Evaluation and Management of Life-Threatening Headaches in the Emergency Department + EMplify podcast audio summary
0
Table of Contents
 

<< Can’t Miss Stroke in the Emergency Department, Table of Contents

Course 1: Evaluation and Management of Life-Threatening Headaches in the Emergency Department + EMplify podcast audio summary excerpt

Though patients often present to the ED seeking relief from headaches that cause significant pain and suffering, 90% of them can be considered “benign.” It is essential to identify the 10% of headache patients who are in danger of having a life-threatening disorder presenting with a sudden and severe headache to ensure that they are treated quickly and effectively.

What are the red flags for recognizing that a headache is potentially life-threatening?

What are the most common causes of life-threatening headaches? (Subarachnoid hemorrhage, cervical artery dissection, central venous thrombosis, idiopathic intracranial hypertension, giant cell arteritis, and posterior reversible encephalopathy syndrome.)

What are the signs and symptoms of these headaches?

When your patient describes his headache, what are the six descriptors that are most concerning?

What are the high-yield laboratory tests?

When SAH is suspected, when is CT required? When is it not?

When is neuroimaging required prior to performing a lumbar puncture?

When is IV antihypertensive medication called for? Which drugs and what dosage?

Table of Contents
  1. Abstract
  2. Case Presentations
  3. Introduction
  4. Critical Appraisal of the Literature
  5. Etiology and Pathophysiology
  6. Differential Diagnosis
    1. Subarachnoid Hemorrhage
    2. Cervical Artery Dissection
    3. Cerebral Venous Thrombosis
    4. Idiopathic Intracranial Hypertension
    5. Giant Cell Arteritis
    6. Posterior Reversible Encephalopathy Syndrome
  7. Prehospital Care
  8. Emergency Department Evaluation
    1. History
    2. Physical Examination
      1. Vital Signs
      2. Neurologic Function
      3. Cranial Nerves
      4. Head and Neck Examination
      5. Fundoscopic Examination
  9. Diagnostic Studies
    1. Laboratory Testing
    2. Radiographic Imaging
      1. Level B Recommendations (Moderate Strength of Evidence)
      2. Level C Recommendations (Weak Strength of Evidence)
      3. Computed Tomography and Subarachnoid Hemorrhage
    3. Lumbar Puncture
    4. Ocular Ultrasonography
  10. Treatment
    1. Subarachnoid Hemorrhage
    2. Cerebral Venous Thrombosis
    3. Idiopathic Intracranial Hypertension
    4. Posterior Reversible Encephalopathy Syndrome
    5. Cervical Artery Dissection
    6. Acute Angle Closure Glaucoma
    7. Giant Cell Arteritis
    8. Pre-Eclampsia
  11. Controversies and Cutting Edge
  12. Disposition
  13. Summary
  14. Risk Management Pitfalls for Emergency Department Management of Severe, Sudden Onset Headache
  15. Time- And Cost-Effective Strategies
  16. Case Conclusions
  17. Clinical Pathway for Emergency Department Management of Subarachnoid Hemorrhage
  18. Tables and Figures
    1. Table 1. Life-Threatening Secondary Causes of Headache
    2. Table 2. Historical and Physical Examination Findings Associated with Subarachnoid Hemorrhage
    3. Table 3. Red Flags for Life-Threatening Headaches
    4. Table 4. Historical Factors and Concerning Descriptors
    5. Table 5. Stepwise Approach to the Fundoscopic Examination
    6. Table 6. Intravenous Antihypertensive Medications for Treating Hypertensive Emergencies
    7. Table 7. Ottawa Subarachnoid Hemorrhage Rule
    8. Table 8. Modified Dandy Criteria for Diagnosing Idiopathic Intracranial Hypertension
    9. Table 9. Medications for Treatment of Acute Angle Closure Glaucoma
    10. Table 10. Criteria for the Diagnosis of Pre Eclampsia (>= 20 Weeks' Gestation)
    11. Figure 1. Ocular Ultrasound Evaluating Elevated Intracranial Pressure
  19. References
Listen to the podcast for this course

Abstract

Headache is the fourth most common reason for emergency department encounters, accounting for 3% of all visits in the United States. Though troublesome, 90% are relatively benign primary headaches --migraine, tension, and cluster headaches. The other 10% are secondary headaches, caused by separate underlying processes, with vascular, infectious, or traumatic etiologies, and they are potentially life-threatening. This issue details the important pathophysiologic features of the most common types of life-threatening headaches, the key historical and physical examination information emergency clinicians must obtain, the red flags that cannot be missed, and the current evidence for best-practice testing, imaging, treatment, and disposition.

