An Investigation to the Diagnostic Validity of MMSE-K and the Psychopathology in a Group of Urban Patients with Dementia of Alzheimer Type

Kim, Min Gul; Lee, Sang Soo; Lee, Young Ho; Lee, Sang Kyoung; Ahn, Dong Sung; Yoon, Sung Hwan; Shim, Joo Chul; Kim, Yong Kwan; Kim, Young Hoon

Abstract

OBJECTIVES
The purpose of present study was to determine the validity of MMSE-K and its items in a group of urban patients with dementia of Alzheimer type and investigate the frequency of psychiatric symptoms and the correlation between the severity of cognitive impairment and that of psychopathology in them.
METHODS
The subjects were 107 residents, aged over 55, of an urban community, who participated voluntarily in a free medical service for dementic patients. At first, MMSE-K were administered to all the participients to screen for the cognitive impairment. They were diagnosed mainly by the criteria of DSM-IV for dementia of Alzheimer type. Other diagnostic procedures were performed at that time and these included: a history taking for the past and present medical and psychiatric illnesses of the subject and its family members, physical and neurological examinations, clinical evaluations using several psychiatric symptom rating scales such as BPRS, HDRS, HARS and Overt Aggression Scale, Hachinski's Ishcemic Scale, evaluations for sleep disturbances and behavioral problems in daily living. The majority, of total 72 subjects who were evaluated as having cognitive dysfunctions, were the patients with dementia of Alzheimer type: 52 dementia of Alzheimer type, 12 vascular dementia, one mixed type of the two, and 7 others. We determined the validity of MMSE-K and its items in 52 subjects with dementia of Alzheimer type except the two, who could not respond well to the instructions of MMSE-K due to severe cognitive impairments, and 34 non-dementic subjects with only mild psychiatric symptoms. In 42 subjects with dementia of Alzheimer type who completed all the clinical rating scales with confidence, we investigated the frequency of psychiatric symptoms and the correlation between the severity of cognitive impairment and psychopathology.
RESULTS
1) The percent of false positive in diagnosing dementia of Alzheimer type using MMSE-K was 8.0%, and the sensitivity of MMSE-K was 82% in our 107 urban subjects. 2) There were statistically significant differences in the the mean scores of all items except the item, judgement, between the patients with dementia of Alzheimer type and non-dementic subjects(p<0.05). The two items, orientation for time and place, and the item, copy two pentagons, had the sensitivity and specificity over 70%. 3) The frequencies of behavioral and psychiatric symptoms in 42 patients with dementia of Alzheimer type were as follows: verbal aggression(50.0%), depression(46.2%), insomnia(30.8%), ...... , hallucination(21.2%) and delusion(15.4%). 4) The more cognitive dysfunctions had the patient with dementia of Alzheimer type, the more higher scores in the thinking disturbance subscale of BPRS they showed(p<0.01).
CONCLUSION
MMSE-K was proved to be a valid instrument to evaluate the cognitive impairments in patients with dementia of Alzheimer type, but the item, judgement, newly admitted to MMSE-K instead of a language item in MMSE, was proved to be lack of power to discriminate the dementic patient from non-dementic subjects. Our subjects with dementia of Alzheimer type had revealed several behavioral and psychiatric symptoms other than cognitive dysfunctions, and those included depression, anxiety, insommnia, aggression, delusion and hallucination which needed intensive pharmacological interventions.