High incidence of dementia conversion than stroke recurrence in poststroke patients of late elder society

Background This study investigated the incidence of current poststroke dementia (PSD), the annual conversion ratio into PSD, and the risk factors for conversion. Methods In a 4.8-year follow-up period, 112 poststroke patients (ischemic stroke and intracerebral hemorrhage) were retrospectively investigated in cognitive examinations. They were categorized into 3 subgroups: converters into PSD, nonconverters who maintained their normal cognitive functions, and reverters who recovered to the normal mentality range. The clinical and demographic characteristics of these 3 subgroups were analyzed. Results Among all 112 poststroke patients (61.6% male, 73.6 ± 10.4 years old), 16.1% had PSD. During the follow-up period, a part of the normal baseline mentality group (83.9% of 112 original patients) newly developed PSD (subdivided into converters) with an annual conversion rate of 7.6%. The reversion rate from the baseline PSD group was 11.3%. There were significant differences in age (P <.05), baseline mini-mental state examination scores (P <.05), body mass index (P <.05), and periventricular and deep white matter hyperintensity grades (P <.05 and P =.01, respectively) between converters and nonconverters. The annual rate of stroke recurrence was only 2.2% in all stroke subtypes. Conclusions In comparison with stroke recurrence (2.2%), 7.6% of the annual PSD conversion rate was very high. Therefore, prevention of direct conversion into PSD without stroke recurrence may be another important aspect of poststroke clinics, especially in late elder society.