What is Nummular Headache (Coin-shaped Headache)?
The International Classification of Headache Disorders sorts headache disorders into two main categories based on their source: primary and secondary. Primary headaches include types such as migraines, trigeminal autonomic cephalgia, tension headaches, and other specific types, including one called a nummular headache. A nummular headache can either be ongoing or occur in sudden, intermittent bouts. The affected area is very distinct, never changing in size or shape, and is round or oval, measuring about 1 to 6 centimeters in diameter. It’s often referred to as a “coin-shaped headache” due to this characteristic. Unlike migraines, nummular headaches don’t come with symptoms like nausea, vomiting, runny nose, tears, red eyes, sensitivity to light or sound, or specific neurological symptoms.
What Causes Nummular Headache (Coin-shaped Headache)?
Secondary headaches are types of headaches that happen because of other health issues like tumors, abscesses, meningitis, sinusitis, or problems with the jaw joint. Nummular headache, on the other hand, is a type of primary headache which means that it doesn’t occur because of any other health problem. It exists on its own and researchers don’t yet know the exact cause of it.
Risk Factors and Frequency for Nummular Headache (Coin-shaped Headache)
Nummular headache is a very rare type of headache. First mentioned in 2002, there have only been a few hundred cases documented since then. In fact, they only make up 0.25% of all headache-related medical consultations. This type of headache tends to affect women more than men, with a ratio of 1.5 to 1.
Signs and Symptoms of Nummular Headache (Coin-shaped Headache)
The International Headache Society has suggested guidelines for diagnosing a specific type of headache. According to them, the diagnosis can be made if the following conditions are met:
- The individual experiences mild to moderate headache that meets conditions B and C.
- The pain is localized to a rounded or elliptical area of the head, ranging from 1 to 6 cm in diameter.
- The headache is persistent, either continuously present or occasionally relieved by spontaneous breaks that can last for weeks or months.
- The symptoms are not due to another medical condition.
Additional updates to these guidelines were proposed in 2012:
- The pain can last for several minutes, hours, or days, and it may either come and go or remain constant.
- The area of pain doesn’t change in size or shape over time.
Testing for Nummular Headache (Coin-shaped Headache)
When trying to diagnose a condition that might be affecting your nervous system, there are several steps your doctor will take. They’ll start with a thorough checkup of your head, including your scalp, head muscles, nerves, and blood vessels.
Your doctor may also order lab tests to understand more about your general health. These can include a complete blood count, tests for kidney and liver health, thyroid function tests, and tests for inflammation and bone health. They might also conduct tests for autoimmune diseases, such as a rheumatoid factor test and an antinuclear antibody test.
If your doctor thinks it’s necessary based on your condition and symptoms, they might also suggest having CT and MRI scans. These are imaging tests that can check for problems in your central nervous system that might be causing your symptoms.
Numerous studies indicate that patients with a type of headache known as nummular headache often have autoimmune diseases. In particular, these patients often have antinuclear antibodies in their blood, indicating an autoimmune response. Sjogren’s syndrome, an autoimmune disease, was notably common in these individuals. Interestingly, many of these patients did not show signs of an autoimmune disease when they first saw a doctor for their headaches.
Treatment Options for Nummular Headache (Coin-shaped Headache)
Different methods like nerve block, radiofrequency treatment, and decompression surgery are often used for treating a type of headache known as epicrania. However, these treatments aren’t usually effective for another type of headache called nummular headaches. For these types of headaches that cause mild to moderate pain, over-the-counter pain relievers may be enough.
But in cases where the headaches are persistent, preventative treatments using certain types of drugs, like gabapentin, pregabalin, and tricyclic antidepressants, have proven successful. There are also some techniques like peripheral nerve stimulation and transcutaneous nerve stimulation, which stimulate the nerves to relieve pain, and these methods have shown good results as well.
A treatment that stands out involves the use of botulinum toxin, commonly known as Botox. For people whose nummular headaches don’t respond to other treatments, injecting 10 to 25 units of Botox in and around the affected area relieved symptoms significantly in a few reported cases. The effects of this treatment begin about a week after the injection and can last up to 14 weeks. After this period, the treatment can be repeated.
What else can Nummular Headache (Coin-shaped Headache) be?
Nummular headache is a type of epicrania, a category of headaches. It can often be confused with migraines or tension-type headaches, and it’s not unusual for those to occur at the same time. The International Headache Society has published a list in its third edition of the International Classification of Headache Disorders of other headache types that need to be considered when diagnosing nummular headache:
Primary headache disorders:
- Migraine headaches
- Tension-type headaches
- Trigeminal autonomic cephalalgias, and more.
Other types of primary headache disorders are also listed, including various neuralgias and conditions such as exercise-induced headaches, sex-related headaches, and cold-stimulus headaches.
Following this, there are secondary headache disorders caused by triggers such as:
- Trauma and injury
- Vascular issues
- Headaches secondary to issues inside the skull
- Chemical or substance abuse
- Infections in the head and neck
Headaches can also be related to disorders of homeostasis, or the body’s ability to maintain stability. These include headaches related to high altitude or flying, sleep apnea, dialysis, high blood pressure, fasting, heart conditions, hypothyroidism, and other homeostatic disorders.
What to expect with Nummular Headache (Coin-shaped Headache)
So far, it is believed to be a harmless condition that persists over a long period of time.
Possible Complications When Diagnosed with Nummular Headache (Coin-shaped Headache)
The term ‘nummular headache’ refers to a type of headache that is still relatively unknown and we don’t have a lot of information about potential complications that can occur over a long period of time. That said, if the condition is treated with neuromodulators, they can make a person extremely tired. Because of this, care should be taken when driving or handling heavy machinery.
Preventing Nummular Headache (Coin-shaped Headache)
It’s important to explain to the patient that this type of headache is generally not harmful. However, they should be advised that if they experience any specific symptoms affecting their nervous system, such as blurred vision or vision loss, muscle weakness, numbness, drooping features on their face, slurred speech, or loss of consciousness, they should seek immediate medical attention.