Case Presentations

A previously healthy 30-year-old man presents to the ED complaining of the “worst headache of my life.” He describes it as sharp, nonradiating, with an abrupt onset 5 hours ago. You are concerned for subarachnoid hemorrhage. You provide pain medication and obtain a noncontrast CT scan of the head, which is negative. The patient is feeling better and wants to go home. You wonder whether a negative CT is sufficient to rule out an SAH or whether a lumbar puncture should be done...

A 55-year-old man with history of nonsmall cell lung cancer who is on cisplatin presents with an acute headache and lethargy for 6 hours. His vital signs are remarkable for a blood pressure of 210/120 mm Hg, heart rate of 70 beats/min, and a temperature of 36.7°C (98°F). His physical exam reveals a lethargic patient with no localizing neurologic signs and no meningismus. You order a noncontrast CT of the head and consider lowering this patient’s blood pressure, though you wonder how much and how fast it should be reduced...

A 45-year-old woman presents to the ED complaining of a severe occipital headache, neck pain, and dizziness. Earlier in the day, she was involved in a motor vehicle crash and suffered “whiplash.” Her neurologic exam is normal, including no nystagmus and normal cerebellar function, but you are concerned that this patient may have a vertebral artery dissection, and you order a CTA head and neck. You wonder: if it’s positive, should the treatment include anticoagulation or antiplatelet therapy...or both?

Introduction

The third edition of the International Classification of Headache Disorders (ICHD-3), published in January 2018, is the most up-to-date and widely accepted standard criteria for the classification of headaches.1 The ICHD-3 classifies headaches into 3 distinct categories: (1) primary headache disorders, including migraine, tension, and cluster headaches; (2) secondary headaches, including potentially life-threatening forms of headaches such as those secondary to vascular disorders, traumatic injury, and disorders in hemostasis; and (3) cranial neuropathies, such as trigeminal neuralgia.

The National Hospital Ambulatory Medical Care Survey reviewed over 10,000 patients presenting to emergency departments (EDs) for acute headache and found that 2% represented secondary headaches.2 Although they are rare, life-threatening headaches require prompt diagnosis and treatment, as delays in some diagnoses can have a mortality rate approaching 50%.3

Evaluating complaints of acute headache is a common practice in the ED, and distinguishing benign from serious pathology can be a diagnostic challenge. A focused workup begins with a careful, well-organized clinical history and physical examination. Physical examination findings such as abnormal vital signs, papilledema, cranial nerve palsies, and neck pain are suggestive of more concerning headache etiologies.4 Resources such as ocular ultrasound, neuroimaging, and lumbar puncture are important strategies, but the sensitivity and specificity of the results must be understood in order to apply them correctly. This issue of Emergency Medicine Practice focuses on the most commonly encountered causes of life-threatening secondary headaches and provides best-practice recommendations on their initial evaluation and management.

Critical Appraisal of the Literature

A literature search from 1993 to 2018 was conducted using PubMed and Ovid MEDLINE®, with the search terms headaches AND emergency, sudden onset, fever, visual symptoms, neurologic deficits, high-risk, trauma, immunocompromised, pregnancy, coagulopathy, and life threatening. The National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews were searched. Guidelines published by the American College of Emergency Physicians (ACEP) and the American Academy of Neurology were searched. International guidelines, including the Canadian and European neurology guidelines, were also reviewed. Over 500 abstracts published within the last 25 years were examined, and 89 of these full-text articles were reviewed and included for reference. Many of the identified articles were prospective studies, meta-analyses, clinical guidelines, and literature reviews.

Risk Management Pitfalls for Emergency Department Management of Severe, Sudden Onset Headache

4. “The 55-year-old patient I evaluated for a new-type headache had no neurologic deficits, so I suspected that the etiology was benign, and I did not obtain imaging.”

