What is a Cluster Headache?

Jul 28

A cluster headache is a rare but debilitating condition that is quite unlike other headache presentations. They arrive without warning, and present as clusters of brief, severe stabbing pains around or behind one eye. They are often described as “icepick” headaches.

During a cluster episode, it is not uncommon to experience 3-4 of these headaches per day for weeks or months at a time, followed by dormant periods with no headaches for months or years. Unfortunately, attacks of cluster headaches always seem to return at some point.

How Common are Cluster Headaches?

Cluster headaches are relatively rare, affecting approximately 1 in every 1,000 people. They are much more common in males. There does appear to be a genetic component to cluster headaches, with first degree relatives having a 5-18 times higher risk of developing cluster headaches compared with the general population (1).

What Causes Cluster Headaches?

While the jury is still out on the definitive mechanism of cluster headaches, the pathophysiology appears to involve abnormal activation of the trigeminovascular complex, a collection of brainstem neurons and associated blood vessels.

The trigeminal nerve receives pain signals from the head, face, brain blood vessels, and upper cervical spine. In cluster headaches there is abnormal activation of the V1 distribution of the trigeminal nerve, the area responsible for pain around and behind the eyes. The cause of this trigeminovascular complex activation is poorly understood (2).

Once a cluster begins, drinking alcohol appears to provoke these headaches. Most people that suffer from cluster headaches have been smokers, however once cluster headaches begin quitting smoking does not seem to stop them (1).

Unique to cluster headaches is activation of the trigeminal-autonomic pathway, which leads to activation of the parasympathetic autonomic nervous system. This results in symptoms such as eyes watering, sinus congestion, and facial sweating (2).

What are the Symptoms of Cluster Headaches?

Cluster headaches present with debilitating episodes of intense and sharp pain around or behind the eye. This pain can radiate throughout that side of the face, and into the head and neck. he affected side of the face can also experience excessive tearing, swelling, pale skin, perspiration, and drooping of the eyelid. Nausea, light sensitivity, and other symptoms associated with migraine can also accompany cluster headaches (14).

How are Cluster Headaches Diagnosed?

In order to receive a cluster headache diagnosis, you must have at least five attacks including the following:

severe or very severe unilateral orbital supraorbital, or temporal pain lasting 15-180 minutes
lacrimation of the eyes
nasal congestion and runny nose
eyelid swelling
forehead and facial sweating and flushing
sensation of fullness in the ear
constricted pupil and drooping eyelid
a sense of restlessness or agitation
attacks have a frequency between one every other day and 8x/day for more than half of the time the disorder is active.

There are also Episodic Cluster Headaches, where attacks occur in periods lasting from 7 days to 1 year, separated by pain-free periods lasting at least 3 months.

The worst cases are chronic cluster headaches, where attacks occur for greater than 1 year without remission.

What are the Consequences of Cluster Headaches?

Cluster headaches impose a major burden on the lives of those that suffer from them. There are negative impacts on employment status, as the pain is so severe to make work impossible during attacks (3). Patients tend to experience higher levels of depression and anxiety. They also demonstrate a tendency to struggle with substance abuse disorders (4).

What Happens in the Brain with Cluster Headaches?

Pain inputs from the head, face, upper cervical spine, meninges, and blood vessels in the brain are conducted into the brainstem through the trigeminal nerve. The trigeminovascular pathway consists of neurons innervating the cerebral blood vessels and meninges, which have their cell bodies in the trigeminal ganglion.

There are neuronal connections with the cerebral blood vessels and dura mater and the brainstem. These fibers run to the trigeminocervical complex (TCC), which also receives pain inputs from the upper cervical spine. the meninges of the brain, the temporomandibular joints, and the skin of the head and face.

The TCC sends pain signals up to the thalamus, resulting in activation of brain structures involved in pain processing.

The cell bodies of the trigeminal ganglion contain several chemicals that cause blood vessels to dilate, including CGRP. This is elevated during cluster headache attacks as a result of trigeminovascular pathway activation (16).

The autonomic symptoms seen of cluster headache arise from the reflex activation of the trigeminal-autonomic reflex pathway, resulting in dilatation of blood vessels and activation of the parasympathetic nervous system. Clinically, this presents as watery, weepy eyes, runny nose, and nasal congestion.

