hypnic headache ( hh ) is a primary headache disorder characterized by attacks that occur only during sleep .
it was first described by raskin in 1988 . since then , about 100 similar cases have been reported in the literature .
however , recently two cases of probable hh are reported in the children less than 10  years [ 3 , 4 ] .
we report a case of relapsing  remitting variety of hh in an adolescent who showed complete response to indomethacin .
a 19-year - old male presented with a 4-year history of relapsing  remitting type of nocturnal headache , which awakened him during sleep . in each relapse
, he had headache almost every night at a consistent time ( about 12  a.m. ) , 34  h after he fell asleep .
the periods of relapse and remission were variable , few weeks to 6  months .
the patient described the headache as non - throbbing and moderate to severe in the intensity .
however , it used to become bilateral in about 10% of the attacks ( especially with severe attacks ) .
the usual duration of attacks was about 60  min ( range 30  min to 5  h ) .
he denied nausea , vomiting , photophobia , phonophobia , any autonomic features , and restlessness during the attacks .
however , rarely , after falling back to sleep he was awakened with another similar headache , usually occurring 34  h after the first attack .
the patient noticed that at least 3  h sleep was essential to get an attack .
because of the fear of an attack , he used to wake ( spontaneously or with the help of an alarm clock ) within 3  h of the onset of sleep .
he would have an attack , immediately or within an hour , if he again goes to bed in less than 60  min after the awakening . waking for the 12  h
a nap of more than 34  h even during the daytime was occasionally associated with the similar type of headache .
the patient consulted in our out patient clinic in the recent relapse of the headache , that was going on for the last 2  months .
the patient was alcoholic , but did not recall any relation of alcohol intake to the onset , frequency , duration , or severity of headache .
he had a trial of sodium valproate ( 500  mg bid ) , amitryptiline ( 75  mg od ) , duloxetine ( 60  mg bid ) , naproxen ( 500  mg bid ) , ibuprofen ( 600  mg tds ) , and propranolol ( 60  mg bid ) .
he could not recall any effect of these drugs in the frequency or severity of headache .
treatment with oral sumatriptan ( 100  mg ) , oral rizatriptan ( 5  mg ) , and oxygen inhalation during an attack provided no relief .
it was ineffective with 25  mg dose ( bedtime ) . gradually increasing the dose to 75  mg at the bedtime ( over 4  days ) produced complete relief .
drug was restarted with the same dose and response was noted on the same day . as patient had relapsing 
remitting course in the past , slow tapering ( over 7  days ) was tried on two occasions in the next 2  months .
the second trial was successful and patient did not have any type of headache in the next 3  months . however , his symptoms recurred after 3  months .
this patient presented with a type of headache fulfilling the international headache society ( ihs ) criteria of hh .
hh is incorporated into group 4 of the ihs classification in the subheading of  other primary headaches  .
the differential diagnosis of headache with an exclusive onset during sleep includes secondary headache and primary headaches such as migraine , trigeminal autonomic cephalalgias and hh . exclusion of intracranial disorders and differentiation from one of the trigeminal autonomic cephalalgias is recommended in the patient of hh in the ihs diagnostic criteria . the features against the diagnosis of cluster headache ( ch )
were the absence of autonomic features and restlessness , no response to triptans and oxygen inhalation during the attacks , and response to indomethacin as a preventive therapy .
the absence of autonomic features , duration up to 5  h , only one attack per day , and bilateral involvement in few attacks were against the diagnosis of paroxysmal hemicrania .
the mean age at onset of headache is 63  years.the onset after the age of 50  years is one of the features in the ihs diagnostic criteria of hh ( although not essential ) .
to the best of our knowledge , he is the youngest person reported who fulfills the diagnostic criteria for hh .
there are two case reports of probable hh in the literature younger than 15  years [ 3 , 4 ] .
besides the age , these two patients did not fulfill the criteria regarding the frequency of attacks per month .
the frequency of more than 15 attacks per month is essential in a person less than 50  years of age .
reported a 9-year - old girl with hypnic - like headache with frequency of 23 attacks per week .
recently , scagni et al .   described an 8-year - old girl with a 5-year history of hypnic - like headache with frequency of one attack per month , and suggested that lower frequency might be observed in children with hh .
these two cases and our observation suggest that the age range at onset may be broader than initially claimed .
the intensity of pain is moderate to severe in more than 95% patients in the literature .
the usual time of onset of the headache attacks in the course of sleep is 24  h after falling asleep .
three hours sleep was usually required to get an attack of headache in our patient .
the average duration of attacks is about 1  h. however , the range may be 15360  min .
the maximum duration of an attack in our patient was about 5  h. the average frequency of headaches is about 1.2 .
however , the patients may have six attacks per night to one in a week .
the episodic form is further subdivided into two types , episodic with no recurrence , and relapsing and remitting variety ( and relapse is not because of withdrawal of the effective drug ) .
episodic form without recurrence may show spontaneous resolution or sustained remission even after withdrawal of the effective drug [ 5 , 6].our case was relapsing  remitting type .
there are only six cases of relapsing  remitting type in the literature ( and 5 of them were reported recently ) [ 5 , 9 ] .
lithium ( 300600  mg at the bedtime ) is the most effective drug for the patients with hh .
the efficacy similar to lithium could be obtained with caffeine , flunarizine , and indomethacin .
the response to indomethacin in our patient confirms this notion ( as our patient had predominantly unilateral headache ) .
peters et al .   reported indomethacin responsive hh in patients with bilateral and holocephalic pain .
the effective dose of indomethacin for the patients of hh is 25150  mg at bedtime ( mean 75  mg ) .
there was temporal relation in the disappearance of headache and the administration of indomethacin on four occasions in the patient .
however , we can not rule out the possibility of coincidence ( disappearance of headache and the administration of indomethacin ) in our patient , as he had many episodes of spontaneous relapse and remission in the past .
the reason as to why few primary headache ( including hh ) disorders are indomethacin sensitive is unknown .
the effects of many other drugs ( such as lithium , melatonin , caffeine , flunarizine , etc . ) in the patients of hh suggest that pathophysiology may be heterogeneous .
the adverse effects of indomethacin in the patients of hh are largely unknown as long - term follow up is lacking in the literature .
although indomethacin is used as a single dose ( bedtime ) in hh ( bid or tds in other headache disorders ) , it is difficult to predict the incidence of side effects as most of the patients are elderly .
daytime headaches were one of the unique side effects of indomethacin in the patients of hh ( not reported with other types of headache ) .
moreover , this case suggests that frequent tapering of the effective drug should be done to look for the spontaneous resolution or relapsing  remitting variety of hh .
 hypnic headache ( hh ) is a rare sleep - associated primary headache disorder that usually begins after the age of 60  years . 
 here we report a 19-year - old male with 4-year history of predominantly left sided hh . 
 he is the youngest person reported who fulfills the ihs diagnostic criteria for hh . 
 the patient had history of relapsing  
 remitting course . 
 the headache occurred every night at a constant time in each relapse . 
 it was non - throbbing , moderate to severe , for 30  min to 5  h , and usually after 3  h of sleep . 
 the patient showed complete response to indomethacin ( 75  mg at bedtime ) . 
 frequent tapering of indomethacin was required to look for the remission phase . 
Introduction
Case report
Discussion