Objectives: Highlight the presentation of behavioral symptoms in addition to the classic clinical trial in idiopathic normal pressure hydrocephalus in the elderly. Identify apathy as the most prevalent behavioral symptom in normal pressure hydrocephalus (NPH) in the elderly.

Methods: A bibliographic review of apathy as a behavioral symptom of NPH is carried out. Likewise, in addition to highlighting apathy as a possible diagnostic marker, the evidence of it as a prognostic marker of therapeutic response is discussed. For this, a review of publications in English and Spanish from the last 10 years was carried out in databases including Cochrane Library, EMBASE, MEDLINE/PubMed, SCOPUS. The MESH terms apathy, Hakims-Adams, idiopathic normal pressure hydrocephalus, chronic hydrocephalus, neuropsychiatric symptoms were used for the search.

Results: Sixteen articles were selected that verified the heterogeneity of the diagnostic criteria for apathy for its detection in patients with NPH. Likewise, it is identified that apathy is the most prevalent behavioral alteration with a prevalence of 60% of patients in this condition. Regarding its predictive value as a prognostic marker for shunt surgical treatment, the evidence is not conclusive either to confirm or to rule out the usefulness of apathy. Conclusions: Apathy should be considered as another diagnostic key in NPH. Thus, the classic description of this condition as a motor-cognitive-urinary syndrome must be reconceptualized as a motor-cognitive-behavioral- urinary syndrome.