ACEP Clinical Policy recommends that patients aged > 50 years who present with a new type of headache and a normal neurologic examination should be considered for an urgent neuroimaging study (Level C recommendation).

5. “She was 7 days post partum and came in complaining of new-onset headache and with a blood pressure of 186/92 mm Hg. Her urinalysis was negative for protein, so I ruled out pre-eclampsia.”

ACOG recommends that diagnosis of severe pre-eclampsia includes new headache and hypertension. Proteinuria is no longer necessary to diagnose pre-eclampsia if other symptoms are present. Postpartum pre-eclampsia and eclampsia may occur up to 4 weeks post partum. Treatment with IV magnesium and antihypertensives is indicated for this patient.

6. “My 60-year-old patient presented with signs of an anterior stroke; however, her last known well time was 12 hours ago, so I did not consult neurosurgery, since she was out of the window for thrombolytics.”

The 2018 AHA Guidelines for endovascular therapy in acute ischemic stroke recommends that, in select patients with signs of acute stroke whose onset is within 6 to 24 hours, mechanical thrombectomy is reasonable (Level IIa recommendation).

Tables and Figures

Life-Threatening Secondary Causes of Headache
Life-Threatening Secondary Causes of Headache

 

Historical and Physical Examination Findings Associated with Subarachnoid Hemorrhage

 

References

Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.

To help the reader judge the strength of each reference, pertinent information about the study, such as the type of study and the number of patients in the study is included in bold type following the references, where available. In addition, the most informative references cited in this paper, as determined by the author, are highlighted.

