All Stories

  1. Risk-factors and multimorbidity in oral anticoagulant-related intracerebral haemorrhage: a comparison of patients in pivotal trials and real life
  2. Development of an electronic patient-reported outcome questionnaire for use at post-stroke follow-up: a complex intervention and programme theory development
  3. Stroke recurrence and all-cause mortality in CPAP-treated sleep-disordered-breathing patients
  4. Circadian rhythm and the influence of light on parameters related to calcium metabolism in stroke patients admitted for rehabilitation
  5. Intravenous glibenclamide for cerebral oedema after large hemispheric stroke (CHARM): a phase 3, double-blind, placebo-controlled, randomised trial
  6. Carbonated Beverage, Fruit Drink, and Water Consumption and Risk of Acute Stroke: the INTERSTROKE Case-Control Study
  7. Dynamic cerebral autoregulation during and 3 months after endovascular treatment in large-vessel occlusion stroke
  8. Cerebral blood flow and cognition after 3 months tadalafil treatment in small vessel disease (ETLAS-2): study protocol for a randomized controlled trial
  9. Tea and coffee consumption and risk of acute stroke: The INTERSTROKE Study
  10. Use of combination therapy is associated with improved LDL cholesterol management: 1-year follow-up results from the European observational SANTORINI study
  11. Blood pressure variability in acute stroke: Risk factors and association with functional outcomes at 1 month
  12. Tobacco use and risk of acute stroke in 32 countries in the INTERSTROKE study: a case–control study
  13. Pre‐morbid sleep disturbance and its association with stroke severity: results from the international INTERSTROKE study
  14. Variations in the prevalence of atrial fibrillation, and in the strength of its association with ischemic stroke, in countries with different income levels: INTERSTROKE case–control study
  15. Effect of the Factor XIa Inhibitor Asundexian According to Baseline Infarct Pattern and on MRI Covert Infarct Outcomes
  16. Circadian Temperature in Moderate to Severe Acute Stroke Patients
  17. Intravenous Thrombolysis in Patients With White Matter Hyperintensities in the WAKE-UP Trial
  18. Pleocytosis in cerebrospinal fluid attributed to ischemic stroke: A review of the literature
  19. Sleep Patterns and the Risk of Acute Stroke
  20. Depressive Symptoms and Risk of Acute Stroke
  21. High-intensity training in patients with lacunar stroke: A one-year follow-up
  22. Patient-tailored transcranial direct current stimulation to improve stroke rehabilitation: study protocol of a randomized sham-controlled trial
  23. Cortical hemodynamic response during cognitive Stroop test in acute stroke patients assessed by fNIRS
  24. Autonomic dysfunction after mild acute ischemic stroke and six months after: a prospective observational cohort study
  25. Alcohol Intake as a Risk Factor for Acute Stroke
  26. An Explorative Investigation of the Effect of Naturalistic Light on Agitation-Associated Behavior in Nursing Home Residents With Dementia: A Pilot Study
  27. Association of Psychosocial Stress With Risk of Acute Stroke
  28. Capillary transit time heterogeneity inhibits cerebral oxygen metabolism in patients with reduced cerebrovascular reserve capacity from steno-occlusive disease
  29. Processes of Care and Associated Factors in Patients With Stroke by Immigration Status
  30. Corrigendum: Sex-differences in oral anticoagulant-related intracerebral hemorrhage
  31. Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events
  32. Reducing delay to endovascular reperfusion after relocating a thrombolysis unit
  33. Factor XIa inhibition with asundexian after acute non-cardioembolic ischaemic stroke (PACIFIC-Stroke): an international, randomised, double-blind, placebo-controlled, phase 2b trial
  34. Long-term immune cell profiling in stroke patients with or without infections
  35. Immigration status and utilization of secondary preventive treatment after ischemic stroke
  36. Association of Lipids, Lipoproteins, and Apolipoproteins with Stroke Subtypes in an International Case Control Study (INTERSTROKE)
  37. Implications of ACC/AHA Versus ESC/EAS LDL-C Recommendations for Residual Risk Reduction in ASCVD: A Simulation Study From DA VINCI
