Migraine surgery
Encyclopedia
Migraine surgery is any surgical operation undertaken with the goal of reducing or preventing migraine
s. Innovative surgical techniques have been developed to help patients with migraine headaches. Migraines affect an estimated 10% of the worldwide population annually and cause significant loss of workdays and billions of dollars in productivity. It is well documented that migraine headaches cause significant disability, and reduce of quality of life that is as dire, if not worse than, debilitating chronic diseases. There have been major pharmacological advances for the treatment of migraine headaches, yet patients must still endure symptoms until the medications take effect. Furthermore, often they still experience a poor quality of life despite an aggressive regimen of pharmacotherapy. For these reasons, surgical solutions to migraines are actively being researched, particularly those involving the surgical cauterization of the superficial blood vessels of the scalp (the terminal branches of the external carotid artery), the removal of muscles or nerves in areas known as "trigger sites", and those involving the correction of a congenital heart defect
. Despite the lack of evidence supporting migraine surgery, there are over a dozen surgeons actively performing the operations in the US.
, a South African headache specialist, who has published a number of articles providing compelling evidence that Wolff was in fact correct.
Ligation of temporal vessels was first described by Abu al-Qasim al-Zahrawi (936 – 1013 AD), a Moorish physician. Historically, it has been reported that Ambroise Paré (1510–1590 AD), father of modern medicine, ligated his own temporal vessels for relief of his migraines. Since then the efficacy of arterial ablation for migraine treatment by ligation, cryotherapy, or cauterization of the relevant vessels has been confirmed repeatedly.
and its frontal branch, and the occipital artery
. These vessels are subcutaneous and the small incisions required to access them mean that the surgery is minimally invasive and can be done in a day facility. As these vessels have no connection with the arterial supply to the brain, MIAS is exceedingly safe with no unpleasant side effects. The cosmetic effect is excellent as most of the incisions are within the hairline.
1) There are certain scalp arteries that most commonly cause the pain of migraine. These are compressed with the fingertip during an attack. If blocking the artery by pressure relieves the pain temporarily, and the pain returns when the finger pressure is removed, then arterial surgery is indicated.
2) Some migraine sufferers get relief from tying a tight band round the head just above the eyes and ears. This closes off the arteries that are causing the pain. If a tight band provides relief, then the surgery is indicated.
3) Certain medications provide relief from migraine pain by constricting or narrowing the scalp arteries. If these medications give relief, then the arterial surgery is indicated. These medications include the:
a) Triptans, namely sumatriptan (Imitrex, Imigran, Cinie, Illument, Migriptan), zolmitriptan (Zomig), eletriptan (Relpax), rizatriptan (Maxalt), frovatriptan (Frova, Migard, Frovamig), naratriptan (Amerge, Naramig), avitriptan (BMS-180,048), and almotriptan (Axert, Almogran).
b) Ergots. Any medications that contain ergotamine or dihydroergotamine.
s are being stimulated
by a surrounding muscle
or specific contact points.
Due to this nerve irritation
, a cascade of events is initiated, leading to the inflammation of the meningeal layers
surrounding the brain
, and to migraine headaches.
Thus far, four trigger areas have been identified as surgical candidates. Three of these are in locations where the nerve passes through a muscle—where the greater occipital nerve
pierces through the semispinalis capitis muscle, the zygomaticotemporal nerve
through the temporalis muscle
, and the supraorbital
/supratrochlear
nerves through the glabella
r muscle group (the corrugator supercilii, depressor supercilii, and procerus muscle
s). The fourth trigger point, however, has been identified in the nose of patients who have significant nasal septum deviation with enlargement of the turbinate
s. The contact between these structures causes the irritation of the trigeminal nerve
end branches and thus triggers migraine headaches. Several large series of studies have been conducted to evaluate the efficacy of surgical obliteration of trigger points. Almost all demonstrated more than 90% response, with at least 50% improvement to complete resolution of migraine pain symptoms.
This type of migraine surgery is not offered as a first line of treatment, but after extensive evaluation and failure of traditional medical treatments. Trials are still ongoing to standardize the procedures of choice for definitive management of migraine headaches, but there have been successful guidelines for surgical therapy, which are being used by several migraine surgery specialists around the globe. Currently this treatment has institutional approval for adults, and trials for the pediatric population are ongoing.
, and subsequent Botox injection and/or nasal endoscopy
. A positive response to Botox has been a positive predictor of a successful outcome. Single or multiple TSs may be treated. Migraine headaches can start in one area depending on their corresponding trigger site and spread to the rest of the head. It is important to identify the initial trigger sites rather than address all the areas of pain, after the inflammation involves the entire trigeminal tree
. Four different types of migraine have been defined based on their trigger point location, and are addressed individually. Sometimes the alleviation of one trigger site results in the unmasking a second site.
Forehead
migraine headaches: In the glabella
r area the supra-orbital
and supra-trochlear
nerves are skeletonized by resect
ing the corrugator
and depressor supercilii muscle
using an endoscopic approach similar that of used for cosmetic forehead lift
.
