Mild Cognitive Impairment is Associated with Mild Parkinsonian Signs in a Door-to-Door Study

Article type: Research Article

Authors: Israeli-Korn, Simon D.^{a; 1} | Massarwa, Magda^{a; 1} | Schechtman, Edna^b | Strugatsky, Rosa^a | Avni, Shiri^c | Farrer, Lindsay A.^d | Friedland, Robert P.^e | Inzelberg, Rivka^{a; c; *}

Affiliations: [a] The Joseph Sagol Neuroscience Center and Neurology Department, Sheba Medical Center, Tel Hashomer, Israel | [b] The Department of Industrial Engineering and Management, Ben Gurion University, Beer Sheva, Israel | [c] The Sackler Faculty of Medicine, Tel Aviv University, Israel | [d] The Departments of Medicine (Genetics Program), Neurology, Genetics and Genomics, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, MA, USA | [e] The Department of Neurology, University of Louisville, Louisville, KY, USA

Correspondence: [*] Correspondence to: Prof. Rivka Inzelberg, Sagol Neuroscience Center, Department of Neurology, Sheba Medical Center, Tel Hashomer 52621, Israel. Tel.: +972 3 530 4753; Fax: +972 3 530 4718; E-mail: [email protected].

Note: [1] The first two authors contributed equally.

Abstract: Mild cognitive impairment (MCI) and healthy aging have been shown to be associated with mild parkinsonian signs (MPS). We performed a door-to-door observational and follow-up study amongst consenting residents of Wadi Ara Arab villages in northern Israel aged ⩾ 65 years (n = 687) to examine whether MPS represent a risk factor for MCI and/or conversion from MCI to Alzheimer's disease (AD). In Phase 1, 223 cognitively normal (CN) and 173 MCI subjects were assessed by interview for medical history, neurological examination, motor part of the Unified Parkinson Disease Rating Scale (mUPDRS) (divided into item-clusters: axial, limb bradykinesia, tremor and rigidity) and cognitive tests. MCI subjects (n = 111) were re-evaluated in Phase 2 for conversion to AD at least one year after initial assessment. MCI subjects had a higher frequency of axial dysfunction (8.7% vs. 1.3%) and limb bradykinesia (10.4% vs. 1.3%) than CN subjects (p < 0.001, both). Stepwise logistic regression analysis estimating the probability of MCI vs. CN revealed higher mUPDRS (OR = 1.19, 95% CI, 1.05 to 1.35, p = 0.006) and higher limb bradykinesia scores (OR = 1.75, 95% CI, 1.2 to 2.56, p = 0.003) and not age as explanatory variables. Presence of MPS did not predict conversion to AD after adjustment for age and time-interval. These results suggest that axial and bradykinetic parkinsonian signs represent risk factors for MCI but MPS may not predict conversion from MCI to AD.

Keywords: Aging, Alzheimer's disease, mild cognitive impairment, mild parkinsonian signs, neuroepidemiology, risk factors

DOI: 10.3233/JAD-2010-101230

Journal: Journal of Alzheimer's Disease, vol. 22, no. 3, pp. 1005-1013, 2010