  1. Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38(1):1-211. (Clinical guideline)
  2. National Hospital Ambulatory Medical Care Survey: 2013 Emergency Department. Accessed January 10, 2019. (Clinical database)
  3. Hop JW, Rinkel GJ, Algra A, et al. Case-fatality rates and functional outcome after subarachnoid hemorrhage: a systematic review. Stroke. 1997;28(3):660-664. (Systematic review; 21 studies)
  4. Goldstein JN, Camargo CA Jr, Pelletier AJ. Headache in United States emergency departments: demographics, work-up and frequency of pathological diagnoses. Cephalalgia. 2006;26(6):684-690. (Retrospective; 21 million ED visits)
  5. Messlinger K. The big CGRP flood - sources, sinks and signaling sites in the trigeminovascular system. J Headache Pain. 2018;19(1):22. (Review article)
  6. Pope JV, Edlow JA. Favorable response to analgesics does not predict a benign etiology of headache. Headache. 2008;48(6):944-950. (Meta analysis; 18 articles)
  7. Edlow JA, Panagos PD, Godwin SA, et al. Clinical policy: critical issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. Ann Emerg Med. 2008;52(4):407-436. (Clinical policy)
  8. Ramirez-Lassepas M, Espinosa CE, Cicero JJ, et al. Predictors of intracranial pathologic findings in patients who seek emergency care because of headache. Arch Neurol. 1997;54(12):1506-1509. (Case-control study; 329 patients)
  9. Graves EJ. Detailed diagnoses and procedures, national hospital discharge survey, 1990. Vital Health Stat. 13.1992;113):1-225. (Retrospective; 263,000 patients)
  10. Ingall T, Wiebers D. Natural history of subarachnoid hemorrhage. In: Whisnant JP, ed. Stroke: Populations, Cohorts, and Clinical Trials. Boston, Mass: Butterworth-Heinemann Ltd; 1993. (Epidemiologic review)
  11. Fridriksson S, Hillman J, Landtblom AM, et al. Aneurysmal subarachnoid hemorrhage. N Engl J Med. 2006;354(4):387-396. (Review article)
  12. Linn FH, Rinkel GJ, Algra A, et al. Headache characteristics in subarachnoid hemorrhage and benign thunderclap headache. J Neurol Neurosurg Psychiatry. 1998;65(5):791-793. (Prospective; 102 patients)
  13. Bassi P, Bandera R, Liero M, et al. Warning signs in subarachnoid hemorrhage: a cooperative study. Acta Neurol Scan. 1991;84(4):277-281. (Retrospective; 364 patients)
  14. Juvela S. Minor leak before rupture of an intracranial aneurysm and subarachnoid hemorrhage of unknown etiology. Neurosurgery. 1992;30(1):7-11. (Retrospective; 303 patients)
  15. Carpenter CR, Hussain AM, Ward MJ, et al. Spontaneous subarachnoid hemorrhage: a systematic review and meta-analysis describing the diagnostic accuracy of history, physical examination, imaging, and lumbar puncture with an exploration of test thresholds. Acad Emerg Med. 2016;23(9):963-1003. (Meta-analysis; 22 studies)
  16. Putaala J, Metso AJ, Metso TM, et al. Analysis of 1008 consecutive patients aged 15 to 49 with first-ever ischemic stroke: the Helsinki young stroke registry. Stroke. 2009;40(4):1195-1203. (Meta-analysis; 1008 patients)
  17. Engelter ST, Grond-Ginsbach C, Metso TM, et al, Cervical Artery Dissection and Ischemic Stroke Patients Study Group. Cervical artery dissection: trauma and other potential mechanical trigger events. Neurology. 2013;80(21):1950-1957. (Prospective cohort; 1897 patients)
  18. Brandt T, Hausser I, Orberk E, et al. Ultrastructural connective tissue abnormalities in patients with spontaneous cervicocerebral artery dissections. Ann Neurol. 1998;44(2):281-285. (Prospective cohort study; 25 patients)
  19. Bruijn SF, Stam J, Kappelle LJ. Thunderclap headache as first symptom of cerebral venous sinus thrombosis. CVST Study Group. Lancet. 1996;348(9042):1623-1625. (Retrospective; 71 patients)
  20. Ferro JM, Canhao P, Stam J, et al. Prognosis of cerebral vein and dural sinus thrombosis: results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Stroke. 2004;35(3):664-670. (Prospective; 624 patients)
  21. Salman MS, Kirkham FJ, MacGregor DL. Idiopathic “benign” intracranial hypertension: case series and review. J Child Neurol. 2001;16(7):465-470. (Case series)
  22. Friedman DI. Medication-induced intracranial hypertension in dermatology. Am J Clin Dermatol. 2005;6(1):29-37. (Review article)
  23. González-Gay MA, Garcia-Porrúa C. Epidemiology of the vasculitides. Rheum Dis Clin North Am. 2001;27(4):729-749. (Expert review)
