If you have been struggling with severe, debilitating headaches at night and have no accompanying symptoms, it might be due to a hypnic headache. It isn’t surprising if you haven’t heard of this type of headache before, since they are extremely rare. As was for the case of a 68-year old woman in a study conducted by the National Headache Foundation, it takes a series of tests to rule out other causes of the headaches while sleeping, until the official hypnic diagnosis is found.
What is a Hypnic Headache?
Also known as an “alarm clock headache” or “hypnic headache syndrome”, these types of headaches only start during sleep, either from a daytime nap or nightly sleep. Headaches experienced while sleeping don’t typically wake you up, but these types of headaches cause an immediate, jolting awakening, similar to an alarm clock, and often at the same time.
Most individuals suffering from headaches during sleep due to hypnic headaches, go to sleep pain-free, but wake up in debilitating pain. Hypnic-based headaches, which are in the group of idiopathic headache syndromes, are more common in adults over 50, though they also occur at age 40 or older.
What Causes Hypnic Headaches?
Researchers are still trying to find out what causes hypnic headaches. Several studies have been conducted, though the results are usually inconclusive. Some suspected causes of the hypnic headache, include benign tumors, very rarely a malignant tumor, previous head injuries and other causes of changes to the small vessel cerebrovascular. Having an MRI may point to the cause of the hypnic headache.
Common Signs and Symptoms
Alarm clock headaches only occur while sleeping and never start while you are awake. They are more common in the middle of the night, typically between 1-3 am. The pain is felt on one side or both sides of the head, and is either a dull or throbbing pain.
There is a large window for the length of these headaches, starting as short as 15 minutes and, miserably, as long as six hours. Some people get either nausea, phonophobia (sensitivity to sound) or photophobia (sensitivity to light) with a hypnic headache, but not all at once. It is also not common to have autonomic symptoms, like nasal congestion or tears.
How Are Hypnic Headaches Diagnosed?
There are strict hypnic headaches diagnostic criteria, created by the International Headache Society’s International Classification of Headache Disorders, for diagnosing this headache type. It is important to follow the criteria, since these types of headaches are such a rare variety.
The diagnostic criteria are as follows:
Dull or throbbing headache
Occurring only in sleep and waking the patient
Occurring first after 50 years old, having 15 or more a month or lasting 15 minutes or longer after waking
Lack of autonomic (involuntary) symptoms
Either nausea, phonophobia (sound sensitivity), or photophobia (light sensitivity)
Not related to another disorder
In addition to meeting the diagnostic criteria for hypnic headaches, your physician will also perform a series of tests. This includes a questionnaire to rule out sleeping or medical conditions associated with the headaches and performing a brain scan to look for a possible cause.
How to Find Relief
Among the different headaches suffered while sleeping, hypnic-based headaches are the most rare, but also very treatable. Medication is the most common treatment, which can include a 300 mg dose of lithium carbonate to be taken at bedtime. However, if you experience dehydration, have renal disease or use diuretics, it should be used with extra caution.
Taking caffeine or a calcium channel blocker before bed may also be used for the treatment of a hypnic headache. Some alarm clock headache sufferers have been prescribed Topamax (topiramate) to prevent these headaches. Anti-inflammatory drugs may also be recommended for preventing or treating them upon waking.
If you have been dealing with headaches during the night that are severe and sudden, waking you from sleep, consult your doctor about the possibility of this rare headache type. Especially if you are over the age of 50, since this is when they are most common. It is likely that your doctor’s treatment helps to not only reduce their occurrence, but prevent them altogether.
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