Standardizing the large-volume "tap test" for evaluating idiopathic normal pressure hydrocephalus: a systematic...

Area of Science:

• Neurology
• Neurosurgery
• Clinical Medicine

Background:

• Idiopathic normal pressure hydrocephalus (iNPH) presents with gait, cognitive, and urinary issues, diagnosed via neuroimaging.
• The "tap test" (CSF removal via lumbar puncture) assesses shunt placement suitability.
• Current iNPH clinical guidelines lack a standardized tap test protocol.

Purpose of the Study:

• To address the lack of standardization in the tap test procedure for iNPH.
• To develop a consensus-based, standardized protocol for the iNPH tap test.

Main Methods:

• A systematic review of PubMed and Embase following PRISMA guidelines was conducted.
• The review focused on CSF volume, needle type, assessments, and timing for the tap test.
• A modified Delphi approach was used to achieve expert consensus on the protocol.

Main Results:

• 222 articles involving 80,322 iNPH participants were reviewed.
• Significant protocol variations were found, leading to minimal concordance across studies.
• A standardized tap test protocol was developed over two years by an expert study group.

Conclusions:

• The literature reveals substantial variability in iNPH tap test methodologies.
• The developed protocol aims to standardize clinical management and improve patient outcomes.
• This standardized protocol will help align future research in idiopathic normal pressure hydrocephalus.