Several early angiographic findings in brain abscess including "the ripple sign".

Abstract

Preoperative suspicion of brain abscess is extremely important. Failure to anticipate it may, on intervention, lead to a possibly catastrophic, gross contamination of the ventricular system and the meninges. It is well established that massive edema, particularly in the white matter, frequently accompanies brain abscess on postmortem examination. The purpose of this paper is to call attention to the association, first noted by Dr. Juan Taveras (14), of marked perifocal edema in the diagnosis of brain abscess by arteriography; the emphasis of the paper is on effects secondary to swelling at a considerable distance from the central focus. In the past (8), the clinical diagnosis of brain abscess has been emphasized in those patients having fever, a primary source of infection, or congenital heart disease which could lead to embolization of the brain with either subacute bacterial endocarditis or paradoxical embolus in right-to-left shunts. We have noted, however, that a significant number of patients with brain abscess do not have these clinical findings and that arteriographic signs may alert the physician to the diagnosis. In these patients the recognition of marked perifocal edema, which may be called the “ripple sign” because of the appearance of concentric bands of radiolucency and radiopacity on the arteriogram, will raise the possibility of brain abscess. Material and Methods The patient material for this report was obtained by reviewing the clinical course and cerebral angiograms of 11 patients with cerebral abscesses who had been seen at Grady Memorial Hospital and Emory University Hospital between 1961 and 1966. They ranged in age from seven to sixty years and in occupation from student to laborer. Three of the 11 studies were done prior to the establishment of rapid serial filming. Radioactive brain scans were performed on 5 patients. Eighty-two consecutive cases of mass lesions seen in 1965 were also reviewed, and the presence of the “ripple sign” was tabulated. Results The clinical and radiologic findings are shown in Tables I and II. The “ripple sign” was present in 8 of the 11 patients with cerebral abscess. Opacification of a capsule, the surest diagnostic sign, was observed in only 3 cases. In one case the patient had a temporal focus and showed only mass displacement. One patient had a chronic fungal abscess which had only slight diffuse swelling. Discussion Arteriography is now established as the first special procedure after plain skull films, brain scan, and ultrasound in the diagnosis of suspected intracranial mass lesions. While the finding of a capsule or stain in brain abscess is diagnostic (1), it is frequently absent: in our series it was present in only 3 of 11 patients.