Idiopathic normal pressure hydrocephalus: Validation of the DESH score in the capital region of Denmark

Objective: Previous research has shown that the Disproportionally Enlarged Subarachnoid-space Hydrocephalus (DESH) score may be a prognostic factor for shunt surgery response for idiopathic normal pressure hydrocephalus (iNPH) patients at 1-month follow-up after shunt surgery. The objective of the current study was external validation in an independent cohort with a longer follow-up period. Secondarily, to assess whether the grading system was confounded by imaging modality. Methods: Preoperative baseline characteristics, magnetic resonance imaging (MRI) and/or computed tomography (CT) scans were retrospectively obtained in 127 shunt-operated iNPH patients. Evans’ index, dilation of Sylvian fissures, tight high convexity, focal sulci, callosal angle, and a combination of these radiologic findings (DESH score) were compared according to patients’ response to shunt treatment at a mean follow-up period of 7.4-months. In addition, the data were adjusted for whether grading was performed by MRI or CT. Results: Multivariate logistic regression, adjusted for age, sex, and imaging modality, demonstrated a significant association between the DESH score and objective shunt response at follow-up (Odds Ratio 1.35, p = 0.036). Bivariate logistic regression revealed no significant difference in DESH score assessments between CT and MRI. Moreover, including or excluding imaging modality in the multivariate model did not meaningfully alter the regression coefficients. Conclusion: Consistent with and supportive of prior findings, the DESH score is associated with shunt response in iNPH patients. No evidence of confounding by imaging modality was identified in this cohort. However, formal equivalence between CT and MRI for DESH scoring remains to be established in studies with paired imaging.