VEPs to four or six repetitive letter and checkerboard stimuli were measured. These stimuli were presented in a first triplet and a single stimulus or in first and second triplets. Three stimuli in a triplet were identical. The subject's task was either naming the letter stimulus or pattern matching the checkerboard. A degree of task-redundancy of the stimuli at intratrial stimulus positions 2 and 3 was varied by means of stimulus duration and indication of the task stimulus prior to the triplet. The stimulus duration was 300 msec and the prior information of the task stimulus was delivered by a letter or checkerboard warning stimulus (WS) in session 1. The stimulus duration was shorter (10 msec in session 2, 20 microseconds in session 3) and the WS of random pattern did not deliver the information of the task stimulus in session 2 and 3. At stimulus positions 2 and 3, the P260 of the occipital VEP enhanced in amplitude for the letter and checkerboard stimuli in session 1, whereas the P260 decreased in amplitude for both stimuli at the same positions in session 3.

Adult↗

PubMedDate not supplied

Neuropathological analysis of dementia in a Japanese leprosarium.

In a neuropathological study of consecutive autopsies, prevalence and cause of dementia in a Japanese leprosarium were investigated, where more than 95% of inpatients with a mean age of 70 years are now free from active leprosy. In 10 years (1983-1992), clinically overt dementia at death was 35/136 (25.7%) in the age group over 65 years (mean age 79.4). Autopsy was performed in 85 cases (mean age 81 years), and clinically overt dementia was seen in 25 subjects (29.4%). Neuropathologically, Alzheimer's disease (AD) was seen in 9 cases (10.6%), vascular dementia (VD) in 9 cases (10.6%), mixed type in 3 cases (3.5%) and unclassified in 4 cases (4.7%). In the age group of 65-84 years, AD was 5/58 (8.6%), VD was 4/58 (6.9%), mixed type was 2/58 (3.4%), and unclassified was 1/58 (1.7%). Compared with previous Japanese general population-based data, where VD was more frequent than AD, the rate of dementia in our leprosarium was high, and pathologically confirmed AD was as common as VD. Recently, a prophylactic effect of the antileprosy and anti-inflammatory drug DDS (dapsone, 4,4'-diaminodiphenyl sulfone) has been suggested. Lepromatous patients take more DDS (51.9%) than tuberculoid patients (11.5%), however, as the dementia rate of tuberculoid leprosy (17.9%) in those 65-84 years old is similar to lepromatous leprosy (15.9%) in our study, we do not support their viewpoint.

Age Factors↗