Cluster headache

Diagnosis  

The diagnosis of a cluster headache usually involves a comprehensive examination, which may require providing details of the attacks, the level of pain, headache location, intensity, frequency, duration, and accompanying symptoms. 

Cluster headaches exhibit a distinctive pain quality and attack pattern. To determine the type and cause, tests and procedures may be necessary, such as: 

• Neurological examination: This exam will check how well the brain works using a variety of tests, including assessing the senses, reflexes, and nerves. This may assist in detecting physical indicators of a neurological illness. In most cluster headache sufferers, the exam is normal. 
• Imaging tests: These tests may be recommended to rule out more dangerous causes of head pain, such as a tumor or aneurysm. This is usually done if one has uncommon or challenging headaches or an abnormal neurological exam. Additional tests may include: 
• Magnetic Resonance Imaging (MRI): This procedure generates comprehensive images of internal body structures such as blood vessels and the brain, utilizing a powerful magnet, radio waves, and computer technology.
• Computed Tomography (CT) scan: A CT scan is a painless and noninvasive procedure that provides detailed images of the brain using a series of X-rays and a computer.

Treatment  

Cluster headaches currently have no known cure. Treatment aims to reduce pain severity, shorten headache duration, and prevent attacks. Due to the rapid onset and short duration of these headaches, prompt–acting medications are necessary. Certain acute medications can offer rapid pain relief. The following therapies are highly effective for both immediate and preventive cluster headache treatment. 

Acute treatments

Fast–acting treatments prescribed by your doctor include: 

• Oxygen: Inhaling pure oxygen through a mask offers rapid relief, typically within 15 minutes. Carrying oxygen equipment might be inconvenient. 
• Triptans: Injectable sumatriptan and nasal spray zolmitriptan, used for migraines, are effective for acute cluster headache. Sumatriptan injections are usually preferred. 

• Octreotide: An injectable synthetic version of somatostatin, octreotide provides relief for some, though it’s slower and less effective than triptans. 
• Local anesthetics: Intranasal lidocaine, a numbing agent, can help with cluster headache pain in some cases. 
• Dihydroergotamine: Injectable dihydroergotamine may relieve cluster headache pain, but the inhaled form isn’t proven effective.

Preventive treatments

Preventive treatments for cluster headaches focus on suppressing attacks: 

• Calcium channel blockers: Verapamil is commonly used to prevent cluster headaches, especially in chronic cases. It might be combined with other drugs and may require longer–term use. Side effects include constipation, nausea, fatigue, ankle swelling, and low blood pressure. 
• Corticosteroids: Fast–acting drugs like prednisone can help those with recent onset or brief cluster periods. Due to serious side effects, they’re unsuitable for prolonged use. 
• Lithium carbonate: Used for bipolar disorder, it’s an option if other treatments fail for chronic cluster headache. Side effects like tremors can be managed through dosage adjustments, with regular blood checks. 
• Noninvasive vagus nerve stimulation (VNS): Delivering electrical stimulation to the vagus nerve through the skin with a handheld controller may reduce cluster headache frequency, although more research is needed. 
• Nerve block: Injecting anesthetic and corticosteroids around the occipital nerve at the back of the head can temporarily improve chronic cluster headaches, often used alongside verapamil. 
• Other options: Anti–seizure medications like topiramate might be used for prevention. 

Surgery 

In rare cases, surgery might be recommended for chronic cluster headache sufferers who don’t respond well to aggressive treatment or cannot tolerate medications or their side effects. 

• Sphenopalatine ganglion stimulation: This involves implanting a neurostimulator controlled by a handheld device. Some research suggests it can provide quick pain relief and reduce headache frequency, but further studies are required. 
• Occipital nerve stimulation: Implanting an electrode near one or both occipital nerves has shown potential benefits in small studies. 
• Nerve pathway–damaging procedures: Some surgical methods target nerve pathways believed to cause pain, like the trigeminal nerve around the eye. However, the long–term effectiveness of these procedures is debated, and complications like muscle weakness or sensory loss make them rarely considered. 

Possible future treatments 

Researchers are investigating potential treatments for cluster headaches: 

• Occipital nerve stimulation: Electrodes are implanted in the back of the head, connected to a generator. These electrodes stimulate the occipital nerve area, potentially blocking pain signals. Some small studies showed pain reduction and headache frequency decrease in chronic cluster headache patients.
• Deep brain stimulation: This unproven approach is considered for cluster headaches resistant to other treatments. An electrode is placed in the hypothalamus, linked to a generator altering brain impulses to alleviate pain. The procedure carries risks due to its deep brain placement, including infection or hemorrhage. It may help those with severe, treatment-resistant chronic cluster headaches.