Ortner, Marion;Hauser, Christine;Schmaderer, Christoph;Muggenthaler, Claudia;Hapfelmeier, Alexander;Sorg, Christian;Diehl-Schmid, Janine;Kurz, Alexander;Förstl, Hans;Ikenberg, Benno;Kotliar, Konstantin;Poppert, Holger;Grimmer, Timo; Decreased Vascular Pulsatility in Alzheimer’s Disease Dementia Measured by Transcranial Color-Coded Duplex Sonography