Evaluation of Diplopia by Emergency Medicine Physicians and Consulting Neurologists

Appropriate evaluation of diplopia requires separating serious from benign causes. If providers are not adept in this task, diagnosis of critical conditions may be delayed and unnecessary testing may result.

Original Contribution Section Editors: Clare Fraser, MD Susan Mollan, MD Evaluation of Diplopia by Emergency Medicine Physicians and Consulting Neurologists Yilin Feng, BA, Patrick W. Commiskey, MD, Tatiana K. Deveney, MD, Lindsey B. De Lott, MD, MS, Jonathan D. Trobe, MD Background: Appropriate evaluation of diplopia requires separating serious from benign causes. If providers are not adept in this task, diagnosis of critical conditions may be delayed and unnecessary testing may result. Methods: We studied the records of 100 consecutive patients who presented to an emergency department between 2010 and 2020 with diplopia as a prominent symptom. We rated the performance of emergency medicine physicians (EMPs) and consulting neurologists (CNs) in the examination, diagnosis, and ordering of diagnostic tests according to standards based on neuro-ophthalmologic consultation and the neuro-ophthalmologic literature. Results: EMPs made no diagnosis or an incorrect diagnosis in 88 (88%) of 100 encounters. They ordered 14 unindicated and 12 incorrect studies, mostly noncontrast computed tomography scans. CNs made an incorrect diagnosis in 13 (31%) encounters. They ordered 6 unindicated and 2 incorrect studies. The total charge for unindicated and incorrect studies ordered by EMPs and CNs was $119,950. Conclusions: EMPs and CNs made frequent errors in the examination, diagnosis, and ordering of diagnostic studies, leading to inefficient care and unnecessary testing. EMPs largely delegated the evaluation of diplopia to their consultants. If such consultative support were not available, the care of diplopic patients would be delayed. CNs performed more complete examinations, but rarely enough to allow appreciation of the pattern of ocular misalignment, contributing to misdiagnoses and ordering errors. The identifica- Department of Ophthalmology and Visual Sciences (YF, PC, TD, LBDL, JDT), Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan; and Department of Neurology (LBDL, JDT), University of Michigan, Ann Arbor, Michigan. The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www. jneuro-ophthalmology.com). Address correspondence to Jonathan D. Trobe, MD, Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, 1000 Wall Street, Ann Arbor, MI 48105; E-mail: [e-mail] e230 tion of these provider errors allows for more targeted teaching in the evaluation of diplopia. Journal of Neuro-Ophthalmology 2022;42:e230–e239 doi: 10.1097/WNO.0000000000001247 © 2021 by North American Neuro-Ophthalmology Society D iplopia, the sensation of seeing 2 images instead of one, may be caused by ocular misalignment, which often betokens serious neurological problems, or by optical aberrations, such as uncorrected refractive errors or deformities in the cornea or lens, which do not require urgent evaluation (1–3). Although diplopia accounted for only an estimated 0.1% of visits to the emergency department (ED) in Italy between 2007 and 2009 (3) and for only an estimated 0.04% of visits in the United States between 2016 and 2017 (4,5), distinguishing between its trivial and serious causes is crucial in determining appropriate management. In one study (4), 60% of ED visits for diplopia resulted in the ordering of noncontrast brain computed tomographic (CT) scans, yet those scans are not sensitive in the detection of serious conditions, especially when diplopia is the only or principal manifestation. A study of 84 consecutive patients referred to neuro-ophthalmologists with prior brain imaging found that 28.1% of patients had undergone the wrong studies (6). Many reports have suggested that subspecialists are valuable in improving management (7–13), but their contribution in the evaluation of diplopia in the ED has not been studied. We conducted a retrospective review of ED evaluation of diplopic patients by emergency medical physicians (EMPs) and consulting neurologists (CNs) at a single tertiary care academic medical center based on standards drawn from neuro-ophthalmologic consultation and the published literature (14–28). METHODS We obtained institutional review board approval for a retrospective analysis of electronic medical records of Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution patients with diplopia examined in the ED of Michigan Medicine. Patient Selection We used the Electronic Medical Record Search Engine (29) of Michigan Medicine to search the records of patients who presented or were transferred to the Michigan Medicine ED from 2010 to 2020. Using the terms “neuro-ophthalmology,” “diplopia,” and “reason for consultation,” we searched backwards from 2020 until we had identified 100 consecutive patients who met the study entry criteria. Patients were included only if diplopia was a prominent symptom as determined by the EMP. All patients were examined by an emergency medicine physician’s assistant or resident EMP, faculty EMP, consulting ophthalmology resident, or neuro-ophthalmology fellow (CO). Forty-two patients were also evaluated by a neurology resident supported in real time by a faculty consultant neurologist (CN). All patients were staffed by a faculty neuro-ophthalmologist, and 70 patients were examined in person by a neuroophthalmologist again later in the outpatient clinic. A definite explanation for diplopia was rendered by the faculty neuro-ophthalmologist (“gold standard diagnosis”). We excluded patients whose diagnosis had been established before evaluation in the ED. Grade 5: grade 4 plus assessment of ocular alignment in the primary gaze position by the cover test or other methods Grade 6: grade 5 plus measurement of ocular alignment in primary and eccentric gaze positions by the cover test or other methods In 30 encounters, EMPs assessed ocular versions, but did not document a history relevant to diplopia, so they were given an examination proficiency grade of 1. In only 1 encounter, CNs did the same thing, so they were given a grade of 1. Grading of Provider Proficiency in Diagnosis We compared the provider diagnosis to the gold standard diagnosis according to the