That's (Kuru) in New Guinea.
I read about this years ago when a doctor went into 'the wild' with his anthropology wife and observed the natives eating the brains of the deceased elderly. It was done as a sign of respect and hope to claim the wisdom of the elders. His studies eventually determined that they were passing along a prion disease...like mad-cow disease.
Yes...it was in New Guinea. But I would think that cannibalism could cause this problem wherever it was practiced.
Unless the video of the Ugandan is “doctored” it would appear that he is showing similar symptoms.