How Narcolepsy is Diagnosed

Developer of Narcolepsy

Narcolepsy can occur in people of both sexes. Symptoms-particularly sleepiness-usually begin in late childhood, the teen years or the early twenties. Narcolepsy can begin after age 30: but such is relatively uncommon. In contrast, while sleep apnea can develop in childhood, it more often becomes a significant and progressive problem later in life. Hence, two valuable clues to the possible diagnosis of narcolepsy in a sleepy person:

Indications of cataplexy

Onset of sleepiness early in life, particularly if no severe snoring was noted then. For example, falling asleep more frequently in school than one's classmates, taking naps after school, and in some cases, hyperactive behavior (which in children, can be a manifestation of impaired alertness).

What causes Narcolepsy

The usual cause appears to be a problem with the chemical "neurotransmitters" that regulate communications between different groups of nerve cells in the brain. Only rare cases have been reported of narcolepsy arising as the consequence of such structural causes as brain tumors, brain infections and head injuries. CT/MRI scans of the brain are normal in the vast majority of cases.

Narcolepsy can "run in families" such that some individuals appear genetically predisposed to develop it. Its onset sometimes follows stressful events, but such does not indicate that it is a psychological disorder. In fact, some breeds of dogs develop narcolepsy on a genetic basis.

Narcolepsy is not a rare condition. It is roughly as common as MS (multiple sclerosis).

How is Narcolepsy diagnosed

A careful history, followed by specific sleep center studies (both an overnight sleep monitoring and a multiple sleep latency test).

Narcolepsy cann't be diagnosed by a "blood test". Such is a common misimpression that resulted from the discovery that most (but not quite all) narcoleptics share particular HLA types (genetically determined markers on white blood cells that are used to determine tissue compatibility--for example, to assess one's ability to donate a kidney to a possible recipient without high likelihood that the transplanted kidney will be rejected). HLA types are evaluated with a blood test.

There are two reasons why these tests cannot be used to diagnose narcolepsy:

  • First, some definite narcoleptics who even have cataplexy will come out negative on these tests.
  • Second, an even greater problem is that up to 25% of the general population will show the same HLA typing that has been associated with narcolepsy!

How is Narcolepsy treated

It is best managed with a combination of medications and common sense! Pills alone are not the answer. One should also eliminate aggravating factors that would make the symptoms worse and the prescribed medications less effective. -For example: one does not manage diabetes by giving insulin and then informing the patient that since they now have medicine, they can do whatever they please...such as eating entire pies and cakes and drinking a case of beer every day! It would be illogical to use such a "medications only" approach for any illness-including narcolepsy.

The physician treating the patient with narcolepsy should be experienced in its management and also take the time needed to educate the patient about the condition and factors that can make it worse-empowering the patient and enabling him or her to "outsmart" the disorder as much as possible.

There are also other disorders of impaired brain alertness mechanisms beside narcolepsy. Even if one excludes causes of their impairment by sedating medications, hormonal imbalances such as hypothyroidism and the like, there are individuals with severe "brain sleepiness" not secondary to problems (such as sleep apnea) occurring during overnight sleep-and who do not have either cataplexy or a tendency to enter REM sleep too rapidly. The term "idiopathic CNS hypersomnolence" has been used to describe such individuals.

Idiopathic CNS hypersomnolence is a diagnosis that is made by excluding other possible causes. CNS means central nervous system, and idiopathic is a polite way of saying that the doctor has no idea what caused the problem!--which does not mean that it cannot be effectively treated.