Diagnostic Criteria
The diagnostic criteria for narcolepsy described in the International Classification of Sleep Disorders indicate that the
diagnosis may be based on clinical symptoms alone,
if EDS and cataplexy are present,
or
on the clinical manifestations AND polysomnographic findings,
if there is no cataplexy. However, most experts agree that it is
advisable to confirm
the diagnosis of narcolepsy with sleep laboratory procedures (PSG and MSLT) before the start of the treatment.
If a doctor considers the mslt a "gold standard" they are not familiar with journal updates, or have shuffled off all their dx and treatment responsibilities to a sleep lab.