Sleep structure: a new diagnostic tool for stage determination in sleeping sickness

Acta Trop. 2005 Jan;93(1):107-17. doi: 10.1016/j.actatropica.2004.10.001.


Human African trypanosomiasis (HAT), due to the transmission of Trypanosoma brucei (T. b.) gambiense and T. b. rhodesiense by tsetse flies, is re-emerging in inter-tropical Africa. It evolves from the hemolymphatic Stage I to the meningo-encephalitic Stage II. The latter is generally treated with melarsoprol, an arseniate provoking often a deadly encephalopathy. A precise determination of the HAT evolution stage is therefore crucial. Stage II patients show: (i) a deregulation of the 24-h distribution of the sleep-wake alternation; (ii) an alteration of the sleep structure, with frequent sleep onset rapid eye movement (REM) periods (SOREMPs). Gambian HAT was diagnosed in eight patients (four, Stage II; three, Stage I; one, "intermediate" case) at the trypanosomiasis clinic at Viana (Angola). Continuous 48-h polysomnography was recorded on Oxford Medilog 9000-II portable systems before and after treatment with melarsoprol (Stage II) or pentamidine (Stage I and "intermediate" stage). Sleep traces were visually analyzed in 20-s epochs using the PRANA software. Stage II patients showed the complete sleep-wake syndrome, partly reversed by melarsoprol 1 month later. Two Stage I patients did not experience any of these alterations. However, the "intermediate" and one Stage I patients exhibited sleep disruptions and/or SOREMPs, persistent after pentamidine treatment. Polysomnography may represent a diagnostic tool to distinguish the two stages of HAT. Especially, SOREMPs appear shortly after the central nervous system invasion by trypanosomes. The reversibility of the sleep-wake cycle and sleep structure alterations after appropriate treatment constitutes the basis of an evaluation of the healing process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Child
  • Female
  • Humans
  • Male
  • Melarsoprol / therapeutic use
  • Polysomnography*
  • Sleep*
  • Trypanocidal Agents / therapeutic use
  • Trypanosoma brucei gambiense / growth & development*
  • Trypanosomiasis, African / diagnosis*
  • Trypanosomiasis, African / drug therapy
  • Trypanosomiasis, African / physiopathology


  • Trypanocidal Agents
  • Melarsoprol