The clinical features of intracranial tumours vary according to the site of the lesion and its type. Symptoms usually occur insidiously over weeks or years with often only minor intellectual and emotional impairment; more rarely, they may present acutely due to haemorrhage or the development of hydrocephalus.
Mass effects of intracranial tumours:
- raised intracranial pressure and brain shift due to space occupying lesion or to obstructive hydrocephalus, leading to:
- supratentorial - tentorial herniation
- infratentorial - tonsillar herniation
Focal damage:
- seizures - present in over one third of patients with intrinsic tumours of the cerebral hemispheres. Late onset - in the third decade or later - and of no obvious cause should raise the suspicion of a brain tumour. Epileptiform convulsions are more frequent with slow growing than rapidly growing tumours. Epilepsy is infrequent with tumours of the posterior fossa or brainstem.
- disturbed function:
- supratentorial - cerebral - cranial nerves I-VI damage
- infratentorial - cerebellar - cranial nerves III-XII damage
Reference:
- Brain's Diseases of the Nervous System 2009; 12th edn. Oxford University Press.