Human African trypanosomiasis, also known as African sleeping sickness, is an illness caused by one of two parasitic zoonoses: Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense.
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Epidemiology
Human African trypanosomiasis is a disease endemic to sub-Saharan Africa. Within this region, the disease is harbored mainly in rural areas 1, where access to medical imaging is often non-existent. Trypanosoma brucei gambiense accounts for the vast majority of reported cases of human African trypanosomiasis. The incidence and prevalence have varied widely over the last two centuries. Under 3,000 cases were reported in 2016, and the incidence is declining 2.
Clinical presentation
In the initial stage (stage I) of human African trypanosomiasis, many symptoms of the disease are non-specific, such as fever and malaise. Untreated, the disease progresses (stage II) to include various neurological manifestations, including encephalitis, coma, and ultimately death.
Pathology
Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense are transmitted by certain species of the tsetse fly, although other transmission routes are possible 3.
Radiographic features
There have been only small case series and case reports of brain MRI of patients with human African trypanosomiasis at stage II (central nervous system involvement) 4-6.
MRI
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T2/FLAIR
symmetric high signal intensity in the supratentorial deep white matter (all cases) 5
high signal intensity in the basal ganglia, cerebellum, and/or brainstem (around half of cases)
DWI: restricted diffusion may be seen in white matter tracts such as the posterior limbs of the internal capsules and splenium of the corpus callosum 5
SWI/GRE/T2*: parenchymal microhemorrhages may be seen 5
Treatment and prognosis
Management consists of antimicrobial therapy, such as 7:
Trypanosoma brucei gambiense: pentamidine in stage I, and nifurtimox-eflornithine combination therapy in stage II
Trypanosoma brucei rhodesiense: suramin in stage I, and melarsoprol in stage II