Temporal
migraine headaches: The temporal area, where the zygomaticotemporal branch of trigeminal nerve passes through the temporalis muscle, is addressed using a similar endoscopic approach but involves removing a segment of the nerve rather than transecting the muscle. This results in a slight sensory defect over temporal skin area, but cross-innervation from other sensory nerves helps to limit the damage.
Rhinogenic migraine headaches: The nasal trigger points where enlarged turbinates are in contact with the nasal septum
are addressed with a septoplasty
and a turbinectomy.
Occipital
migraine headaches: The posterior neck
area where the greater occipital nerve
passes through the semispinalis capitis muscle is addressed with an open surgical approach with resection of a small segment of the semispinalis muscle and shielding the nerves with a subcutaneous adipose flap.
It is estimated that 20-25% of the general population in the United States
has a PFO. Medical research studies have shown that migraineurs are twice as likely as the general population to have a PFO, that over 50% of sufferers of migraine with aura have a PFO, that patients with a PFO are 5.1 times more likely to suffer from migraines and 3.2 times more likely to have migraines with aura than the general population, and that patients with migraine with aura are much more likely to have a large opening than the general PFO population.
(literally oval hole) is present in all fetus
es. Because a fetus' blood is oxygenated
through the mother's placenta
and not through breathing
, the pulmonary system is unneeded. To make the fetal circulatory system more effective, the hole exists so that blood can travel from the right atrium
to the left atrium
without entering the pulmonary circulation
. When the baby is born and begins breathing, the resistance in the lungs decreases dramatically, and blood begins to travel into the pulmonary system. This results in increased pressure
in the left atrium, which then forces the flap down and effectively seals the hole. Once fully fused, the resulting structure is called the fossa ovalis
(literally oval ditch). If the hole is not fully sealed, it is said to be patent (literally open).
Early speculation regarding this link centered on the idea that, because blood bypasses the detoxificaiton process in the lungs and reenters the circulatory system uncleaned, this "toxic blood" may contain various substances that then trigger migraines. There is speculation that one of these substances is 5-HT, more commonly known as serotonin
. Normally, 5-HT is filtered in the pulmonary circulation. However, if blood is bypassing that filtration process, 5-HT can re-enter systemic circulation
and travel to and enter the brain. Numerous studies have related 5-HT to migraine pathogenesis, and the current pharmacological treatment of choice is a triptan
drug, which binds to serotonin receptors in the brain and leads to the migraine being cured. This evidence lends support to the theory that 5-HT is one of the substances that triggers a migraine in a patient with a PFO.
There is speculation that microemboli that develop in the venous system pass through the PFO and are able to reach the central nervous system
. The paradoxical embolism
then reaches the cortex
, triggering cortical spreading depression
, a phenomenon that leads to migraines. There is also evidence that the number of gas bubbles in a paradoxical gas embolism is correlated with the severity of the headache.
One study has found a genetic linkage
between migraines and PFOs. It was found that PFOs have an autosomal dominant pattern of inheritance
, and that migraine with aura appears to be coinherited in some families.
It has been shown that the changes in interarterial pressure that occur with a PFO cause an increase in atrial natriuretic peptide
(ANP), and that the ANP concentration in migraineurs with aura is lower than the concentration in control subjects. A study has shown that when the cortical spreading depression phenomenon was induced in mice, ANP was expressed
in the brain. As well, ANP levels are elevated in patients with a PFO. All together, this suggests a possible correlation between ANP concentration and migraine with aura.
explained an advantage to non-pharmacological migraine relief. He said, "In contrast to drugs, PFO closure appears highly effective against migraines and usually has no side effects". Because PFO closure continues to prove successful, new devices are being produced to make the surgery easier to perform and less invasive.
Recent studies, however, have emphasised caution in relating PFO closure surgeries to migraines, stating that the favourable studies have been poorly-designed retrospective studies and that insufficient evidence exists to justify the dangerous procedure. As well, at least one patient with infrequent migraines who underwent the surgery ended up with daily migraines for at least 6 months, and others have reported short-term increases in migraine frequency and intensity following the surgery.
From Coherex Medical Inc. of Salt Lake City, a device called the Coherex FlatStent PFO Closure System is being tested as a new product for PFO closure. This device is first being studied by a European clinical study in Frankfurt, Germany. If this study proves to be a success, the device will begin to undergo FDA approval. The Coherex Closure System is an alternative to the typical method of repairing a PFO by placing a disk on each side of the defect and clamping them together to form a solid wall. The typical method doesn't always work particularly well with PFOs because the lengths, widths and dimensions of the defect are always different. The Coherex device is small and looks delicate, although it's not. One of its unique features is that it's deployed inside the tunnel of the PFO, so it closes the defect from within Because of its construction, it adapts to a PFO's individual shape in terms of length and width, thus avoiding the typical problem with PFO closure. Besides pulling the opening closed, it has a sponge polymer that encourages tissue to grow into it and integrate it into the heart's structure.
Another closure system is in use right now called CardioSEAL. This device looks like a small umbrella made out of Dacron fabric and folded into a special catheter. This catheter is inserted into a vein in the leg like the Coherex device. In order to close the PFO valve, each umbrella opens up and the device is pushed out of the catheter. The device is absorbed into the heart as the heart tissues grow over the implant in time.
