Emerging Role of Microglia-Mediated Neuroinflammation in Epilepsy after Subarachnoid Hemorrhage


Epilepsy is a common and serious complication of subarachnoid hemorrhage (SAH), giving rise to increased morbidity and mortality. It’s difficult to identify patients at high risk of epilepsy and the application of anti-epileptic drugs (AEDs) following SAH is a controversial topic. Therefore, it’s pressingly needed to gain a better understanding of the risk factors, underlying mechanisms and the optimization of therapeutic strategies for epilepsy after SAH. Neuroinflammation, characterized by microglial activation and the release of inflammatory cytokines, has drawn growing attention due to its influence on patients with epilepsy after SAH. In this review, we discuss the risk factors for epilepsy after SAH and emphasize the critical role of microglia. Then we discuss how various molecules arising from pathophysiological changes after SAH activate specific receptors such as TLR4, NLRP3, RAGE, P2X7R and initiate the downstream inflammatory pathways. Additionally, we focus on the significant responses implicated in epilepsy including neuronal excitotoxicity, the disruption of blood-brain barrier (BBB) and the change of immune responses. As the application of AEDs for seizure prophylaxis after SAH remains controversial, the regulation of neuroinflammation targeting the key pathological molecules could be a promising therapeutic method. While neuroinflammation appears to contribute to epilepsy after SAH, more comprehensive experiments on their relationships are needed.

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Data Availability

All material and datasets are available as required.



subarachnoid hemorrhage


central nervous system


anti-epileptic drugs


blood-brain barrier


middle cerebral artery


nonconvulsive seizures


vessel-associated microglia


Matrix metalloproteinase 9


high mobility group box-1


vascular smooth muscle cells


heme oxygenase


carbon monoxide




Toll-like receptor 4


NOD-like receptor 3


receptor for advanced glycation end products


P2X7 receptor


nuclear factor-κB


mitogen-activated protein kinases


transcription factor activator protein-1


NIMA related kinase 7


two-pore domain weak inwardly rectifying K + channel 2


the inward rectifier K+


Cl − intracellular channels


enzyme-linked immunosorbent assay


transforming growth factor-β receptor


meningeal lymphatic vessels


glucocorticoid receptor


annexin A1


valproic acid


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This work was supported by grants from the Natural Science Fund of Guangdong Province (No. 2017A030313597), “Climbing Program” Special Fund of Guangdong Province (No. pdjh2019b0100, No. pdjh2020b0112) and Southern Medical University (No. LX2016N006, No. KJ20161102, No.201912121004S, No.201912121013, No. S202012121088, No. X202012121354, No. 19NJ-YB03).

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Jun Wang initiated this project. Jingxue Liang and Jiahong Deng performed the literature research and contributed to the original draft. Other authors participated in the revision of the manuscript.

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Correspondence to Jun Wang.

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1. There is a close relationship between epilepsy and inflammatory state after SAH.

2. Microglia and specific receptors are involved in neuroinflammation after SAH.

3. Several anti-inflammatory therapies have been reported to exert neuroprotective effects on epilepsy.

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Wang, J., Liang, J., Deng, J. et al. Emerging Role of Microglia-Mediated Neuroinflammation in Epilepsy after Subarachnoid Hemorrhage. Mol Neurobiol (2021). https://doi.org/10.1007/s12035-021-02288-y

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  • Microglia
  • Epilepsy
  • Subarachnoid hemorrhage
  • Neuroinflammation