Brain Oedema

Chapter 12 - Anticoagulation and Management of Seizures and Brain Oedema in Brain Tumour Patients

The breakdown of the healthy blood–brain barrier (BBB) is one of the key diagnostic findings in malignant gliomas, and contributes substantially to symptoms related to increased intracranial pressure.

Brain oedema in glioblastoma has several causes:
1. Glioma cells differ from normal astrocytes by loss of polarity, due to expression of aquaporin 4 (AQP4) molecules mainly in the endfeet of normal astrocytes, contacting pericytes or endothelial cells. AQP4 is involved in regulation of extracellular space volume, K+ buffering, interstitial fluid resorption, waste clearance and neuronal excitability. Redistribution of AQP4 over glioma cells severely impairs functionality of the BBB.

2. Accelerated cell division and increased metabolic demands in high-grade gliomas cause hypoxia, triggering increased expression of Vascular endothelial growth factor (VEGF), leading to neoangiogenesis and formation of abnormal vessels with dysfunctional BBB and increased permeability.

Current therapeutic options to treat symptomatic brain oedema and restore BBB function consist mainly of treatment with glucocorticoids or, experimentally, molecules targeting VEGF. There are currently no evidence-based dosing or tapering regimens; both options are effective, but efficacy is transient and side effect burden has to be considered carefully. Osmotic treatment with mannitol shows only a short-lived response.

Revision Questions

  1. Describe the mechanisms of brain oedema in patients with gliomas.
  2. How does bevacizumab decrease brain oedema?
  3. List the side effects of dexamethasone used to prevent/alleviate brain oedema in patients with gliomas.

« Previous Page Next Page »

Last update: 18 September 2017