Timing of surgery for excess fluid around the brain

Inclusion criteria: Patients who have any or all of the following symptoms: gait disturbance, cognitive dysfunction, or urinary dysfunction, and meet the criteria of Evans' index > 0.3, will undergo nuclear medicine examination (head MRI, DaT-SPECT, IMP-SPECT, MIBG myocardial scintigraphy). Patients with disproportionately enlarged subarachnoid-space hydrocephalus (DESH) and gait disturbance should undergo CSF examination. For patients with symptoms of gait disturbance but no DESH, a tap test is performed and cognitive function tests (MMSE: Mini Mental Scale Examination, FAB: Frontal Assessment Battery, TMT: Trail making test), evaluation of urinary dysfunction (I-PSS: International prostate symptom score, OABSS: Overactive bladder symptom score, ICIQ-SF: International Consultation on Incontinence Questionnaire Short Form), evaluation of parkinsonism (Dopa challenging test, MDS UPDRS part III: MDS-Unified Parkinson's Disease Rating Scale part III, iNPHGS: iNPH grading score) are performed before and after (on the day of the tap test, 3 days later, and 7 days later), and if symptoms improve, a diagnosis of normal pressure hydrocephalus is made. Exclusion criteria: Select patients with no pre-existing subarachnoid hemorrhage, meningitis, head trauma, congenital hydrocephalus, or aqueductal stenosis.If the CSF test shows CSF amyloid-beta42 < 500 pg/ml, CSF total tau > 600 pg/ml, and CSF phosphorylated tau > 60 pg/ml, the patient is likely to have Alzheimer's disease and should be excluded.