Semin Neurol 2015; 35(05): 506-521
DOI: 10.1055/s-0035-1564298
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Diagnosing Stroke in Acute Vertigo: The HINTS Family of Eye Movement Tests and the Future of the “Eye ECG”

David E. Newman-Toker
1   Department of Neurology and Otolaryngology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
,
Ian S. Curthoys
2   School of Psychology, University of Sydney, Sydney, Australia
,
G. Michael Halmagyi
3   Department of Neurology, Royal Prince Alfred Hospital, Camperdown, Australia
› Author Affiliations
Further Information

Publication History

Publication Date:
06 October 2015 (online)

Abstract

Patients who present to the emergency department with symptoms of acute vertigo or dizziness are frequently misdiagnosed. Missed opportunities to promptly treat dangerous strokes can result in poor clinical outcomes. Inappropriate testing and incorrect treatments for those with benign peripheral vestibular disorders leads to patient harm and unnecessary costs. Over the past decade, novel bedside approaches to diagnose patients with the acute vestibular syndrome have been developed and refined. A battery of three bedside tests of ocular motor physiology known as “HINTS” (head impulse, nystagmus, test of skew) has been shown to identify acute strokes more accurately than even magnetic resonance imaging with diffusion-weighted imaging (MRI-DWI) when applied in the early acute period by eye-movement specialists. Recent advances in lightweight, high-speed video-oculography (VOG) technology have made possible a future in which HINTS might be applied by nonspecialists in frontline care settings using portable VOG. Use of technology to measure eye movements (VOG-HINTS) to diagnose stroke in the acute vestibular syndrome is analogous to the use of electrocardiography (ECG) to diagnose myocardial infarction in acute chest pain. This “eye ECG” approach could transform care for patients with acute vertigo and dizziness around the world. In the United States alone, successful implementation would likely result in improved quality of emergency care for hundreds of thousands of peripheral vestibular patients and tens of thousands of stroke patients, as well as an estimated national health care savings of roughly $1 billion per year. In this article, the authors review the origins of the HINTS approach, empiric evidence and pathophysiologic principles supporting its use, and possible uses for the eye ECG in teleconsultation, teaching, and triage.

 
  • References

  • 1 Saber Tehrani AS, Coughlan D, Hsieh YH , et al. Rising annual costs of dizziness presentations to U.S. emergency departments. Acad Emerg Med 2013; 20 (7) 689-696
  • 2 Newman-Toker DE, McDonald KM, Meltzer DO. How much diagnostic safety can we afford, and how should we decide? A health economics perspective. BMJ Qual Saf 2013; 22 (Suppl. 02) ii11-ii20
  • 3 Newman-Toker DE, Camargo Jr CA, Hsieh YH, Pelletier AJ, Edlow JA. Disconnect between charted vestibular diagnoses and emergency department management decisions: a cross-sectional analysis from a nationally representative sample. Acad Emerg Med 2009; 16 (10) 970-977
  • 4 Kerber KA, Morgenstern LB, Meurer WJ , et al. Nystagmus assessments documented by emergency physicians in acute dizziness presentations: a target for decision support?. Acad Emerg Med 2011; 18 (6) 619-626
  • 5 Kerber KA, Burke JF, Skolarus LE , et al. Use of BPPV processes in emergency department dizziness presentations: a population-based study. Otolaryngol Head Neck Surg 2013; 148 (3) 425-430
  • 6 Kerber KA, Brown DL, Lisabeth LD, Smith MA, Morgenstern LB. Stroke among patients with dizziness, vertigo, and imbalance in the emergency department: a population-based study. Stroke 2006; 37 (10) 2484-2487
  • 7 Eagles D, Stiell IG, Clement CM , et al. International survey of emergency physicians' priorities for clinical decision rules. Acad Emerg Med 2008; 15 (2) 177-182