  24. Smetana GW, Shmerling RH. Does this patient have temporal arteritis? JAMA. 2002;287(1):92-101. (Meta-analysis; 41 studies)
  25. Danesh-Meyer H, Savino PJ, Gamble GG. Poor prognosis of visual outcome after visual loss from giant cell arteritis. Ophthalmology. 2005;112(6):1098-1103. (Prospective case series; 41 patients)
  26. Hunder GG. Clinical manifestations of giant cell (temporal) arteritis. UpToDate. Accessed January 10, 2019. (Evidence-based website)
  27. Hinchey J, Chaves C, Appignani B, et al. A reversible posterior leukoencephalopathy syndrome. N Engl J Med. 1996;334(8):494-500. (Retrospective; 13 patients)
  28. Port JD, Beauchamp NJ Jr. Reversible intracerebral pathologic entities mediated by vascular autoregulatory dysfunction. Radiographics. 1998;18(2):353-367. (Review article)
  29. Staykov D, Schwab S. Posterior reversible encephalopathy syndrome. J Intensive Care Med. 2012;27(1):11-24. (Review article)
  30. Fugate JE, Claassen DO, Cloft HJ, et al. Posterior reversible encephalopathy syndrome: associated clinical and radiologic findings. Mayo Clin Proc. 2010;85(5):427-432. (Retrospective; 113 patients)
  31. Zohrevandi B, Monsef Kasmaie V, Asadi P, et al. Diagnostic accuracy of Cincinnati pre-hospital stroke scale. Emerg (Tehran). 2015;3(3):95-98. (Retrospective; 448 patients)
  32. Mount HR, Boyle SD. Aseptic and bacterial meningitis: evaluation, treatment, and prevention. Am Fam Physician. 2017;96(5):314-322. (Review article)
  33. Bo SH, Davidsen EM, Gulbrandsen P, et al. Acute headache: a prospective diagnostic work-up of patients admitted to a general hospital. Eur J Neurol. 2008;15(12):1293-1299. (Prospective; 433 patients)
  34. Searls DE, Pazera L, Korbel E, et al. Symptoms and signs of posterior circulation ischemia in the New England Medical Center Posterior Circulation Registry. Arch Neurol. 2012;69(3):346-351. (Case series; 407 patients)
  35. Broadway DC. How to test for a relative afferent pupillary defect (RAPD). Community Eye Health. 2012;25(79-80):58-59. (Clinical technique review)
  36. Prasad S, Volpe NJ. Paralytic strabismus: third, fourth, and sixth nerve palsy. Neurol Clin. 2010;28(3):803-833. (Clinical technique review)
  37. Wall M, White WN 2nd. Asymmetric papilledema in idiopathic intracranial hypertension: prospective interocular comparison of sensory visual function. Invest Ophthalmol Vis Sci. 1998; 39(1):134-142. (Observational; 476 patients)
  38. Locker TE, Thompson C, Rylance J, et al. The utility of clinical features in patients presenting with nontraumatic headache: an investigation of adult patients attending an emergency department. Headache. 2006;46(6):954-961. (Prospective; 589 patients)
  39. Stanford Medicine 25. Introduction to the fundoscopic/ophthalmoscopic exam. Accessed January 10, 2019. (Clinical technique review)
  40. Parikh M, Miller NR, et al. Prevalence of a normal C-reactive protein with an elevated erythrocyte sedimentation rate in biopsy-proven giant cell arteritis. Ophthalmology. 2006;113(10):1842-1845. (Retrospective; 116 patients)
  41. Kermani TA, Schmidt J, et al. Utility of erythrocyte sedimentation rate and C-reactive protein for the diagnosis of giant cell arteritis. Semin Arthritis Rheum. 2012;41(6):866-871. (Retrospective; 764 patients)
  42. Touger M, Birnbaum A, Wang J, et al. Performance of the RAD-57 pulse co-oximeter compared with standard laboratory carboxyhemoglobin measurement. Ann Emerg Med. 2010;56(4):382-388. (Cross-sectional cohort; 23 patients)
  43. Lalive PH, de Moerloose P, Lovblad K, et al. Is measurement of D-dimer useful in the diagnosis of cerebral venous thrombosis? Neurology. 2003;61(8):1057-1060. (Prospective; 54 patients)
  44. Kosinski CM, Mull M, Schwarz M, et al. Do normal D-dimer levels reliably exclude cerebral sinus thrombosis? Stroke. 2004;35(12):2820-2825. (Prospective; 343 patients)
  45. Alons IM, Jellema K, Wermer MJ, et al. D-dimer for the exclusion of cerebral venous thrombosis: a meta-analysis of low risk patients with isolated headache. BMC Neurol. 2015;15:118. (Retrospective; 636 patients)
  46. Smith E, Kumar V. BET 1: does a normal D-dimer rule out cerebral venous sinus thrombosis (CVST)? Emerg Med J. 2018;35(6):396-397. (Expert review)
  47. Quon JS, Glikstein R, et al. Computed tomography for non-traumatic headache in the emergency department and the impact of follow-up on testing on altering the initial diagnosis. Emerg Radiol. 2015;22(5):521-525. (Prospective observational; 865 patients)
