Abstract: Aims: To assess the urodynamic patterns present in patients with adult normal pressure hydrocephalus (NPH) in our
institution. Methods: Retrospectively conducted study on patients diagnosed with NPH by the Neurosurgery
Department of our institution, without etiological treatment or urogynecological disorders, who underwent an
urodynamic study (UDS) performed according to methods proposed by the International Society of Continence (ICS).
Clinical information, complementary tests and UDS were collected, and descriptive analysis was performed, with special
focus in urodynamic final diagnosis. Results: Eighty-oneUDSperformed between 2003 and 2013. Fifty-one Males (63%).
Mean age: 74.898.58 years old (range 52–88 years). Classical triad of symptoms: gait disturbance, dementia, and
urinary incontinence (UI) presented in 48.1%. Urinary urgency in 80.9% and UI in 70%. In two cases (2.5%) UDS was not
valuable. Urodynamic features of the 79 remaining studies revealed overactive detrusor (OD) in 56 patients (70.9%),
being associated with Stress UI (SUI) in one case and with bladder outlet obstruction (BOO) in 19. SUI in six patients
(7.6%) and BOO in five (6.3%). Detrusor underactivity in four cases (5%) and normal study in eight (10.1%). About 47.1%
of males presented BOO. Cerebrospinal fluid shunt surgery was performed on 32 patients during follow-up, with
subsequent clinical improvement in 90.6% of them. Conclusions: OD was the most frequent diagnosis within UDS
conducted on adult NPH patients in our institution, with BOO in an elevated percentage of them. Etiological treatment
led to symptomatic improvement in most of patients.