Another device for PFO Closure is called the AMPLATZER PFO Occluder device.
It consists of two wire mesh discs filled with polyester fabric. It is folded into a special delivery catheter, similar to the catheter used during a catheterization. The catheter is inserted into a vein in the leg, advanced into the heart and through the defect.
When the catheter is in proper position, the device is slowly pushed out of the catheter until the discs of the device sit on each side of the defect (like a sandwich). The two discs are linked together by a short connecting waist. The discs and the waist are filed with polyester fabric to increase the device’s closing ability.
Over time, heart tissue grows over the implant, and it becomes part of the heart. The tissue grows over the device over time.
University of Washington Medical Center tests the effectiveness of PFO closure in eliminating migraines in a clinical trial called the Premium Trial. All patients must meet certain criteria to qualify for the study including a diary that recounts the severity and frequency of migraines and undergoing tests to eliminate other medical reasons for migraines. A random selection process is then used to determine which patients have their PFO repaired and which ones do not. After a year, the patients will find out if they had the actual procedure and physicians will be able to determine if the process really worked.
The surgery is not performed by cutting open the chest and working on the heart. Instead, a catheter is pushed up to the hole in the heart after it is inserted in a vein in the leg. In order to keep the study blind, all patients are blindfolded and wear headphones while being mildly sedated. All patients receive a catheter in the leg, but not all catheters are pushed up to the heart.
One clinical trial being undertaken began in October 2007 called the ESCAPE Migraine trial to test the relation to PFO closure to migraine relief. Feldman, along with Dr. Susan Rubin, are co-principal investigators of the trial. “The clinical trial expects to enroll 500 patients in the U.S. who have not found relief from migraines with preventive medicine, have experienced unwanted side effects from drug therapy or have been advised by a doctor against medications due to another condition”. This trial will use the closure system called the Premere PFO Closure System that uses the catheter system in the leg to go to the heart. This closure system was designed by St. Jude Medical but is only available for this clinical trial because it has not been approved by the Food and Drug Administration. The study is closed to new participants and has completed final data collection for its primary outcome. Results are expected to be released in fall of 2013.
The procedure involves two-thirds of the patients who had their PFO closed, while the other third had a tube placed in their heart to measure the size of their PFO. The risk of migraine is related to the size of the PFO. Patients will not know until the end of the trial if they were assigned to receive PFO closure. Once the trial is complete, trial participants will meet with a cardiologist for a heart evaluation and a neurologist to evaluate and monitor their migraines after intervention. They were asked to maintain an electronic journal of their migraines for one year. The apparent relation between an opening of the PFO valve and migraines may receive further validation through this study.
s are medical stimulators implanted in the region of the spinal cord. They are sometimes used in cases of severe migraine headache on patients who tend to have multiple attacks per month.
(BoNT-A, popularly known as Botox) injections have been reported by various headache specialists as a potential treatment for migraines.
In 2008, a subcommittee of the American Academy of Neurology
(AAN) assessed the effectiveness of botulinum toxin in numerous disorders, with one report focusing on autonomic disorders and pain, including 'chronic daily headache'—they noted that this group's headaches were "mainly transformed migraines", and 'chronic tension-type headaches' were not included—and 'episodic migraines'. For chronic daily headaches, four studies were analyzed where the reduction in headache frequency when injected with BoNT-A was compared to a placebo
-injected control group. While two of these studies showed favourable results, others observed no significant benefits. The AAN has thus reported that they can not yet draw any conclusions on the effectiveness of BoNT-A injections in chronic daily headaches. It was noted that, in one study where subjects were stratified based on whether or not they were currently being treated with a prophylactic medication, patients who were not taking prophylactic medications concomittantly fared significantly better than those who were.
In the same report, the AAN concluded that the injections were "probably ineffective" in treating episodic migraines. Other studies have reached the same conclusion.
Studies examining the effectiveness of BoTN-A injections that were not included in the AAN report have yielded positive results. It has been noted, however, that repeated injections are required to keep the headaches under control—the BoTN-A may have a cumulative effect—and they do not address the headaches which are triggered from the septum and turbinates.
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
s. Innovative surgical techniques have been developed to help patients with migraine headaches. Migraines affect an estimated 10% of the worldwide population annually and cause significant loss of workdays and billions of dollars in productivity. It is well documented that migraine headaches cause significant disability, and reduce of quality of life that is as dire, if not worse than, debilitating chronic diseases. There have been major pharmacological advances for the treatment of migraine headaches, yet patients must still endure symptoms until the medications take effect. Furthermore, often they still experience a poor quality of life despite an aggressive regimen of pharmacotherapy. For these reasons, surgical solutions to migraines are actively being researched, particularly those involving the surgical cauterization of the superficial blood vessels of the scalp (the terminal branches of the external carotid artery), the removal of muscles or nerves in areas known as "trigger sites", and those involving the correction of a congenital heart defect
Congenital heart defect
A congenital heart defect is a defect in the structure of the heart and great vessels which is present at birth. Many types of heart defects exist, most of which either obstruct blood flow in the heart or vessels near it, or cause blood to flow through the heart in an abnormal pattern. Other...
