Headache
By Any Other Name Hurts Just as Much-and Could be Worse
By Lucio C. Victor Jr.
Virtually no one is spared from headache. Nine out of ten people have at least one headache annually while about 40 percent of people worldwide report a severe, disabling headache each year. Although most headaches are benign in nature, it can, in at least five percent of patients, manifest a serious condition like neoplasm, subarachnoid hemorrhage, meningitis, ruptured aneurysm, or giant cell arteritis.
Headache may result from the distension, traction of dilatation of intracranial or extracranial arteries. It can also stem from traction or displacement of large intracranial veins or their dural envelope; compression, traction, or inflammation of cranial and spinal nerves; spasm, inflammation, or trauma to cranial and cervical muscles; meningeal irritation and raised intracranial pressure; or other possible mechanisms such as activation of brainstem structures (Harrison's Principles of Internal Medicine 15th edition).
Meanwhile, pain sensitive structures in the head are also touted as causes of headache. These are: the scalp, middle meningeal artery, dural sinuses, falx cerebri, and the proximal segments of the large pial arteries. Likewise, electrical stimulation of the midbrain in the area of the dorsal raphe can result in migraine-like headaches.
Splitting Heads
 Arguably one of the most common headaches, migraine afflicts about 15 percent of women and six percent of men. this benign and recurring syndrome of headache may be accompanied by nausea, vomiting and other symptoms such as scintillating scotoma or dizziness.
According to Dr. Darwin Dasig, associate professor in physiology and neurosciences at the University of the Philippines-College of Medicine, migraine has a strong impact on the quality of life and well-being of persons afflicted by it despite lack of association with severe morbidity and mortality. More often than not, patients feel a migraine is a serious condition because the severity of pain and associated symptoms are usually out of the ordinary.
It has been established that migraine may be triggered by red wine, menstruation, hunger, lack of sleep, glare, estrogen, anxiety/worry, perfumes, octopamine from citrus fruits, phenylethylamine from chocolates, tyramine from cheese, and monosodium glutamate (MSG) in food. Although not all cases of migraine carry a genetic predisposition, one type, familial hemiplegic migraine, has been described to be of polygenic inheritance with an environmental component involved.
Dr. Dasig, who is also a neurology consultant at the Makati Medical Center, says that despite the volumes of literature on migraine, many theories still abound regarding its etiology and pathophysiology. The most popular of these are the vascular, endothelial cell, neuronal, and serotonin and dopamine theories. These theories do in some way explain most of the features associated with migraine.
Dr. Dasig recommends that clinicians investigate further any headache presenting with signs and symptoms suggestive of an underlying structural pathology, especially those that are potentially life-threatening.
If the headache turns out to be due to migraine, avoidance of precipitating factors and measures to relieve the headache and associated symptoms make up the initial treatment strategy.
Migraine may actually present with or without an aura and the headache can last anywhere from four to 72 hours. Aura is described as a hemisensory deficit with visual symptoms experienced hours or minutes before the actual headache. Migraine with aura is known as classical migraine; those without are called common migraine.
The typical stages of migraine begin with a promontory wherein the patient presents with irritability hours before the attack. Thern comes the aura. Whether or not the migraine is classical or common, the dilatation stage ensues. This is the stage where throbbing pain is felt in the temporal area, usually unilateral in presentation. Bilaterally throbbing temporal pain is actually less common as the unilateral pain in migraine.
The last stage is the postdrome syndrome where there is cerebral edema causing intense pain. At this point, patients have been observed to prefer sleeping in a dark, cool, and quiet room.
Despite the seemingly clear-cut description of the classical and common forms of migraine, there are atypical presentations known as migraine equivalents. Says Dr. Dasig: "Migraine equivalents are difficult to define. There is even a controversy as to whether they exist independently or are truly part of the migraine mainly because of the absence of headache."
Examples would be patients who present only with nausea and dizziness that may be be mistaken for vertigo or other causes of dizziness. Sometimes patients consult first with an ophthalmologist because they may present only with scintillating scotomas or photopsias. This latter case may actually be ophthalmic or retinal migraine. If ptosis presents, then the migraine may be ophthalmoplegic.
In complicated cases, the patient presents with migraine but with an associated persistent neurological deficit. Such cases may be a basilar migraine where the patient feels dizzy and feel photophobia and vertigo before the throbbing pain.
Hemiplegic migraine may present like a hemiplegic stroke followed by the headache. In either case, it may seem difficult to commit to a diagnosis of migraine because other causes of the symptoms have to be ruled out.
Keeping the Pain Down
Once migraine is established, lifestyle modification and preventive and palliative measures may be taken. Lifestyle modifications help lessen the recurrence of headaches, which can be achieved by circumventing triggers.
If the cause of the migraine is hormonal, then oral contraceptives may be used to regulate the hormones. If diet is the trigger, then avoiding culprit foods and hunger may be practised. Likewise, physical and emotional stress and anxiety may be put at bay with stress management programs or activities.
Symptomatic treatment can be initiated with pharmacologic agents that act on different levels of the migraine process. Tryptans are serotonin agonists mainly selective to the serotonin 1B/1D receptors. These do not activate other serotonin receptors, keeping the effects of the drug limited to the target receptors.
Since serotonin receptors are also located in cardiac muscles, these drugs are not recommended for persons at risk of developing ischemic heart disease. Studies on tryptans have shown this class of drugs to be highly effective during an acute migraine attack.
On the other hand, ergotamine and dihydroergotamine are non-selective serotonin receptor agonists that effectively vasoconstrict dilated vessels. Ergot alkaloids are known to induce ergotism, a condition where headaches develop because of a decrease in the blood levels of the ergot alkaloids especially after the body has been accustomed to a sustained level of the pharmacologic agent.
Nonsteroidal antiinflammatory drugs (NSAIDs) have shown some use. However, precautions with chronic NSAID use should be exercised to avoid NSAID-induced gastropathy.
Prophylactic medication is available and may be used when indicated. Tricyclic anti-depressants (amitriptyline) usually top the list, followed by beta blockers (propranolol, metoprolol), calcium channel blockers (flunarazine, verapamil) and serotonin-selective reuptake inhibitors (SSRIs). Anticonvulsants (carbamazepine, lamotrigine, and gabapentin) may also be used but are not on top of the list. Dr. Dasig says that these drugs may not relieve acute pain when taken during a migraine attack but would decrease the frequency and severity of headaches when taken regularly.
Dr. Dasig stresses that proper diagnosis will have to be established and the right therapy must be initiated to effectively control the attacks. Despite being benign, migraine's impact on the quality of life and the productivity of those affected can be severe. It is, therefore, important to establish the triggers, control them if possible, and prescribe the most appropriate medication for the patient.
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