2 ‘Foggy’ Thinking
Brain fog is another very common symptom of narcolepsy that gets a little less attention. This is similar to the above sleepiness, wherein the brain is tired and less able to function properly. When someone is tired normally, it often points to a build-up of waste products in the brain such as adenosine which can make neurons fire more sluggishly. That is not what causes the brain fog and tiredness observed in narcolepsy, however – which is instead a sign of low hypocretin or orexin. This is a neurochemical that is responsible for regulating sleep cycles and wakefulness, and for helping the brain to switch off at the right times.
With this chemical acting inappropriately, the patient might, therefore, see elevations in other neurotransmitters like melatonin and GABA. These are ‘sleep hormones’ and inhibitory neurotransmitters, which work by downregulating the activity of the neurons and making them less likely to fire. In short, this results in thoughts moving more slowly and coming less regularly. It may feel a little like being drunk, or still half asleep.