. Despite the lack of evidence supporting migraine surgery, there are over a dozen surgeons actively performing the operations in the US.
Arterial surgery
The rationale for arterial surgery for the treatment of migraine is based upon the work done by Harold Wolff and his co-workers in the 1940s. Wolff first subjected the condition of migraine to rigorous scientific experimentation, and showed convincingly that in some migraine sufferers the pain originates in the distended terminal branches of the external carotid artery. Wolff’s theory has since been confirmed many times. There have been attempts to debunk Wolff's vascular theory, and for years it has been out of favor. Recently however, there has been renewed interest in Wolff's vascular theory of migraine led by Elliot ShevelElliot Shevel
Elliot Shevel BDS, DipMFOS, MBBCh is a South African Maxillo-Facial and Oral Surgeon, best known for his contribution to understanding of the underlying processes involved in the pain of migraine. He is, inter alia, a tireless campaigner to have the work of Harold Wolff, which many migraine...
, a South African headache specialist, who has published a number of articles providing compelling evidence that Wolff was in fact correct.
Minimally Invasive Arterial Surgery (MIAS)
There is compelling evidence to show that migraine pain often originates in the terminal branches of the external carotid artery. In migraine sufferers with extracranial vascular pain, and in whom digital compression of the relevant artery reduces or abolishes the pain, surgical ligation or cauterization of the relevant vessel or vessels provides permanent relief from not only the pain of migraine, but also the associated symptoms such as the aura, light sensitivity (photophobia), sensitivity to sound (phonophobia), nausea, and vomiting. MIAS is highly successful in migraine sufferers where a definite positive diagnosis has been made, by examining the patient while they are experiencing migraine pain. The terminal branches of the external carotid artery are systematically compressed against the underlying tissues to determine exactly which vessels are responsible for the pain. When the relevant vessels are compressed, the pain either diminishes significantly or disappears completely. In this way, a positive diagnosis is made.Ligation of temporal vessels was first described by Abu al-Qasim al-Zahrawi (936 – 1013 AD), a Moorish physician. Historically, it has been reported that Ambroise Paré (1510–1590 AD), father of modern medicine, ligated his own temporal vessels for relief of his migraines. Since then the efficacy of arterial ablation for migraine treatment by ligation, cryotherapy, or cauterization of the relevant vessels has been confirmed repeatedly.
When is arterial surgery indicated?
This treatment modality is of particular value in: 1) patients who have not responded to conventional drug therapy, 2) patients who are unable to use drug therapy because they experience unacceptable side effects, or 3) patients who would prefer not to be on permanent medication. Included in this category are those with Chronic Daily Headache (headache on more than 15 days per month) and patients with what is known as "refractory headache" - headache that has not benefited from any other form of treatment. A recent study has shown that patients with chronic migraine experienced a significant reduction in pain levels and significant improvement in their quality of life following the surgery. The most common vessels involved in the pain of migraine are the terminal branches of the external carotid artery, and in particular, the superficial temporal arterySuperficial temporal artery
In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it bifurcates into the superficial temporal artery and maxillary artery....
and its frontal branch, and the occipital artery
Occipital artery
The occipital artery arises from the external carotid artery opposite the facial artery, its path is below the posterior belly of digastric to the occipital region. This artery supplies blood to the back of the scalp and sterno-mastoid muscles...
. These vessels are subcutaneous and the small incisions required to access them mean that the surgery is minimally invasive and can be done in a day facility. As these vessels have no connection with the arterial supply to the brain, MIAS is exceedingly safe with no unpleasant side effects. The cosmetic effect is excellent as most of the incisions are within the hairline.
How do we diagnose who will benefit from arterial surgery?
There are a number of methods used to diagnose whether arterial surgery will be of benefit.1) There are certain scalp arteries that most commonly cause the pain of migraine. These are compressed with the fingertip during an attack. If blocking the artery by pressure relieves the pain temporarily, and the pain returns when the finger pressure is removed, then arterial surgery is indicated.
2) Some migraine sufferers get relief from tying a tight band round the head just above the eyes and ears. This closes off the arteries that are causing the pain. If a tight band provides relief, then the surgery is indicated.
3) Certain medications provide relief from migraine pain by constricting or narrowing the scalp arteries. If these medications give relief, then the arterial surgery is indicated. These medications include the:
a) Triptans, namely sumatriptan (Imitrex, Imigran, Cinie, Illument, Migriptan), zolmitriptan (Zomig), eletriptan (Relpax), rizatriptan (Maxalt), frovatriptan (Frova, Migard, Frovamig), naratriptan (Amerge, Naramig), avitriptan (BMS-180,048), and almotriptan (Axert, Almogran).
b) Ergots. Any medications that contain ergotamine or dihydroergotamine.