  • 8 Stanton VA, Hsieh YH, Camargo Jr CA , et al. Overreliance on symptom quality in diagnosing dizziness: results of a multicenter survey of emergency physicians. Mayo Clin Proc 2007; 82 (11) 1319-1328
  • 9 Newman-Toker DE, Stanton VA, Hsieh YH, Rothman RE. Frontline providers harbor misconceptions about the bedside evaluation of dizzy patients. Acta Otolaryngol 2008; 128 (5) 601-604
  • 10 Kerber KA, Newman-Toker DE. Misdiagnosing dizzy patients: common pitfalls in clinical practice. Neurol Clin 2015; 33 (3) 565-575
  • 11 Newman-Toker DE, Moy E, Valente E, Coffey R, Hines A. Missed diagnosis of stroke in the emergency department: a cross-sectional analysis of a large population-based sample. Diagnosis 2014; 1 (2) 155-166
  • 12 Savitz SI, Caplan LR, Edlow JA. Pitfalls in the diagnosis of cerebellar infarction. Acad Emerg Med 2007; 14 (1) 63-68
  • 13 Baloh RW, Honrubia V, Jacobson K. Benign positional vertigo: clinical and oculographic features in 240 cases. Neurology 1987; 37 (3) 371-378
  • 14 Aw ST, Todd MJ, Aw GE, McGarvie LA, Halmagyi GM. Benign positional nystagmus: a study of its three-dimensional spatio-temporal characteristics. Neurology 2005; 64 (11) 1897-1905
  • 15 Bhattacharyya N, Baugh RF, Orvidas L , et al; American Academy of Otolaryngology-Head and Neck Surgery Foundation. Clinical practice guideline: benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 2008; 139 (5) (Suppl. 04) S47-S81
  • 16 Fife TD, Iverson DJ, Lempert T , et al; Quality Standards Subcommittee, American Academy of Neurology. Practice parameter: therapies for benign paroxysmal positional vertigo (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2008; 70 (22) 2067-2074
  • 17 Ichijo H. Positional nystagmus of horizontal canalolithiasis. Acta Otolaryngol 2011; 131 (1) 46-51
  • 18 Aw ST, Fetter M, Cremer PD, Karlberg M, Halmagyi GM. Individual semicircular canal function in superior and inferior vestibular neuritis. Neurology 2001; 57 (5) 768-774
  • 19 Weber KP, Aw ST, Todd MJ, McGarvie LA, Curthoys IS, Halmagyi GM. Head impulse test in unilateral vestibular loss: vestibulo-ocular reflex and catch-up saccades. Neurology 2008; 70 (6) 454-463
  • 20 Halmagyi GM, Weber KP, Curthoys IS. Vestibular function after acute vestibular neuritis. Restor Neurol Neurosci 2010; 28 (1) 37-46
  • 21 Kattah JC, Talkad AV, Wang DZ, Hsieh YH, Newman-Toker DE. HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke 2009; 40 (11) 3504-3510
  • 22 Tarnutzer AA, Berkowitz AL, Robinson KA, Hsieh YH, Newman-Toker DE. Does my dizzy patient have a stroke? A systematic review of bedside diagnosis in acute vestibular syndrome. CMAJ 2011; 183 (9) E571-E592
  • 23 Newman-Toker DE, Kerber KA, Hsieh YH , et al. HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. Acad Emerg Med 2013; 20 (10) 986-996
  • 24 Cohn B. Can bedside oculomotor (HINTS) testing differentiate central from peripheral causes of vertigo?. Ann Emerg Med 2014; 64 (3) 265-268
  • 25 Mantokoudis G, Tehrani AS, Wozniak A , et al. VOR gain by head impulse video-oculography differentiates acute vestibular neuritis from stroke. Otol Neurotol 2015; 36 (3) 457-465
  • 26 Bashir K, Alessai GS, Salem WA, Irfan FB, Cameron PA. Physical maneuvers: effective but underutilized treatment of benign paroxysmal positional vertigo in the ED. Am J Emerg Med 2014; 32 (1) 95-96
  • 27 Bashir K, Qotb MA, Alkahky S, Fathi AM, Mohamed MA, Cameron PA. Are emergency physicians and paramedics providing canalith repositioning manoeuvre for benign paroxysmal positional vertigo?. Emerg Med Australas 2015; 27 (2) 179-180
  • 28 Newman-Toker DE, Saber Tehrani AS, Mantokoudis G , et al. Quantitative video-oculography to help diagnose stroke in acute vertigo and dizziness: toward an ECG for the eyes. Stroke 2013; 44 (4) 1158-1161
  • 29 Roberts TA, Jenkyn LR, Reeves AG. On the notion of doll's eyes. Arch Neurol 1984; 41 (12) 1242-1243
  • 30 Furman JM, Jacob RG. Jongkees' formula re-evaluated: order effects in the response to alternate binaural bithermal caloric stimulation using closed-loop irrigation. Acta Otolaryngol 1993; 113 (1) 3-10
