Authors :
Presenting Author: Chung Fu Hsu, MD – Chung Shan Medical University Hospital
Yue Loong Hsin, MD – Department of Neurology – Chung Shan Medical University Hospital; Chao-Yu Shen, MD – Department of Medical imaging – Chung Shan Medical University Hospital; Ping Huei Tsai, Ph.D – Department of Medical Imaging – Chung Shan Medical University Hospital; Pan Fu Kao, MD, MSc, PhD – Department of Nuclear Medicine – Chung Shan Medical University Hospital
Rationale: Late-onset epilepsy in older adults with non-lesional magnetic resonance imaging (MRI) presents a diagnostic challenge, as the underlying etiology is often unknown. Neurodegenerative disorders, particularly Alzheimer's disease, are recognized as frequent contributors to seizures in older age. The epileptogenic properties of Aβ have gained attention in recent years. Initially recognized as a histopathological hallmark of AD and brain blood-barrier (BBB) damage have also been proposed to contribute to epileptogenesis and progression of epilepsy.
Methods: Data acquisition - The MRI data were acquired in Chung Shan Medical University Hospital using a Siemens Skyra 3T scanner equipped with a 32-channel head coil. A volumetric turbo field echoT1-weighted structural sequence was acquired and Dynamic contrast enhancement MRI(DCE-MRI) using axial brain T1 maps were then acquired using a T1-weighted three-dimensional (3D) spoiled gradient echo pulse sequence and variable flip angle method. And amyloid-PET imaging scan using Florbetaben (FBB) tracer was administered as a single intravenous bolus injection (300 ± 14 MBq), and patients underwent PET/CT imaging to visualize and quantify Aβ deposits in the brain.
Data analysis - The post-processing analysis using the ROCKETSHIP toolbox with Patlak model to visualize the regional BBB permeability and the use of Amyquant® with automated pipeline for PET imaging presenting as Z-score.
Results: We present a unique case of newly diagnosed focal epilepsy in an elderly patient, presenting as focal motor seizure of left limbs lasts for hours, the electroencephalography showed periodic epileptiform discharge over right centroparietal region, the symptoms got gradually relieved with anti-seizure medication. One month later, the patient underwent FBB amyloid-PET imaging and DCE-MRI to investigate amyloid-beta (Aβ) burden and BBB integrity. Increased Aβ deposition exclusively in the right lateral parietal region was identified, along with abnormal permeability and leakage of the contrast agent in the right frontoparietal cortices, both abnormalities coincided with the epileptic focus one month earlier. Notably, the patient did not exhibit significant cognitive decline during the one-year follow-up. These findings suggest a potential link between Aβ deposition, focal BBB dysfunction, and the occurrence of focal seizures. We hypothesize that pathological protein aggregation, specifically cortical amyloid accumulation, may underlie cryptogenic late-onset epilepsy with a presumed symptomatic etiology.
Conclusions: This case highlights the need for further investigation into the complex interactions between amyloid pathology, epileptic activity, BBB dysfunction, and cognitive function. Understanding the mechanisms underlying the association between amyloid accumulation and epileptic activity could have clinical implications, guiding the identification and management of older individuals with cryptogenic epilepsy. Additionally, it underscores the value of amyloid imaging in the diagnostic workup of older adults with epilepsy, enabling the identification of underlying etiologies and informing personalized treatment approaches.
Funding: None