Trigger site release
It has been theorized that trigger sites (TSs) exist where sensory nerveSensory nerve
Sensory nerves are nerves that receive sensory stimuli, such as how something feels and if it is painful, smooth, rough, etc.They are made up of nerve fibers, called sensory fibers .Sensory neurons are neurons that are activated by sensory input Sensory nerves are nerves that receive sensory...
s are being stimulated
Stimulation
Stimulation is the action of various agents on nerves, muscles, or a sensory end organ, by which activity is evoked; especially, the nervous impulse produced by various agents on nerves, or a sensory end organ, by which the part connected with the nerve is thrown into a state of activity.The word...
by a surrounding muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
or specific contact points.
Due to this nerve irritation
Irritation
Irritation or exacerbation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant...
, a cascade of events is initiated, leading to the inflammation of the meningeal layers
Meninges
The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...
surrounding the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, and to migraine headaches.
Thus far, four trigger areas have been identified as surgical candidates. Three of these are in locations where the nerve passes through a muscle—where the greater occipital nerve
Greater occipital nerve
The greater occipital nerve is a spinal nerve, specifically the medial branch of the dorsal primary ramus of cervical spinal nerve 2. This nerve arises from between the first and second cervical vertebrae, along with the lesser occipital nerve. It ascends after emerging from the suboccipital...
pierces through the semispinalis capitis muscle, the zygomaticotemporal nerve
Zygomaticotemporal nerve
The zygomaticotemporal nerve or zygomaticotemporal branch is derived from the maxillary branch of the trigeminal nerve...
through the temporalis muscle
Temporalis muscle
The temporal muscle is one of the muscles of mastication.-Structure:It arises from the temporal fossa and the deep part of temporal fascia...
, and the supraorbital
Supraorbital nerve
The supraorbital nerve is a terminal branch of the frontal nerve.It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid...
/supratrochlear
Supratrochlear nerve
The supratrochlear nerve is a branch of the frontal nerve, which itself comes from the ophthalmic division of the trigeminal cranial nerve.It is smaller than the nearby supraorbital nerve...
nerves through the glabella
Glabella
The glabella, in humans, is the space between the eyebrows and above the nose. It is slightly elevated, and joins the two superciliary ridges.-Etymology:The term is derived from the Latin glabellus, meaning smooth, as this area is usually hairless....
r muscle group (the corrugator supercilii, depressor supercilii, and procerus muscle
Procerus muscle
The Procerus is a small pyramidal slip of muscle deep to the superior orbital nerve, artery and vein.-Origin and insertion:It arises by tendinous fibers from the fascia covering the lower part of the nasal bone and upper part of the lateral nasal cartilage....
s). The fourth trigger point, however, has been identified in the nose of patients who have significant nasal septum deviation with enlargement of the turbinate
Turbinate
In anatomy, a nasal concha is a long, narrow and curled bone shelf that protrudes into the breathing passage of the nose...
s. The contact between these structures causes the irritation of the trigeminal nerve
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
end branches and thus triggers migraine headaches. Several large series of studies have been conducted to evaluate the efficacy of surgical obliteration of trigger points. Almost all demonstrated more than 90% response, with at least 50% improvement to complete resolution of migraine pain symptoms.
This type of migraine surgery is not offered as a first line of treatment, but after extensive evaluation and failure of traditional medical treatments. Trials are still ongoing to standardize the procedures of choice for definitive management of migraine headaches, but there have been successful guidelines for surgical therapy, which are being used by several migraine surgery specialists around the globe. Currently this treatment has institutional approval for adults, and trials for the pediatric population are ongoing.
Details of the procedure
Patients have to be screened preoperatively with a full neurological examinationNeurological examination
A neurological examination is the assessment of sensory neuron and motor responses, especially reflexes, to determine whether the nervous system is impaired...
, and subsequent Botox injection and/or nasal endoscopy
Rhinoscope
A rhinoscope is a thin, tube-like instrument used to examine the inside of the nose. A rhinoscope has a light and a lens for viewing and may have a tool to remove tissue.- External links :...
. A positive response to Botox has been a positive predictor of a successful outcome. Single or multiple TSs may be treated. Migraine headaches can start in one area depending on their corresponding trigger site and spread to the rest of the head. It is important to identify the initial trigger sites rather than address all the areas of pain, after the inflammation involves the entire trigeminal tree
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
. Four different types of migraine have been defined based on their trigger point location, and are addressed individually. Sometimes the alleviation of one trigger site results in the unmasking a second site.
Forehead
Forehead
For the Arsenal striker see GervinhoIn human anatomy, the forehead is the fore part of the head. It is, formally, an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp...
migraine headaches: In the glabella
Glabella
The glabella, in humans, is the space between the eyebrows and above the nose. It is slightly elevated, and joins the two superciliary ridges.-Etymology:The term is derived from the Latin glabellus, meaning smooth, as this area is usually hairless....
r area the supra-orbital
Supraorbital nerve
The supraorbital nerve is a terminal branch of the frontal nerve.It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid...
and supra-trochlear
Supratrochlear nerve
The supratrochlear nerve is a branch of the frontal nerve, which itself comes from the ophthalmic division of the trigeminal cranial nerve.It is smaller than the nearby supraorbital nerve...
nerves are skeletonized by resect
Segmental resection
Segmental resection is a surgical procedure to remove part of an organ or gland. It may also be used to remove a tumor and normal tissue around it. In lung cancer surgery, segmental resection refers to removing a section of a lobe of the lung.- External links :* entry in the public domain NCI...
