Idiopathic normal pressure hydrocephalus (iNPH) is a disease that often appears in elderly population, causing gait and/or balance disturbance, cognitive decline and urinary incontinence. The prevalence of iNPH is around 3.7% and there are a lot of patients with the disease without receiving a shunt. The diagnosis of iNPH is based on International Guidelines which are updated twice since 2005. The disease has an insidious onset and progress gradually. The patients describe that the symptoms may were caused by age-related reason. The major difference of iNPH with other neurodegenerative diseases is that it is treatable with a shunt surgery and that could improve patients’ symptoms up to 84% raising the hypothesis of reversibility. Hence, iNPH is a big challenge for the neurologists. Additionally, the pathophysiological mechanism behind this disease is still unclear.

The overall aim of this thesis is to increase the knowledge of the clinical and radiological signs in patients with iNPH and identify predicting factors for better shunt surgery outcomes.

Paper I

To identify any disturbance of circadian rhythm in iNPH-patients. The aim was to study any changes of the diurnal rhythm (mesor and circadian period) as well as any changes of the diurnal amplitude and acrophase of the activity in iNPH-patients before and after a shunt operation.  

Paper II

To identify, with the use of DTI, significant changes in hydrocephalus patients compared to controls. To correlate the radiological DTI results with the clinical features (cognition and gait) before and after a shunt surgery. To investigate early white matters changes in patients with iNPH and possibly reversibility after a shunt surgery. To establish a new technique in investigation of patients with iNPH and early identify this group. A significant correlation between ROIs results in one or more brain areas with the iNPH-results will give us the opportunity to use a specific DTI protocol to easier identify iNPH-patients who will have positive results with a shunt operation.

Paper III

To identify any retinal changes (retinal nerve fiber layer [RNFL] thickness, ganglion cell layer [GCL] thickness, optic disc area, rim area, and optic volume) in patients with iNPH compared with healthy individuals. Additionally, to identify any changes in the clinical symptoms before and after a CSF tap test corresponding to the OCT findings.  

Paper IV

To identify possible urinary and bowel symptoms in patients with iNPH and compare them to healthy individuals. The secondary aim is to evaluate possible improvement after the shunt operation.