  • 31 Halmagyi GM, Curthoys IS. A clinical sign of canal paresis. Arch Neurol 1988; 45 (7) 737-739
  • 32 Halmagyi GM, Aw ST, Cremer PD, Curthoys IS, Todd MJ. Impulsive testing of individual semicircular canal function. Ann N Y Acad Sci 2001; 942: 192-200
  • 33 Cremer PD, Halmagyi GM, Aw ST , et al. Semicircular canal plane head impulses detect absent function of individual semicircular canals. Brain 1998; 121 (Pt 4) 699-716
  • 34 Kim JS, Kim HJ. Inferior vestibular neuritis. J Neurol 2012; 259 (8) 1553-1560
  • 35 Halmagyi GM, Aw ST, Karlberg M, Curthoys IS, Todd MJ. Inferior vestibular neuritis. Ann N Y Acad Sci 2002; 956: 306-313
  • 36 Curthoys IS. The interpretation of clinical tests of peripheral vestibular function. Laryngoscope 2012; 122 (6) 1342-1352
  • 37 Duncan GW, Parker SW, Fisher CM. Acute cerebellar infarction in the PICA territory. Arch Neurol 1975; 32 (6) 364-368
  • 38 Guiang Jr RL, Ellington OB. Acute pure vertiginous dysequilibrium in cerebellar infarction. Eur Neurol 1977; 16 (1-6) 11-15
  • 39 Rubenstein RL, Norman DM, Schindler RA, Kaseff L. Cerebellar infarction—a presentation of vertigo. Laryngoscope 1980; 90 (3) 505-514
  • 40 Huang CY, Yu YL. Small cerebellar strokes may mimic labyrinthine lesions. J Neurol Neurosurg Psychiatry 1985; 48 (3) 263-265
  • 41 Amarenco P, Roullet E, Hommel M, Chaine P, Marteau R. Infarction in the territory of the medial branch of the posterior inferior cerebellar artery. J Neurol Neurosurg Psychiatry 1990; 53 (9) 731-735
  • 42 Disher MJ, Telian SA, Kemink JL. Evaluation of acute vertigo: unusual lesions imitating vestibular neuritis. Am J Otol 1991; 12 (3) 227-231
  • 43 Magnusson M, Norrving B. Cerebellar infarctions as the cause of ‘vestibular neuritis’. Acta Otolaryngol Suppl 1991; 481: 258-259
  • 44 Kase CS, Norrving B, Levine SR , et al. Cerebellar infarction. Clinical and anatomic observations in 66 cases. Stroke 1993; 24 (1) 76-83
  • 45 Magnusson M, Norrving B. Cerebellar infarctions and ‘vestibular neuritis’. Acta Otolaryngol Suppl 1993; 503: 64-66
  • 46 Norrving B, Magnusson M, Holtås S. Isolated acute vertigo in the elderly; vestibular or vascular disease?. Acta Neurol Scand 1995; 91 (1) 43-48
  • 47 Thömke F, Hopf HC. Pontine lesions mimicking acute peripheral vestibulopathy. J Neurol Neurosurg Psychiatry 1999; 66 (3) 340-349
  • 48 Hotson JR, Baloh RW. Acute vestibular syndrome. N Engl J Med 1998; 339 (10) 680-685
  • 49 Newman-Toker DE, Kattah JC, Alvernia JE, Wang DZ. Normal head impulse test differentiates acute cerebellar strokes from vestibular neuritis. Neurology 2008; 70 (24 Pt 2) 2378-2385
  • 50 Lee H, Kim HA. Nystagmus in SCA territory cerebellar infarction: pattern and a possible mechanism. J Neurol Neurosurg Psychiatry 2013; 84 (4) 446-451
  • 51 Schmid-Priscoveanu A, Straumann D, Böhmer A, Obzina H. Vestibulo-ocular responses during static head roll and three-dimensional head impulses after vestibular neuritis. Acta Otolaryngol 1999; 119 (7) 750-757
  • 52 Schmid-Priscoveanu A, Böhmer A, Obzina H, Straumann D. Caloric and search-coil head-impulse testing in patients after vestibular neuritis. J Assoc Res Otolaryngol 2001; 2 (1) 72-78
  • 53 Kattah JC, Wang DZ, Zagardo MT, Pyle KR. Head impulse sign in cerebellar, medullary, and labyrinthine stroke. J Vestib Res 2004; 14: 100-101
  • 54 Lee H, Sohn SI, Cho YW , et al. Cerebellar infarction presenting isolated vertigo: frequency and vascular topographical patterns. Neurology 2006; 67 (7) 1178-1183
  • 55 Cnyrim CD, Newman-Toker D, Karch C, Brandt T, Strupp M. Bedside differentiation of vestibular neuritis from central “vestibular pseudoneuritis”. J Neurol Neurosurg Psychiatry 2008; 79 (4) 458-460
  • 56 Johnston SC, Rothwell PM, Nguyen-Huynh MN , et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet 2007; 369 (9558) 283-292
  • 57 Saber Tehrani AS, Kattah JC, Mantokoudis G , et al. Small strokes causing severe vertigo: frequency of false-negative MRIs and nonlacunar mechanisms. Neurology 2014; 83 (2) 169-173
