Diffuse meningeal enhancement in patients with overdraining, long-standing ventricular shunts.

The authors report two elderly men with diffuse meningeal enhancement 13 and 21 years following insertion of ventriculojugular shunts. Lumber puncture documenting low CSF pressures suggests that diffuse meningeal enhancement in patients with long-standing ventricular shunts may be secondary to dural venous dilatation rather than meningeal fibrosis. The authors theorize that these elderly patients, neither of whom had postural headache, may be less subject to brain "sag" because of decreased brain weight.