Which of the following statements is/are true?

C. Bacterial meningitis may lead to the development of hydrocephalus.

D. A bacterial brain abscess commonly presents as a mass lesion of the brain, without systemic signs of infection such as fever or leukocytosis.

DISCUSSION: Cranial osteomyelitis can arise from hematogenous spread, but more often it results from direct spread from an infected paranasal sinus, inoculation by a penetrating object, or operative infection of a craniotomy bone flap. Subdural empyema ordinarily cannot be brought under control with antibiotics alone, and it does require surgical drainage. One of the sequelae that can follow bacterial meningitis is hydrocephalus, which is usually due to the obliteration of subarachnoid spaces and interference with CSF reabsorption. A brain abscess, per se, is not ordinarily accompanied by systemic signs of infection; these can be present if the patient also has meningitis or an active infection elsewhere. CT, especially after intravenous administration of a contrast agent, is an excellent way to demonstrate a brain abscess.