| Time phases | Time points | Events | Main reasons | Mechanisms | PHE classification | References |
| Hyperacute | Within a few hours | Clot retraction and mass effect | (i) Increase in the interstitial osmotic pressure. (ii) Oligemic and metabolic changes. | (i) Transendothelial Na+ gradient. (ii) Extracellular accumulation of neurotoxins (e.g., glutamate). | Cytotoxic or ionic edema | [14, 22–25, 90] |
| Acute | First 2 days | Coagulation cascade | Activation of thrombin and fibrinogens. | (i) Increase in inflammatory mediators (e.g., TNF-α, IL-1β, IL-6, IL-12, and ICAMs). (ii) Activation of complement mediators (e.g., C3a and C5a). (iii) Increased expression of matrix metalloproteinases (e.g., MMP-9) and aquaporins (e.g., AQP4). (iv) Inflammatory cell infiltration. (v) Free radical generation. | BBB breakdown and vasogenic edema | [14, 16, 22, 32, 33, 35, 37–40, 43, 44, 47, 48, 51, 52] |
| Delayed | ≥3 days | Erythrocyte lysis | Hemoglobin and its degradation products (e.g., heme, ferric iron, and carbon monoxide). | Increase in the response to oxidative stress and the inflammatory response. | BBB breakdown and vasogenic edema | [2, 14, 22, 57–72] |
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