Abstracts

Rationale: Alzheimer's disease (AD) and epilepsy are both major chronic neurologic disorders with a high prevalence in older adults, and a possible bidirectional link has been reported. The presence of epilepsy and subclinical epileptiform activity (SEA) in the early course of AD and its increase over the course of the disease suggests that it may be one of the features for early recognition and intervention. Amyloid-β(Aβ) deposition is thought to play an important mediating role in the seizures and SEA of AD patients. However, the current diagnosis of epilepsy and SEA in AD is inadequate and delayed due to insufficient knowledge of the clinical features of patients with AD with epilepsy(ADEP). In addition, the spatial distribution of Aβin patients with AD EP remains unknown.


Methods: We recruited 12 patients with ADEP, 35 patients with AD, 19 patients with late-onset epilepsy and 12 healthy controls from West China Hospital of Sichuan University. We collected basic demographic and sociologic information about the subjects including age, years of education, and occupation. We asked detailed questions about dementia and epilepsy-related medical history, including age of onset, seizure type and frequency, current medications, and family history. All subjects underwent standardized neuropsychological assessments with questionnaires .We performed 18F-Florbetapir PET MRI scan for all subjects. PET and MRI images were aligned using Matlab and SPM, and standardised uptake ratio(SUVR) values were extracted and compared on both region of interest (ROI) level and voxel level. Demographics, epilepsy disease information and neuropsychological scale scores were obtained using statistical methods include chi-square test, Mann-Whitney U test.


Results: Patients with ADEP had their first seizure at 64.6 years of age, on average 3.7 years after the onset of cognitive decline.The most common type of epilepsy in ADEP is focal motor onset with impaired consciousness.The ADEP patients had less Aβ accumulation in cingulate gyrus, orbital gyrus, insula and the whole brain than patients with AD, and more Aβaccumulation in brain regions such as orbital gyrus, amygdala, hippocampus and the whole brain than patients with late-onset epilepsy(p＜0.01, unadjusted) . The MoCA scores of patients with epilepsy co-occurring with AD group were higher than those of AD group and lower than those of late-onset epilepsy group, and there was a statistically significant difference between the three groups. There were no statistically significant differences between the three groups of subjects in terms of gender, age, and years of education. The SUVR of Aβin the cingulate gyrus of ADEP patients showed a tendency to be inversely related to the length of ASMs use and the duration of epilepsy.


Conclusions: Our study explored the epileptic and cognitive characteristics of patients with ADEP, revealing in particular the different Aβdistribution patterns in patients with ADEP, AD and late-onset epilepsy. We call for early recognition and intervention of epilepsy and SEA in AD patients.




Funding: This work was financially supported by TianYuan Special Funds of the National Natural Science Foundation of China(No. 12026607).