Graff-Radford NR.  Alzheimer CSF biomarkers may be misleading in   normal-pressure hydrocephalus.  Neurology 2014; 83:1573-1575.
  Preshunt in NPH have low Ab42 and tau protein, that improve post   shunt.  Author attributes to impaired clearance of these proteins in   NPH,  same is true for tau protein.  After shunting, "room for the ICF   space increases during sleep and ability for the proteins to better drain into   the CSF (increases).  Physicians should not rely on CSF biomarkers to look   for Alz disease among patients being assessed for Alzheimer's disease.    
  Blogger comment
  nice clinical practical pearl.  In NPH the whole idea of evaluation is   to separate out bad surgical candidates from good ones by identifying   Alzheimer's patients and others.  
