International Psychogeriatrics

Research Article

Vascular risk factors and the effect of white matter lesions on extrapyramidal signs in Alzheimer's disease

Moon Ho Parka1a2 c1, Joo Young Mina3, Do-Young Kwona2, Seung Hwan Leea4, Hae Ri Naa1a5, Sung Tae Choa6 and Duk L. Naa1a7

a1 Clinical Research Center for Dementia (CRCD), Seoul, Republic of Korea

a2 Departments of Neurology, Korea University Medical College and Korea University Ansan Hospital, Ansan, Republic of Korea

a3 Fiona Clinic Hospital, Seoul, Republic of Korea

a4 Department of Neurology, Kangwon National University, Chuncheon, Republic of Korea

a5 Department of Neurology, Bobath Memorial Hospital, Seongnam, Republic of Korea

a6 Department of Urology, Hallym University, Seoul, Republic of Korea

a7 Department of Neurology, Sungkyunkwan University School of Medicine and Samsung Medical Center, Seoul, Republic of Korea

ABSTRACT

Background: Extrapyramidal signs (EPSs), which are important characteristics of Parkinson's disease (PD), occur frequently in Alzheimer's disease (AD). Although AD and PD share common clinical features such as EPSs, these diseases vary with respect to vascular risk factors. The presence of vascular risk factors increases the risk of AD; however, these factors have been known to be inversely associated with PD. We aimed to assess the effect of vascular risk factors and white matter lesions (WMLs) on EPSs in AD.

Methods: We recruited 1,187 AD patients and 333 controls with neither cognitive impairment nor EPSs. All participants underwent detailed clinical evaluations which included assessments of vascular risk factors, cognitive function, and EPSs, as well as WMLs on brain MRIs. EPS subtypes were classified into tremor-dominant, postural instability gait difficulty, or indeterminate; WMLs subtypes were classified into periventricular WML (pvWML) or deep WML (dWML).

Results: EPSs were present in 17.9% of subjects with AD and were significantly associated with vascular risk factors such as age, male gender, diabetes mellitus, and WMLs. Additionally, a multivariate logistic regression analysis showed that EPSs in AD were associated with pvWML (odds ratio (OR), 1.61–2.52), not with dWML. With respect to EPS subtypes, the majority (78.4%) of EPSs in AD were postural instability gait difficulty, which was also associated with WMLs (OR 1.84–2.41), pvWML (OR 2.09–3.14), and dWML (OR 1.83–3.42).

Conclusions: EPSs in AD are associated with selected vascular risk factors as well as WMLs.

(Received June 10 2010)

(Revised August 01 2010)

(Revised October 05 2010)

(Accepted October 07 2010)

(Online publication November 29 2010)

Correspondence:

c1 Correspondence should be addressed to: Moon Ho Park, MD, PhD, Department of Neurology, Korea University College of Medicine, 516, Gojan-1-dong, Danwon-gu, Ansan-si, Gyeonggi-do 425-707, Republic of Korea. Phone: +82-31-412-5150; Fax:+82-31-412-5154. Email: parkmuno@yahoo.co.kr.