“Histamine desensitization treatment
has been done at a number of specialty clinics,
such as the Diamond Headache Clinic in
Chicago, for more than 40 years…
The treatment is well-tolerated
and about 70 percent of patients with
chronic cluster headache who have not
responded to previous therapy do benefit
from this treatment modality.”
be induced by alcohol, nitroglycerine, or histamine.
Many patients voluntarily abstain from drinking alcohol
during the cycle until they are in remission when they
can consume alcohol without provoking the attack. Low
oxygen saturation, especially as a result of sleep apnea or
from being in higher altitudes, may trigger a cluster attack
during the cycle. In contrast to migraine, food, hormonal
changes, and weather changes do not play a major role as
cluster attack triggers.
The cause and the mechanism of cluster headache are very
complex and not well understood. All scanning, including
head CT and brain MRI, are always negative and do not
elucidate the cause. However, studies using MRA (an MRI
of the intracranial blood vessels) have revealed dilatation –
swelling of a short segment of artery behind the eye on the
same side of pain. Furthermore, PET scans that measure
important bodily functions, such as blood flow, oxygen use,
and sugar (glucose) metabolism, demonstrated activation
of a part of the hypothalamus on the same side of pain. The
hypothalamus is a very important part of the brain, just
above the brainstem, that controls the endocrine system,
hormonal cycles, autonomic system, and “biological clock.”
That result indicates that the hypothalamus is a generator
or modulator of the mechanism of cluster headache.
The autonomic symptoms, hormonal fluctuation, and
clockwise periodicity are influenced by the hypothalamus
and its dysfunctional biological clock (pacemaker). The
pain is generated by activation of the trigeminal neurovascular system.
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HeadW ise ®
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Volume 4, Issue 3 • 2015
How to treat this disease?
The diagnosis is fairly straightforward. The clinical picture
of cluster headache is so characteristic that it should not
be misdiagnosed for some other headache or disorder. If
the patient has only recently experienced the initial cycle
of cluster headache, an MRI of the brain is recommended
to rule out secondary headache due to a brain tumor,
aneurysm, or other intracranial process. No other testing
is necessary.
The treatment of cluster is twofold. Its aim is to abort
the acute headache attack as well as shorten and stop the
cluster cycle. During remission periods, the patient does
not need to continue any treatment. Therapy should be
initiated at the very beginning of a new cycle. The most
effective and safest therapeutic modality is pure 100
percent oxygen, delivered via mask at the high flow rate of
10 to 15L per minute. Usually, the attack is aborted within
5 to 10 minutes with oxygen therapy. Many patients will
use a small oxygen tank at home as well as at work, so that
it can be used whenever an attack commences.
Because of the brevity of attacks (lasting less than one
hour), no oral medication, including narcotic analgesics
will have time to be effective. The triptans in either
injectable or nasal spray formulations are effective for a
brief period and in aborting the attacks. The triptans
include sumatriptan and zolmotriptan. However, their
use is contraindicated in patients with uncontrolled high
blood pressure or cardiovascular disease. Other options
that may be effective are injectable dihydroergotamine or
the nonsteroidal anti-inflammatory agents (NSAIDs).
Preventative treatment should be initiated as soon as
the new cycle starts. Steroid burst and verapamil are
drugs of choice. Other drugs are added if the attacks
are not alleviated, including valproic acid, doxepin,
indomethacin, topiramate, gabapentin, and triptans with
a longer duration of effects. Lithium may be quite effective
particularly in the treatment of the chronic form of cluster
headache. All medications may cause adverse reactions and
the patient needs to be cautioned to avoid exceeding the
maximum individual or daily dose when attempting to
stop the terrible pain.
Some nerve blocks, mainly the occipital and
sphenopalatine, may also be effective for a short time.
Treatment with botulinum toxin has not been proven
to be beneficial in cluster headache. Surgical procedures,
including cutting or chemically destroying a nerve pathway
or a ganglion (cluster of nerve cells), are seldom performed.
These intervenetions are only performed in select patients
who experience continuous one-sided headache and who
are not depressed. These surgical procedures have a high
rate of failure or complications.
Chronic cluster is a complicated form of cluster headache.
The attacks occur daily, sometimes multiples times a day
or a few times a week. There is no respite nor remission,
and the attacks will affect the patient day after day, week
after week, and month after month. These headaches do
not respond to