There is no blood test it’s a spinal tap. The spinal tap is only done if there is a need to keep taking antidepressants or other medications that interfere with rem sleep.

Generally, one should have the narcolepsy HLA test (HLA DQB1*02:06) as it is present in 99% of those with NT1. It is necessary, but not sufficient for the diagnosis. If the HLA is positive, then a spinal tap showing very low or no hypocretin can confirm objectively the presence of true NT1. The sleep studies can be fairly inaccurate to diagnose this condition but the brain failing to produce hypocretin (orexin) IS the condition.

I had to have that HLA test, the night time sleep test and the nap test for my sleep specialist to determine that I had narcolepsy type 1. However I had video evidence of my cataplexy attacks and done a lifetime of searching to figure out what was wrong. Including being cleared of any nocturnal seizure disorders and other abnormalities that could cause the seizure like experiences. I never connected the cataplexy to emotion at first because it first began occuring in conjunction with waking up from disturbed sleep and several ​forms of hypnogogic/hypnopompic hallucinations. I remember the vindication I felt when I finally received my diagnosis in may of last year, although it was short lived in some ways. Being decades behind in diagnosis has contributed to several other struggles. It's good to see lots of research is being done into sleep disorders at the moment because going through this can be very lonely and severely debilitatibg. I honestly thought I had MS or something for a little while. @@andyberkowskimd