Cerebrovascular Complications of CNS Infections

The most common cerebrovascular complication of infection overall is cerebral infarction. A less common complication is hemorrhage either from ruptured infective aneurysm or from vasculitic destruction of the vessel wall. The central nervous system (CNS) vasculature can be affected by systemic or local CNS infectious processes. Infections can compromise the arteries or the veins-dural venous sinuses. The arterial involvement includes (1) infectious intracranial aneurysm (IIA) or (2) infectious vasculitis. The venous involvement results in venous or dural venous sinus thrombophlebitis. We will present common imaging patterns on CT (computed tomography) and MRI (magnetic resonance imaging) of the arterial and venous complications of infections. We will approach the cerebrovascular complications of infections by anatomic distribution. The imaging findings for infective aneurysm are similar for different pathogens; also the imaging characteristics in infectious vasculitis are usually nonspecific and overlap for different organisms and even with noninfectious vasculitides. Infectious vasculitis can be caused by a large number of pathogens. In this chapter we will also discuss the most common organisms causing infectious vasculitis.