Brain abscess (or cerebral abscess) is an abscess caused by inflammation and collection of infected material coming from local (ear infection, infection of paranasal sinuses, infection of the mastoid air cells of the temporal bone, epidural abscess) or remote (lung, heart, kidney etc.) infectious sources within the brain tissue. The infection may also be introduced through a skull fracture following a head trauma or surgical procedures. Brain abscess is usually associated with congenital heart disease in young children. It may occur at any age but is most frequent in the third decade of life. An abscess is a collection of pus collected in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e. ... A sinus is a pouch or cavity in any organ or tissue, or an abnormal cavity or passage caused by the destruction of tissue. ... Mastoid can mean: Of, relating to or in the region of the mastoid process. ... An abscess is a collection of pus collected in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e. ... The lungs flank the heart and great vessels in the chest cavity. ... The heart and lungs (from an older edition of Grays Anatomy) The heart (Latin cor) is a hollow, muscular organ that pumps blood through the blood vessels by repeated, rhythmic contractions. ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... The human brain is the center of the central nervous system in humans and the primary control center for the peripheral nervous system. ... Head injury is a trauma to the head, that may or may not include injury to the brain (see also brain injury). ... Congenital heart disease is heart disease in the newborn, and includes congenital heart defects, congenital arrythmias, and cardiomyopathies. ...

Features

The symptoms of brain abscess are caused by a combination of increased intracranial pressure due to a space-occupying lesion (headache, vomiting, confusion, coma), infection (fever, fatigue etc.) and focal neurologic brain tissue damage (hemiparesis, aphasia etc.). The most frequent presenting symptoms are headache, drowsiness, confusion, seizures, hemiparesis or speech difficulties together with fever with a rapidly progressive course. The symptoms and findings depend largely on the specific location of the abscess in the brain. An abscess in the cerebellum, for instance, may cause additional complaints as a result of brain stem compression and hydrocephalus. Neurologic examination may reveal a stiff neck in occasional cases (erroneously suggesting meningitis). The famous triad of fever, headache and focal neurologic findings are highly suggestive of brain abscess but are observed only in a minority of the patients. Intracranial pressure is the pressure of the cerebrospinal fluid within the central nervous system. ... This article is in need of attention from an expert on the subject. ... Hemiparesis is the paralysis of one side of the body. ... Aphasia is a loss or impairment of the ability to produce or comprehend language, due to brain damage. ... // Definition Mental Confusion or Decreased Alertness is the inability to think clearly and quickly; put simply, feeling things just are not right. ... Seizures (or convulsions) are temporary alterations in brain function expressing themselves into a changed mental state, tonic or clonic movements and various other symptoms. ... Hemiparesis is the paralysis of one side of the body. ... The brain stem is the stalk of the brain below the cerebral hemispheres. ...

Pathophysiology

Brain abscesses are usually polymicrobial in nature.

The most common organism recovered from cultures is the bacterium Streptococcus. However, a wide variety of other bacteria (Proteus, Pseudomonas, Pneumococcus, Meningococcus, Haemophilus), fungi and parasites may also cause the disease. Fungi and parasites are especially associated with immunocompromised patients. Organisms that are most frequently associated with brain abscess in patients with AIDS are Toxoplasma gondii and Cryptococcus neoformans, though in infection with the latter organism, symptoms of meningitis generally predominate. Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Species S. faecalis S. pneumoniae S. pyogenes S. suis S. viridans Streptococcus is a genus of spherical, Gram-positive bacteria of the phylum Firmicutes. ... In Greek mythology, Proteus is an early sea-god, one of several deities whom Homer calls the Old Man of the Sea, whose name suggests the first, as protogonos is the firstborn. No mention is made of his parents, until for later mythographers he became the son of Poseidon in... Species P. fluorescens P. putida etc. ... Binomial name Streptococcus pneumoniae Streptococcus pneumoniae is a species of Streptococcus that is a major human pathogen. ... Neisseria is a genus of bacteria, included among the proteobacteria, a large group of gram-negative forms. ... Haemophilus or Hemophilus is a genus of parasitic rod-shaped bacteria. ... Divisions Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Yellow fungus Fungus growing on a tree in Borneo For the fictional character, see Fungus the Bogeyman. ... A parasite is an organism that lives in or on the living tissue of a host organism at the expense of that host. ... // Medical procedures Medical workers who follow universal precautions or body substance isolation such as wearing latex gloves when giving injections and washing the hands frequently can help prevent infection of HIV. The risk of being infected with HIV from a single prick with a needle that has been used on... Binomial name Toxoplasma gondii (Nicolle & Manceaux), 1908 Toxoplasma gondii is a species of parasitic protozoa, belonging to the Apicomplexa, that can cause the disease toxoplasmosis in humans. ... Cryptococcus neoformans is a species of fungus that can live in both plants and animals. ... Inferior view of a brain with meningitis caused by Haemophilus influenzae. ...

Diagnosis

The diagnosis is established by a computed tomography (CT) (with contrast) examination. At the initial phase of the inflammation (which is referred to as cerebritis), the immature lesion does not have a capsule and it may be difficult to distinguish it from other space-occupying lessions or infarcts of the brain. Within 4-5 days the inflammation and the concomitant dead brain tissue are surrounded with a capsule, which gives the lesion the famous ring-enhancing appearance on CT examination with contrast (since intravenously applied contrast material can not pass through the capsule, it is collected around the lesion and looks as a ring surrounding the relatively dark lesion). Lumbar puncture procedure, which is performed in many infectious disorders of the central nervous system is contraindicated in this condition (as it is in all space-occupying lesions of the brain) because removing a certain portion of the cerebrospinal fluid may alter the concrete intracranial pressure balances and cause a part of the brain tissue to move out of the skull (brain herniation). CT apparatus in a hospital Computed tomography (CT), originally known as computed axial tomography (CAT) and body section roentgenography, is a medical imaging method employing tomography where digital processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional... In medicine, a lumbar puncture (colloquially known as a spinal tap) is a diagnostic procedure that is done to collect a sample of cerebrospinal fluid (CSF) for biochemical, microbiological and cytological analysis. ... Cerebrospinal fluid, CSF in short, is the clear fluid that occupies the subarachnoid space (the space between the skull and cortex of the brain). ...

Ring enhancement may also be observed in cerebral hemorrhages (bleeding) and some brain tumors. However, in the presence of the rapidly progressive course with fever, focal neurologic findings (hemiparesis, aphasia etc) and signs of increased intracranial pressure, the most likely diagnosis should be the brain abscess. See the article about cancer for the main article about malignant tumors. ...

Treatment

The treatment includes lowering the increased intracranial pressure and starting intravenous antibiotics (and meanwhile identifying the causative organism mainly by blood culture studies). Surgical aspiration or removal of brain abscess are performed for patients that are resistant to medical treatments. An antibiotic is a drug that kills or slows the growth of bacteria. ...