FINAL DIAGNOSIS: CRYPTOCOCCAL MENINGITIS WITH VASCULITIS AND CEREBRAL INFARCT
Transient ischemic attacks are an unusual presentation of cryptococcal meningitis (1). More typical are headache, fever, mental status change, and cranial nerve palsies. Considerable variation in presentation is well documented, however, and delays in making a diagnosis of cryptococcal meningitis are not uncommon (2). Of note in this case was a three-day history of headache prior to admission. A diagnosis was made by cerebrospinal fluid analysis, which showed WBC 310 x 109/L (62% lymphocytes and 28% segmented neutrophils), no red blood cells, total protein 128 mg/dL, and glucose 103 mg/dL (serum glucose 150mg/dL). Encapsulated yeast were identified in India ink preparations. Immunosuppression is often, but not invariably, associated with cryptococcal meningitis. Diabetes mellitus was the only known risk factor for impaired immunity in this patient. Defective leukocyte function is believed to play a role in increased susceptibility to infection in patients with diabetes mellitus (3). A head CT on admission was normal. Two published series (4,5) have found that head CTs are normal in 43% or 52% of cryptococcal meningitis cases at initial presentation. When CT scans are abnormal, they show edema, either diffuse or focal, hydrocephalus, or mass lesions. Of concern, regarding the repeat head CT seen in Figure 1, was whether the hypodense left frontal lobe lesion represented a cerebral infarction or a cryptococcoma. Previous studies of mass lesions in cryptococcal meningitis indicate that cryptococcomas are typically hypodense (6). However, the lesion represented an acute infarct, predominantly of the corpus callosum. Microscopically, the infarct was well circumscribed, involving a vascular territory perfused by a branch of the anterior cerebral artery, and many of the small leptomeningeal vessels over the infarct were surrounded by chronic inflammatory cells, giant cells, and cryptococcal organisms. Infarction in cryptococcal meningitis is uncommon but well documented and has occasionally been attributed to vasculitis, as appears to have occurred in this case (7,8). Overall mortality due to cryptococcal meningitis has been estimated at 22%. This case illustrates the importance of recognizing diabetes mellitus as a risk factor for impaired immunity. It further serves to emphasize the clinical variability of cryptococcal meningitis, describing an unusual presentation and, finally, reports an unusual complication of cryptococcal meningitis, i.e. vasculitis and cerebral infarction.
Contributed by Nancy C. Karpinski, M.D. and Henry C. Powell, M.D.