ing the corrugator
Corrugator supercilii muscle
The Corrugator supercilii is a small, narrow, pyramidal muscle, placed at the medial end of the eyebrow, beneath the Frontalis and just above Orbicularis oculi....
and depressor supercilii muscle
Depressor supercilii muscle
The Depressor Supercilii is an eye muscle of the human body. The nature of this muscle is in some dispute. Few printed anatomies include it and many authorities consider it to be part of the orbicularis oculi muscle ....
using an endoscopic approach similar that of used for cosmetic forehead lift
Forehead lift
A forehead lift, also known as a browlift or browplasty, is a cosmetic surgery procedure used to elevate a drooping eyebrow that may obstruct vision and/or to remove the deep “worry” lines that run across the forehead and may portray to others anger, sternness, hostility, fatigue or other...
.
Temporal
Temple (anatomy)
Temple indicates the side of the head behind the eyes. The bone beneath is the temporal bone as well as part of the sphenoid bone.-Anatomy:Cladists classify land vertebrates based on the presence of an upper hole, a lower hole, both, or neither in the cover of dermal bone which formerly covered the...
migraine headaches: The temporal area, where the zygomaticotemporal branch of trigeminal nerve passes through the temporalis muscle, is addressed using a similar endoscopic approach but involves removing a segment of the nerve rather than transecting the muscle. This results in a slight sensory defect over temporal skin area, but cross-innervation from other sensory nerves helps to limit the damage.
Rhinogenic migraine headaches: The nasal trigger points where enlarged turbinates are in contact with the nasal septum
Nasal septum
The nasal septum separates the left and right airways in the nose, dividing the two nostrils.It is depressed by the Depressor septi nasi muscle.-Composition:The fleshy external end of the nasal septum is sometimes also called columella....
are addressed with a septoplasty
Septoplasty
Septoplasty is a corrective surgical procedure done fix to straighten the nasal septum, the partition between the two nasal cavities. Ideally, the septum should run down the center of the nose. When it deviates into one of the cavities, it narrows that cavity and impedes airflow. Often the...
and a turbinectomy.
Occipital
Occipital
The word occipital, in zoology, pertains to the occiput .Occipital is a descriptor for several areas of animal & human anatomy.*External occipital protuberance* Internal occipital crest* Greater occipital nerve...
migraine headaches: The posterior neck
Posterior triangle of the neck
-Boundaries:It has the following boundaries:Apex: Union of the sternocleidomastoid and the trapezius muscles at the superior nuchal line of the occipital boneAnterior: Posterior border of the sternocleidomastoideus...
area where the greater occipital nerve
Greater occipital nerve
The greater occipital nerve is a spinal nerve, specifically the medial branch of the dorsal primary ramus of cervical spinal nerve 2. This nerve arises from between the first and second cervical vertebrae, along with the lesser occipital nerve. It ascends after emerging from the suboccipital...
passes through the semispinalis capitis muscle is addressed with an open surgical approach with resection of a small segment of the semispinalis muscle and shielding the nerves with a subcutaneous adipose flap.
Patent foramen ovale closure
Several clinical trials are currently under way in an effort to determine the existence of a causal linkage between migraines and the presence of a patent foramen ovale (PFO), a hole between the upper chambers (the atria) of the heart. There is significant evidence that a link exists between migraine with aura and the presence of a PFO.It is estimated that 20-25% of the general population in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
has a PFO. Medical research studies have shown that migraineurs are twice as likely as the general population to have a PFO, that over 50% of sufferers of migraine with aura have a PFO, that patients with a PFO are 5.1 times more likely to suffer from migraines and 3.2 times more likely to have migraines with aura than the general population, and that patients with migraine with aura are much more likely to have a large opening than the general PFO population.
Anatomy
The foramen ovaleForamen ovale
There are multiple structures in the human body with the name foramen ovale :* In the fetal heart, the foramen ovale is a shunt from the right atrium to left atrium....
(literally oval hole) is present in all fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
es. Because a fetus' blood is oxygenated
Oxygenation (medical)
Oxygenation occurs when oxygen molecules enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood...
through the mother's placenta
Placenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
and not through breathing
Breathing
Breathing is the process that moves air in and out of the lungs. Aerobic organisms require oxygen to release energy via respiration, in the form of the metabolism of energy-rich molecules such as glucose. Breathing is only one process that delivers oxygen to where it is needed in the body and...
, the pulmonary system is unneeded. To make the fetal circulatory system more effective, the hole exists so that blood can travel from the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
to the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
without entering the pulmonary circulation
Pulmonary circulation
Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen-depleted Blood away from the heart, to the Lungs, and returns oxygenated blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn...
. When the baby is born and begins breathing, the resistance in the lungs decreases dramatically, and blood begins to travel into the pulmonary system. This results in increased pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
in the left atrium, which then forces the flap down and effectively seals the hole. Once fully fused, the resulting structure is called the fossa ovalis
Fossa ovalis
Fossa ovalis can refer to:* Fossa ovalis , also called the saphenous opening* Fossa ovalis , an embryonic remnant of the foramen ovale...
