Beschreibung:
<jats:title>ABSTRACT</jats:title><jats:sec id="S1041610221000661_as1"><jats:title>Objectives:</jats:title><jats:p>To examine the relationship between cerebrospinal fluid (CSF) biomarkers of Alzheimer’s disease (AD) and tap test response to elucidate the effects of comorbidity of AD in idiopathic normal-pressure hydrocephalus (iNPH).</jats:p></jats:sec><jats:sec id="S1041610221000661_as2"><jats:title>Design:</jats:title><jats:p>Case–control study.</jats:p></jats:sec><jats:sec id="S1041610221000661_as3"><jats:title>Setting:</jats:title><jats:p>Osaka University Hospital.</jats:p></jats:sec><jats:sec id="S1041610221000661_as4"><jats:title>Participants:</jats:title><jats:p>Patients with possible iNPH underwent a CSF tap test.</jats:p></jats:sec><jats:sec id="S1041610221000661_as5"><jats:title>Measurements:</jats:title><jats:p>Concentrations of amyloid beta (Aβ) 1–40, 1–42, and total tau in CSF were measured. The response of tap test was judged using Timed Up and Go test (TUG), 10-m reciprocation walking test (10MWT), Mini-Mental State Examination (MMSE), and iNPH grading scale. The ratio of Aβ1–42 to Aβ1–40 (Aβ<jats:sub>42/40</jats:sub> ratio) and total tau concentration was compared between tap test-negative (iNPH-nTT) and -positive (iNPH-pTT) patients.</jats:p></jats:sec><jats:sec id="S1041610221000661_as6"><jats:title>Results:</jats:title><jats:p>We identified 27 patients as iNPH-nTT and 81 as iNPH-pTT. Aβ<jats:sub>42/40</jats:sub> ratio was significantly lower (mean [SD] = 0.063 [0.026] vs. 0.083 [0.036], p = 0.008), and total tau in CSF was significantly higher (mean [SD] = 385.6 [237.2] vs. 293.6 [165.0], p = 0.028) in iNPH-nTT than in iNPH-pTT. Stepwise logistic regression analysis revealed that low Aβ<jats:sub>42/40</jats:sub> ratio was significantly associated with the negativity of the tap test. The response of cognition was significantly related to Aβ<jats:sub>42/40</jats:sub> ratio. The association between Aβ<jats:sub>42/40</jats:sub> ratio and tap test response, especially in cognition, remained after adjusting for disease duration and severity at baseline.</jats:p></jats:sec><jats:sec id="S1041610221000661_as7"><jats:title>Conclusions:</jats:title><jats:p>A low CSF Aβ<jats:sub>42/40</jats:sub> ratio is associated with a poorer cognitive response, but not gait and urinary response, to a tap test in iNPH. Even if CSF biomarkers suggest AD comorbidity, treatment with iNPH may be effective for gait and urinary dysfunction.</jats:p></jats:sec>