  • 58 Huh YE, Koo JW, Lee H, Kim JS. Head-shaking aids in the diagnosis of acute audiovestibular loss due to anterior inferior cerebellar artery infarction. Audiol Neurootol 2013; 18 (2) 114-124
  • 59 Chen L, Lee W, Chambers BR, Dewey HM. Diagnostic accuracy of acute vestibular syndrome at the bedside in a stroke unit. J Neurol 2011; 258 (5) 855-861
  • 60 Batuecas-Caletrío Á, Yáñez-González R, Sánchez-Blanco C , et al. [Peripheral vertigo versus central vertigo. Application of the HINTS protocol]. Rev Neurol 2014; 59 (8) 349-353
  • 61 Häusler R, Levine RA. Auditory dysfunction in stroke. Acta Otolaryngol 2000; 120 (6) 689-703
  • 62 Tatu L, Moulin T, Bogousslavsky J, Duvernoy H. Arterial territories of human brain: brainstem and cerebellum. Neurology 1996; 47 (5) 1125-1135
  • 63 Lee H, Baloh RW. Sudden deafness in vertebrobasilar ischemia: clinical features, vascular topographical patterns and long-term outcome. J Neurol Sci 2005; 228 (1) 99-104
  • 64 Lee H, Sohn SI, Jung DK , et al. Sudden deafness and anterior inferior cerebellar artery infarction. Stroke 2002; 33 (12) 2807-2812
  • 65 Lee H, Cho YW. Auditory disturbance as a prodrome of anterior inferior cerebellar artery infarction. J Neurol Neurosurg Psychiatry 2003; 74 (12) 1644-1648
  • 66 Lee H, Ahn BH, Baloh RW. Sudden deafness with vertigo as a sole manifestation of anterior inferior cerebellar artery infarction. J Neurol Sci 2004; 222 (1-2) 105-107
  • 67 Gerace C, Pianura C. Sudden deafness without vertigo as a sole manifestation of AICA infarct. Neurol Sci 2008; 29 (5) 371-372
  • 68 Park JH, Kim H, Han HJ. Recurrent audiovestibular disturbance initially mimicking Ménière's disease in a patient with anterior inferior cerebellar infarction. Neurol Sci 2008; 29 (5) 359-362
  • 69 Kim JS, Cho KH, Lee H. Isolated labyrinthine infarction as a harbinger of anterior inferior cerebellar artery territory infarction with normal diffusion-weighted brain MRI. J Neurol Sci 2009; 278 (1-2) 82-84
  • 70 Lee H, Kim JS, Chung EJ , et al. Infarction in the territory of anterior inferior cerebellar artery: spectrum of audiovestibular loss. Stroke 2009; 40 (12) 3745-3751
  • 71 Martines F, Dispenza F, Gagliardo C, Martines E, Bentivegna D. Sudden sensorineural hearing loss as prodromal symptom of anterior inferior cerebellar artery infarction. ORL J Otorhinolaryngol Relat Spec 2011; 73 (3) 137-140
  • 72 Ikegami-Takada T, Izumikawa M, Doi T, Takada Y, Tomoda K. AICA syndrome with facial palsy following vertigo and acute sensorineural hearing loss. Auris Nasus Larynx 2012; 39 (2) 244-248
  • 73 Lee H. Audiovestibular loss in anterior inferior cerebellar artery territory infarction: a window to early detection?. J Neurol Sci 2012; 313 (1-2) 153-159
  • 74 Stefan H, Wappenschmidt J, Kiefer H. Occlusions of the basilar artery: Pathologic-anatomical and clinical findings in different occlusion types and their prognosis. Neurosurg Rev 1981; 4 (1) 41-52
  • 75 Huang MH, Huang CC, Ryu SJ, Chu NS. Sudden bilateral hearing impairment in vertebrobasilar occlusive disease. Stroke 1993; 24 (1) 132-137
  • 76 von Campe G, Regli F, Bogousslavsky J. Heralding manifestations of basilar artery occlusion with lethal or severe stroke. J Neurol Neurosurg Psychiatry 2003; 74 (12) 1621-1626
  • 77 Yi HA, Lee SR, Lee H, Ahn BH, Park BR, Whitman GT. Sudden deafness as a sign of stroke with normal diffusion-weighted brain MRI. Acta Otolaryngol 2005; 125 (10) 1119-1121
  • 78 Chiang CI, Chou CH, Hsueh CJ, Cheng CA, Peng GS. Acute bilateral hearing loss as a “worsening sign” in a patient with critical basilar artery stenosis. J Clin Neurosci 2013; 20 (1) 177-179
  • 79 Kim E, Son MK, Kang CK, Lee YB. Vertebrobasilar occlusion presenting as sudden isolated bilateral sensorineural hearing loss: case report. J Cerebrovasc Endovasc Neurosurg 2013; 15 (3) 225-228
  • 80 Lee H. Sudden deafness related to posterior circulation infarction in the territory of the nonanterior inferior cerebellar artery: frequency, origin, and vascular topographical pattern. Eur Neurol 2008; 59 (6) 302-306