  38. A Systematic Review of the Circadian Rhythm of Bone Markers in Blood
  39. Is the TOAST Classification Suitable for Use in Personalized Medicine in Ischemic Stroke?
  40. Use of reperfusion therapy and time delay in patients with ischaemic stroke by immigration status: A register‐based cohort study in Denmark
  41. Quantification of Tau-A in serum after brain injury: a comparison of two analytical platforms, ELISA and electrochemiluminescence immunoassay
  42. Sex-Differences in Oral Anticoagulant-Related Intracerebral Hemorrhage
  43. Melatonin profile in healthy, elderly subjects - A systematic literature review
  44. Role of Proxy Respondents in International Stroke Research: Experience of the INTERSTROKE Study
  45. Atrial fibrillation after closure of patent foramen ovale in the REDUCE clinical study
  46. Clinical outcomes of light therapy in hospitalized patients – A systematic review
  47. Patent Foramen Ovale Closure Decreases the Incidence but Not the Size of New Brain Infarction on Magnetic Resonance Imaging: An Analysis of the REDUCE Trial
  48. Workforce Attachment after Ischemic Stroke – The Importance of Time to Thrombolytic Therapy
  49. Impact of the circadian clock on fibrinolysis and coagulation in healthy individuals and cardiovascular patients – A systematic review
  50. Stroke admissions and revascularization treatments in Denmark during COVID‐19
  51. Incidence of stroke, transient ischaemic attack and determinants of poststroke mortality among immigrants in Denmark, 2004‒2018: a population-based cohort study
  52. Sleep-disordered breathing and cerebral small vessel disease—acute and 6 months after ischemic stroke
  53. Assessment of patients with a suspected cardioembolic ischemic stroke. A national consensus statement
  54. Trends in incidence of oral anticoagulant-related intracerebral hemorrhage and sales of oral anticoagulants in Capital Region of Denmark 2010–2017
  55. Global Impact of COVID-19 on Stroke Care and IV Thrombolysis
  56. Five-Year Outcomes of PFO Closure or Antiplatelet Therapy for Cryptogenic Stroke
  57. Importance of Rapid Clinical Recognition of the Anterior Opercular Syndrome (Foix-Chavany-Marie Syndrome): A Case Report
  58. Specialized Outpatient Clinic vs Stroke Unit for TIA and Minor Stroke
  59. Sudden Bilateral Deafness in a Patient with Transient Ischemic Attack: A Case Report
  60. Renal Impairment and Risk of Acute Stroke: The INTERSTROKE Study
  61. Variations in knowledge, awareness and treatment of hypertension and stroke risk by country income level
  62. Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial
  63. Urinary Sodium and Potassium, and Risk of Ischemic and Hemorrhagic Stroke (INTERSTROKE): A Case–Control Study
  64. Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data
  65. Characteristics and Outcomes in Patients With COVID-19 and Acute Ischemic Stroke
  66. EU-Wide Cross-Sectional Observational Study of Lipid-Modifying Therapy Use in Secondary and Primary Care: the DA VINCI study
  67. Review on motor imagery based BCI systems for upper limb post-stroke neurorehabilitation: From designing to application
  68. Corrigendum to ‘Comparison of Antiplatelet Therapies for Prevention of Patent Foramen Ovale-Associated Stroke’ [Journal of Stroke and Cerebrovascular Diseases, Vol. 29, No. 4 (April), 2020: 104632]
  69. Comparison of Antiplatelet Therapies for Prevention of Patent Foramen Ovale-Associated Stroke
  70. Lemierre's syndrome with stroke and stenosis of the internal carotid artery suggesting focal vasculitis
  71. Quantitative Signal Intensity in Fluid-Attenuated Inversion Recovery and Treatment Effect in the WAKE-UP Trial
  72. SiPP (Stroke in Pregnancy and Postpartum): A prospective, observational, international, multicentre study on pathophysiological mechanisms, clinical profile, management and outcome of cerebrovascular diseases in pregnant and postpartum women
