Corneal and conjuctival reflexes are usually intact, the pupils are symmetrical and react normally to light. The eyes are usually divergent with normal doll's eye movement. Papilloedema is rare but retinal haemorrhages are sometimes seen. 2-5 Cerebral malaria is also known as 'symmetric encephalopathy' because of presence of symmetrical upper motor neurone signs. Muscle tone is increased and tendon reflexes are usually brisk with patellar and ankle clonus, along with extensor plantar responses.
Abdominal reflexes are usually absent.
Extensor posturing suggesting brainstem dysfunction, either due to cerebral malaria or profound hypoglycaemia, is a common and important sign. In advanced stages decerebrate and decorticate rigidity are frequently present and often associated with sustained upwards deviation of eyes, extension of neck, pouting of lips and periodic sterterous breathing pattern. The cause of death is not apparent most of the time. Progressive deterioration of brainstem function may lead to cardiac and respiratory arrest. In these patients small cerebral vessels are packed with parasitized red blood cells.