  • 81 Raupp SF, Jellema K, Sluzewski M, de Kort PL, Visser LH. Sudden unilateral deafness due to a right vertebral artery dissection. Neurology 2004; 62 (8) 1442
  • 82 Choi KD, Chun JU, Han MG, Park SH, Kim JS. Embolic internal auditory artery infarction from vertebral artery dissection. J Neurol Sci 2006; 246 (1-2) 169-172
  • 83 Kim JS, Lopez I, DiPatre PL, Liu F, Ishiyama A, Baloh RW. Internal auditory artery infarction: clinicopathologic correlation. Neurology 1999; 52 (1) 40-44
  • 84 Beyea JA, Agrawal SK, Parnes LS. Recent advances in viral inner ear disorders. Curr Opin Otolaryngol Head Neck Surg 2012; 20 (5) 404-408
  • 85 Baloh RW. Clinical practice. Vestibular neuritis. N Engl J Med 2003; 348 (11) 1027-1032
  • 86 Schuknecht HF, Kitamura K. Second Louis H. Clerf Lecture. Vestibular neuritis. Ann Otol Rhinol Laryngol Suppl 1981; 90 (1 Pt 2): 1-19
  • 87 Ben-David J, Luntz M, Podoshin L, Sabo E, Fradis M. Vertigo as a prognostic sign in sudden sensorineural hearing loss. Int Tinnitus J 2002; 8 (2) 127-128
  • 88 Kitahara T, Takeda N, Nishiike S, Okumura S, Kubo T. Prognosis of inner ear periphery and central vestibular plasticity in sudden deafness with vertigo. Ann Otol Rhinol Laryngol 2005; 114 (10) 786-791
  • 89 Jung JY, Kim YH, Suh MW. Difference in the nature of dizziness between vestibular neuritis and sudden sensorineural hearing loss with vertigo. Otol Neurotol 2012; 33 (4) 623-628
  • 90 Rahko T, Karma P. New clinical finding in vestibular neuritis: high-frequency audiometry hearing loss in the affected ear. Laryngoscope 1986; 96 (2) 198-199
  • 91 Wayman DM, Pham HN, Byl FM, Adour KK. Audiological manifestations of Ramsay Hunt syndrome. J Laryngol Otol 1990; 104 (2) 104-108
  • 92 Lee H. Recent advances in acute hearing loss due to posterior circulation ischemic stroke. J Neurol Sci 2014; 338 (1-2) 23-29
  • 93 Hydén D, Akerlind B, Peebo M. Inner ear and facial nerve complications of acute otitis media with focus on bacteriology and virology. Acta Otolaryngol 2006; 126 (5) 460-466
  • 94 Newman-Toker DE, Kattah J. HINTS to identify stroke in ED patients with dizziness (in reply). Acad Emerg Med Feb 13, 2014
  • 95 Newman-Toker DE, Edlow JA. High-stakes diagnostic decision rules for serious disorders: the Ottawa subarachnoid hemorrhage rule. JAMA 2013; 310 (12) 1237-1239
  • 96 Axer H, Grässel D, Brämer D , et al. Time course of diffusion imaging in acute brainstem infarcts. J Magn Reson Imaging 2007; 26 (4) 905-912
  • 97 Laupacis A, Sekar N, Stiell IG. Clinical prediction rules. A review and suggested modifications of methodological standards. JAMA 1997; 277 (6) 488-494
  • 98 Stiell IG, Bennett C. Implementation of clinical decision rules in the emergency department. Acad Emerg Med 2007; 14 (11) 955-959
  • 99 Stiell IG, Greenberg GH, McKnight RD , et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA 1993; 269 (9) 1127-1132
  • 100 Perry JJ, Stiell IG, Sivilotti ML , et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA 2013; 310 (12) 1248-1255
  • 101 Robinson DA. A method of measuring eye movement using a scleral search coil in a magnetic field. IEEE Trans Biomed Eng 1963; 10: 137-145
  • 102 MacDougall HG, Weber KP, McGarvie LA, Halmagyi GM, Curthoys IS. The video head impulse test: diagnostic accuracy in peripheral vestibulopathy. Neurology 2009; 73 (14) 1134-1141
  • 103 Luis L, Costa J, Vaz Garcia F, Valls-Solé J, Brandt T, Schneider E. Spontaneous plugging of the horizontal semicircular canal with reversible canal dysfunction and recovery of vestibular evoked myogenic potentials. Otol Neurotol 2013; 34 (4) 743-747
  • 104 Hirvonen TP, Aalto H, Jutila T. Labyrinthine function after semicircular canal surgery on seventeen patients with cholesteatoma. Clin Otolaryngol 2015;
  • 105 Kim HA, Lee H. Isolated vestibular nucleus infarction mimicking acute peripheral vestibulopathy. Stroke 2010; 41 (7) 1558-1560
