Evaluation of coexistence of Alzheimer's disease in idiopathic normal pressure hydrocephalus using ELISA analyses for CSF biomarkers.

Abstract

BACKGROUND: We investigated levels of the beta-amyloid 1-42 (Abeta42), total tau

protein (T-tau) and tau phosphorylated at position threonine 181 (P-tau) in

cerebrospinal fluid (CSF) of idiopathic normal pressure hydrocephalus (iNPH)

patients and tried to find their clinical implications in the evaluation and

treatment of iNPH. METHOD: Twenty-five possible iNPH patients were prospectively

enrolled and their CSF was collected to analyze levels of Abeta42, T-tau and

P-tau using ELISA method. Gait disturbance, urinary incontinence, and cognitive

impairment were semi-quantified and detailed neuropsychological (NP) test was

performed. RESULT: Eight iNPH patients were classified into the lower CSF Abeta42

group and 17 patients were classified into the higher CSF Abeta42 group. There

was no difference in the iNPH grading score and its improvement after LP between

the two groups. The lower CSF Abeta42 group showed more deficits in attention,

visuospatial function and verbal memory in the baseline NP test and less

improvement in phonemic categorical naming and frontal inhibitory function after

LP. CONCLUSIONS: Our study suggested that concomitant AD in iNPH patients might

contribute to lumbar puncture or shunt unresponsiveness, especially in the field

of cognitive dysfunction.