Hydrocephalus

CSF is produced mainly in the ventricles, flows through the ventricular system and subarachnoid space, and is absorbed into venous circulation. Obstructive hydrocephalus occurs when flow is blocked, such as aqueductal stenosis, tumor, hemorrhage, or scarring. Communicating hydrocephalus occurs when CSF can move through the ventricles but absorption is impaired, such as after meningitis or subarachnoid hemorrhage. In infants, open sutures may allow head enlargement before classic adult raised-ICP signs dominate. In older children and adults, a closed skull means ventricular enlargement can produce headache, vomiting, vision change, altered level of consciousness, gait change, or seizures. Normal pressure hydrocephalus is different: enlarged ventricles are associated with gait disturbance, cognitive decline, and urinary urgency or incontinence, often without the dramatic pressure symptoms seen in acute hydrocephalus. For REx-PN (Canada), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the role named in the stem before distractors compete. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or...