Primary amoebic meningoencephalitis
Primary amoebic meningoencephalitis (PAM), also known as naegleriasis, is an almost invariably fatal infection of the brain by the free-living protozoan Naegleria fowleri. Symptoms include headache, fever, nausea, vomiting, a stiff neck, confusion, hallucinations and seizures.
Source: Wikipedia — Primary amoebic meningoencephalitis (CC BY-SA 4.0)