  73. An exploratory investigation of the effect of naturalistic light on fatigue and subjective sleep quality in stroke patients admitted for rehabilitation: A randomized controlled trial
  74. Multiple Soluble Components of the Glycocalyx Are Increased in Patient Plasma After Ischemic Stroke
  75. Self-Reported Physical Activity and Cardiovascular Disease Risk Factors in Patients with Lacunar Stroke
  76. Effect of Home-Based High-Intensity Interval Training in Patients With Lacunar Stroke: A Randomized Controlled Trial
  77. An exploratory investigation of the effect of naturalistic light on depression, anxiety, and cognitive outcomes in stroke patients during admission for rehabilitation: A randomized controlled trial
  78. Acute endovascular reperfusion treatment in patients with ischaemic stroke and large‐vessel occlusion (Denmark 2011–2017)
  79. Brain Computer Interface for Neuro-rehabilitation With Deep Learning Classification and Virtual Reality Feedback
  80. The Effects of Naturalistic Light on Diurnal Plasma Melatonin and Serum Cortisol Levels in Stroke Patients during Admission for Rehabilitation: A Randomized Controlled Trial
  81. Statin treatment before stroke reduces pro-inflammatory cytokine levels after stroke
  82. An adaptive CSP filter to investigate user independence in a 3-class MI-BCI paradigm
  83. An end-to-end deep learning approach to MI-EEG signal classification for BCIs
  84. Characterization of Recurrent Strokes With and Without Patent Foramen Ovale Closure
  85. Neuroregeneration and Vascular Protection by Citalopram in Acute Ischemic Stroke (TALOS)
  86. Strengthening nursing role and functions in stroke rehabilitation 24/7: A mixed-methods study assessing the feasibility and acceptability of an educational intervention programme
  87. Assessing low-frequency oscillations in cerebrovascular diseases and related conditions with near-infrared spectroscopy: a plausible method for evaluating cerebral autoregulation?
  88. Rivaroxaban or aspirin for patent foramen ovale and embolic stroke of undetermined source: a prespecified subgroup analysis from the NAVIGATE ESUS trial
  89. MRI-Guided Thrombolysis for Stroke with Unknown Time of Onset
  90. Motor Imagery based Brain Computer Interface Paradigm for Upper Limb Stroke Rehabilitation
  91. Rivaroxaban for Stroke Prevention after Embolic Stroke of Undetermined Source
  92. Practice patterns and outcomes after stroke across countries at different economic levels (INTERSTROKE): an international observational study
  93. Nursing staffs self-perceived outcome from a rehabilitation 24/7 educational programme – a mixed-methods study in stroke care
  94. Impaired cerebrovascular reactivity in obstructive sleep apnea: a case-control study
  95. P2Y12 Receptor Antagonist, Clopidogrel, Does Not Contribute to Risk of Osteoporotic Fractures in Stroke Patients
  96. Strengthening the role and functions of nursing staff in inpatient stroke rehabilitation: developing a complex intervention using the Behaviour Change Wheel
  97. Call for human contact and support: an interview study exploring patients’ experiences with inpatient stroke rehabilitation and their perception of nurses’ and nurse assistants’ roles and functions
  98. Nurses’ and nurse assistants’ beliefs, attitudes and actions related to role and function in an inpatient stroke rehabilitation unit-A qualitative study
  99. Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease
  100. Patent Foramen Ovale Closure or Antiplatelet Therapy for Cryptogenic Stroke
  101. Screening with doppler ultrasound for carotid artery stenosis in patients with stroke or transient ischaemic attack
  102. Can pelvic floor muscle training improve quality of life in men with mild to moderate post‑stroke and lower urinary tract symptoms?
