[Relationship between white matter lesions and theresponse of cerebral spinal fluid tap test and clinical features in the patients with idiopathic normal pressure hydrocephalus]

Objective: To explore the relationship between white matter lesions and clinical features and response of cerebral spinal fluid (CSF) tap test in patients with idiopathic normal pressure hydrocephalus(iNPH). Methods: Possible iNPH patients were enrolled from outpatients and inpatients in Peking Union Medical College Hospital between 2014 and 2019. All patients underwent detailed neuropsychological and walking assessments, CSF tap test, as well as head magnetic resonance imaging. The Fazekas score of white matter lesions, the fractional anisotropy (FA)and mean diffusivity (MD) values of regions of interest by means ofdiffusion tensor imaging (DTI) were compared between CSF tap test positive and negative response groups. The correlation between DTI parameters and clinical characteristics was analyzed. Results: Forty-three patients (29 male and 14 female, age range: 52-79 years] wererecruited.Compared with the negative group, patients in the positive group tended to have higher Fazekas score of periventricular white matter(U=108.00, P=0.03), higher MD value of the region near anterior horn of left lateral ventricles[(1.14±0.27)×10^-9mm²/s vs (0.85±0.08) ×10^-9mm²/s, P=0.003], lower FA value of the region near anterior horn of the right lateral ventricles[(0.20±0.07)vs(0.27±0.09), P=0.058], and higher MD value near the posterior horn of right lateral ventricle [(1.17±0.34)×10^-9mm²/s vs (0.95±0.01)×10^-9mm²/s, P=0.003]. FA and MD were significantly correlated with motor function, cognitive and functional scores, and iNPH grading scale (iNPHGS) scores(all P<0.05). Conclusions: The white matter lesions might be one of the pathogeneses of lNPH and apathological changewhich can be reversed by CSF drainage. More white matter lesions should not be the contraindication of CSF drainage surgery.