OBJECTIVE: The clinical differentiation between parkinsonism in idiopathic normal pressure hydrocephalus (iNPH) and Parkinson's disease (PD) remains challenging in initial phase. We addressed whether an early cognitive profiling might support the differential diagnosis of early iNPH and PD.
METHODS: We retrospectively evaluated the neuropsychological tests of iNPH 40 subjects with early symptoms resembling parkinsonism with 47 "de novo" PD patients (dnPD). Only neuropsychological tests performed within one year from the first motor symptom were included. The cognitive spectrum of iNPH and dnPD were also compared with a sample of 70 normal controls (NC).
RESULTS: We showed a clear difference in the cognitive profile of iNPH, dnPD patients and NC. The 65% of the iNPH subjects showed a diffuse cognitive impairment, including memory, visuospatial abilities, fronto-executive functioning and attention, whereas only the 25.5% of the dnPD patients presented an executive dysfunction. 35% iNPH and 74.5% PD patients, respectively, performed within the normal range (p<0.05).
CONCLUSION: Subjects with iNPH showed an early and diffuse alteration of cognition with respect to dnPD patients. Performing a prompt and accurate neuropsychological evaluation might support the differential diagnosis of these two conditions of parkinsonism. This article is protected by copyright. All rights reserved.