**1. Introduction**

Normal-pressure hydrocephalus (NPH) is the earliest identified cause of dementia which can be potentially treated [1, 2]. NPH was described by Hakim and Adams in 1965, and the entity was characterized by gait disturbances, impaired cognition, and urinary incontinence that is associated with ventricular enlargement without rise in cerebrospinal fluid (CSF) pressure [3, 4]. NPH may be primary or idiopathic NPH (without known precipitating factors) or secondary (due to trauma, hemorrhage, infection, mass lesions, or delayed aqueductal stenosis) [5–7].
