My apologies TG I didn't realise you had already had polysomnography. (sleep study)
So, they really should be able to give you a fairly clear picture from that. It is very clear from a PSG when there is narcolepsy due to the rapid onset of REM & the frequent limb movements that are not due to apnoea events or RLS (restless leg syndrome). Though I suspect if they are concerned you will be asked to attend an overnight clinic for a polysomnograph. The usual course of events in diagnosing narcolepsy is to have an overnight PSG & then a MSLT (multiple sleep latency test). This is a recording of your tendency to fall asleep durin the day. It shows an objective measure of daytime sleepiness and the REM abnormality present in all narcoleptic patients. Usually narcoleptic patients have at least 2 but usually more sleep onset REM periods during the multiple sleep latency test.
As you probably have learned there are symptoms that form the narcolepsy pentad. These are cataplexy which briefly is a sudden but transient loss of muscle control usually triggered by strong emotions. This is present in at least 75% of narcoleptic patients. Hypnagogic hallucinations which is a distorted perception occurs in roughly half of narcoleptic patients it occurs when a person goes from sleep to wakefulness. This is usually described as bizarre and sometimes terrifying. The other is sleep paralysis where there is an inability to move or talk and it can last seconds to minutes. Sometimes people feel like they can't breathe during this but on polysomnography they are shown to be breathing it just feels like they are not. (to the patient)

Usually with narcolepsy there is a very disturbed sleep pattern so during PSG the practitioner will note frequent movements and awakenings not necessarily caused by apnoeas.

To diagnose narcolepsy according to the "International Classification of Sleep Disorders" a patient can be diagnosed based on only clinical symptoms only if both cataplexy & excessive day time sleepiness is observed. (using PSG)

If cataplexy is not present (have you had this TG? - they would have noted it) a diagnosis is made on the PSG findings.

How this looks on PSG is that the 1st REM sleep period in a healthy person is roughly 80-120 minutes after the onset of night sleep. In narcolepsy this initial REM period occurs within 15 minutes.

Narcoleptic patients will typically sleep within 30 seconds of lying down. (sometimes a little longer)

The other part of narcolepsy that I find particularly fascinating but which is incredibly disturbing for the patient and those around them is automatic behaviour without awareness. Narcolepsy has been used as a reasoning behind homocide, suicide and other violent attacks...

I hope very much that you don't have this as it's a very very disturbing condition. Usually treatment is required using drug therapy - typically stimulants (Ritalin is often used) MAOI's & other antidepressants. Often people who do have narcolepsy suffer from depression due to the terrifying experiences they have during sleep. Also the social implications of falling to the floor etc etc.
Often they cannot work or live alone. It is very challenging.

Good luck with your appointment. I did some work at Epworth years ago now... I think it was 1996!

Lulu the falling down your X is displaying does sound narcoleptic... A CT of the head is obviously important to rule out any shadows etc. I hope he is seen by a respiratory physician/ent as well... He really does need to see a sleep specialist - often they will be seen by a nurse first to have an array of tests and interviews and then the specialist will see them.

TG a deviated septum is a cause of obstructed sleep apnoea so it's great that you are having it corrected. Even mild sleep apnoea can play havoc with ones energy levels and daytime sleepiness.

Good luck on your journey & don't forget to let us know how you go.