Assertion: narcolepsy's cause | /r/CapableOf | remain unclear
Facets:
value: in cases of narcolepsy without cataplexy
type: OTHER
Source sentences:
text: In some cases of narcolepsy, however, the levels of orexin appear to be normal and the exact cause of the condition remains unclear.
text: In cases of narcolepsy without cataplexy, the cause of the symptoms remains unclear.