Isolated angiitis of the CNS and bacterial endocarditis: similarities and differences.

Both isolated angiitis of the central nervous system (IAN) and bacterial endocarditis (BE) may present with similar clinical and auxiliary findings. The differentiation is extremely important because of the different treatment regimens. We compared the findings of six patients with biopsy-proven IAN with the data of six patients with BE. Patients with IAN were younger (27-62 years) and presented with multiple strokes (n = 4), intracerebral hemorrhage (n = 1), epileptic seizures (n = 2), or encephalopathy (n = 1). All IAN patients had pathologic cerebrospinal fluid (CSF) findings (pleocytosis n = 5; protein elevation n = 4), and angiography revealed multilocular stenoses in two cases while digital subtraction angiography was normal in four. BE patients (32-77 years) presented multiple (n = 3) or single ischemic strokes (n = 2) or encephalopathy and headache (n = 2). While all patients showed inflammatory serum findings (C-reactive protein n = 6, leucocytosis n = 4), CSF-pleocytosis was present in two cases only. Angiography revealed a vasculitic pattern in two patients. The diagnosis of BE was established based on transesophageal echocardiography and blood cultures. Leptomeningeal and brain biopsies performed in two cases were normal. Both IAN and BE may present multiple strokes and encephalopathy. The frequency of a vasculitic pattern in angiography is similar in both conditions. While inflammatory serum findings are the rule in BE, pathologic CSF findings were present in all IAN patients. Transesophageal echocardiography and blood cultures should be performed in order to diagnose or exclude BE. Without brain biopsy, immunosuppressive therapy may be dangerous in suspected IAN.