E5225. Diagnosis and Management of NPH Beyond Wet, Wacky, and Wobbly: What Radiologists can Learn From Critical Review of Major Society Guidelines
  1. Kevin Chorath; University of Washington
  2. Kyle Hulse; University of Washington
  3. Omer Hamza; University of Khartoum
  4. Eric Chen; University of Washington
  5. Ali Ravanpay; University of Washington
  6. Lei Wu; University of Washington
Diagnosis of normal pressure hydrocephalus (NPH) is difficult given its pathological similarity to a myriad of other diseases; moreover, the neuroimaging hallmarks of NPH are difficult to distinguish from those of cerebral atrophy in general with varying degree of ventriculomegaly. Because this disorder is potentially treatable, there is increased focus on improving diagnosis through noninvasive imaging techniques. Several clinical practice guidelines have been published to inform the assessment of NPH, but, to date, there is no comprehensive review of guideline quality or methodological rigor.

Materials and Methods:
A comprehensive literature search was performed to identify clinical practice guidelines (CPGs) for the diagnosis of NPH. Four reviewers independently evaluated each CPG using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool, which is a validated instrument designed for guideline developers and users to assess the methodological quality of CPGs. Scaled domain scores were generated and the threshold used for satisfactory guideline quality was greater than 70%. Additionally, intraclass correlation coefficients (ICC) were generated to determine level of agreement between reviewers.

Four guidelines were selected for final evaluation based on inclusion/exclusion criteria. Only one guideline by the American Academy of Neurology was classified as “average” quality, and the remaining were classified as “low.” The ‘Clarity and Presentation’ domain received the highest mean scores (66.7 ± 15.9), and the ‘Applicability’ domain received the lowest mean scores (36.5 ± 19.9). ICC analysis showed high magnitude of agreement between reviewers with a range of 0.85–0.97. Notably, none of the guidelines included a neuroradiologist in the development process of the CPGs, nor provided readily available strategies on the use of specific imaging biomarkers and volumetric segmentation/CSF flow imaging in the initial diagnosis and follow up of NPH.

Reflecting upon our quality appraisal, it is evident that the quality and methodological rigor of NPH guidelines can be improved upon in the future. Our findings also elucidate the existing discrepancies and variabilities on how specific imaging biomarkers and volumetric segment/CSF flow imaging can be used in initially diagnosing and following this vulnerable patient population. Moreover, our findings highlight the failure to incorporate important stakeholders, including radiologists, in the development process of these guidelines.