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Abstract Idiopathic normal pressure hydrocephalus (INPH) is an adult onset syndrome of uncertain origin involving non-obstructive enlargement of the cerebral ventricles. In the absence of papilledema and with normal cerebrospinal fluid (CSF) opening pressure on lumbar puncture. Hakim and Adams first described the syndrome of NPH in 1965 as a syndrome characterized by a clinical triad of progressive gait disturbance, dementia and urinary incontinence. These symptoms vary in severity and appearance. Gait impairment is the most common clinical feature in INPH, with a frequency ranging from 80% to 100% and it is often the patient’s initial complaint. The second most frequent symptom is cognitive impairment, which ranges from 42% to 100%. Urinary incontinence ranges from 34% to 82%, where full clinical triad is present in 38-82% of cases. The pathophysiology of INPH remains unknown, and the assessment of these patients is still debated, however suggested mechanisms include reduction of blood flow leading to reduced periventricular metabolism and axonal degeneration without significant cortical damage and stretching of the periventricular white matter. Diagnosis of INPH can be achieved through detailed history, physical examination, and neuroimaging which is considered as an obligatory part in the evaluation of suspected INPH to document ventricular enlargement, to rule out macroscopic obstruction to CSF flow and other pathology. Magnetic resonance imaging (MRI) is considered the method of choice due to the vastness of information it provides, but computed tomography (CT) is an acceptable alternative. Prognostic tests like the CSF tap test, the lumbar infusion test and intracranial pressure (ICP) monitoring have made it easier to identify the patients who will most likely benefit from surgery. No rule for conservative treatment in management of INPH. Surgical treatment is mandatory because it has been associated with a positive impact on the course of the disease, in terms of the quality of life of patients and caregivers.The treatment for INPH is surgical diversion of CSF where ventriculoperitoneal shunt (VP shunt) is the most commonly used method but more recent studies have suggested a positive effect of endoscopic third ventriculostomy (ETV). The purpose of this review was to provide an overview of the current literature investigating the treatment and outcome in INPH patients. Upon results retrieved from our review it was evident that overall outcome was close for both procedures, however regarding each symptomatology, VP shunt was superior on ETV especially in the domain of cognitive impairment, thus suggesting that ETV is not useful for treating INPH patients if the presenting/most debilitating symptom is cognitive impairment. On the other hand the overall complication rate with ETV was much more less than those encountered with VP shunts. Therefore, if INPH patients could be treated by ETV with the same long-term effects as VP shunt, the risk of long-term complications would be reduced, were reduction of long-term complications would be an advantage for elderly patients who often have other comorbidities. There is a disproportionality between study population for each treatment modality (VP shunt 704, while ETV 191). Only 3 prospective studies has investigated the outcome of INPH patient after ETV with no RCTs. There was no standardized method used for preoperative and postoperative assessment to define the preoperative clinical status of the patients and postoperative outcomes. Moreover there was a great variability in postoperative follow up duration. Future studies will require prospective analysis of outcomes, standardized surgical techniques, and standardization of reported results. Meaningful results will probably require a multi-centre effort. |