epicrania fugax ( ef ) is a novel syndrome first described by pareja et al .   in 2008 in ten patients that complained of a very brief unilateral pain paroxysms , starting in posterior cranial regions and rapidly spreading to ipsilateral eye , forehead or nose , along a linear or zigzag trajectory . in some cases ,
pain was accompanied by autonomic signs such as conjunctival injection , lacrimation or rhinorrhea . to this first series
, 15 new patients with the same clinical features have been added , so reinforcing the proposal of ef as a new headache variant or a new headache syndrome [ 24 ] .
recently , two patients who fulfilled all the characteristics for ef except the direction of radiation have been reported .
since the first description of bref in february 2010 , we made , in an outpatient headache clinic located in a tertiary hospital , a prospective search of the patients complaining of brief pain paroxysms running front to back , from anterior to posterior cephalic regions . as we searched for a novel headache syndrome
a detailed history was obtained in all the cases , including precipitant event and the coexistence of other types of headache .
the characteristics of pain paroxysms were carefully evaluated , including temporal features ( duration and frequency ) and spatial features ( site of origin , trajectory , and site of ending ) .
other characteristics such as pain quality , pain intensity ( assessed with a visual analogical scale ) , or pain accompaniments , especially autonomic signs have been included .
subsequently , a complete physical and neurological examination was performed , including inspection , palpation and sensory examination of the stemming area , as well as palpation of the supraorbital , infraorbital , supratrochlear , minor occipital and greater occipital nerves . computed tomography or magnetic resonance imaging of the head , and routine blood work - up with erythrocyte sedimentation rate and immunological screening
we also made a prospective search of patients with a clinical picture from march 2008 , which would be comprised under the headings or epicrania fugax with forward radiation , as was described by pareja at al .
we compared the characteristics of both groups with a chi - square test and also fisher s exact test , if necessary .
through a one - year period , we assessed nine patients ( four males , five females ) , with pain paroxysms comparable to bref . mean age at onset was 43.4    13.1  years ( range 2662 ) .
demographic and clinical features of these nine patients are shown in table  1 . through a three - year period ,
18 patients ( 6 males , 12 females ) with fref were attended in our headache clinic .
comparison of demographic and clinical characteristics in bref and fref patients is summarized in table  2.table  1demographic and clinical features of nine bref patientspatient no.123456789sex ( m / f)fmfmmffmfage ( years)654639525828533329age at onset623939525826533329other headachesnomigrainemigrainetensin - typemigrainenononomigraineinterictal painnononononocircumscribedcircumscribednonopain paroxysmshead sideleftrightleftleftrightleftrightrightleftsite of origineyeforeheadeyeeyeeyefrontalfrontalfrontaleyesite of endoccipitaloccipitaloccipitaloccipitalparietalparietaloccipitaloccipitaloccipitaltrajectorylinearlinearlinearlinearlinearlinearlinearlinearlinearcharacterstabbingstabbingburningstabbingpressingstabbingelectricstabbingstabbingduration ( sec)551031533155intensity ( vas)6710459975accompanimentsnonononotearing itching eyerhinorrhoea itching eyenonoitching eyetriggersnonononophysical activitytouchnononofrequency8/day12/week1/week1/day1/day20/day20/day12/day1/daytemporal patternchronicremittingremittingchronicremittingchronicchronicchronicchronictherapyamitriptylinenonoamitriptylinegabapentinlamotriginecarbamazepinegabapentinegabapentineresponsecompletecompletenocompletecompletepartialpartialm male , f female , vas visual analogical scale ( 0 : no pain , 10 : the worst imaginable pain)table  2main features of bref and fref patientsbref ( n  =  9)fref ( n  =  18)sex ( f / m)5/412/6age at onset ( mean    sd)43.4    13.142.5    17.7duration sec ( mean    sd)7.1    4.95.7    4.3frequency / day ( mean    sd)7    8.49.9    15.4intensity vas ( mean    sd)6.9    2.16.8    2.1autonomic signs3/910/18interictal pain2/910/18triggers2/94/18preventative requirement7/912/18bref backward radiation epicrania fugax , fref forward radiation epicrania fugax m male , f female , sd standard deviation , sec seconds vas visual analogical scale ( 0 : no pain , 10 : the worst imaginable pain ) demographic and clinical features of nine bref patients m male , f female , vas visual analogical scale ( 0 : no pain , 10 : the worst imaginable pain ) main features of bref and fref patients bref backward radiation epicrania fugax , fref forward radiation epicrania fugax m male , f female , sd standard deviation , sec seconds vas visual analogical scale ( 0 : no pain , 10 : the worst imaginable pain ) we found no differences between bref and fref , respectively , in age at onset ( 43.4    13.1 vs. 42.5    17.7  years ) , and female / male ratio ( 5/4 vs. 12/6 ) .
a complete examination of stemming points did not reveal trophic changes in any of the patients and sensory disturbances were appreciated in 8 out of 12 patients , who suffered interictal pain .
palpation of pericranial nerves did not detect abnormal findings , and laboratory tests and imaging studies were also normal in all the cases .
pain paroxysms were strictly unilateral in all bref patients ( in five cases on the left and in four on the right ) .
four cases described a history of migraine and one of tension - type headache , but ef was considered as quite different from the other headaches .
pain started in eye ( n  =  5 ) , forehead ( n  =  1 ) or frontal region ( n  =  3 ) , and inmediately spread backwards along a linear trajectory to occipital ( n  =  7 ) or parietal ( n  =  2 ) scalp . in two of the patients , there was an interictal pain in stemming point located in a circumscribed area , resembling nummular headache
paroxysms were described as stabbing in most of the patients ( n  =  6 ) , or as electric , burning or pressing ( 1 patient each ) .
