Mycotic Aneurysm of the Circle of Willis

Abstract

In the Gulstonian Lectures of 1885, Sir William Osler 1 stated, "The meningeal complication of endocarditis has not received much attention." Osler's remark is as revealing today as it was then.We shall review a case of subacute bacterial endocarditis in which a mycotic aneurysm of the right middle cerebral artery was discovered at autopsy. This lesion of the intracranial vessels has been noted in only 34 previous cases.2 A brief review of the pathological changes of mycotic aneurysm of the circle of Willis will be given. In the present period of antibiotic therapy, studying a case of this type constitutes a rare pathological experience. REPORT OF A CASEAn unmarried white woman, 50, was admitted in a comatose condition with a left hemiplegia of six days' duration. She was known to have recently had a blood transfusion and to have had severe anemia for over two years. Liver extract had been given for the anemia. The family stated that she had always been weak. She had undergone a hysterectomy two years previously for uterine tumors. Examination disclosed relative cardiac dulness in the left midaxillary line with the point of maximal impulse in the left ante¬ rior axillary line at the sixth interspace. A loud blowing systolic bruit was best heard over the apex of the heart and was well transmitted to the left posterior portion of the chest. Blood pres¬ sure was 126/74, pulse rate 96, and temperature 100.6 F. Fist percussion over the kidney area was painful. The urine was positive for occult blood, with 65 mg. albumin and a rare granular cast. Hypochromic anemia was verified, with 7 gm. of hemoglobin and 2,500,000 red blood cells. The blood urea nitrogen was 80 mg. with a total protein of 7 gm. The blood was a type A, Rh positive, and Hr' positive; serologie reactions were negative. Fig. 1.-Mycotic aneurysms of the right middle cerebral artery, indi¬ cated by the arrow. The white granular necrotic wall is characteristic of the gross lesion. Thickening of the adjacent segments of the middle cerebral artery due to acute arteritis is showrt, as well as pressure necrosis and hemorrhage involving the adjacent cerebral tissue.While in the hospital, the patient had a septic temperature, varying from 98 to 102.8 F. Her comatose condition changed to semistupor after a blood transfusion and penicillin therapy. How¬ ever, she was unable to speak at any time and died on the fifth day of hospitalization.Autopsy revealed an enlarged heart, weighing 410 gm., and left ventricular hypertrophy with a partly calcified, crayfish-like vege¬ tation, measuring 1.4 by 0.6 cm., attached to the free edge of the posterior mitral leaflet. The spleen weighed 350 gm. and showed gross infarction. Both kidneys were enlarged, weighing 210 gm., and showed a light pink-gray cortical surface with nu- Fig. 2.-Photomicrograph of the area of acute arteritis, with practically complete destruction of the internal elastic lamina of the right middle cerebral artery incident to the lodgement of an infected embolus and production of a mycotic aneurysm. merous ...

Rupture of Spleen in Subacute Bacterial Endocarditis

“…Involvement of the cerebral arteries can simulate a cerebral vascular accident. 23 Mycotic aneurysms of the intra-abdominal arteries are likely to be silent. In Sherlock's series of splenic artery aneurysms of combined etiology,6 34% of the patients had abdominal pain, usually confined to the left upper quadrant and parox¬ ysmal in character.…”