Characteristics of clinical features and related evaluation of Alzheimer disease and vascular dementia

Yonghui PAN; Shurong DUAN; Qingjie ZHAO

ABSTRACT

BACKGROUND:

Alzheimer disease (AD) and vascular dementia (VD),the two major types of dementia in old age, differ from each other in pathological mechanism, treatment and prognosis. Up to now, no effective therapeutic method for AD is available, but VD can be treated effectively so that patients' quality of life can be improved.

OBJECTIVE:

To investigate the clinical features of brain electrical activity mapping (BEAM) and brain evoked potentials (BEP) between AD and VD patients.

DESIGN:

Retrospective analysis based on AD and VD patients.

SETTING:

Neurological Department, the First Clinical Medical College of Harbin Medical University.

PARTICIPANTS:

All inpatients and discharged patients were selected filiated to Harbin Medical University from December 1996 to December 2000. The history was provided by the patients themselves or their relatives who lived together with them. Nine cases of AD and fourteen cases of VD were diagnosed according to the diagnostic standard for AD and VD set by the National Institute of Neurological and Communicative Disorder and Stroke-the Alzheimer disease and Related Disorder Association, and Chinese Classification and Diagnostic Criteria of Mental Disease (4th edition). According to the clinical rating standard, the patients had mild or moderate degree of dementia.

METHODS:

AD and VD patients were analyzed with retrospective analynitive functions, including long-term and short-term memory, calculation,comprehension, abstract thinking, dyschronism and disorientation; c. emotional reaction, including depression, anxiety, fear, euphoria, compulsive laughing and crying; d personality alteration, including indifference,optimally were collected from the abnormal segment signals. After calculation, 4 frequency band powers of θ,δ, α and β of the total power of 1-30 N1, P2, N2 and P3 and the waves of P2 and P3 were measured. Comparison between the two groups and rate comparison were made with t-test and χ2 test, respectively.ease, cognitive functions and noncognitive functions between AD patients

RESULTS:

Data of 9 AD and 14 VD patients as well as 15 normal old cognitive functions and noncognitive functions between AD patients and VD patients The onset of AD was slow, but that of VD was abrupt. Cognitive functions of AD patients were decreased, including memory decline,calculation decrement, abstract thinking disorder, dyschronism and disorientation. The cognitive functions of VD group were characterized by partial decrement and intermittent ladderlike aggravation. Memory decline and calculation ability decrease were the main characteristics, but other cognitive dysfunctions could not be observed as much as in AD. The patients of AD group often had depression as the most common emotional disorder.Personality alteration took initiative decrement as the most common one,whereas emotional disorder in the patients of VD group was presented by compulsive crying and laughing. One patient seldom had more than two and VD patients BEAM of 7 AD patients was characterized by the power of θ frequency band of the whole head increased. The level of increase was consistent with the level of dementia (score of MMSE). At the same time,the power of α and β frequency bands declined, and the power of δ increased later, the left side (F3) was significantly higher than the right side AD and VD patients The changes of BEP in the two group patients had poorly differentiated waves, with lower P300 wave and obviously delayed latent period. The abnormality degree of patients in AD group was more obvious than that in VD group.with memory decline and calculation ability decrease as the main characteristics in VD patients. The noncognitive functions of AD patients were more aftients were presented as the increased power of the whole head in the former ones and the increased power of θ frequency band in the latter ones. The changes were coincident with the severity of dementia in AD, but not in VD.effect of the former one was greater than that of the latter one.