Effect of Physical Disability on Instrumental Activities of Daily Living in Alzheimer's Disease, Amnestic Mild Cognitive Impairment (MCI), and Vascular Dementia and Vascular MCI of Subcortical Type

ABSTRACT

BACKGROUND: Physical disability may result in some impairment of the score for Instrumental Activities of Daily Living (IADL). The aim of this study was to evaluate the effect of physical disability on IADL in patients with Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), subcortical vascular dementia (SVD), and vascular mild cognitive impairment of the subcortical type (svMCI). METHODS: Fifty-six patients with AD, 30 with SVD, 27 with aMCI, and 21 with svMCI were recruited consecutively from a memory clinic. Informants for the subjects completed a Korean version of the IADL (K-IADL). In addition, the informants were asked to choose the cause of each dependent activity of K-IADL from the following cognitive impairment, physical disability, or both. The cause of the physical disability was defined as being focal neurologic symptoms, other physical disease, or both. RESULTS: Compared to AD patients, SVD patients had higher K-IADL scores [2.02+/-0.80 (mean+/-SD) vs. 1.45+/-0.90, p<0.01] and focal neurologic signs (FNS; 8.0+/-5.8 vs. 0.0+/-0.0, p<0.001), and lower Barthel Index scores (14.7+/-5.1 vs. 19.6+/-1.2, p<0.001). Patients with svMCI had higher FNS (3.8+/-4.5 vs. 0.0+/-0.0, p<0.001) compared to those with aMCI. The most common cause of dependency of activities in K-IADL was cognitive impairment in AD, aMCI, and svMCI patients, and the combined effect of cognitive impairment and physical disability in those with SVD. The cause of physical disability was FNS in 96% of SVD patients and in all patients with svMCI. CONCLUSIONS: The effects of FNS as well as cognitive impairment should be considered when measuring the IADL of the patients with SVD or svMCI.