Fumihito Yoshii1,2, Hiroe Onaka3, Saori Kohara3, Masafuchi Ryo4, Wakoh Takahashi4. 1. Department of Neurology, Saiseikai Shonan Hiratsuka Hospital, Hiratsuka, Japan, yoshii@is.icc.u-tokai.ac.jp. 2. Department of Neurology, Tokai University Oiso Hospital, Oiso, Japan, yoshii@is.icc.u-tokai.ac.jp. 3. Department of Clinical Technology, Tokai University School of Medicine, Isehara, Japan. 4. Department of Neurology, Tokai University Oiso Hospital, Oiso, Japan.
Abstract
INTRODUCTION: Olfactory dysfunction is commonly associated with Alzheimer's disease (AD) and may be related to disorder of the central olfactory processing system. In this work, therefore, we examined the relationships between olfactory changes and the most affected cognitive domain or degree of brain atrophy in patients with AD and mild cognitive impairment (MCI). METHODS: The subjects were 55 AD patients and 27 MCI patients. Smell identification tests were performed using Odor Stick Identification Test for Japanese -(OSIT-J). The severity and nature of cognitive dysfunctions were evaluated using the AD Assessment Scale-cognitive subscale, Japanese version (ADAS-Jcog). MRI with voxel-based specific regional analysis system for AD software was used for evaluation of brain atrophy. RESULTS: -OSIT-J scores were significantly correlated with total -ADAS-Jcog scores, as well as with ADAS-Jcog subscale items of word recall task, orientation (memory domain) and ideational praxis. Smell identification deficit was proportional to the degree of atrophy of the medial temporal lobe. CONCLUSION: Smell identification deficit in AD/MCI is strongly associated with the memory domain of cognitive function and with atrophy of the medial temporal lobe.
INTRODUCTION:Olfactory dysfunction is commonly associated with Alzheimer's disease (AD) and may be related to disorder of the central olfactory processing system. In this work, therefore, we examined the relationships between olfactory changes and the most affected cognitive domain or degree of brain atrophy in patients with AD and mild cognitive impairment (MCI). METHODS: The subjects were 55 ADpatients and 27 MCI patients. Smell identification tests were performed using Odor Stick Identification Test for Japanese -(OSIT-J). The severity and nature of cognitive dysfunctions were evaluated using the AD Assessment Scale-cognitive subscale, Japanese version (ADAS-Jcog). MRI with voxel-based specific regional analysis system for AD software was used for evaluation of brain atrophy. RESULTS: -OSIT-J scores were significantly correlated with total -ADAS-Jcog scores, as well as with ADAS-Jcog subscale items of word recall task, orientation (memory domain) and ideational praxis. Smell identification deficit was proportional to the degree of atrophy of the medial temporal lobe. CONCLUSION: Smell identification deficit in AD/MCI is strongly associated with the memory domain of cognitive function and with atrophy of the medial temporal lobe.