Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Lectures by Greg Podgorski, Utah State University Why Migraines Strike Current Issues in Biology, Volume 6 Scientific American
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike More than 300 million people worldwide suffer from migraine Migraine costs the U.S. roughly $17 billion each year in lost work, disability payments and health care expenses New understanding of the neurobiology of migraine give hope that effective treatment will be available soon
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike Migraine always involves severe headache and is often accompanied by nausea and sensitivity to light and sound About twice as many women as men suffer migraine The frequency and duration of migraine varies widely, with the average being one or two day-long attacks per month
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike There is a genetic influence in migraine, but the genetics are complex with many genes working with the environment to influence migraine susceptibility Migraine headache was long thought to be caused by a constriction of brain blood vessels We now know that brain blood flow increases prior to migraine and that this is unlikely to be the source of the pain
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike About 30% of migraine sufferers experience hallucinations known as aura before their headaches begin A spreading wave of intense neural activity in the brain’s cortex followed by a prolonged inhibition of the formerly excited cells occurs during aura Though first discovered in patients with aura, this cortical spreading depression probably underlies migraine pain in all migraine sufferers
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike Migraine pain comes when trigeminal nerves are activated and transmit pain signals from the membranes that surround the brain The pain signals are sent to an area in the brain stem called the trigeminal nucleus and eventually relayed to the sensory cortex, which is involved in pain perception An open question is what first activates the trigeminal nerve system in migraine
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike There are two schools of thought for how migraine pain in triggered One view is that cortical spreading depression induces pain
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike Another view of migraine pain is that malfunctioning neurons in the brain stem are the trigger
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike All current drugs to prevent migraine were developed for other disorders and work only 50% of the time in 50% of patients All these drugs inhibit cortical spreading depression, but only as a side-effect of their main action Drugs designed specifically to prevent cortical spreading depression and the onset of migraine are being developed
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike Drugs designed to treat rather than prevent migraine also have problems Triptans work through their side-effect of blocking a chemical signal between trigeminal neurons and the trigeminal nucleus The main effect of triptans is the unwanted action of constricting blood vessels throughout the body New drugs are being developed that specifically inhibit the release of chemical signals sent from the trigeminal neurons to the brain stem
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Why Migraines Strike Scientists and physicians are finally coming to see migraine as a complex, potentially treatable disorder, not an imaginary affliction
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Migraine affects more: a) men than woman b) woman than men c) older adults than younger adults d) younger adults than older adults
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Migraine affects more: b) woman than men
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension It was incorrectly thought that migraine is due to: a) decreased brain blood flow b) increased brain blood flow c) decreased activity of trigeminal neurons d) swelling of the membranes that surround the brain
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension It was incorrectly thought that migraine is due to: a) decreased brain blood flow
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Aura involves: a) severe pain before migraine headache b) severe pain after migraine headache c) hallucinations before migraine headache d) the headache of migraine
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Aura involves: c) hallucinations before migraine headache
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Cortical spreading depression is: a) the psychological depression experienced by many migraine sufferers b) a spreading wave of nerve activity depression in the Raphe nucleus of the brain stem c) a wave-like activation of the trigeminal neurons d) a spreading wave of nerve stimulation followed by nerve inactivity in the brain’s cortex
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Cortical spreading depression is: d) a spreading wave of nerve stimulation followed by nerve inactivity in the brain’s cortex
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension The pain of migraine is triggered when: a) trigeminal neurons transmit pain signals from the membranes surrounding the brain b) cortical spreading depression reaches the pain processing center of the cortex c) increased blood flow causes the brain to swell d) light or sound induce increased nerve stimulation in hypersensitive individuals
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension The pain of migraine is triggered when: a) trigeminal neurons transmit pain signals from the membranes surrounding the brain
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Current generation drugs to treat or prevent the onset of migraine: a) were developed to prevent cortical spreading depression b) were developed to block specific chemical signals between the brain stem and cortex c) were developed to decrease the activity of trigeminal neurons d) work almost entirely through their side-effects
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension Current generation drugs to treat or prevent the onset of migraine: d) work almost entirely through their side-effects
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension A promising target for drugs to treat migraine pain is: a) blocking the chemical signal sent from trigeminal neurons to the brain stem b) increasing the extent of cortical spreading depression c) constricting blood vessels in the brain d) suppressing nerve activity throughout the brain
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Testing Your Comprehension A promising target for drugs to treat migraine pain is: a) blocking the chemical signal sent from trigeminal neurons to the brain stem
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Thinking About Science If nerve clusters in the brain stem inhibit trigeminal neurons from firing, what would be a promising approach to preventing migraine pain? a) develop drugs that increase the activity of brain stem nerve clusters b) develop drugs that decrease the activity of brain stem nerve clusters c) develop drugs that increase the activity of trigeminal neurons d) develop drugs that decrease the sensitivity of trigeminal neurons to the signal from brain stem nerve clusters
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Thinking About Science If nerve clusters in the brain stem inhibit trigeminal neurons from firing, what would be a promising approach to preventing migraine pain? a) develop drugs that increase the activity of brain stem nerve clusters
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Biology and Society If migraines affected more men than woman, migraine research would be more advanced because migraine would not have been viewed as an imaginary affliction Strongly Agree Strongly Disagree A. E. C. B. D.
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Interpreting Charts and Graphs In this model, which of the following would NOT be a reasonable approach to preventing migraine pain? a) block cortical spreading depression b) increase the efficiency of signaling between the trigeminal neurons and brain stem c) decrease the output of the signal from the brain stem to the thalamus d) decrease the sensitivity of the thalamus to the signal from the brain stem
Copyright © 2010 Pearson Education, Inc. publishing as Benjamin Cummings Why Migraines Strike Interpreting Charts and Graphs In this model, which of the following would NOT be a reasonable approach to preventing migraine pain? b) increase the efficiency of signaling between the trigeminal neurons and brain stem