The Role of Neurofilament Light (NfL) in Patients With Hydrocephalus

Inclusion Criteria: * In group A: * Patients with diagnosed communicating hydrocephalus * MMSE \> 10 points * Absence of any structural laesion on MRI or CT * Accepted Informed consent * In group B: * MMSE \> 10 points * Absence of any structural laesion on MRI or CT * Accepted Informed consent * Elective spinal surgery without affecting dural sac and the spinal cord * Surgery shorter than 120 minutes of lasting the general anesthesia Exclusion Criteria: * Non-communicating hydrocephalus * Structural laesion on MRI or CT (tumour, contusion, aneurysm) * MMSE \< 10 points * Life-expectancy shorter than 1 year * Pre-existing other type of demetia (m. Alzheimer, vascular dementia) * Surgery lasting more than 120 minutes * Blood loss more than 500 ml * Opening of dural sac (liquororhea) * Adverse events during general anestesia: MAP\<60 mm Hg more than 5 minutes, arythmia with need for farmacological treatment