Background: Normal-pressure hydrocephalus (NPH) presents with the triad of gait difficulty, urinary incontinence, and cognitive decline. However, the definitive diagnosis and treatment may be challenging at times due to secondary causes of NPH (sNPH) versus idiopathic NPH (iNPH), co-existing other degenerative, vascular, and metabolic causes of similar clinical presentations.
Objective: The objective of this narrative review is to outline the approach to patient evaluation and decision-making in cases where there is clinical suspicion of iNPH.
Methods: This review article intends to provide a practical approach to the patients with a suspected diagnosis of iNPH.
Results: The cardinal clinical features with a guide from investigations like magnetic resonance imaging (MRI) brain and cerebrospinal fluid (CSF) analysis, and CSF tap assessment have been outlined. The interpretation of conflicting MRI brain findings or CSF analysis may need resolution by further tests. The decision algorithm following the examination and investigations has been included to address the dilemma in the case of a non-supportive MRI and/or CSF tap test.
Conclusion: iNPH is a treatable cause of the cognitive decline and gait disorder. While neurodegenerative causes may accompany iNPH, any patient with improvement after CSF drainage deserves therapeutic intervention.
Keywords: Cerebrospinal fluid; diagnosis; lumbar puncture; normal-pressure hydrocephalus.