Infection of the sinuses causes pain and purulent discharge and may extend into the cranium, causing the following complications: Cavernous sinus thrombosis Brain, epidural, or subdural abscesses Septic cortical thrombophlebitis Meningitis Pneumococcal meningitis Acute purulent meningitis is frequently caused by pneumococci and may be secondary to bacteremia resulting from other foci (notably pneumonia); direct extension from infection of the ear, mastoid process, or paranasal sinuses; or basilar fracture of the skull involving one of these sites or the cribriform plate (usually with cerebrospinal fluid leakage), thus giving bacteria in the paranasal sinuses, nasopharynx, or middle ear access to the central nervous system.