 Cluster Headache Update
Frequently
Asked Questions
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Update on Cluster Headaches (by Todd
D. Rozen, MD)
Introduction
Cluster headache is considered the most severe headache syndrome known to humans.
Treatment of cluster is difficult and sufferers often need to see headache specialists
to get proper therapy. Our knowledge about the underlying cause of cluster headache
is expanding and with this has come newer treatment options (medicinal and surgical).
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An alarming trend
Even though cluster headache has a presentation that is distinct from other primary headache conditions such as migraine and tension-type headache, cluster patients
often do not receive the correct diagnosis. 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.
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Distinguishing cluster headaches
Patients with cluster headache usually experience severe one-sided headaches in
or around the eye that will last from 15 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 because doing so seems to worsen the pain.
Subsequently, a cluster patient will typically pace the floor or even bang their
head against the wall to distract and attempt to alleviate their pain.
Cluster patients will usually have between 1 and 3 individual headache attacks per
day. The headaches often start in the first dream phase of sleep (REM sleep) causing
the cluster patient to awaken with a severe headache 60 to 90 minutes after falling
asleep. (See related article, Cluster Headaches
and Sleep.) Cluster patients have cycles or clusters of pain; they will
have daily headaches for periods of time, and then experience remission periods
where the headaches go away for weeks to months at a time.
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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.
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.
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Treating cluster headaches
All cluster headache patients require treatment. Other headache syndromes can sometimes
be managed non-medicinally but in regard to cluster headache, medication, sometimes
even multiple medications at one time, are indicated.
Cluster headache treatment can be divided into three classes: 1) abortive or acute
therapy (treatment given at the time of an attack); 2) transitional therapy, which
can be considered intermittent or short-term preventive treatment; 3) preventive
therapy which consists of daily medication aimed at decreasing the frequency, intensity,
and duration of cluster headache attacks.
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Abortive therapy
The goal of abortive therapy for cluster headache is fast, effective and consistent
relief.
Because a cluster headache is relatively short in duration, the abortives should work within 10-15 minutes to be considered adequate therapy.
Sumatriptan
- Has been effective in cluster headache. A doctor must be consulted before use
- Injectable — most effective, often giving complete relief within 15 minutes after
injection
- Nasal spray formulation is not as effective as injectable
- Oral tablets are not effective in cluster due to the 1-2 hours it takes for the
medication to produce relief; the individual cluster headache is over by then
Oxygen
- Excellent abortive for cluster
- Shown to work in up to 70% of cluster patients
- Safe and easy to use
- Typical dosing — 100% oxygen given
via face mask (nasal cannula not effective) at 7-10 liters/minute for 20 minutes. Pain relief typically occurs after 10-20
minutes
Zolmitriptan
- First oral triptan effective in cluster
- Doses for cluster are higher than that used for migraine
- Response — not as good as with oxygen therapy or injectable sumatriptan but an option
in patients who cannot tolerate injections and have either failed oxygen therapy
or find it difficult to use in certain situations
Dihydroergotamine (DHE)
- Available in injectable and nasal spray preparations
- Most cluster patients experience relief within 15 minutes when DHE is given intravenously;
relief is slower with intramuscular or subcutaneous formulations
Olanzapine
- Effective and safe to use in patients unable to take sumatriptan or oxygen
- In one study, typically alleviated pain within 20 minutes after oral treatment
- May induce sleepiness, but most cluster patients prefer sedation to agitation
- Needs further study to ascertain effective dose
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Transitional therapy
Transitional therapy is a short-term preventive treatment that bridges the time
between cluster diagnosis and when a true preventive agent becomes effective. Transitional
preventives are started at the same time the true preventive is begun (see below).
The transitional preventive should provide the cluster patient with almost immediate
pain relief and allow the patient to be headache-free or near headache-free while
the maintenance preventive medication is being tapered up to an effective level.
When the transitional agent is tapered off (typically in one to two weeks) the maintenance
preventive will have kicked in, thus the patient will have no gap in headache prevention.