  • 106 Tohgi H, Takahashi S, Chiba K, Hirata Y ; The Tohoku Cerebellar Infarction Study Group. Cerebellar infarction. Clinical and neuroimaging analysis in 293 patients. Stroke 1993; 24 (11) 1697-1701
  • 107 Chen L, Todd M, Halmagyi GM, Aw S. Head impulse gain and saccade analysis in pontine-cerebellar stroke and vestibular neuritis. Neurology 2014; 83 (17) 1513-1522
  • 108 Robinson DA, Zee DS, Hain TC, Holmes A, Rosenberg LF. Alexander's law: its behavior and origin in the human vestibulo-ocular reflex. Ann Neurol 1984; 16 (6) 714-722
  • 109 Lin CY, Young YH. Clinical significance of rebound nystagmus. Laryngoscope 1999; 109 (11) 1803-1805
  • 110 Lee SU, Kim HJ, Kim JS. Pseudo-spontaneous and head-shaking nystagmus in horizontal canal benign paroxysmal positional vertigo. Otol Neurotol 2014; 35 (3) 495-500
  • 111 Kim HJ, Lee SH, Park JH, Choi JY, Kim JS. Isolated vestibular nuclear infarction: report of two cases and review of the literature. J Neurol 2014; 261 (1) 121-129
  • 112 Brodsky MC, Donahue SP, Vaphiades M, Brandt T. Skew deviation revisited. Surv Ophthalmol 2006; 51 (2) 105-128
  • 113 Zee DS. Considerations on the mechanisms of alternating skew deviation in patients with cerebellar lesions. J Vestib Res 1996; 6 (6) 395-401
  • 114 Halmagyi GM, Brandt T, Dieterich M, Curthoys IS, Stark RJ, Hoyt WF. Tonic contraversive ocular tilt reaction due to unilateral meso-diencephalic lesion. Neurology 1990; 40 (10) 1503-1509
  • 115 Brandt T, Dieterich M. Pathological eye-head coordination in roll: tonic ocular tilt reaction in mesencephalic and medullary lesions. Brain 1987; 110 (Pt 3) 649-666
  • 116 Dieterich M, Brandt T. Wallenberg's syndrome: lateropulsion, cyclorotation, and subjective visual vertical in thirty-six patients. Ann Neurol 1992; 31 (4) 399-408
  • 117 Dieterich M, Brandt T. Thalamic infarctions: differential effects on vestibular function in the roll plane (35 patients). Neurology 1993; 43 (9) 1732-1740
  • 118 Brandt T, Dieterich M. Skew deviation with ocular torsion: a vestibular brainstem sign of topographic diagnostic value. Ann Neurol 1993; 33 (5) 528-534
  • 119 Brandt T, Dieterich M. Vestibular syndromes in the roll plane: topographic diagnosis from brainstem to cortex. Ann Neurol 1994; 36 (3) 337-347
  • 120 Mossman S, Halmagyi GM. Partial ocular tilt reaction due to unilateral cerebellar lesion. Neurology 1997; 49 (2) 491-493
  • 121 Chen CM, Lin SH. Ipsiversive partial ocular tilt reaction in a patient with acute paramedian thalamic infarctions. Acta Neurol Taiwan 2006; 15 (1) 29-33
  • 122 Zwergal A, Cnyrim C, Arbusow V , et al. Unilateral INO is associated with ocular tilt reaction in pontomesencephalic lesions: INO plus. Neurology 2008; 71 (8) 590-593
  • 123 Halmagyi GM, Gresty MA, Gibson WP. Ocular tilt reaction with peripheral vestibular lesion. Ann Neurol 1979; 6 (1) 80-83
  • 124 Wolfe GI, Taylor CL, Flamm ES, Gray LG, Raps EC, Galetta SL. Ocular tilt reaction resulting from vestibuloacoustic nerve surgery. Neurosurgery 1993; 32 (3) 417-420 , discussion 420–421
  • 125 Safran AB, Vibert D, Issoua D, Häusler R. Skew deviation after vestibular neuritis. Am J Ophthalmol 1994; 118 (2) 238-245
  • 126 Vibert D, Häusler R, Safran AB, Koerner F. Ocular tilt reaction associated with a sudden idiopathic unilateral peripheral cochleovestibular loss. ORL J Otorhinolaryngol Relat Spec 1995; 57 (6) 310-315
  • 127 Vibert D, Häusler R, Safran AB, Koerner F. Diplopia from skew deviation in unilateral peripheral vestibular lesions. Acta Otolaryngol 1996; 116 (2) 170-176
  • 128 Cosetti MK, Tawfik K, Fouladvand M, Roland Jr JT, Lalwani AK. Diplopia due to skew deviation following neurotologic procedures. Otol Neurotol 2012; 33 (5) 840-842
  • 129 Wong AM, Tweed D, Sharpe JA. Vertical misalignment in unilateral sixth nerve palsy. Ophthalmology 2002; 109 (7) 1315-1325
  • 130 Weber KP, MacDougall HG, Halmagyi GM, Curthoys IS. Impulsive testing of semicircular-canal function using video-oculography. Ann N Y Acad Sci 2009; 1164: 486-491
