Intracranial pressure, cerebral blood flow and brain oedema

The normal autoregulatory systems that keep the intracranial pressure (ICP) within a tight physiological range will be outlined, along with the various mechanisms that culminate in pathological decompensation and raised ICP. Intracranial hypertension is a common neurosurgical problem that can be due to many causes including intracranial mass lesions and associated oedema, disorders of cerebrospinal fluid circulation or more diffuse intracranial pathologies. In this article we will review the three main types of cerebral oedema: cytotoxic, vasogenic and transependymal, their different mechanisms of formation and treatment. The signs and symptoms of intracranial hypertension will be described, together with indications for ICP monitoring and measurement methods. A detailed stepwise approach to managing raised ICP, including medical and surgical strategies, will be provided and the evidence of these treatments discussed. In the future, further appropriately powered, prospective, randomized controlled trials will be required to better guide treatment of this condition.