Steroids (e.g., prednisone, dexamethasone)
- Best transitional therapy for cluster
- Typically effective within 24 to 48 hours of administration
- Usually discontinued after 8-10 days of treatment when main preventive agent has
started to become effective
- Long-term use not recommended because of very severe side effects with extended
usage
Dihydroergotamine (DHE)
- Can be used as either abortive or transitional therapy
- Best given intravenously in a hospital or outpatient infusion setting
- Typically relieves pain in 1-2 days of repetitive treatment; pain may not return
for days to months which allows time for a preventive(s) to become effective
Naratriptan
- Dose — 7 days at 2.5 mg twice daily while transitioning to a preventive program
- Drawback — if an attack occurs when a cluster patient is on naratriptan, sumatriptan
cannot be used as an abortive; however, oxygen therapy can be used in this case
Occipital nerve blockade
- Injection of anesthetic agent and a small dose of steroid into the region of the
greater occipital nerve (base of skull) can provide relief averaging 13 days
- Can be performed in an outpatient setting with minimal discomfort for the patient
- Comparable to getting Novocain at the dentist
- More studies are necessary to establish this as a legitimate transitional treatment
for cluster headache
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Preventive therapy
The main goal of cluster headache preventive therapy is to make a patient cluster-free
on preventives even though they are still in a cluster cycle. Preventive agents
are absolutely necessary in cluster headache. The maintenance preventive should
be started at the time a transitional agent is given. Sometimes very large dosages,
much higher than that suggested in the literature, are necessary when treating cluster
headache. A well-recognized trait of cluster patients is that they can tolerate
medications much better than non-cluster patients. It is not uncommon for cluster
patients to require several preventive medications at once to get better results.
Most physicians treating cluster will increase the dosages of the preventive agents
very quickly to get a desired response.
Preventive medications are only used while the patient is in cycle and then are
tapered off once a cluster period has ended. If a patient decides to remain on a
preventive agent even after their cluster cycle has ended, it does not appear to
prevent a subsequent cluster period from starting.
Verapamil
- May be best first-line therapy for both episodic and chronic cluster
- Can be used in conjunction with sumatriptan, ergotamine, corticosteroids, and other
preventive agents
- Non-sustained-release formulation appears to work better than sustained release
preparation
- If more than 480 mg a day is needed, an electrocardiogram (EKG) is necessary before
each dose change thereafter to guard against heart block
Topiramate
- Newer anti-seizure medication that appears to be effective in both migraine and
cluster headache
- Effective for both episodic and chronic cluster sufferers
- Topiramate in fairly low dosages can turn off cluster headaches on average within
1-2 weeks after starting the medication
Lithium carbonate
- Effective but narrow therapeutic window and high side effect profile make it less
desirable than newer preventives
- Effective in both episodic and chronic cluster headaches
- Serum lithium concentrations should be checked during initial treatment stages to
guard against toxicity; renal and thyroid functions need to be checked prior to starting lithium
Methysergide
- Role as a preventive is limited since it can potentially cause fibrotic complications
- Patients should not remain on methysergide more than 6 months at a time
Valproic acid
- Similar efficacy in both episodic and chronic cluster treatment
- May be more effective in patients whose cluster headaches are accompanied by migraine-type
features, such as nausea, vomiting, photophobia, and phonophobia
Naratriptan
- Remains effective in the body for a longer period of time than other available triptans
- Drawback — if breakthrough attack occurs, sumatriptan (another triptan) cannot be
used as abortive; however, oxygen therapy can be used in this case
- Caution is urged when using a daily triptan in a patient who smokes
Melatonin
- Natural sleep hormone that is not produced in normal amounts by cluster patients.
