Directory of health resources for healthcare professionals.

There are many types of drugs that can prevent migraine in sufferers who have frequent attacks. There would be little point in taking tablets every day if the attacks occur only once a year. Even monthly attacks, particularly when mild or responsive to simple remedies, should not require regular medication. It is when attacks occur several times a month and are interfering with life’s ordinary activities that daily tablets may restore a patient to a normal life.1. There can be little doubt that there is a familial tendency although its strength and the way in which migraine is inherited are still debatable. No drugs can alter this susceptibility.2. There are predisposing or provocative factors which trigger an attack in a sensitive individual. These include factors such as stress, tension, or depression and drugs are very effective in relieving these factors.3.   Drugs can interfere with the biochemical changes that occur before or during a migraine attack
*58/152/5*

No conscious awareness of anything is possible until it has captured our attention. Our sense organs in the eyes, ears, nose and body are in continuous action, day and night, whether we are awake or asleep. The central nervous system receives steady reports of all the events these sense organs are capable of detecting. Obviously, it would be a disaster of excess if we were continuously aware of the entire mass of arriving information. We completely ignore most of the information most of the time. And yet any fraction of this inflow is capable of riveting attention. For this to happen, there has to be a selective attention mechanism which must have a set of rules. Those rules are not arbitrary. Every species displays its rules, which incorporate a selection of those events that are important to its survival and well-being. Some rules seem to be built in. Large, sudden, novel occurrences have precedence in their attention-grabbing ability. I propose, that the arrival in the nervous system of messages signalling tissue damage is another of these built-in high-priority events.In some species the built-in selection can be very precise. At London Zoo, Ronald Melzack arranged for a cut-out cardboard outline of a hawk, with its characteristic short head and long tail, to be dragged on wires above ducklings raised in isolation. They froze and peeped alarm calls. To reset the apparatus, he dragged the cardboard cut-out backwards across the ducklings. Now they saw a short tail and long neck and crackled with delight at the possible arrival of mother.Obviously there is a learned component of our selective attention mechanism. The bored radar operator sits staring at the screen, which is a snow storm of random blinking dots. Let one of these dots begin to move in a consistent line and attention locks onto that dot to the exclusion of all others. Let a migraine sufferer detect a small twinkling area in the visual field and his attention is riveted on this trivial event because he has learned that the aura of his oncoming migraine attack begins with just such a scintillating area.In social animals, subtle triggers of attention can be shared. In West Africa, two species of monkeys feed together in flocks but eat different fruits. Their main enemy is the monkey eagle. One of the species is quicker than the other to spot arriving eagles, so both species benefit from the alarm of one. In Australia, a grouse selects her ground nest close to a tree containing a hawk because the hawk’s superior height and eyesight detects distant predators long before the earthbound grouse can. And so it is with humans, where attention is infectious.The attention mechanism must be continuously scanning the available information in the incoming messages and assigning a priority of biological importance. We have already described as an example of ‘thoughtless’ decision, the switch of attention in the car driver who is in conversation with a passenger while engaged in ‘unconscious’ skilled driving, until some fool cuts in front of him, whereupon attention promptly switches from conversation to avoidance. This brings out the second rule of selective attention, which is that only one target at a time is permitted. Obviously, it is possible to switch attention back and forth quite rapidly. However, at any one instant, only one collection of information is available for conscious sensory analysis. This one object can itself be preset. An example is the detection of your name being mentioned in the random buzz of conversation at a cocktail party. Similarly it is possible to scan a long list of names and detect the one you seek with no recall of any of the other names.It is not intuitively obvious that attention can be directed to only one subject at any one time. It would seem a rather ridiculous limitation in a mental process that clearly has freedom to rove over vast areas: ‘Shoes and ships and sealing-wax, cabbages and kings’, as Lewis Carroll put it. An explanation for this strict limit on attention could be that sensory events are analyzed in terms of the action that might be appropriate to the event. If the aim of attention relates to appropriate action, then it follows that a fundamental requirement of nature is that only one action at a time is permitted. It is not possible to move forwards and backwards simultaneously. You must make up your mind. The explanation for the singularity of momentary attention would then derive from the purpose of attention, which is to assemble and highlight those aspects of the sensory input which would be relevant to carrying out one act.Of course, rival sensory events may compete for attention. The tale of the ass who starves to death when placed equidistant between two bales of hay is indeed a myth that would never happen. Even real asses have a built-in requirement to make a choice. There may be many events occurring simultaneously, each of which demands attention. They are ordered by rank into a hierarchy in terms of biological importance. The practical consequence of this ordering was described repeatedly in the earlier chapters on the apparent paradox of the painless injury. Each of these victims was involved in a situation where some action, other than attending to their wound, had top priority. Getting out of a burning aircraft is more urgent than attending to a broken leg, for example. The attention does not oscillate between the two demands. One is assigned complete domination until safety is achieved. Only then is the alternative assigned the top position, attention shifts and pain occurs.The workman in the course of a skilled task and the footballer about to score a goal carry on to complete the task with full attention despite the conflicting demands of their coincidental injury. Only when the conditions of the top priority fade is there a reassessment of the next most urgent priority. In conditions of complete ‘emergency analgesia’, pain emerges as the dominant fact when the emergency is over. This priority ranking of importance is partly built in, partly learned from personal experience and partly a component of culture.Therapy that is based on a moulding of attention is effective. It is called distraction. When a toddler trips, smacks into the pavement and howls, what does a parent do? Pick it up, dance about, utter the inane ‘coo’, ’00′ and ‘ah’, and kiss it better. These are distractions. Because you can attend to only one thing at a time, it also follows that you can have only one pain at a time. This fact led to many excellent folk remedies, such as hot poultices, horse linaments and mustard plasters. They are called counterstimulants. When pain really sets in, attention is utterly monopolized and nothing else exists in the world but the pain. Many therapies attempt to intrude on this fixation. The distraction that is effective may be simple but it will depend on established priorities. A game of cards, letting the cat out, or the sight of a hated neighbour can provide a brief interlude in pain. Some victims discover this for themselves and prolong their brief holidays from pain by inventing distractions; others get professional help in occupational therapy.In another distraction therapy, given the pretentious title of cognitive therapy, the victim learns to daydream and play out an internal fantasy. It may be that they are on a warm sunny beach, or at a football match or in their favourite bar. Some people can become very skilled at these distractions and give themselves longer and longer respites from their miserable pain*73\219\2*