In most cases of narcolepsy, a medical provider will perform a polysomnogram and a multiple sleep latency test. Called the PSG and MSLT respectively, these tests will record eye movements, heart rate, blood pressure, and brain activity. This will help to determine if an individual is indeed falling asleep during a relaxing situation with extreme regularity.
It can take 10+ years for the symptoms of narcolepsy to begin showing themselves. It is also difficult to diagnose this condition because it is quite rare and the signs and symptoms tend to mimic more common conditions, such as depression or a sleep disorder.
Narcolepsy can also be mistaken for a seizure disorder, laziness, or even a learning problem.
In addition to the sleep tests, a medical provider may also request a sample of spina cord fluid via a lumbar puncture. This is not a blood test, but a needle will be inserted into the lower back to withdraw the spinal fluid. People with narcolepsy tend to have low levels of hypocretin, which is a chemical that is used by the body to promote wakefulness.
So This Means There Isn’t a Blood Test for Narcolepsy?
In 2014, a paper published by Alberto De la Herran-Arita showed that there is a connection between an autoimmune deficiency and narcolepsy. This paper found that patients with narcolepsy had CD4+ T cells present, which were not present in the control groups. A blood test is currently in the developmental stages to be able to detect these cells, which could lead to more definitive blood testing for this condition.
Blood tests for DQB1*06:02 have been in place for some time as a way to confirm narcolepsy as well. This marker is found in up to 95% of individuals who have narcolepsy with cataplexy, which means they feel weakness that is precipitated by an emotion, such as laughter. Cataplexy is present in up to 80% of patients with a narcolepsy diagnosis.
In individuals with narcolepsy, however, the percentage of people with this marker drops to about 50%. The HLA gene being tested with the narcolepsy blood test will also come back as positive for 1 in 4 people in the general population. The absence of this marker does not guarantee that narcolepsy will not be present either.
What Are the Symptoms of Narcolepsy?
The signs and symptoms of this neurological disorder usually begin between the ages of 15-25, but it can begin at any age. The primary symptom involves excessive daytime sleepiness, which is fatigue that interferes with normal daily living activities – even when getting enough sleep the night before. This type of sleepiness can affect concentration, energy levels, mental cloudiness, and lead to extreme exhaustion.
Some people may experience a loss of voluntary muscle control. Slurred speech may occur, or in extreme cases, a total body collapse could occur. Intense emotions may trigger an episode of these symptoms.
Narcolepsy has also been known to cause vivid and frightening hallucinations. All of the senses may be involved in the hallucination and may occur during awakening or accompany sleep onset.
Many with a narcolepsy diagnosis have also report issues with sleep paralysis. This involves an inability to speak or move after waking up at night, despite the mind being awake and attempting to speak or move. Episodes of sleep paralysis may last for several seconds or several minutes, but full movement and speech is regained after the episode.
Can Narcolepsy Be Treated?
There is no known cure for narcolepsy at this time.
Drug treatments can help to control the symptoms of narcolepsy that are the most debilitating. This involves stimulants for daytime hours, while treating abnormal REM sleep patterns with antidepressants.
There is also a prescription drug called Xyrem, which patients with narcolepsy report does a good job of helping them to get asleep and stay asleep more consistently.
Lifestyle adjustments may also affect the bothersome signs and symptoms of narcolepsy. This includes scheduling short daytime naps periodically, keeping to a bedtime routine, avoiding caffeine or alcohol, avoiding nicotine, and eating smaller meals throughout the day. A normal exercise routine can also reduce symptoms in some individuals.
The narcolepsy blood test will not form the foundation of a diagnosis at this moment in time. New discoveries may change this fact in the future, but for now, the primary method for diagnosis this condition is through sleep studies. The blood tests are just a way to gain supplementary information to support the conclusions from the sleep studies.
If you have concerns about narcolepsy or are experiencing the signs and symptoms of this disorder, then use this guide to speak with your doctor about how you feel. Only a qualified medical professional can determine if narcolepsy could be affecting your health.