PUB - Publikationen an der Universität Bielefeld

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait disturbances, urinary incontinence, and cognitive impairment. Occurring in older age, iNPH is often mimicked by other neurological conditions. While the pattern of cognitive deficits is known to differ from other age-associated cognitive syndromes (AACS), there is no recommended standard test set for iNPH to date. In this study, we evaluate whether tests of attention and working memory differ between iNPH and AACS. Method: A total of 50 patients with suspected iNPH (23 iNPH, 27 AACS) receiving lumbar puncture (LP) in a neurological acute clinic were consecutively included in the study over 4 years. In a prospective study design, patients completed the Wechsler Memory Scale–Revised (WMS-R) digit spans, symbol digit modalities test (SDMT), and the Test of Attentional Performance (TAP) alertness subtest prior to and following LP. Subsequent group assignment (iNPH vs. AACS) was based on neurological assessment. Between-group comparisons were analyzed using Mann–Whitney rank sum test, and within-group change was analyzed using the Wilcoxon signed rank test. Results: In the iNPH group, post-LP improvements were found for the TAP index of phasic alertness ( p = .005) and WMS-R digit span backward ( p = .008). Both groups improved in SDMT score while between- group comparisons of this variable revealed a significant difference. Conclusions: Improvements of phasic alertness and working memory hold diagnostic value to differen- tiate iNPH from AACS. Test–retest effects in the AACS group SDMT results impede differentiation and need to be discussed.