Abstract
BACKGROUND: The determinants of the severity of idiopathic normal pressure hydrocephalus (iNPH) have not been examined previously. OBJECTIVE: To reveal the clinical determinants of the clinical severity of iNPH in detail. To provide some clinical remarks and contributions to the understanding of the pathophysiology. METHODS: We scanned the data of iNPH patients evaluated in our movement disorders outpatient clinics between January/2024 and September/2024. In addition to clinical features, we evaluated the data of the iNPH grading scale score and upper extremity bradykinesia score from our database. The Radscale was evaluated in all the individuals by a senior consultant neurologist. RESULTS: Ultimately, we evaluated 49 iNPH patients with a median age of 71 years (IQR = 10.5). Comparisons between patients with distinct severity stages revealed differences in only the upper extremity bradykinesia score (6 versus 1 point, P = 0.004) and rates of constipation (63.6% versus 29.6, P = 0.023) which were higher in the severe stage group. Correlation analyses revealed correlations between the iNPH grading scale score and upper extremity bradykinesia score (CC: 0.416, P = 0.004). However, the stepwise regression analyses revealed only constipation as a predictor of the iNPH scale score [R2: 0.181, P = 0.005]. CONCLUSIONS: Our results do not indicate a considerable role for neuroimaging markers in the determination of the clinical severity of iNPH. Notably, we draw attention to constipation as a determinant of disease severity; this clarification might provide contributions to clinical practice as well as our understanding of the underlying pathophysiology.