  103. Subclinical leaflet thrombosis in surgical and transcatheter bioprosthetic aortic valves: an observational study
  104. Treatment diary for botulinum toxin spasticity treatment: a pilot study
  105. Mechanical Thrombectomy with the Embolus Retriever with Interlinked Cages in Acute Ischemic Stroke: ERIC, the New Boy in the Class
  106. Impact of naturalistic lighting on hospitalized stroke patients in a rehabilitation unit: Design and measurement
  107. Lower Urinary Tract Symptoms, Erectile Dysfunction, and Quality of Life in Poststroke Men: A Controlled Cross-Sectional Study
  108. Answer to “On the importance of polysomnography after stroke”
  109. Visual attention in posterior stroke and relations to alexia
  110. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast‐enhanced T1‐weighted perfusion MRI
  111. Early blood pressure lowering treatment in acute stroke. Ordinal analysis of vascular events in the Scandinavian Candesartan Acute Stroke Trial (SCAST)
  112. Global and regional effects of potentially modifiable risk factors associated with acute stroke in 32 countries (INTERSTROKE): a case-control study
  113. Outcomes With Edoxaban Versus Warfarin in Patients With Previous Cerebrovascular Events
  114. Polysomnographic indicators of mortality in stroke patients
  115. Thrombolysis in acute ischemic stroke is associated with lower long-term hospital bed day use: A nationwide propensity score-matched follow-up study
  116. Medical dispatchers recognise substantial amount of acute stroke during emergency calls
  117. Pharyngeal Electrical Stimulation for Treatment of Dysphagia in Subacute Stroke
  118. Cardioversion of Atrial Fibrillation in ENGAGE AF-TIMI 48
  119. Mortality and use of psychotropic medication in patients with stroke: a population-wide, register-based study
  120. Phosphodiesterase4D (PDE4D) — A risk factor for atrial fibrillation and stroke?
  121. Is Pelvic Floor Muscle Training Effective for Men With Poststroke Lower Urinary Tract Symptoms? A Single-Blinded Randomized, Controlled Trial
  122. Sleep apnea diagnosis varies with the hypopnea criteria applied
  123. Cost of stroke: a controlled national study evaluating societal effects on patients and their partners
  124. Effect of motion artifacts and their correction on near-infrared spectroscopy oscillation data: a study in healthy subjects and stroke patients
  125. The effect of pelvic floor muscle training on sexual function in men with lower urinary tract symptoms after stroke
  126. Automatic Real-Time Embedded QRS Complex Detection for a Novel Patch-Type Electrocardiogram Recorder
  127. Causes of Death Data in the Global Burden of Disease Estimates for Ischemic and Hemorrhagic Stroke
  128. Evaluation of pre-hospital transport time of stroke patients to thrombolytic treatment
  129. Acute Ischemic Stroke and Long-Term Outcome After Thrombolysis
  130. RAAS and stress markers in acute ischemic stroke: preliminary findings
  131. Implementation of supported conversation for communication between nursing staff and in-hospital patients with aphasia
  132. Automatic quality classification of entire electrocardiographic recordings obtained with a novel patch type recorder
  133. Acute headache and persistent headache attributed to cervical artery dissection: Field testing of ICHD-III beta
  134. Registration of acute stroke: validity in the Danish Stroke Registry and the Danish National Registry of Patients
  135. Edoxaban versus Warfarin in Patients with Atrial Fibrillation
  136. Treatment of Brain Tumors: Electrochemotherapy
  137. Altered Low Frequency Oscillations of Cortical Vessels in Patients with Cerebrovascular Occlusive Disease – A NIRS Study
  138. Multiple brain metastases - current management and perspectives for treatment with electrochemotherapy
  139. Low frequency oscillations in cephalic vessels assessed by near infrared spectroscopy
  140. Relation Between Change in Blood Pressure in Acute Stroke and Risk of Early Adverse Events and Poor Outcome
  141. Cone pathway function in relation to asymmetric carotid artery stenosis: correlation to blood pressure
  142. Vorapaxar in the Secondary Prevention of Atherothrombotic Events
  143. A Systematic Comparison of Motion Artifact Correction Techniques for Functional Near-Infrared Spectroscopy
  144. Thrombolysis outcomes in acute ischemic stroke patients with prior stroke and diabetes mellitus
  145. Hemiplegic Migraine Aura Begins With Cerebral Hypoperfusion: Imaging in the Acute Phase
  146. Preclinical Validation of Electrochemotherapy as an Effective Treatment for Brain Tumors
  147. Diffusion-Weighted MRI for Verification of Electroporation-Based Treatments
  148. The angiotensin-receptor blocker candesartan for treatment of acute stroke (SCAST): a randomised, placebo-controlled, double-blind trial
