Gray and White Matter Degenerations in Subjective Memory Impairment: Comparisons with Normal Controls and Mild Cognitive Impairment

Subjective memory impairment (SMI) is now increasingly recognized as a risk factor of progression to dementia. This study investigated gray and white matter changes in the brains of SMI patients compared with normal controls and mild cognitive impairment (MCI) patients. We recruited 28 normal controls, 28 subjects with SMI, and 29 patients with MCI aged 60 or older. We analyzed gray and white matter changes using a voxel-based morphometry (VBM), hippocampal volumetry and regions of interest in diffusion tensor imaging (DTI). DTI parameters of corpus callosum and cingulum in SMI showed more white matter changes compared with those in normal controls, they were similar to those in MCI except in the hippocampus, which showed more degenerations in MCI. In VBM, SMI showed atrophy in the frontal, temporal, and parietal lobes compared with normal controls although it was not as extensive as that in MCI. Patients with SMI showed gray and white matter degenerations, the changes were distinct in white matter structures. SMI might be the first presenting symptom within the Alzheimer's disease continuum when combined with additional risk factors and neurodegenerative changes.

The Neurocognitive Function Between the Patients Who had Subjective Memory Impairment and Mild Cognitive Impairment

BACKGROUND: This study investigated the characteristic differences of neurocognitive function in patients with subjective memory impairment and in those with mild cognitive impairment. METHODS: Patients with complaints of subjective memory impairment were categorized into subjective memory impairment (SMI, n=42) and mild cognitive impairment (MCI, n=42) based on their scores in the Korean version of Mini-Mental State Examination, Activities of Daily Living (ADL), and Clinical Dementia Rating and the neurologist's diagnosis and evaluation. The neurocognitive function and depression rating between the SMI and the MCI groups were compared using the Seoul Neuropsychological Screening Battery and the Geriatric Depression Scale. RESULTS: The SMI group showed normal concentration, visual-spatial construction ability, and depression and deficits in the processing of memory consolidation through the delay test of verbal learning. The MCI group also showed no deficits in concentration but showed impairments in delayed recall and recognition test of verbal learning, visual memory test, and frontal lobe/executive functions. CONCLUSION: The MCI group showed more distinctive neurocognitive deficits in delayed recall and recognition test of verbal learning; encoding, storage, and retrieval of visual memory; and naming ability compared to the SMI group. The implications and suggestions of this study and further research were discussed.

Risk Factors for Subjective Memory Impairment in Cognitively Normal Elderly

OBJECTIVES: We examined the risk factors for subjective memory impairment in cognitively normal elderly. METHODS: One hundred fifty five cognitively normal elderly individuals with subjective memory impairment and 126 normal control subjects without subjective memory impairment were selected. All participants underwent clinical evaluation for dementia and clinical psychiatric disorder conformed to the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet and Korean version of Mini-International Neuropsychiatric Interview, respectively. Korean version of Geriatric Depression Scale-Revised was administered to evaluate depression. Subjective memory impairment was defined as 1) subjective memory complaint by the participant and/or the informants and 2) evidence of memory impairment. RESULTS: Depression [odds ratio (OR)=1.07, 95% confidence interval (CI)=1.03-1.10] and female (OR=2.27, 95% CI=1.17-4.39) significantly increased the risk of subjective memory impairment in cognitively normal elderly. CONCLUSION: Depression can be a risk factor of subjective memory impairment in cognitively normal elderly. The clinicians should be vigilant regarding the presence of depression when assessing the subjects with subjective memory complaint.

Subjective Memory Impairment, Cognitive Function, and Depression: A Cross-Sectional Study in a Community Dwelling Elderly Population / 신경정신의학

OBJECTIVE: Research on the associated factors of subjective memory impairment(SMI) has reported conflicting findings. This study aimed to investigate the associations of SMI with objective cognitive function, depression, and various socio-demographic characteristics and to measure possible differences in cognitively impaired and intact elderly peoples. METHODS: A community study of individuals aged 65 or over was conducted in Kwangju, South Korea. SMI was assessed by means of asking a single item question and its associations with cognitive function(Korean version of Mini-Mental State Examination; MMSE-K), depression(Korean form of Geriatric Depression Scale), and socio-demographic factors were investigated. In addition, analyses were repeated for the cognitively impaired and intact samples separately. RESULTS: Of 1,134 participants, 596(53%) were categorized as having SMI. Depression, lower score on MMSE-K, and past manual occupation were significantly associated with SMI. Further analyses for cognitively impaired and intact samples showed some different results. For the cognitively impaired sample(n=412), SMI was significantly associated with depression and past manual occupation. For the cognitively intact sample(n=722), depression, lower score on MMSE-K, and male gender were significantly associated factors. CONCLUSION: Depression was consistently associated with SMI regardless of cognitive status. Other than depression, associated factor profiles differed between cognitively impaired and intact older populations.