there was no significant difference between bref and fref , respectively , in paroxysms duration ( 7.1    4.9 vs. 5.7    4.3  s ) , pain intensity in a 010 visual analogical scale ( 6.9    2.1 vs. 6.8    2.1 ) , frequency of episodes per day ( 7    8.4 vs. 9.9    15.4 ) , presence of triggers ( 22.2 vs. 22.2% ) and prophylactic treatment requirement ( 77.7 vs. 66.6% ) .
patients in bref group presented less frequently interictal pain in stemming point ( 22.2 vs. 55.5% ) and accompanying autonomic signs ( 33.3 vs. 55.5% ) , but in both the cases without statistical significance .
in 2008 , pareja et al .   described a headache whose features did not fit any of the acknowledged headaches and they named it as epicrania fugax .
this headache was framed within epicranias , a term proposed to group all the headaches that apparently stem from the superficial or extracranial structures , including the scalp and the layers of the skull .
common to this group of pain syndromes are a focal location or a sequence of multidirectional paroxysms , shortage of autonomic signs , and a dysesthesic area .
regarding ef , there are several entities to which differential diagnosis have to be considered . for instances ,
psh is a primary headache syndrome , with a female preponderance , characterized by short ( 3  s or less ) stabbing pain paroxysms in a localized area that start and end in the same place [ 10 , 11 ] .
frequency of paroxysms is highly variable and they usually occur with an irregular or sporadic temporal pattern .
though the consecutive stabs may sporadically shift from one region to another giving an illusion of movement , clinical radiation observed in ef is definitely not typical for psh .
nummular headache ( nh ) resembles ef in the presence of a focal painful area .
pain in nh is typically continuous and , when paroxysms are superimposed , they begin and end in situ [ 9 , 13 ] .
eight of our patients ( two in bref and six in fref groups ) had a nummular type head pain in the stemming area between ef paroxysms , as it has been previously described [ 3 , 14 ] .
lacrimation , rhinorrhoea and itching eye are autonomic signs that appears in some of our patients .
these signs are typical of other headache syndromes such as sunct ( shortlasting , unilateral , neuralgiform headache attacks with conjunctival injection and tearing ) or suna ( shortlasting , unilateral , neuralgiform headache attacks with cranial autonomic features )
. these headaches are also present with painful neuralgiform attacks in the orbital and periorbital regions , triggered by tactile stimuli on trigeminal and extrageminal territories , and lasting from 2  s to 10  min .
however , the dynamic component of pain , either posterior  anterior or anterior  posterior , in fref and bref are inherent qualities of epicrania fugax , not described in sunct or suna . unlike sunct , suna   can be diagnosed with the presence of just one cranial autonomic feature and the attacks have a wider range of duration .
thus , some of ef patients could be diagnosed of suna but the presence of a dynamic component of pain in ef is a quality not described for suna [ 1618 ] .
this is the essential attribute of ef : a fast and ample  movement  of the pain through one side of the head , no matter where the stemming point is .
origin of this pain is probably peripheral according to the existence of a stemming or trigger zone in a focal area , and the stabbing or electric character of the pain .
paroxysms of pain can originate in the terminal branches of supraorbital nerve ( son ) or greater occipital nerve ( gon ) , and eventually extend to the peripheral fibers or branches .
it has been proposed that the spreading of the pain is due to the electric transmission or paracrine diffusion of chemical mediators .
central mechanisms in which trigeminal afferents are implicated can not be excluded , mainly in those patients presenting with autonomic signs .
we report nine patients with the same features described for ef , except the direction of radiation .
when we compare them with a group of patients fulfilling the characteristics of ef , we do not find differences between both the groups .
our report reinforces ef as an independent headache syndrome and proposes bref as a not infrequent variant of ef .
another option is to in considered bref and fref as the same entity with the different presentations .
 epicrania fugax ( ef ) is a novel syndrome , described as a paroxysmal and brief head pain , starting in posterior cranial regions and rapidly spreading forward ipsilateral eye , nose or forehead . 
 two patients with comparable clinical features stemming from frontal scalp to ipsilateral posterior regions have been recently described and proposed as backward radiation epicrania fugax ( bref ) . 
 we report a new series of nine bref and compare their clinical characteristics with 18 forward radiation ef ( fref ) . since first description of bref in february 2010 we have assessed nine patients ( four males , five females ) with this clinical picture at an outpatient headache office in a tertiary hospital . 
 comparison is established with 18 fref patients ( 6 males , 12 females ) , attended since the publication of first series of ef in march 2008 . 
 we found no differences between bref and fref , respectively , in age at onset ( 43.4    13.1 vs. 42.5    17.7  years ) , female / male ratio ( 5/4 vs. 12/6 ) , pain intensity ( 6.9    2.1 vs. 6.8    2.1 in a 010 visual analogical scale ) , duration ( 7.1    4.9 vs. 5.7    4.3  s ) and frequency of episodes per day ( 7    8.4 vs. 9.9    15.4 ) . 
 patients in bref group presented less frequently interictal pain in stemming point ( 22.2 vs. 55.5% ) and accompanying autonomic signs ( 33.3 vs. 55.5% ) , but without statistical significance in both the cases . 
 this series reinforces the proposal of ef as a new headache variant or a new headache syndrome . clinical picture of brief pain paroxysms starting in the anterior scalp and radiating backwards does not fit known headaches or neuralgias and might correspond to a reverse variant of ef , clinical characteristics of which are comparable to fref . 
Introduction
Methods
Results
Discussion
Conclusion