Answer to Dali?

Correct answer is D. The patient was suffering from normal pressure hydrocephalus, the CSF was building up deep to her arachnoid mater. Presumably, the tumor found in the back of her brain was impeding outflow of the venous circulation backing up the CSF from draining out. Generally, a variety of symptoms can be expressed with this condition, including papilledema, or swelling of the optic nerve, but all can be relieve if the retained CSF is drained by placing a shunt. It is the CSF that is causing the normal pressure hydrocephalus. Hence, draining the venous return would not reduce the pressure, even if it were possible to perform such a procedure. The different layers indicated include the following: 1 = Dura mater; 2 = superior sagittal sinus; this is for venous return. 3 = transverse sinus; this is also for venous return. 4 = the arachnoid mater; CSF resides immediately deep to this layer of the meninges. 5 = dura mater left behind in the brain.

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Answer to this question is based on material presented in lectures 7 of the Head and Neck Dissection Review Series.