Analysis of diagnostic value of iNPH Radscale’s radiological signs in different forms of hydrocephalus

Abstract

INTRODUCTION: Idiopathic normal-pressure hydrocephalus (iNPH) is a pathological process in the brain including widening of CSF-containing spaces and Hakim-Adams syndrome. Among different scales allowing us to select shunt- responsive patients, we chose iNPH RadScale that ranges different radiological signs, some of them are of high specificity for iNPH, and others are common for all kinds of hydrocephalus.

OBJECTIVE: assessment of MRI radiological signs of iNPH RadScale in patients with iNPH, other forms of hydrocephalus and hydrocephalus-associated disorders to determine the correlation between iNPH diagnosis and presence of iNPH RadScale signs.

METHODS: we used preoperative brain MRI of 175 patients to assess radiological signs in them, 117 of them have iNPH, 58 — other forms of hydrocephalus. The iNPH RadScale contains 7 radiological signs, maximum 12 points. We used СЫ-square criteria and Pearson’s correlation to compare each of the radiological signs between the groups.

RESULTS: Only 2 radiological signs have got very strong correlation with iNPH: focally enlarged sulci (r=0,874, р<0,001) and Sylvian fissures dilation (r=0,917, p<0,001), and medium level of correlation for high-convexity tightness (r=0,323, p<0,05). Other radiological signs had the equal occurrence in both groups of patients (r<0,3, p>0,05). There was no significant difference (p<0,05) in iNPH RadScale score between the groups because of heterogeneity of the secondary hydrocephalus’ group.

CONCLUSION: iNPH RadScale has 4 signs common for all forms of hydrocephalus and 3 signs which have high specificity for iNPH. Thus, we can conclude that DESH-syndrome and locally dilated convexital sulci can highly likely confirm the iNPH diagnosis.