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Cluster Headache Update

Introduction

Cluster headache is considered one of the most severe headache syndromes. Treatment of cluster headache is sometimes challenging and sufferers often need to see specialists to get effective therapy. Our knowledge about the underlying cause of cluster headache is expanding and with this has come newer treatment options (medicinal and surgical).

The correct diagnosis is often delayed

A recent study determined that it takes an average of 6.6 years for a cluster patient to be diagnosed correctly by the medical profession. It is important to get a correct diagnosis since treatment of cluster differs from that of other headache conditions.

Symptoms

Patients with cluster headache usually experience severe one-sided headaches in or around the eye that will last from 30 to 180 minutes without treatment. The headache is commonly associated with eye tearing, eyelid drooping, eye redness, or nasal congestion or discharge on the side of the head pain. During a cluster attack, patients cannot and do not want to remain still.  A cluster patient will typically pace the floor or even bang their fist against the wall.

Cluster headache patients will usually have between 1 and 8 individual attacks each day. The attacks may occur any time day or night but are common during the nighttime.  They may be associated with the dream state of sleep or REM sleep. (See related article, Cluster Headaches and Sleep.)

Cluster patients have cycles or clusters of pain, thus the name; they will have daily headaches for periods of time and then experience remission periods when the headaches do not occur.

What causes cluster headaches?

The exact cause of cluster headache is still unknown. What is known is that cluster headache evolves from activation of the trigeminal nerve and autonomic nervous system with principal involvement of the hypothalamus in the shenopalatine ganglion.  When the trigeminal nerve is activated it causes pain in and around the eye. When the autonomic nervous system is activated it produces the associated symptoms that come along with a cluster headache (eye tearing, nasal discharge, etc.).  We believe that the trigeminal nerve and autonomic nervous system are turned on by an area in the brain called the hypothalamus, the part of the nervous system that regulates a person's sleep/wake cycle. The hypothalamus is likely the generator of cluster headaches and has recently become a new treatment target for difficult to treat cluster patients.