What is Short-Lasting Unilateral Neuralgiform Headache?
Headaches and pain disorders are the main reasons for sickness and disability worldwide. There are many types of headaches recognized in a worldwide classification system. One type of headache is called the ‘short-lasting unilateral neuralgiform headache’, which is a kind of headache that affects one side of the face and is linked to the trigeminal nerve in the face. This type of headache may also involve body functions like tearing or flushing.
There are two main types of these headaches: One type is called ‘SUNCT’, which stands for ‘Short-lasting Unilateral Neuralgiform Headache Attacks with Conjunctival Injection and Tearing’. The other type is called ‘SUNA’, which stands for ‘Short-lasting Unilateral Neuralgiform Headache with Autonomic Symptoms’. This article will explain more about SUNA.
While these types of headaches are relatively rare, they can be easy to identify due to their specific set of signs and symptoms. Both SUNCT and SUNA are part of a group of headache disorders known as ‘trigeminal autonomic cephalalgias’ (or TACs for short). These headaches are known for happening very frequently – possibly up to 600 times a day, but on average less than 100 times a day. The pain from these headaches can range from moderate to severe, and it can either pulsate or be sharp at times.
What Causes Short-Lasting Unilateral Neuralgiform Headache?
To trigger a migraine, something must stimulate a nerve in your head called the trigeminal nerve. This stimulant can be something straightforward or something harmful. When the trigeminal nerve is triggered, it sends signals to a group of nerves in your head and neck known as the trigeminal-cervical complex. This complex includes parts of the spinal cord in the neck (C1/C2 dorsal horns) and a section of the brainstem (the trigeminal nucleus caudalis).
From there, nerve cells send signals to another part of the brain (the superior salivary nucleus or SSN) in an area called the pons. This area sends parasympathetic (rest and digest system) nerve fibers that connect to the sphenopalatine ganglion, a bundle of nerves behind the nose.
After these nerve fibers connect at this ganglion (which is a cluster of nerve cells), they continue on to affect the tear gland (lacrimal gland) and the lining of the nose and palate (roof of the mouth). This process plays a significant role in causing the symptoms associated with migraines.
Risk Factors and Frequency for Short-Lasting Unilateral Neuralgiform Headache
SUNCT and SUNA are relatively rare conditions, with around 6.6 out of 100,000 people having them. Only about 1.2 new cases per 100,000 people are reported each year. These conditions typically start to develop in people aged 35 to 65, with the average age being 48. However, there’s a twist – SUNCT is usually found more in men, while SUNA is more common in women. This pattern is also seen in a related condition called trigeminal neuralgia. Additionally, there has been a single case reported where a family had SUNCT, suggesting it might be inherited in some cases.
- The rate of SUNCT and SUNA is 6.6 per 100,000 people.
- Each year, there are about 1.2 new cases per 100,000 people.
- Most people start to show symptoms between 35 and 65, with the average age being 48.
- SUNCT is more prevalent in men, while SUNA is more prevalent in women.
- There has been a reported case of SUNCT running in a family.
Signs and Symptoms of Short-Lasting Unilateral Neuralgiform Headache
Short-lasting Unilateral Neuralgiform Headache (SUNCT) and Short-lasting, Unilateral, Neuralgiform headache attacks with Conjunctival injection (SUNA) are conditions involving suddenly occurring headaches. These headaches are normally very intense and quick, lasting from a few seconds to 10 minutes. They are typically felt around the eye or temporal region, described as sharp, jabbing, burning, or like electric shocks. At least 20 attacks must happen for a diagnosis of these conditions.
These headaches are often accompanied by at least one other symptom, which include:
- Redness of the eye
- Stuffy or runny nose
- Tearing
- Swelling of the eyelid
- Increased sweating on the face or neck
- Redness or discomfort in the ear
- Narrowing or drooping of the pupil.
Similar to Trigeminal Neuralgia, SUNCT and SUNA can be triggered by irritations like chewing, touching the face, brushing teeth, changes in temperature, or even loud noises. These conditions are different from Trigeminal Neuralgia because they exhibit evidence of cranial nerve symptoms. While migraines and other types of facial pain can cause some similar symptoms, they are not as pronounced as those associated with SUNCT or SUNA.
Testing for Short-Lasting Unilateral Neuralgiform Headache
SUNCT/SUNA are conditions that can be due to an underlying problem in certain areas of the brain, such as the pituitary gland or the back part of the brain (posterior fossa). Because of this, it’s important to do a brain MRI with a focus on the pituitary gland and run some blood tests to check how well the pituitary gland is functioning. These steps are key in understanding and diagnosing conditions like SUNCT/SUNA.