  • 131 Macdougall HG, McGarvie LA, Halmagyi GM, Curthoys IS, Weber KP. The video Head Impulse Test (vHIT) detects vertical semicircular canal dysfunction. PLoS ONE 2013; 8 (4) e61488
  • 132 MacDougall HG, McGarvie LA, Halmagyi GM, Curthoys IS, Weber KP. Application of the video head impulse test to detect vertical semicircular canal dysfunction. Otol Neurotol 2013; 34 (6) 974-979
  • 133 Manzari L, Burgess AM, MacDougall HG, Bradshaw AP, Curthoys IS. Rapid fluctuations in dynamic semicircular canal function in early Ménière's disease. Eur Arch Otorhinolaryngol 2011; 268 (4) 637-639
  • 134 Manzari L, Burgess AM, Curthoys IS. Vestibular function in Lermoyez syndrome at attack. Eur Arch Otorhinolaryngol 2012; 269 (2) 685-691
  • 135 Manzari L, MacDougall HG, Burgess AM, Curthoys IS. New, fast, clinical vestibular tests identify whether a vertigo attack is due to early Ménière's disease or vestibular neuritis. Laryngoscope 2013; 123 (2) 507-511
  • 136 Mantokoudis G, Saber Tehrani AS, Kattah JC , et al. Quantifying the vestibulo-ocular reflex with video-oculography: nature and frequency of artifacts. Audiol Neurootol 2015; 20 (1) 39-50
  • 137 Paul NL, Simoni M, Rothwell PM ; Oxford Vascular Study. Transient isolated brainstem symptoms preceding posterior circulation stroke: a population-based study. Lancet Neurol 2013; 12 (1) 65-71
  • 138 Martin-Schild S, Albright KC, Tanksley J , et al. Zero on the NIHSS does not equal the absence of stroke. Ann Emerg Med 2011; 57 (1) 42-45
  • 139 Oppenheim C, Stanescu R, Dormont D , et al. False-negative diffusion-weighted MR findings in acute ischemic stroke. AJNR Am J Neuroradiol 2000; 21 (8) 1434-1440
  • 140 Kerber KA, Schweigler L, West BT, Fendrick AM, Morgenstern LB. Value of computed tomography scans in ED dizziness visits: analysis from a nationally representative sample. Am J Emerg Med 2010; 28 (9) 1030-1036
  • 141 Kim AS, Sidney S, Klingman JG, Johnston SC. Practice variation in neuroimaging to evaluate dizziness in the ED. Am J Emerg Med 2012; 30 (5) 665-672
  • 142 Caplan LR, Adelman L. Neurologic education. West J Med 1994; 161 (3) 319-322
  • 143 Newman-Toker DE, Perry JJ. Acute diagnostic neurology: challenges and opportunities. Acad Emerg Med 2015; 22 (3) 357-361
  • 144 Cutfield NJ, Seemungal BM, Millington H, Bronstein AM. Diagnosis of acute vertigo in the emergency department. Emerg Med J 2011; 28 (6) 538-539
  • 145 Vanni S, Pecci R, Casati C , et al. STANDING, a four-step bedside algorithm for differential diagnosis of acute vertigo in the Emergency Department. Acta Otorhinolaryngol Ital 2014; 34 (6) 419-426
  • 146 Bartl K, Lehnen N, Kohlbecher S, Schneider E. Head impulse testing using video-oculography. Ann N Y Acad Sci 2009; 1164: 331-333
  • 147 Impulse ICS Available at: http://icsimpulse.com/ . Accessed June 15, 2015
  • 148 Eye See Cam Available at: http://www.interacoustics.us/eyeseecam . Accessed June 15, 2015
  • 149 Newman-Toker DE. AVERT Phase II Trial: Acute video-oculography for vertigo in emergency rooms for rapid triage. Baltimore, MD: Johns Hopkins University; 2014. . ClinicalTrials.gov Identifier: NCT02483429. Available at: https://clinicaltrials.gov/ct2/show/NCT02483429?term=avert&rank=6
  • 150 Nelson RE, Saltzman GM, Skalabrin EJ, Demaerschalk BM, Majersik JJ. The cost-effectiveness of telestroke in the treatment of acute ischemic stroke. Neurology 2011; 77 (17) 1590-1598
  • 151 Audebert HJ, Boy S, Jankovits R , et al. Is mobile teleconsulting equivalent to hospital-based telestroke services?. Stroke 2008; 39 (12) 3427-3430
  • 152 Omron R, Saber-Tehrani AS, Duval-Arnold J , et al. The participation in a vertigo day resulted in better resident comfort with discharging patients without receiving a CT scan in patients with vestibular neuritis [abstract]. Paper presented at: Society for Academic Emergency Medicine Annual Meeting; May 9–12, 2012; Chicago, IL