  149. Is well-being associated with lower urinary tract symptoms in patients with stroke?
  150. Drug and Gene Electrotransfer to the Brain
  151. Electrochemotherapy for Primary and Secondary Brain Tumors
  152. Spontaneous Low-Frequency Oscillations in Cerebral Vessels: Applications in Carotid Artery Disease and Ischemic Stroke
  153. Angiotensin Receptor Blockade in Acute Stroke. the Scandinavian Candesartan Acute Stroke Trial: Rationale, Methods and Design of a Multicentre, Randomised- and Placebo-Controlled Clinical Trial (NCT00120003)
  154. Risk factors for ischaemic and intracerebral haemorrhagic stroke in 22 countries (the INTERSTROKE study): a case-control study
  155. Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials
  156. No effect of pure oxygen inhalation on headache induced by glyceryl trinitrate
  157. Delayed Migraine-Like Headache in Healthy Volunteers After a Combination of Acetazolamide and Glyceryl Trinitrate
  158. Effect of Telmisartan on Functional Outcome, Recurrence, and Blood Pressure in Patients With Acute Mild Ischemic Stroke
  159. Nitroglycerin provocation in normal subjects is not a useful human migraine model?
  160. Prednisolone reduces nitric oxide‐induced migraine
  161. Calcitonin gene-related peptide (CGRP) levels during glyceryl trinitrate (GTN)-induced headache in healthy volunteers
  162. ExStroke Pilot Trial of the effect of repeated instructions to improve physical activity after ischaemic stroke: a multinational randomised controlled clinical trial
  163. High cardiovascular event rates in patients with asymptomatic carotid stenosis: the REACH registry*
  164. Relative and Cumulative Effects of Lipid and Blood Pressure Control in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels Trial
  165. Cardiovascular risk factor control and outcomes in peripheral artery disease patients in the Reduction of Atherothrombosis for Continued Health (REACH) Registry
  166. Baseline blood pressure, low- and high-density lipoproteins, and triglycerides and the risk of vascular events in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial
  167. Results of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial by Stroke Subtypes
  168. Lack of Effect of Norepinephrine on Cranial Haemodynamics and Headache in Healthy Volunteers
  169. Assymetry of Temporal Artery Diameters During Spontaneous Attacks of Cluster Headache
  170. Are activity limitations associated with lower urinary tract symptoms in stroke patients? A cross-sectional, clinical survey
  171. Are activity limitations associated with lower urinary tract symptoms in stroke patients? A cross-sectional, clinical survey
  172. Effects of aspirin plus extended-release dipyridamole versus clopidogrel and telmisartan on disability and cognitive function after recurrent stroke in patients with ischaemic stroke in the Prevention Regimen for Effectively Avoiding Second Strokes (PR...
  173. Thrombolysis with Alteplase 3 to 4.5 Hours after Acute Ischemic Stroke
  174. Aspirin and Extended-Release Dipyridamole versus Clopidogrel for Recurrent Stroke
  175. Telmisartan to Prevent Recurrent Stroke and Cardiovascular Events
  176. Effect of atorvastatin in elderly patients with a recent stroke or transient ischemic attack
  177. Prevalence of Lower Urinary Tract Symptoms (LUTS) in stroke patients: A cross‐sectional, clinical survey
  178. Nitric oxide-induced headache may arise from extracerebral arteries as judged from tolerance to isosorbide-5-mononitrate
  179. Efficacy and Safety of Recombinant Activated Factor VII for Acute Intracerebral Hemorrhage
  180. Involvement of calcitonin gene-related peptide in migraine: regional cerebral blood flow and blood flow velocity in migraine patients
  181. Intracranial hemodynamics during intravenous infusion of glyceryl trinitrate
  182. Patients' perceptions of the benefits and problems of using the ActiGait implanted drop-foot stimulator
  183. Phase II trial to evaluate the ActiGait implanted drop-foot stimulator in established hemiplegia
  184. Dipyridamole May Induce Migraine in Patients With Migraine Without Aura
  185. The Danish Prostatic Symptom Score (DAN‐PSS‐1) questionnaire is reliable in stroke patients
  186. No increase of calcitonin gene–related peptide in jugular blood during migraine
