Ultimately the parasites invade the brain, causing first behavioral changes such as fear and mood swings followed by headache, fever, and weakness . Simultaneously the patient may develop myocarditis . Death may occur within 6 months from cardiac failure or infection if the person is infected with rhodesiense. Gambiense infection may require up to 2 years before symptoms of infection in the central nervous system appear. Gambiense-infected people develop drowsiness during the day but insomnia at night.
Sleep becomes uncontrollable as the disease progresses until the patient becomes comatose .
Pentamidine injections protect against gambiense but have not yet been demonstrated as effective against rhodesiense. Insect control could help prevent the spread of sleeping sickness. Both diseases should be treated immediately upon diagnosis. The diseases are easier to treat during the blood-borne stage and more difficult to treat once meningoencephalitis develops.