(literally oval ditch). If the hole is not fully sealed, it is said to be patent (literally open).
Pathophysiological theories
In certain scenarios, such as when a person sneezes, the pressure in the left atrium decreases and the flap over the still-present foramen ovale opens temporarily. When this happens, blood is able to bypass the lungs and therefore the filtration process in the pulmonary system. There are at least 4 theories as to how this defect leads to migraines.Toxic circulation
Early speculation regarding this link centered on the idea that, because blood bypasses the detoxificaiton process in the lungs and reenters the circulatory system uncleaned, this "toxic blood" may contain various substances that then trigger migraines. There is speculation that one of these substances is 5-HT, more commonly known as serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
. Normally, 5-HT is filtered in the pulmonary circulation. However, if blood is bypassing that filtration process, 5-HT can re-enter systemic circulation
Systemic circulation
Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. This physiologic theory of circulation was first described by William Harvey...
and travel to and enter the brain. Numerous studies have related 5-HT to migraine pathogenesis, and the current pharmacological treatment of choice is a triptan
Triptan
Triptans are a family of tryptamine-based drugs used as abortive medication in the treatment of migraines and cluster headaches. They were first introduced in the 1990s...
drug, which binds to serotonin receptors in the brain and leads to the migraine being cured. This evidence lends support to the theory that 5-HT is one of the substances that triggers a migraine in a patient with a PFO.
Micro-emboli
There is speculation that microemboli that develop in the venous system pass through the PFO and are able to reach the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
. The paradoxical embolism
Paradoxical embolism
A paradoxical embolism is a kind of stroke or other form of arterial thrombosis caused by embolism of a thrombus of venous origin through a lateral opening in the heart, such as a patent foramen ovale....
then reaches the cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
, triggering cortical spreading depression
Cortical spreading depression
Cortical spreading depression is a wave of electrophysiological hyperactivity followed by a wave of inhibition, usually in the visual cortex.The term is used by neuroscientists to represent at least one of the following cortical processes:...
, a phenomenon that leads to migraines. There is also evidence that the number of gas bubbles in a paradoxical gas embolism is correlated with the severity of the headache.
Genetic linkage
One study has found a genetic linkage
Genetic linkage
Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...
between migraines and PFOs. It was found that PFOs have an autosomal dominant pattern of inheritance
Inheritance
Inheritance is the practice of passing on property, titles, debts, rights and obligations upon the death of an individual. It has long played an important role in human societies...
, and that migraine with aura appears to be coinherited in some families.
Atrial natriuretic peptides
It has been shown that the changes in interarterial pressure that occur with a PFO cause an increase in atrial natriuretic peptide
Atrial natriuretic peptide
Atrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
(ANP), and that the ANP concentration in migraineurs with aura is lower than the concentration in control subjects. A study has shown that when the cortical spreading depression phenomenon was induced in mice, ANP was expressed
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
in the brain. As well, ANP levels are elevated in patients with a PFO. All together, this suggests a possible correlation between ANP concentration and migraine with aura.
Procedures
It has been shown that migraine frequency and severity is reduced if the hole is patched surgically. Mark Reisman, cardiologist at Seattle's Swedish Medical CenterSwedish Medical Center
Swedish Medical Center is a large nonprofit health care provider located in Seattle, Washington. It has three main hospital locations in Seattle and is also affiliated with many other suburban hospitals and clinics. As of 2009 it has 7000 employees and 2,300 credentialed physicians.-History:Swedish...
explained an advantage to non-pharmacological migraine relief. He said, "In contrast to drugs, PFO closure appears highly effective against migraines and usually has no side effects". Because PFO closure continues to prove successful, new devices are being produced to make the surgery easier to perform and less invasive.
Recent studies, however, have emphasised caution in relating PFO closure surgeries to migraines, stating that the favourable studies have been poorly-designed retrospective studies and that insufficient evidence exists to justify the dangerous procedure. As well, at least one patient with infrequent migraines who underwent the surgery ended up with daily migraines for at least 6 months, and others have reported short-term increases in migraine frequency and intensity following the surgery.
Coherex FlatStent Closure System
From Coherex Medical Inc. of Salt Lake City, a device called the Coherex FlatStent PFO Closure System is being tested as a new product for PFO closure. This device is first being studied by a European clinical study in Frankfurt, Germany. If this study proves to be a success, the device will begin to undergo FDA approval. The Coherex Closure System is an alternative to the typical method of repairing a PFO by placing a disk on each side of the defect and clamping them together to form a solid wall. The typical method doesn't always work particularly well with PFOs because the lengths, widths and dimensions of the defect are always different. The Coherex device is small and looks delicate, although it's not. One of its unique features is that it's deployed inside the tunnel of the PFO, so it closes the defect from within Because of its construction, it adapts to a PFO's individual shape in terms of length and width, thus avoiding the typical problem with PFO closure. Besides pulling the opening closed, it has a sponge polymer that encourages tissue to grow into it and integrate it into the heart's structure.