  48. Jordan YJ, Lightfoote JB, Jordan JE. Computed tomography imaging in the management of headache in the emergency department: cost efficacy and policy implications. J Natl Med Assoc. 2009;101(4):331-335. (Retrospective; 882 patients)
  49. Silbert PL, Mokri B, Schievink WI. Headache and neck pain in spontaneous internal carotid and vertebral artery dissections. Neurology. 1995;45(8):1517-1522. (Retrospective; 161 patients)
  50. Kim BS, Do HM, Marks MP. Diagnosis and management of cerebral venous and sinus thrombosis. Semin Cerebrovasc Dis Stroke. 2004;4(4):205-216. (Review article)
  51. Lysandropoulos AP, Rossetti AO. Postictal cortical visual impairment: a symptom of posterior reversible encephalopathy. Epilepsy Behav. 2010;17(2):276-277. (Case report)
  52. Lamy C, Oppenheim C, Méder JF, et al. Neuroimaging in posterior reversible encephalopathy syndrome. J Neuroimaging. 2004;14(2):89-96. (Review article)
  53. Perry JJ, Spacek A, Forbes M, et al. Is the combination of negative computed tomography result and negative lumbar puncture result sufficient to rule out subarachnoid hemorrhage? 2008;51(6):707-713. (Prospective; 592 patients)
  54. Perry JJ, Stiell IG, Sivilotti ML, et al. Sensitivity of computed tomography performed within six hours of onset of headache for diagnosis of subarachnoid hemorrhage: prospective cohort study. BMJ. 2011;343:d4277. (Prospective; 3132 patients)
  55. Dubosh NM, Bellolio MF, Rabinstein AA, et al. Sensitivity of early brain computed tomography to exclude aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis. Stroke. 2016;47(3):750-755. (Meta-analysis; 8907 patients)
  56. Connolly ES Jr, Rabinstein AA, Carhuapoma JR, et al. Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2012;43(6):1711-1737. (Clinical guideline)
  57. Fiorito-Torres F, Rayhill M, Perloff M. Idiopathic intracerebral hypertension (IIH)/pseudotumor: removing less CSF is best (I9-1.006). Neurology. 2014;82(10 Supplement):I9-1.006. (Retrospective review; 41 patients)
  58. Czuczman AD, Thomas LE, Boulanger AB, et al. Interpreting red blood cells in lumbar puncture: distinguishing true subarachnoid hemorrhage from traumatic tap. Acad Emerg Med 2013; 20(3):247-256. (Case series; 4496 patients)
  59. Perry JJ, Alyahya B, Sivlotti ML, et al. Differentiation between traumatic tap and aneurysmal subarachnoid hemorrhage: prospective cohort study. BMJ. 2015;350:h568. (Prospective cohort study; 1739 patients)
  60. Brodsky MC, Vaphiades M. Magnetic resonance imaging in pseudotumor cerebri. Ophthalmology 1998;105(9):1686-1693. (Retrospective case series; 40 patients)
  61. Blaivas M, Theodoro D, Sierzenski PR. Elevated intracranial pressure detected by bedside emergency ultrasonography of the optic nerve sheath. Acad Emerg Med. 2003;10(4):376-381. (Prospective; 35 patients)
  62. Tayal VS, Neulander M, Norton HJ, et al. Emergency department sonographic measurement of optic nerve sheath diameter to detect findings of increased intracranial pressure in adult head injury patients. Ann Emerg Med. 2007;49(4):508-514. (Prospective; 59 patients)
  63. Soldatos T, Chatzimichail K, Papathanasiou M, et al. Optic nerve sonography: a new window for the non-invasive evaluation of intracranial pressure in brain injury. Emerg Med J. 2009;26(9):630-634. (Expert review)
  64. Jauch EC, Saver JL, Adams HP Jr, et al. Guidelines for the early management of patients with acute ischemic stroke. Stroke. 2013;44(3):870-947. (Clinical guideline)
  65. Anderson CS, Heeley E, Huang Y, et al. Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage. N Engl J Med. 2013;368(25):2355-2365. (Prospective; 2794 patients)
  66. Qureshi AI, Palesch YY, Barsan WG, et al. Intensive blood-pressure lowering in patients with acute cerebral hemorrhage. N Engl J Med. 2016;375(11):1033-1043. (Prospective; 1000 patients)
  67. Perry JJ, Stiell IG, Sivilotti ML, et al. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study. BMJ. 2010;341:c5204. (Prospective cohort; 1999 patients)
  68. Perry JJ, Stiell IG, Sivilotti MLA, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA. 2013;310(12):1248-1255. (Multicenter cohort; 2131 patients)
  69. Bellolio MF, Hess EP, Gilani WI, et al. External validation of the Ottawa subarachnoid hemorrhage clinical decision rule in patients with acute headache. Am J Emerg Med. 2015;33(2):244-249. (Retrospective; 454 patients)
