Nodding syndrome: Origins and natural history of a longstanding epileptic disorder in sub-Saharan Africa

Background: Repetitive involuntary head nodding was first reported in the 1960s in the Wapogoro tribe of Tanzania. Objectives: We describe the natural history of head nodding in the Wapogoro tribe, with special reference to the earliest reported dates of onset. Methods: We analyzed clinical data from 150 historical patients seen between 1960 and 1971. Results: Head nodding with or without grand mal convulsions was present in 33/150 (~20%) cases, was mostly familial and equally distributed by gender. Age at onset of head nodding ranged from 2-22 years (mean: ~10 years) in the period 1934-1962. Head nodding preceded onset of grand mal convulsions by up to 12 months, and motor and psychomotor deficits indicative of brain damage developed with time. Fourteen of the 33 cases died at 13-39 years of age (mean: ~20 years) while nineteen aged 16-28 years (mean: ~16 years) were still alive. Conclusion: Historical accounts of head nodding (amesinzia kichwa, Swahili) among the Wapogoro tribe fit the August 2012 World Health Organization (WHO) case definition of probable Nodding Syndrome. Reported to have existed in this population for at least 80 years, Nodding Syndrome is a progressive seizure disorder that leads to generalized convulsions (kifafa), brain damage and death.