial brain abscess is a universal health problem with a high morbidity and mortality rate such that the disease today presents a leading public health problem and a major burden on health care facilities all around the world (17, 19). The infectious origin of the brain abscess causes significant damage to the central nervous system with typically four stages leading to capsule formation (5). The central nervous system is incapable of mounting a sufficient defense against the pyogens leading to pyogenic abscess (12).

The clinical presentation of intracranial abscess is dependent on the site, size, number of lesions, and any secondary cerebral injury (8, 13, 27). Common presenting symptomatology, such as headache, neurologic dysfunction, pyrexia, and altered sensorium (3, 6), as well as a raised level of serum markers confers a high degree of clinical suspicion and may be found in up to 75% of cases; however, the main diagnostic tools today are the imaging modalities (15).

Despite advances in neuroradiologic imaging techniques and antimicrobial chemotherapy (11), the incidence of cerebral abscesses may be increasing, with a growing number of opportunistic infections in immunocompromised patients, such as organ transplant recipients (4) and patients with advanced HIV disease (26). There are a lot of data and research about intracranial brain abscess from developed countries; however, there is a paucity of data from developing countries such as Pakistan because there is neither a national database nor any relevant authority. Nevertheless, individual studies have been carried out in local cities in the past. The magnitude of the problem as well as significant morbidity and mortality, not to mention the cost of admission and the treatment expenditure incurred by the state, motivated us to carry out our research. Factors such as patients' age, gender, presenting symptoms, treatment, and their outcome in terms of mortality and morbidity were taken into consideration. The main objective of our study was to determine the etiology, management, bacteriological spectrum, and outcome of brain abscess of patients brought to Aga Khan University Hospital (AKUH), Karachi, with a history of neurologic symptoms and to examine the factors associated with it.