CardioSEAL
Another closure system is in use right now called CardioSEAL. This device looks like a small umbrella made out of Dacron fabric and folded into a special catheter. This catheter is inserted into a vein in the leg like the Coherex device. In order to close the PFO valve, each umbrella opens up and the device is pushed out of the catheter. The device is absorbed into the heart as the heart tissues grow over the implant in time.
AMPLATZER PFO Occluder
Another device for PFO Closure is called the AMPLATZER PFO Occluder device.
It consists of two wire mesh discs filled with polyester fabric. It is folded into a special delivery catheter, similar to the catheter used during a catheterization. The catheter is inserted into a vein in the leg, advanced into the heart and through the defect.
When the catheter is in proper position, the device is slowly pushed out of the catheter until the discs of the device sit on each side of the defect (like a sandwich). The two discs are linked together by a short connecting waist. The discs and the waist are filed with polyester fabric to increase the device’s closing ability.
Over time, heart tissue grows over the implant, and it becomes part of the heart. The tissue grows over the device over time.
Premium trial
University of Washington Medical Center tests the effectiveness of PFO closure in eliminating migraines in a clinical trial called the Premium Trial. All patients must meet certain criteria to qualify for the study including a diary that recounts the severity and frequency of migraines and undergoing tests to eliminate other medical reasons for migraines. A random selection process is then used to determine which patients have their PFO repaired and which ones do not. After a year, the patients will find out if they had the actual procedure and physicians will be able to determine if the process really worked.
The surgery is not performed by cutting open the chest and working on the heart. Instead, a catheter is pushed up to the hole in the heart after it is inserted in a vein in the leg. In order to keep the study blind, all patients are blindfolded and wear headphones while being mildly sedated. All patients receive a catheter in the leg, but not all catheters are pushed up to the heart.
ESCAPE migraine trial
One clinical trial being undertaken began in October 2007 called the ESCAPE Migraine trial to test the relation to PFO closure to migraine relief. Feldman, along with Dr. Susan Rubin, are co-principal investigators of the trial. “The clinical trial expects to enroll 500 patients in the U.S. who have not found relief from migraines with preventive medicine, have experienced unwanted side effects from drug therapy or have been advised by a doctor against medications due to another condition”. This trial will use the closure system called the Premere PFO Closure System that uses the catheter system in the leg to go to the heart. This closure system was designed by St. Jude Medical but is only available for this clinical trial because it has not been approved by the Food and Drug Administration. The study is closed to new participants and has completed final data collection for its primary outcome. Results are expected to be released in fall of 2013.
The procedure involves two-thirds of the patients who had their PFO closed, while the other third had a tube placed in their heart to measure the size of their PFO. The risk of migraine is related to the size of the PFO. Patients will not know until the end of the trial if they were assigned to receive PFO closure. Once the trial is complete, trial participants will meet with a cardiologist for a heart evaluation and a neurologist to evaluate and monitor their migraines after intervention. They were asked to maintain an electronic journal of their migraines for one year. The apparent relation between an opening of the PFO valve and migraines may receive further validation through this study.
Spinal cord stimulation
Spinal cord stimulatorSpinal Cord Stimulator
A spinal cord stimulator is a device used to exert pulsed electrical signals to the spinal cord to control chronic pain. Spinal cord stimulation , in the simplest form, consists of stimulating electrodes, implanted in the epidural space, an electrical pulse generator, implanted in the lower...
s are medical stimulators implanted in the region of the spinal cord. They are sometimes used in cases of severe migraine headache on patients who tend to have multiple attacks per month.
Non-surgical procedures
Botulinum neurotoxin ABotulinum toxin
Botulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...
(BoNT-A, popularly known as Botox) injections have been reported by various headache specialists as a potential treatment for migraines.
In 2008, a subcommittee of the American Academy of Neurology
American Academy of Neurology
The American Academy of Neurology is a professional society for neurologists and neuroscientists. As a medical specialty society it was established in 1949 by A.B. Baker of the University of Minnesota to advance the art and science of neurology, and thereby promote the best possible care for...
(AAN) assessed the effectiveness of botulinum toxin in numerous disorders, with one report focusing on autonomic disorders and pain, including 'chronic daily headache'—they noted that this group's headaches were "mainly transformed migraines", and 'chronic tension-type headaches' were not included—and 'episodic migraines'. For chronic daily headaches, four studies were analyzed where the reduction in headache frequency when injected with BoNT-A was compared to a placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
-injected control group. While two of these studies showed favourable results, others observed no significant benefits. The AAN has thus reported that they can not yet draw any conclusions on the effectiveness of BoNT-A injections in chronic daily headaches. It was noted that, in one study where subjects were stratified based on whether or not they were currently being treated with a prophylactic medication, patients who were not taking prophylactic medications concomittantly fared significantly better than those who were.
In the same report, the AAN concluded that the injections were "probably ineffective" in treating episodic migraines. Other studies have reached the same conclusion.
Studies examining the effectiveness of BoTN-A injections that were not included in the AAN report have yielded positive results. It has been noted, however, that repeated injections are required to keep the headaches under control—the BoTN-A may have a cumulative effect—and they do not address the headaches which are triggered from the septum and turbinates.