However, diagnosing these conditions primarily depends on your symptoms. Medical professionals follow established guidelines outlined by the International Classification of Headache Disorders. This means observing the types and patterns of your headaches. For a diagnosis, you would typically need to have experienced:
A) At least 20 headaches that meet the below criteria
B) Headaches that are moderately intense, occur around the temple or eye area on one side, and last from 1 to 600 seconds.
C) Also, during a headache, you should have at least one of these symptoms on the same side of your head where the pain is:
1. Tearing and redness of the eyes
2. A stuffy or runny nose
3. Swelling of the eyelid
4. Sweating around the head and neck
5. Redness of the head and neck
6. A feeling of fullness and discomfort in the ear
7. A drooping eyelid or very small (pinpoint) pupil
D) You must experience at least one attack every day when the disease is active.
These headaches tend to occur quite often when the condition is active. It has also been observed that SUNCT and SUNA may be linked to certain seasons.
Treatment Options for Short-Lasting Unilateral Neuralgiform Headache
There are three types of treatment for trigeminal autonomic cephalalgia, which include specific conditions such as SUNCT (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing) and SUNA (Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic features): quick relief treatments, preventative treatments, and bridge therapy, which is used to manage symptoms until preventative treatments take effect.
Short-term Prevention
A trial run of intravenous lidocaine, which is a local anesthetic or numbing medication, reported some relief in patients suffering from SUNCT and SUNA. For safety, this treatment requires heart and blood pressure monitoring, and therefore, must be given in a critical care setting, such as an intensive care unit (ICU) or a similar monitored inpatient setting.
Long-term Prevention
Many studies show good results for lamotrigine, an anticonvulsant medication, as first-line therapy for these conditions. Up to 80% of patients reported improvement. Other drugs that can be used for long-term prevention include carbamazepine and oxcarbazepine, medications used to control seizures, and topiramate and gabapentin, two other types of anticonvulsant medication.
Non-drug Treatments
Non-drug treatments such as nerve blocks and nerve stimulation have also shown benefits. Specifically, blocking the greater occipital nerve and the infra and supraorbital nerves, which are located around the eyes, has helped some patients. Stimulating the occipital nerve, located at the back of the head, has also produced good results.
The response to intravenous lidocaine and the lack of response to indomethacin, an anti-inflammatory medication, are useful in both diagnosing and treating these conditions.
What else can Short-Lasting Unilateral Neuralgiform Headache be?
There are several medical conditions that could display similar symptoms to autonomic cephalalgias, a type of severe headache. These could include:
- Cluster headache
- Paroxysmal hemicrania (a rare type of headache)
- Idiopathic chronic facial pain syndrome (unexplained long-term facial pain)
- Atypical migraine (an unusual type of migraine)
- Hemicrania continua (a headache that occurs on one side of the head)
- Trigeminal neuralgia (facial pain due to a nerve disorder)
- Retinal migraine headache (migraines associated with visual disturbances)
What to expect with Short-Lasting Unilateral Neuralgiform Headache
SUNCT, being a rare condition, has an unclear natural history. This means we don’t fully understand how the condition progresses over time. Some patients with SUNCT and SUNA, however, have been living with it for up to 46 years. It’s important to note that this disease is not associated with increased death rate and is not fatal.
The good news is that the prognosis, or the likely course of the disease, is getting better. This is because more treatment options are becoming available.
Possible Complications When Diagnosed with Short-Lasting Unilateral Neuralgiform Headache
SUNCT syndrome doesn’t lead to any lasting brain or nervous system problems. Between episodes, most people seem to be perfectly normal. However, the social and financial impact of SUNCT is still unclear.
Main Points:
- SUNCT syndrome doesn’t cause long-term neurological complications
- Most patients behave normally when not experiencing an episode
- The social and financial implications are still unknown
Preventing Short-Lasting Unilateral Neuralgiform Headache
SUNCT syndrome, a type of headache, has no known risk factors or ways to prevent it. Some people suffering from SUNCT syndrome might have ongoing mild pain due to factors related to migraines and they might be using too much pain medicine. Therefore, it’s important for patients to understand the possible harmful effects of taking too many pain medicines. Taking these medicines more than needed can make the condition worse by increasing the number of attack episodes and making them more severe.