  • 153 Daudelin DH, Selker HP. Medical error prevention in ED triage for ACS: use of cardiac care decision support and quality improvement feedback. Cardiol Clin 2005; 23 (4) 601-614 , ix
  • 154 Newman-Toker DE, Edlow JA. TiTrATE: a novel, evidence-based approach to diagnosing acute dizziness and vertigo. Neurol Clin 2015; 33 (3) 577-599
  • 155 Singh H, Giardina TD, Meyer AN, Forjuoh SN, Reis MD, Thomas EJ. Types and origins of diagnostic errors in primary care settings. JAMA Intern Med 2013; 173 (6) 418-425
  • 156 Berwick DM. Making good on ACOs' promise—the final rule for the Medicare shared savings program. N Engl J Med 2011; 365 (19) 1753-1756
  • 157 Gold D, Newman-Toker DE, Sharfstein JM. Neurology and the Affordable Care Act. JAMA Neurol 2015; 72 (6) 623-624
  • 158 Park HK, Kim JS, Strupp M, Zee DS. Isolated floccular infarction: impaired vestibular responses to horizontal head impulse. J Neurol 2013; 260 (6) 1576-1582
  • 159 Physician Fee Schedule Search Centers for Medicare & Medicaid Services; 2014. Available from: http://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/PhysicianFeeSched/index.html?redirect=/PhysicianFeeSched/ . Accessed January 26, 2014
  • 160 Chalela JA, Kidwell CS, Nentwich LM , et al. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison. Lancet 2007; 369 (9558) 293-298
  • 161 Hwang DY, Silva GS, Furie KL, Greer DM. Comparative sensitivity of computed tomography vs. magnetic resonance imaging for detecting acute posterior fossa infarct. J Emerg Med 2012; 42 (5) 559-565
  • 162 Ozono Y, Kitahara T, Fukushima M , et al. Differential diagnosis of vertigo and dizziness in the emergency department. Acta Otolaryngol 2014; 134 (2) 140-145
  • 163 Kabra R, Robbie H, Connor SE. Diagnostic yield and impact of MRI for acute ischaemic stroke in patients presenting with dizziness and vertigo. Clin Radiol 2015; 70 (7) 736-742
  • 164 Smith-Bindman R, Lipson J, Marcus R , et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med 2009; 169 (22) 2078-2086
  • 165 Mortelé KJ, Oliva MR, Ondategui S, Ros PR, Silverman SG. Universal use of nonionic iodinated contrast medium for CT: evaluation of safety in a large urban teaching hospital. AJR Am J Roentgenol 2005; 184 (1) 31-34
  • 166 Josephson SA, Dillon WP, Smith WS. Incidence of contrast nephropathy from cerebral CT angiography and CT perfusion imaging. Neurology 2005; 64 (10) 1805-1806
  • 167 2012 Medicare hospital outpatient prospective payment schedule rates: computed tomography procedures. Malvern, PA: Siemens Medical Solutions USA; 2012. Available from http://www.medical.siemens.com/siemens/en_US/rg_marcom_FBAs/files/Reimbursement/CT_2012_Final_HOPPS_Payment_Rates.pdf . Accessed March 24, 2013
  • 168 Preventing accidents and injuries in the MRI suite The Joint Commission; 2008. Available at: http://www.jointcommission.org/sentinel_event_alert_issue_38_preventing_accidents_and_injuries_in_the_mri_suite/ . Accessed June 20, 2015
  • 169 Shellock FG, Spinazzi A. MRI safety update 2008: part 1, MRI contrast agents and nephrogenic systemic fibrosis. AJR Am J Roentgenol 2008; 191 (4) 1129-1139
  • 170 2012 Medicare hospital outpatient prospective payment schedule rates: magnetic resonance imaging. Malvern, PA: Siemens Medical Solutions USA, Inc; 2012. Available at: http://www.medical.siemens.com/siemens/en_US/rg_marcom_FBAs/files/Reimbursement/MR_2012_Final_HOPPS_Payment_Rates.pdf . Accessed March 24, 2013
  • 171 Kamalian S, Atkinson WL, Florin LA, Pomerantz SR, Lev MH, Romero JM. Emergency department CT screening of patients with nontraumatic neurological symptoms referred to the posterior fossa: comparison of thin versus thick slice images. Emerg Radiol 2014; 21 (3) 251-256
  • 172 Newman-Toker DE, Hsieh YH, Camargo Jr CA, Pelletier AJ, Butchy GT, Edlow JA. Spectrum of dizziness visits to US emergency departments: cross-sectional analysis from a nationally representative sample. Mayo Clin Proc 2008; 83 (7) 765-775
  • 173 Edlow JA, Newman-Toker DE, Savitz SI. Diagnosis and initial management of cerebellar infarction. Lancet Neurol 2008; 7 (10) 951-964