Magnetisation transfer ratio is low in normal-appearing cerebral white matter in patients with normal pressure hydrocephalus

We measured the magnetisation transfer ratios (MTR) of normal-appearing ros tral (PR) and caudal (PC) periventricular white matter, the genu (CG) and t he splenium (CS) of the corpus callosum and the thalamus (TH) in 12 patient s with normal-pressure hydrocephalus (NPH) and compared them with 16 health y control subjects. We found a significantly lower MTR in the NPH group tha n in the normal group for PR;, PC, CG, and CS but not for TH. MT measuremen ts give additional information which cannot be gained by conventional MRI, suggesting that NPH is associated with diffuse white; matter damage, even i n normal-appearing cerebral white matter.