Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark.
Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Valdemar Hansens Vej 13, Glostrup, 2600, Denmark.
Alzheimers Res Ther. 2024 Apr 12;16(1):80. doi: 10.1186/s13195-024-01432-9.
In epilepsy, the ictal phase leads to cerebral hyperperfusion while hypoperfusion is present in the interictal phases. Patients with Alzheimer's disease (AD) have an increased prevalence of epileptiform discharges and a study using intracranial electrodes have shown that these are very frequent in the hippocampus. However, it is not known whether there is an association between hippocampal hyperexcitability and regional cerebral blood flow (rCBF). The objective of the study was to investigate the association between rCBF in hippocampus and epileptiform discharges as measured with ear-EEG in patients with Alzheimer's disease. Our hypothesis was that increased spike frequency may be associated with increased rCBF in hippocampus.
A total of 24 patients with AD, and 15 HC were included in the analysis. Using linear regression, we investigated the association between rCBF as measured with arterial spin-labelling MRI (ASL-MRI) in the hippocampus and the number of spikes/sharp waves per 24 h as assessed by ear-EEG.
No significant difference in hippocampal rCBF was found between AD and HC (p-value = 0.367). A significant linear association between spike frequency and normalized rCBF in the hippocampus was found for patients with AD (estimate: 0.109, t-value = 4.03, p-value < 0.001). Changes in areas that typically show group differences (temporal-parietal cortex) were found in patients with AD, compared to HC.
Increased spike frequency was accompanied by a hemodynamic response of increased blood flow in the hippocampus in patients with AD. This phenomenon has also been shown in patients with epilepsy and supports the hypothesis of hyperexcitability in patients with AD. The lack of a significant difference in hippocampal rCBF may be due to an increased frequency of epileptiform discharges in patients with AD.
The study is registered at clinicaltrials.gov (NCT04436341).
在癫痫中，发作期导致大脑过度灌注，而在发作间期则存在灌注不足。阿尔茨海默病（AD）患者癫痫样放电的发生率增加，一项使用颅内电极的研究表明，这些放电在海马体中非常频繁。然而，目前尚不清楚海马体兴奋性过高与局部脑血流（rCBF）之间是否存在关联。本研究旨在探讨 AD 患者中用耳 EEG 测量的 rCBF 与癫痫样放电之间的关系。我们的假设是，尖峰频率的增加可能与海马体 rCBF 的增加有关。
共纳入 24 例 AD 患者和 15 例 HC 进行分析。我们采用线性回归分析，研究了动脉自旋标记 MRI（ASL-MRI）测量的海马体 rCBF 与耳 EEG 评估的每 24 小时尖峰/锐波数之间的关系。
AD 组与 HC 组之间的海马体 rCBF 无显著差异（p 值=0.367）。AD 患者的尖峰频率与海马体标准化 rCBF 之间存在显著的线性关系（估计值：0.109，t 值=4.03，p 值<0.001）。与 HC 相比，AD 患者颞顶叶皮质等典型显示组间差异的区域发生了变化。
AD 患者的尖峰频率增加伴随着海马体血流增加的血液动力学反应。这种现象在癫痫患者中也有发现，支持 AD 患者过度兴奋的假说。AD 患者海马体 rCBF 无显著差异可能是由于癫痫样放电频率增加所致。
本研究在 clinicaltrials.gov 注册（NCT04436341）。
Zotero 插件
