The CERAD Neuropsychological Battery in Patients with Idiopathic Normal Pressure Hydrocephalus Compared with Normal Population and Patients with Mild Alzheimer’s Disease

Article type: Research Article

Authors: Nerg, Ossi^{a; b; 1; *} | Junkkari, Antti^{a; 1; 2} | Hallikainen, Ilona^{b; 1} | Rauramaa, Tuomas^{c; d} | Luikku, Antti^a | Hiltunen, Mikko^e | Jääskeläinen, Juha E.^a | Leinonen, Ville^a | Hänninen, Tuomo^{b; f; *} | Koivisto, Anne^{b; f; g; h; 1}

Affiliations: [a] Neurosurgery of NeuroCenter, Kuopio University Hospital and Unit of Neurosurgery, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland | [b] Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland | [c] Unit of Pathology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland | [d] Department of Pathology, Kuopio University Hospital, Kuopio, Finland | [e] Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland | [f] Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland | [g] Unit of Neurosciences, Faculty of Medicine, University of Helsinki, Helsinki, Finland | [h] Geriatrics / Internal Medicine and Rehabilitation, Helsinki University Hospital, Helsinki, Finland

Correspondence: [*] Correspondence to: Ossi Nerg, MD, MSc, Unit of Neurosurgery, NeuroCenter, Kuopio University Hospital, PL 100, 70029 KYS, Kuopio, Finland. Tel.: +358 445980904; E-mail: ossi.nerg@kuh.fi.

Note: [1] These authors contributed equally to this work.

Note: [2] Author conducting the biostatistical analyses: Antti Junkkari, MD, PhD.

Abstract: Background:The usefulness of CERAD Neuropsychological Battery for describing the cognitive impairment in idiopathic normal pressure hydrocephalus (iNPH) is unknown. Objective:To compare the cognitive profile of patients with iNPH to patients with mild Alzheimer’s disease (AD) and age-matched cognitively healthy individuals by using the CERAD-NB. Methods:We studied CERAD-NB subtest results, including the Mini-Mental State Examination (MMSE), between 199 patients with probable iNPH, 236 patients with mild AD, and 309 people with normal cognition, using age, education, and gender adjusted multivariate linear regression model. In addition, the effects of AD-related brain pathology detected in frontal cortical brain biopsies in iNPH patients’ cognitive profiles were examined. Results:The iNPH patients performed worse than cognitively healthy people in all CERAD-NB subtests. Despite similar performances in the MMSE, AD patients outperformed iNPH patients in Verbal Fluency (p = 0.016) and Clock Drawing (p < 0.001) tests. However, iNPH patients outperformed AD patients in the Boston Naming Test and Word List Recall and Recognition (p < 0.001). AD-related pathology in brain biopsies did not correlate with the CERAD-NB results. Conclusion:At the time of the iNPH diagnosis, cognitive performances differed from cognitively healthy people in all CERAD-NB subtests. When the iNPH and AD patients’ results were compared, the iNPH patients performed worse in Verbal Fluency and Clock Drawing tests while the AD group had more pronounced episodic memory dysfunctions. This study demonstrates significant differences in the CERAD-NB subtests between cognitive profiles of iNPH and AD patients. These differences are not captured by the MMSE alone.

Keywords: Alzheimer’s disease, CERAD-NB, Mini-Mental Status Examination, neuropsychological test, normal pressure hydrocephalus

DOI: 10.3233/JAD-201363

Journal: Journal of Alzheimer's Disease, vol. 81, no. 3, pp. 1117-1130, 2021