Headache, cluster

Cluster Headache

Cluster headache is a neurological disorder characterized by recurrent, severe headaches on one side of the head, typically around the eye. These headaches are often accompanied by autonomic symptoms such as tearing, nasal congestion, and eyelid swelling. Cluster headaches are known for their extreme intensity and are sometimes referred to as "suicide headaches" due to the excruciating pain they cause.

Clinical Features

Cluster headaches are part of a group of headache disorders known as trigeminal autonomic cephalalgias. They are distinguished by their periodicity and the following clinical features:

• Unilateral Pain: The pain is strictly one-sided and usually occurs around the eye, temple, or forehead.
• Severe Intensity: The pain is described as burning, piercing, or throbbing and is considered one of the most painful conditions known.
• Short Duration: Each headache attack lasts between 15 minutes and 3 hours.
• Cluster Periods: Attacks occur in clusters, typically lasting weeks to months, followed by remission periods.
• Autonomic Symptoms: These include tearing (lacrimation), nasal congestion, rhinorrhea, eyelid edema, and facial sweating on the affected side.

Epidemiology

Cluster headaches are relatively rare, affecting about 0.1% of the population. They are more common in males than females, with a male-to-female ratio of approximately 3:1. The typical age of onset is between 20 and 40 years.

Pathophysiology

The exact cause of cluster headaches is not fully understood, but they are believed to involve the hypothalamus, which regulates circadian rhythms. The trigeminal nerve, which is responsible for facial sensation, is also implicated in the pain pathway. The autonomic symptoms are thought to result from activation of the parasympathetic nervous system.

Diagnosis

Diagnosis of cluster headache is primarily clinical, based on the characteristic symptoms and headache pattern. The International Classification of Headache Disorders (ICHD) provides criteria for diagnosis. Neuroimaging may be used to rule out other causes of headache.

Treatment

Treatment of cluster headaches involves both acute and preventive strategies:

• Acute Treatment: High-flow oxygen therapy and subcutaneous sumatriptan are effective in aborting attacks.
• Preventive Treatment: Verapamil is the first-line preventive medication. Other options include lithium, topiramate, and corticosteroids.

Prognosis

Cluster headaches can be debilitating, but with appropriate treatment, many patients can achieve significant relief. The condition may go into remission for extended periods, but recurrences are common.

Also see

• Migraine
• Tension-type headache
• Trigeminal neuralgia
• Hypothalamus