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Superior sulcus tumour — SCE Respiratory MCQ

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HardLung CancerSuperior sulcus tumourSCE Respiratory

A patient with narcolepsy and cataplexy has CSF orexin-A measured with a validated assay. Which result independently supports narcolepsy type 1 when the clinical syndrome is appropriate?

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Correct answer: E — At or below 110 pg/mL or one-third of the normal assay mean

E is correct. Narcolepsy type 1 can be established by chronic sleepiness with cataplexy and compatible MSLT findings, or by CSF orexin-A at or below 110 pg/mL or below one-third of the mean obtained in normal subjects using the same validated assay. HLA-DQB1*06:02 is associated but insufficiently specific for diagnosis. Intermediate and normal orexin concentrations do not independently establish type 1, and SOREMP criteria belong to PSG/MSLT interpretation rather than being substituted by an arbitrary orexin band.

Reference: https://pmc.ncbi.nlm.nih.gov/articles/PMC9159677/