Abscess of the Brain.
Etiology.—This lesion is usually found between the ages of twenty and forty, and more frequently in males than in females. It is generally, if not always, secondary, and may arise from an extension of suppurative inflammation of the ear, nose, or orbit, especially where the bones are involved; from head injuries as fracture of the skull, or from a punctured wound; from pyemia, septicemia, gangrene of the lung, ulcerative endocarditis, and necrosis of bones; from intercranial tumors, and from the specific infectious fevers. It is more apt to occur among the poorer classes, especially where due to middle-ear diseases following scarlet fever, and where the child has not had the proper care.
Pathology.—The abscess varies as to size and character of its contents. It may be single or multiple, usually the former. Pus of varying consistency, blood, and pyogenic organisms make up its contents. It is most frequently found in the, temporo-sphenoidal lobe, owing to its relation to the middle ear. It is rarely found in the cerebellum, and still less so in the pons and medulla. The neighboring- brain-substance is generally softened and reveals the change due to inflammation. Where of long standing, a thick layer of fibrous tissue is found walling off the abscess.
Symptoms.—These vary, according to size, location, cause, and character of the inflammation. Where there are severe complications, as head injuries or meningitis, the symptoms may be so masked as to escape detection. They may appear quite rapidly, or come on insidiously. Where acute, the symptoms are of acute septic infection; there is a chill, followed by rise of temperature, intense headache, vertigo, vomiting, mental dullness, or delirium and convulsions.
When it comes on slowly, being secondary to septicemia or ulcerative endocarditis, in addition to symptoms of the primary lesions, there will be chills, irregular fever, sometimes the temperature being subnormal, nausea, vomiting, headache, and convulsions. The motor and sensory symptoms depend upon the extent and location of the abscess. There may be aphasia, hemiplegia, clonic spasms, or hemianopsia. The reflexes are generally much exaggerated. Choked disks are rare, though congestion of the eye-grounds is common. Respiration is usually slow, from ten to fifteen per minute, while the Cheyne-Stokes respiration is sometimes observed.
In rare cases the abscess ruptures into the ear or nose, and relief is experienced by drainage from those channels. If the abscess be in the "silent regions," and small in size, the symptoms may be so slight as to escape detection.
Diagnosis.—In acute cases preceded by head injuries, there will be but little difficulty in determining the lesion. With a history of injury followed by intense headache, fever, delirium, optic neuritis, and convulsions, the diagnosis would be easy. In the more chronic cases, an accurate history and a careful examination of the patient should be made for endocarditis, septic lung lesions, bone necrosis, etc., and should these be followed by irregular fever, nausea, vomiting, headache, coma, convulsions, motor and sensory symptoms, such as aphasia, hemiplegia, etc., the diagnosis should not be difficult.
Prognosis.—This is always grave, though if free drainage be secured, either by spontaneous rupture into the nasal or aural opening, or by surgical measures, the patient will frequently recover.
Treatment.—Though the antiseptics would be indicated in all cases of sepsis, the treatment is surgical, and consists of early evacuation and thorough drainage.