Besides a general correlation between the two diseases , the migraine attack itself temporarily correlates with RLS episodes . In a study done at China Medical University in Taiwan , Dr . Chen and his colleagues studied patient diaries that record both migraine headaches episodes and RLS episodes . They found that a patient is more likely to experience a RLS episode within 2 days of a migraine attack . In addition , there is a correlation between the severity of the migraine and the RLS – the worse the migraine , the worse the RLS episode that develops . This correlation , however , does not support the opposite as migraine attacks tend to follow RLS attacks only within one day .
The reason why the two diseases are correlated is unknown in part due to our lack of knowledge of the exact neurological mechanism for RLS . And , to some extent , what triggers a migraine attack . There are , however , various educated speculations . One theory is that sleep quality confers a common link between the two diseases . Patients with RLS tend to have poor sleep qualities ( from both the symptom of leg discomfort as well as the syndrome itself ) and as many migraineurs would agree , a poor night ’ s sleep can often trigger a migraine attack . As Dr . Oosterhout from Leiden University Medical center stated : “ Restless leg syndrome is associated with lower sleep quality and fragmented sleep , which are known triggers for migraine attacks .”
Of course , he does not preclude the possibility of another hypothesis – that a neurochemical called dopamine is the cause of both conditions . Dopamine is a chemical in the brain that modulates rewards and risk-taking behaviors . It is also implicated in both RLS and migraine . Dopamineblocking medications , for example , have been shown to help with migraine . Medications that act like dopamine in the brain ( dopamine agonists ), on the other hand , tend to
help with RLS . Dr . Chen , who reported on the migraine diary study , postulates that as dopamine tends to be lower at night but higher during the day , this diurnal imbalance may precipitate the characteristic night time attacks of RLS . Incidentally , levels of serotonin , a sister neurochemical molecule that works against dopamine and prevents dopamine ’ s release , are high after a migraine attack . This transient opposition after a migraine , Dr . Chen argues , maybe what provokes RLS after a migraine .
However , dopamine is not the only link between migraine and RLS . Researchers have also speculated that iron homeostasis ( balance ) might be a culprit . Iron is an important factor in dopamine and iron deficiency is one of the most common causes of RLS . Incidentally , while iron levels are normal in migraineurs , MRI studies offer some evidence that abnormal iron deposs in the brain may be involved in migraine attacks . It is possible that the iron imbalance between how the body allocates iron in the brain versus the rest of the body may play a part in both migraine and RLS . The iron hypothesis has support in genetic research . In a paper published in 2015 , Dr . Fuh from Taiwan ’ s National Yang-Ming University School of Medicine suggests that a gene called MEIS1 is associated with increased risk of RLS in migraine patients . This gene plays a part in the iron transportation pathway in the body . Dr . Fuh ’ s team speculated that variations of MEIS1 gene affects iron transportation which in turn affects dopamine , causing RLS and migraine .
Regardless of the cause of restless leg syndrome and migraine , RLS is an important syndrome to recognize in migraine . As Dr . Chen suggests , if there really is a bidirectional link between RLS and migraine severity ( and frequency ), then improvement in one syndrome may benefit the other . HW
22 HeadWise ® | Volume 6 , Issue 3 • 2017
170767 _ LOT A _ NHF Feb 2017 Vol . 6 Issue 3 . indd 22 2 / 15 / 17 12:48 AM