  187. The Effect of Propranolol on Glyceryltrinitrate-Induced Headache and Arterial Response
  188. A Double-Blind Study of SB-220453 (Tonerbasat) in the Glyceryltrinitrate (GTN) Model of Migraine
  189. The Prophylactic Effect of Valproate on Glyceryltrinitrate induced Migraine
  190. The Effect of Nitric Oxide Synthase Inhibition on Histamine Induced Headache and Arterial Dilatation in Migraineurs
  191. A dose?response study of nitric oxide synthase inhibition in different vascular beds in man
  192. Cgrp May Play A Causative Role in Migraine
  193. Human migraine models
  194. Human Migraine Models
  195. Headache Characteristics During the Development of Tolerance to Nitrates: Pathophysiological Implications
  196. Induction of Nitrate Tolerance is not a Useful Treatment in Cluster Headache
  197. Nitric Oxide and Migraine
  198. Headache Induced by a Nitric Oxide Donor (nitroglycerin) Responds to Sumatriptan. A Human Model for Development of Migraine Drugs
  199. Effect of a Nitric Oxide Donor (Glyceryl Trinitrate) on Nociceptive Thresholds in Man
  200. Histamine-1 receptor blockade does not prevent nitroglycerin induced migraine
  201. Experimental Headache in Humans
  202. Increased Cerebrovascular pCO2 Reactivity in Migraine with Aura- a Transcranial Doppler Study During Hyperventilation
  203. Venous plasma levels of endothelin-1 are not altered immediately after nitroglycerin infusion in healthy subjects
  204. Cerebral Blood Flow Velocities are Reduced During Attacks of Unilateral Migraine Without Aura
  205. Reduced arterial diameter during static exercise in humans
  206. Transcranial Doppler and cardiovascular responses during cardiovascular autonomic tests in migraineurs during and outside attacks
  207. Arterial diameter during central volume depletion in humans
  208. The Role of Nitric Oxide in Migraine Pain
  209. Nitroglycerin-Induced Headache is Not Dependent on Histamine Release: Support For a Direct Nociceptive Action of Nitric Oxide
  210. A nitric oxide donor (nitroglycerin) triggers genuine migraine attacks
  211. Interictal “patchy” regional cerebral blood flow patterns in migraine patients. A single photon emission computerized tomographic study
  212. CO2 Measurements During Transcranial Doppler Examinations in Headache Patients: Methodological Considerations
  213. Nitric oxide is a key molecule in migraine and other vascular headaches
  214. Improved Description of the Migraine Aura by a Diagnostic Aura Diary
  215. Altered peripheral vesodilator profile of nitroglycerin during long-term infusion of N-acetylcysteine
  216. Arterial Supersensitivity to Nitric Oxide (Nitroglycerin) in Migraine Sufferers
  217. Effect of serotonin receptor blockade on endocrine and cardiovascular responses to head-up tilt in humans
  218. Nitric oxide supersensitivity: a possible molecular mechanism of migraine pain
  219. Small arteries can be accurately studied in vivo, using high frequency ultrasound
  220. Lack of tolerance of headache and radial artery diameter during a 7 hour intravenous infusion of nitroglycerin
  221. Central venous oxygen saturation during hypovolaemic shock in humans
  222. Presentation of a New Instrument: The Diagnostic Headache Diary
  223. N-Acetylcysteine enhances nitroglycerin-induced headache and cranial arterial responses
  224. Dose-dependent headache response and dilatation of limb and extracranial arteries after three doses of 5-isosorbide-mononitrate
  225. Subcutaneous Sumatriptan in Acute Migraine
  226. Flunarizine Versus Metoprolol in Migraine Prophylaxis: A Double-Blind, Randomized Parallel Group Study of Efficacy and Tolerability
  227. Migraine pain associated with middle cerebral artery dilatation: reversal by sumatriptan
  228. Timing and topography of cerebral blood flow, aura, and headache during migraine attacks
  229. Arterial responses during migraine headache
  230. Clinical Characteristics of Migraine and Episodic Tension‐Type Headache in Relation to Old and New Diagnostic Criteria
  231. Determination of the luminal diameter of the radial artery in man by high frequency ultrasound: A methodological study
  232. Intravenous nitroglycerin as an experimental model of vascular headache. Basic characteristics