What are cluster headaches?
Cluster headaches, much like migraines, are a primary headache disorder. They belong to a group of headache disorders collectively referred to as the Trigeminal Autonomic Cephalgias (TAC) and are the most common of them. These headaches are unilateral and associated with autonomic symptoms.
A patient is said to have cluster headaches if they’ve experienced at least five lifetime attacks characterized by severe, unilateral, orbital, or temporal pain lasting between 15 and 180 minutes when untreated. The headache must be associated with either a sense of restlessness/agitation or autonomic symptoms on the side of the headache or both. Autonomic symptoms include runny nose, congestion, tearing, blood shot eye, facial swelling, ear pain, drooping eyelid, or changes in the size of the pupil. Cluster headaches may sometimes be associated with migraine type symptoms such as nausea and sensitivity to sound and light. Furthermore, cluster headaches tend to follow a rhythm where patients experience clusters under certain conditions or certain times of the year.
Who gets cluster headaches?
The prevalence of cluster headaches in the general population is less than 1%. Depending on which population is examined, these headaches affect males twice and up to six times as often as females. The typical age of onset for cluster headaches is 20-40 years of age. Cluster headaches do appear to have a genetic predisposition. In fact, having a first degree relative with cluster headaches can increase the odds of developing cluster headaches up to 39 fold and up to 8 fold in the case of a second degree relative.
What are the risk factors for cluster headaches?
Apart from genetic predisposition, there are several risk factors for triggering cluster headaches. These include but are not limited to alcohol consumption, high altitudes, smoking cigarettes, and use of Nitroglycerin.
How are cluster headaches classified?
The classification of cluster headaches primarily rests on pattern of symptoms. If a patient experiences two or more cluster attacks over the span of seven days to a year with at least three months of symptom remission between attacks they’re said to have episodic cluster headaches. If they do not experience any periods of remission, or the period of remission is shorter than three months, that is referred to as chronic cluster headaches.
How are cluster headaches diagnosed and treated?
The diagnosis of cluster headaches is primarily clinical. However, a Neurologist will often order a brain MRI study to ensure there are no secondary causes for the cluster headaches which include but are not limited to stroke, tumor, infection, and vascular abnormality.
Cluster headaches are treated with two types of medications. Abortive treatments are medications prescribed and used during an active cluster attack with the hopes to shorten its duration and reduce its severity. Prophylactic treatments are medications or injections taken regularly with the hopes to reduce the frequency of cluster attacks as well as their intensity/duration.
There are a handful of acute abortive therapies for cluster headaches the most common being Triptan type drugs (Sumatriptan and Zolmitriptan). These powerful vasoconstrictors can be administered orally, subcutaneously, and intranasally. Of note, patients with cluster headaches often respond well to treatment with Oxygen therapy by nasal canula for 15 minutes at 12 liters/minute. A trial of oxygen is recommended during an acute cluster attack as it can be both diagnostic and therapeutic.
Patients experiencing frequent and disabling headache attacks are often prescribed medications with the intent to prevent attacks before they even start. Commonly prescribed medications include Topiramate (a medication use for epilepsy and migraines as well), Verapamil (a medication used for hypertension and migraines as well), Lithium (a medication used for bipolar disorder as well), steroids (medications often used for inflammatory diseases), and melatonin (a supplement often used as a sleep aid).
In patients who have poor response to oral therapy, two injections can be employed. Occipital nerve block is an in office procedure that involves the administration of steroids and anesthetic to the occipital nerves in the back of the head. Alternatively, use of a targeted therapy that blocks a key molecular signal in the pain pathway of cluster headaches is now possible. This is called Emgality, a subcutaneous injection once monthly.
If you experience headaches that might be cluster headaches that are disabling, please consider making an appointment at the Iberia Medical Center Neurology clinic.
Dr. Oliver Achi, Neurologist, Medical Director of Neurology Services, Iberia Medical Center
Appointments with Dr. Achi: 337.374.7242