Virus encephalitis as a cause of coma is rare. It is important to bear in mind cerebral malaria in the tropics so in any comatose patient who has recently returned form a country in which malaria is prevalent. Early treatment is completely effective. Coma also occurs in African try panosomiasis, but is a late complication. Cerebral: Tumor an other causes of raised intracranial pressure. As pressure rises the brain becomes displaced and ischemic. Consciousness is lost slowly and signs of pressure coning and papilloedema develop.