Cluster headache bouts occur at the same time each year, particularly during the change in clocks to daylight savings in seasons. This is probably linked with photoperiodism, otherwise known as length of daylight, and involves brain structures including the hypothalamus and suprachiasmatic nucleus.

Melatonin is an important hormone involved in sleep. It is produced in the pineal gland. Cycles of melatonin release are involved in sleep-wake cycles. The main stimulus for the daily cyclic production of melatonin is light intensity, with melatonin secretion decreasing in the light and increasing in the dark. For episodic cluster headache patients, melatonin secretion has been found to be lower during attacks, resulting in sleep disorders associated with the headaches (5).

There appears to be a mechanism involving poor utilization of oxygen within fibers from the parasympathetic system to blood vessels in the brain. Oxygen has been shown to affect these nerve fibers, and supplemental oxygen can decrease the firing of the trigeminal vascular and autonomic complexes (6).

How are Cluster Headaches Usually Treated?

There are several traditional approaches to treatment of cluster headaches. These may involve medications known as Triptans. Supplemental oxygen can be used to decrease the pain of a cluster headache. In circumstances where these are ineffective, more invasive therapies may be employed including nerve block injections, and in some cases, surgery (15).

How is the NeuroRescue Program Different?

Neuromodulation strategies have started to emerge as useful treatment for cluster headaches. These can involve electrical stimulation of the vagus or supraorbital nerves, or using Transcranial Magnetic Stimulation (TMS) to disrupt the electrical impulses in the brain that trigger cluster headaches (7).

We use several of these neuromodulation strategies, and many others, in our NeuroRescue program treatment for our cluster headache patients.

As we have seen, abnormal activation of the trigeminovascular system is believed to be one of the driving factors behind cluster headaches. In your NeuroRescue program, we utilize gentle stimulation of the supraorbital nerve and trigeminal nerve branches to help modulate blood flow and neurotransmitter release in the appropriate regions of the brain.

This therapy practice is supported through the 2018 study in the Journal of Headache and Pain. The study describes the connection behind cluster headaches and the trigeminovascular system (8). The trigeminovascular system represents one possible common pathophysiological pathway and network in both migraines and cluster headaches. Many of the strategies shown to be effective in reducing migraine symptoms do so by modulating the trigeminovascular system, and we have seen them be effective in reducing the frequency and intensity of cluster headaches as well. These include transcranial direct current stimulation (11), vestibular rehabilitation (12), and photobiomodulation strategies using low-level laser (13). All of these have been shown to decrease frequency and intensity of migraine headaches. A 2016 study in the journal Practical Neurology takes a broad view of non-invasive neurostimulation for the treatment of episodic and chronic headaches, and shows them to be very beneficial forms of therapy (9).

We also utilize transcutaneous vagus nerve stimulation (tVNS) to help minimize cluster headache symptoms. The vagus nerve is a major component of the parasympathetic nervous system, which is the part of the autonomic nervous system that allows things to relax. Stress responses decrease, skeletal muscle relaxes, and blood vessels dilate, allowing proper blood flow to the areas that need it, reducing the likelihood of an onset of Cluster Headaches. Research has demonstrated very encouraging responses to tVNS in episodic and chronic cluster headaches (10).

We have also found hyperbaric oxygen therapy to be beneficial for cluster headache prevention. Hyperbaric therapy has been shown to be helpful to attenuate cluster episodes (13).

We use these strategies and many others in our approach to treatment of cluster headaches. We design your unique NeuroRescue program to address every structural and neurological factor involved in your headaches. We also evaluate the influences of metabolism, inflammation, and other chemical factors that may be promoting your pain. We evaluate the function of all of the muscles, joints, ligaments, and nerves in your cervical spine and jaw, which are major pain inputs to the trigeminovascular system. We assess the neurological mechanisms that control their function, and the central brain and brainstem systems that normally function to shut off pain. We combine all of this information into a comprehensive protocol that does not just help you mask your headache symptoms. Instead, we get to the unique root of your problem, address it at a foundational level, and help you rebuild the functional integration necessary for your headaches to finally be resolved.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain that have been impacted by your condition. We begin by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your ability to balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your brain are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your brain. It works to improve energy, endurance, and functional capacity within your fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to return you to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with cluster headaches can be challenging, but there is hope for recovery and remission. To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.