Communicating hydrocephalus vs non-communicating hydrocephalus?

Communicating hydrocephalus vs non-communicating hydrocephalus?

• A. Communicating involves obstruction; non-communicating involves impaired reabsorption.
• B. Communicating involves impaired reabsorption without obstruction; non-communicating involves obstruction.
• C. Both involve obstruction but differ in location.
• D. Communicating is due to hemorrhage.

Answer: (B)

Communicating hydrocephalus happens when CSF can flow through the ventricular system into the subarachnoid space, but reabsorption into the venous system is impaired at the arachnoid granulations. There’s no internal blockage within the ventricles. Non-communicating (obstructive) hydrocephalus, by contrast, results from a physical obstruction within the ventricular pathways (such as aqueductal stenosis or a mass) that prevents CSF from moving from the ventricles to the subarachnoid space. So the best statement is that communicating involves impaired reabsorption without obstruction, while non-communicating involves obstruction. This fits the physiology, whereas the other options mix up which mechanism is involved or imply obstruction where there isn’t one.

Communicating hydrocephalus happens when CSF can flow through the ventricular system into the subarachnoid space, but reabsorption into the venous system is impaired at the arachnoid granulations. There’s no internal blockage within the ventricles. Non-communicating (obstructive) hydrocephalus, by contrast, results from a physical obstruction within the ventricular pathways (such as aqueductal stenosis or a mass) that prevents CSF from moving from the ventricles to the subarachnoid space. So the best statement is that communicating involves impaired reabsorption without obstruction, while non-communicating involves obstruction. This fits the physiology, whereas the other options mix up which mechanism is involved or imply obstruction where there isn’t one.