Synonyms.—Hemorrhagic Pachymeningitis; Hematoma of the Dura Mater.
Definition.—Extravasation of blood into the inner membrane of the dura mater.
Etiology.—This is a secondary lesion, following inflammation of the external membrane of the dura mater, or occurring as the result of tuberculosis, Bright's disease, leukemia, erysipelas, pyemia, puerperal fever, syphilis, or any other disease causing degeneration of the blood-vessels.
Pathology.—On the inner surface of the dura, a fibrous exudate is found which develops into fibrous connective tissue in which one or more slight, rarely profuse, hemorrhages occur, and as a result a quantity of blood accumulates between the dura and the arachnoid; hence the term hematoma is applied to it. A favorite location is beneath the parietal bone. It may be bilateral, though usually but one side is affected.
Symptoms.—These are not characteristic; in fact, they may be so obscured by the primary disease giving rise to it as to pass unnoticed. Pressure symptoms are frequently present, and monoplegia or hemiplegia may occur. Headache is perhaps the most constant symptom, and convulsions are not unfrequent.
Diagnosis.—This is extremely difficult, the clinical symptoms not being sufficiently constant to suggest the lesion.
Prognosis.—This is unfavorable, there always being a tendency to meningitis and danger from thrombosis.
Treatment.—This will always be along the line of meningitis, and when a large hemorrhage is recognized, surgical measures will be necessary.