STUDY OBJECTIVE: To describe sleep characteristics and rapid eye movement (REM) 
sleep behavior disorder in patients with Guadeloupean atypical parkinsonism 
(Gd-PSP), a tauopathy resembling progressive supranuclear palsy that mainly 
affects the midbrain. It is possibly caused by the ingestion of sour sop 
(corossol), a tropical fruit containing acetogenins, which are mitochondrial 
poisons.
DESIGN: Sleep interview, motor and cognitive tests, and overnight 
videopolysomnography.
PATIENTS: Thirty-six age-, sex-, disease-duration- and disability-matched 
patients with Gd-PSP (n = 9), progressive supranuclear palsy (a tauopathy, n = 
9), Parkinson disease (a synucleinopathy, n = 9) and controls (n = 9).
SETTINGS: Tertiary-care academic hospital.
RESULTS: REM sleep behavior disorder was found in 78% patients with Gd-PSP (43% 
of patients reported having this disorder several years before the onset of 
parkinsonism), 44% of patients with idiopathic Parkinson disease, 33% of 
patients with progressive supranuclear palsy, and no controls. The percentage of 
muscle activity during REM sleep was greater in patients with Gd-PSP than in 
controls (limb muscle activity, 8.3%+/-8.7% vs 0.1%+/- 0.2%; chin muscle 
activity, 24.3%+/- 23.7% vs 0.7%+/-2.0%) but similar to that of other patient 
groups. The latency and percentage of REM sleep were similar in patients with 
Gd-PSP, patients with Parkinson disease, and controls, whereas patients with 
progressive supranuclear palsy had delayed and shortened REM sleep.
CONCLUSION: Although Gd-PSP is a tauopathy, most patients experience REM sleep 
behavior disorder. This suggests that the location of neuronal loss or 
dysfunction in the midbrain, rather than the protein comprising the histologic 
lesions (synuclein versus tau aggregation), is responsible for suppressing 
muscle atonia during REM sleep. Subjects with idiopathic REM sleep behavior 
disorder should avoid eating sour sop.