Please support Burma cyclone relief & Sichuan earthquake relief
Click here to donate

• rapidly growing tumours usually lead to earlier and more serious deterioration as a result of a decompensation of brain mechanisms that normally control pressure within cranium. These tumours displace brain structures along the paths of least resistance and from one intracranial compartment to another: "herniation syndromes". Often fatal unless rapidly treated
• cerebral oedema of vasogenic type: responsive to steroids. Dexamethasone most commonly used steroid for the treatment of brain tumours. Minimal mineralocorticoid effect. Compared to other treatments for ­ ICP onset is slow. Dose 16-40 mg/day in divided doses. Oral and IV doses are the same
• 21-aminosteroids may provide anti-oedema effect of steroids without associated glucocorticoid side effects
• in brain tumour patients too rapid an infusion of mannitol may cause a deterioration in neurological function by expanding vascular volume and hence CBV. Pretreatment with 5-10 mg of frusemide may prevent this response

• results from obstruction of bulk flow of CSF along its normal route of circulation or an overproduction of CSF relative to absorption (very rare)
• tumour may block flow of CSF in ventricles or connecting channels within the brain (foramina or aqueduct) causing non-communicating or obstructive hydrocephalus or in the subarachnoid pathways causing communicating hydrocephalus.

• presentation is with signs and symptoms of raised ICP
• CT shows dilatation of ventricular system proximal to obstruction with normal sized pathways distal to block (noncommunicating) or with dilatation of all four ventricles (communicating)

• drainage (temporary/permanent)
• treatment of tumour

• important cause of morbidity
• approximately 40% of patient with glioma present with fits and 55% have at least one episode by the time their tumour is diagnosed
• classically cause focal fits but can cause almost any type
• phenytoin first line treatment. Patients on dexamethasone frequently require higher doses for therapeutic levels and seizure control. As steroid dose is decreased phenytoin levels may become toxic. Cranial irradiation predisposes some patients on anticonvulsants (especially phenytoin) to Stevens-Johnson and erythema multiforme reactions
• prophylactic anticonvulsants are not indicated for patients who have not had fits. However may be indicated in the perioperative period (stop 7 days post-op) or when ICP significantly elevated to prevent acute detioration

• infection
• haemorrhage
• shunt obstruction

• seizures, nausea and vomiting at time of procedure occur occasionally. N & V probably due to transient rise in ICP. Prophylactic anticonvulsants and steroids commonly used
• major late complication is focal radiation necrosis which can behave as an expanding mass and mimic tumour progression. Can be distinguished from tumour using PET scanning

• haemorrhage, oedema and infection may result from catheter placement or following removal

• may result in early, or delayed symptomatic deterioration
• early reactions primarily related to steroid-responsive oedema

• CT: solitary, irregular mass surrounded by oedema. Usually low density but may be high or mixed. Mass effect usual. ± calcification (especially low grade tumours). Most show partial enhancement; may involve only outer portion resulting in "ring enhancement"
• MRI: mass, often with adjacent oedema. Variety of signal intensities but in general lower in signal intensity than normal brain on T₁ weighted images and higher on T₂ weighted images

• CT: high or low density. Usually enhance. Often surrounded by substantial oedema. Typically multiple. A single met cannot be distinguished from a glioma by either CT or MRI
• MRI: similar to CT

• CT: arise from vault, falx or tentorium in characteristic sites the commonest being the parasaggital region, over cerebral convexities and sphenoid ridges. Slightly denser than brain due to calcium. Marked enhancement. May be sclerosis and thickening of adjacent bone
• MRI

• enhance on both CT and MRI

• CT: pituitary adenoma may enhance vividly. Similar appearances may be seen with large aneurysm, meningioma or craniopharyngioma
• SXR: may be enlargement or destruction of sella

• most frequently seen cerebral metastases are from lung and breast cancer. Melanoma and systemic lymphoma also tend to spread to brain

©Charles Gomersall, May, 2008 unless otherwise stated. The author, editor and The Chinese University of Hong Kong take no responsibility for any adverse event resulting from the use of this webpage.
Copyright policy    Contributors