This may be an inciting factor in cluster headaches that occur in the night
- Can be used along with other cluster medications; may be able to use a lower dose of other medications when used with melatonin
- Trials have shown that fairly large doses can stop cluster attacks. Suggested dose
is 6 to 9 mg at bedtime
- Purchased over-the-counter and appears to have minimal side effects. No current
governmental regulation; therefore, if one brand does not help, trying another brand
of melatonin may be worthwhile
- Should consult physician before starting
Other possible preventives
- A small number of case reports suggest the use of transdermal clonidine, Baclofen,
tizanidine, nasal capsaicin, and Thorazine for cluster prevention
- These preventives should only be tried when other well-recognized preventives have
failed and if there is no contraindication for their use
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New types of surgical treatment for
cluster headache
Surgical treatment for cluster headache should only be considered after a patient
has exhausted all medicinal options. In some instances the surgery can produce side
effects that are worse than the cluster headaches themselves. Surgical treatments
that have been utilized for the treatment of cluster headaches and have recently
been reported in the headache literature include:
Radiofrequency thermocoagulation
Radiofrequency thermocoagulation is the most commonly used surgical technique for
cluster and it provides the best option for pain relief. The results of radiofrequency
rhizotomies in cluster are encouraging although there are only a handful of studies
in the literature. Overall with radiofrequency about 50% of patients have done very
well, 20% fair to good and about 30% fail the procedure. Adverse events with radiofrequency
include moderate to severe facial dysesthesias, corneal sensory loss and anesthesia
dolorosa. Other less common but devastating side effects include intracranial hemorrhage,
stroke, infection, and motor weakness which typically resolves over 1 to 6 months.
Glycerol trigeminal rhizotomy
This is an alternative therapy to radiofrequency (RF). Sterile glycerol acts as
a mild denervating agent when injected into the gasserian ganglion. Overall this
technique may have the same initial pain free rates as RF but has much higher recurrence
rates. Distinct advantages over RF are that certain side effects occur less frequently.
Trigeminal nerve root section
This procedure involves cutting (lesioning) the trigeminal nerve at the root entry
zone. A recent study documented results in seventeen chronic cluster headache patients.
The authors stated that trigeminal nerve section is an effective treatment with
acceptable morbidity for patients with medically refractory chronic cluster headache
and that total nerve section is associated with a better surgical outcome.
Microvascular decompression
Microvascular decompression is a very invasive technique involving craniectomy.
The goal of the procedure is to try to restore normal anatomy by removing a vascular
loop compressing a nerve. The role of microvascular decompression in cluster is
not as well defined as in trigeminal neuralgia. Microvascular decompression of the
trigeminal nerve with or without microvascular decompression or section of the nervus
intermedius was recently reported to be effective in chronic cluster headache. However,
long-term follow-up saw the success rate decrease to 46.6%. Repeat procedures were
not beneficial.
Gamma knife radiosurgery
Gamma knife is a form of neurosurgery in which the trigeminal nerve (the nerve that
causes cluster headache) is injured by a beam of radiation. (See Figure
1) This procedure can be done as an outpatient and typically only takes
several hours to complete. At present only a handful of medical institutions have
gamma knife capabilities.
Only one study has looked at the use of gamma knife in cluster and the results were
promising. What is attractive about this technique is that it can be done in an
outpatient setting and appears to have a low complication rate. However, no one
yet knows what the true delayed complications of gamma knife are, especially in
young patients. The impression is that it works initially but there are high relapse
rates (return of cluster pain) bringing to question if this treatment strategy is
indeed useful in cluster. More studies are necessary.
Deep brain / hypothalamic stimulation
A truly investigational surgical treatment for cluster headache has been carried
out by an Italian group. Based upon studies suggesting the hypothalamus as a generator
of cluster headache, a stimulator was placed into the hypothalamus of six study
patients with refractory cluster headache to see if stimulating the hypothalamus
could stop a patient from having cluster headaches. (See Figure 1)
The researchers found that once the stimulator was turned on the cluster headaches
started to disappear. In some patients pain relief was immediate while in others
it took up to four months to have the patient become pain-free. So far the patients
have had no side effects with the stimulator. This treatment is completely experimental
at present and is not available anywhere in the United States because it needs to
be better studied for safety issues. What this study does represent is that a better
understanding of what causes cluster headache can lead to better treatment options
for patients.
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Conclusion
Encouraging times are ahead for sufferers of cluster headache. We are continually
learning more about what causes cluster and new treatments are arising all the time.
It is important for cluster patients to realize that most physicians understand
how severe a patient's pain really is and will go to great effort to provide safe
and effective treatment.
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Figure 1
Anatomy of cluster headache. The hypothalamus is activated and this turns on the
trigeminal nerve and autonomic systems. The trigeminal nerve activation leads to
pain in and around the eye. The autonomic system activation leads to eye tearing
and nasal discharge that occur during a cluster headache. For surgical treatment
gamma knife radiosurgery injures the trigeminal nerve. In deep brain stimulation
a stimulator is placed into the hypothalamus.
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