  70. Rosengart AJ, Huo JD, Tolentino J, et al. Outcome in patients with subarachnoid hemorrhage treated with antiepileptic drugs. J Neurosurg. 2007;107(2):253-260. (Retrospective; 3552 patients)
  71. Diringer MN, Bleck TP, Claude Hemphill J 3rd, et al. Critical care management of patients following aneurysmal subarachnoid hemorrhage: recommendations from the Neurocritical Care Society’s Multidisciplinary Consensus Conference. Neurocrit Care. 2011;15(2):211-240. (Clinical guideline)
  72. Saposnik G, Barinagarrementeria F, American Heart Association Stroke Council and the Council on Epidemiology and Prevention, et al. Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American HeartAssociation/American Stroke Association. Stroke. 2011;42(4):1158-1192. (Expert guidance)
  73. Cundiff DK. Anticoagulants for cerebral venous thrombosis: harmful to patients? Stroke. 2014;45(1):298-304. (Meta-analysis; 5155 patients)
  74. Medel R, Monteith SJ, Crowley RW, et al. A review of therapeutic strategies for the management of cerebral venous sinus thrombosis. Neurosurg Focus. 2009;27(5):E6. (Guideline)
  75. Friedman DI, Jacobson DM. Diagnostic criteria for idiopathic intracranial hypertension. Neurology. 2002;59(10):1492. (Review article)
  76. Thambisetty M, Lavin PJ, Newman NJ, et al. Fulminant idiopathic intracranial hypertension. Neurology. 2007;68(3):229-232. (Retrospective case series; 16 cases)
  77. Sinclair AJ, Burdon MA, Nightingale PG, et al. Low energy diet and intracranial pressure in women with idiopathic intracranial hypertension: prospective cohort study. BMJ. 2010;341:c2701. (Prospective cohort; 25 patients)
  78. NORDIC Idiopathic Intracranial Hypertension Study Group Writing Committee, Wall M, McDermott MP, et al. Effect of acetazolamide on visual function in patients with idiopathic intracranial hypertension and mild visual loss: the idiopathic intracranial hypertension treatment trial. JAMA. 2014;311(16):1641-1651. (Prospective cohort; 165 patients)
  79. Thurtell MJ, Wall M. Idiopathic intracranial hypertension (pseudotumor cerebri): recognition, treatment, and ongoing management. Curr Treat Options Neurol. 2013;15(1):1-12. (Review)
  80. Bartynski WS, Boardman JF. Distinct imaging patterns and lesion distribution in posterior reversible encephalopathy syndrome. AJNR Am J Neuroradiol. 2007;28(7):1320-1327. (Retrospective; 136 patients)
  81. Debette S, Grond-Ginsbach C, Bodenant M, et al. Cervical Artery Dissection Ischemic Stroke Patients (CADISP) Group. Differential features of carotid and vertebral artery dissections: the CADISP study. Neurology. 2011;77(12):1174-1181. (Retrospective; 981 patients)
  82. Flis CM, Jager HR, Sidhu PS. Carotid and vertebral artery dissections: clinical aspects, imaging features and endovascular treatment. Eur Radiol. 2007;17(3):820-834. (Expert opinion)
  83. Emanuel ME, Parrish RK 2nd, Gedde SJ. Evidence-based management of primary angle closure glaucoma. Curr Opin Ophthalmol. 2014;25(2):89-92. (Review article)
  84. Jackson J, Carr LW, The American Optometric Association Consensus Panel on Care of the Patient with Primary Angle Closure Glaucoma, et al. Optometric clinical practice guidelines. Care of the patient with primary angle closure glaucoma. Accessed January 10, 2019. (Guideline)
  85. Lexicomp Online®, Lexi-Drugs®, Hudson, Ohio: Lexi-Comp, Inc. Wolter Kluwer. Accessed January 10, 2019. (Drug information database)
  86. Mazlumzadeh M, Hunder GG, Easley KA, et al. Treatment of giant cell arteritis using induction therapy with high-dose glucocorticoids: a double-blind, placebo-controlled, randomized prospective clinical trial. Arthritis Rheum. 2006;54(10):3310-3318. (Prospective; 27 patients)
  87. ACOG Task Force on Hypertension and Pregnancy. Hypertension in pregnancy. American College of Obstetricians and Gynecologists. Accessed January 10, 2019. (Expert/guideline recommendations)
  88. Yancey LM, Withers E, Bakes K, et al. Postpartum preeclampsia: emergency department presentation and management. J Emerg Med. 2011;40(4):380-384. (Case series)
  89. Schoen JC, Campbell RL, Sadosty AT. Headache in pregnancy: an approach to emergency department evaluation and management. West J Emerg Med. 2015;16(2):291-301. (Review article)

Topic Table of Contents | Next >>