Abstract text (incl. figure legends and references)

Background: SARSCoV2 the virus responsible for the COVID19 pandemic had not only respiratory symptoms,but also neurological symptoms, and headache is a frequent complaint.Pathophysiology of headache in the context of COVID 19 has some mechanisms that can be involved in persistence of headache after acute stage of the disease. These mechanisms include systemic inflammation that can stimulate cytokine storm,can activate trigeminovascular system at the meninges,and in some patients this inflammatory response may be sustained after infection and can play role at post Covid headache. Methods:We have seen 510 patients that have been presented at emergency department and neurology consult at SRDwith headache after covid 19(2-10months after infections).15%of patients had severe covid infections with respiratory insuficience and have been recovered in hospital(76 patients)and85%(434 patients) have been treated ambulatory.the most of patients had bilateral frontal headache(52%)and holocranic headache(22%), and hemicranic migraine type(26%). Most of patients had oppressive pain,72%(367 patients)had moderate headache and 28%(143patients) had severe continous headache. Middle age of patients was52years old and65%were female(331)and 35%male(179) and mean time of headache was 3.6month from all patients 30%(153 patients) have been known with primary headache, and76%had migraine (116 patients,78 female,38 male),22%tensive type headache (34 patients, 20 female and 14 male) and2% had cluster headache (3patients were mens) .From all 510 of patients 45%(230) had also other post covid symptoms like dizziness,memory problems, insomnia,brain fog,depression and anxiouse state etc. Conclusions:The mechanisms of persistent headache for months after covid 19 infections means to be stimulate by inflammatory mechanisms with stimulation of the trigeminovascular system,andCGRP (calcitoni gene-related peptide) released by pulmonary endings nerve during viral infections may stimulate migraine.