following scale: Grade 1: no documented diagnosis or incorrect diagnosis Grade 2: incompletely documented but correct diagnosis (e.g., if the gold standard diagnosis was “third nerve palsy, ischemic” and the provider documented only “third nerve palsy”) Grade 3: completely documented, correct, but not favored diagnosis (e.g., if the gold standard diagnosis was “third nerve palsy, ischemic” and the provider documented “myasthenia gravis or ischemic third nerve palsy”) Grade 4: completely documented, correct, and favored diagnosis Data Collection From the electronic medical notes recorded by each EMP, CN, CO, and faculty neuro-ophthalmologist, we collected data on the demographics, history, and physical examination pertinent to diplopia, differential diagnoses, diagnostic testing, and patient outcome. We assumed that any undocumented components of the evaluation had not been performed. Three independent abstractors—2 medical students (Y.F.and P.W.C.) and 1 neuro-ophthalmologist who is board certified in ophthalmology and neurology (J.D.T.) —reviewed the charts and concurred on the excerpted data. Grading of Provider Proficiency in Examination In the absence of consensus guidelines, we developed a grading scale based on consultation with neuroophthalmologists and recommendations from the pertinent neuro-ophthalmologic literature (14–17,25–27). We rated the proficiency of EMPs and CNs in history taking and ophthalmic examination according to the following scale: Grade 1: no pertinent history elicited Grade 2: history elicited as to whether diplopia was monocular or binocular, varied with gaze position, or whether the images were separated horizontally, vertically, obliquely, or torsionally Grade 3: grade 2 plus assessment of ocular versions Grade 4: grade 3 plus assessment of ocular alignment in the primary (straight ahead) gaze position by visualizing the relative position of the eyes Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Assessment of Provider Proficiency in the Ordering of Diagnostic Studies We assessed provider proficiency based on adherence to best ED practices as suggested by consultation with neuroophthalmologists and the pertinent neuro-ophthalmologic literature (14–19,28). We used the following definitions: (1) Unindicated study: a study that should not have been ordered (2) Incorrect study: a study that was ordered but not preferred (3) Omitted study: a study that was indicated but not ordered Regarding gold standard diagnoses and practices most appropriate for the ED, we used the following definitions as suggested by consultation with neuro-ophthalmologists and the pertinent neuro-ophthalmologic literature (14–19,28). (1) Isolated third nerve palsy. Defined by typical neuroophthalmic features and the absence of other pertinent features. Best ED practice: computed tomographic angiography (CTA) or MRA (to rule out aneurysm). (2) Nonisolated third nerve palsy. Defined by typical neuroophthalmic features and accompanying neurologic or systemic abnormalities that would suggest a nonischemic, nonaneurysmal cause. Best ED practice: brain MRI. (3) Isolated fourth nerve palsy, nondecompensated, nonischemic profile. Defined by typical neuro-ophthalmic e231 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) features of a nondecompensated palsy in a patient aged ,60 years who lacked arteriosclerotic risk factors that would suggest an ischemic cause. Best ED practice: brain MRI. Isolated fourth nerve palsy, nondecompensated, ischemic profile. Defined by typical neuro-ophthalmic features of a nondecompensated palsy in a patient aged.60 years or a younger patient who had arteriosclerotic risk factors that would suggest an ischemic cause. Best ED practice: no imaging. Isolated fourth nerve palsy, decompensated. Defined by typical neuro-ophthalmic features of a decompensated palsy. Best ED practice: no imaging. Nonisolated fourth nerve palsy. Defined by typical neuro-ophthalmic features and accompanying neurologic or systemic abnormalities that would suggest a nonischemic cause. Best ED practice: brain MRI. Isolated sixth nerve palsy, nonischemic profile. Defined by typical neuro-ophthalmic features in a patient aged ,60 years who lacked arteriosclerotic risk factors that would suggest an ischemic cause. Best ED practice: brain MRI. Isolated sixth nerve palsy, ischemic profile. Defined by typical neuro-ophthalmic features in a patient aged .60 years or a younger patient who had arteriosclerotic risk factors that would suggest an ischemic cause. Best ED practice: no imaging. Nonisolated sixth nerve palsy. Defined by typical neuro-ophthalmic features and other pertinent neurologic or systemic abnormalities that would suggest a nonischemic cause. Best ED practice: brain MRI. Multiple ipsilateral cranial nerve palsies. Defined by typical neuro-ophthalmic features of multiple cranial nerve palsies on the same side. Best ED practice: brain MRI. Decompensated phoria, uncomplicated profile. Defined by comitant esotropia or exotropia and no neurologic or systemic abnormalities that would suggest an underlying cause for decompensation other than aging. Best ED practice: no imaging. Decompensated phoria, complicated profile. Defined by comitant esotropia or exotropia and neurologic or systemic abnormalities that would suggest an underlying cause for decompensation other than aging. Best ED practice: brain CT or MRI. Monocular diplopia. Defined by diplopia present with either eye covered. Best ED practice: no imaging. Skew deviation. Defined by comitant or incomitant hyperdeviation with a pattern that did not conform to other causes of diplopia or with one or more signs of brainstem or cerebellar dysfunction. Best ED practice: brain MRI. Myasthenia gravis. Defined by typical ophthalmic features and confirmed by positive acetylcholine receptor antibody (ARAB) and/or electromyography. Best ED practice: ARAB. e232 (16) Orbital myositis. Defined by monocular ductional deficits and clinical features of an orbitopathy. Best ED practice: orbit-based CT or MRI. (17) Giant cell arteritis. Defined by diplopia in a patient aged .60 years who had clinical features of polymyalgia rheumatica, headache, or scalp tenderness. Best ED practice: C-reactive protein and/or erythrocyte sedimentation rate. (18) Internuclear ophthalmoplegia. Defined by monocular or binocular adduction deficit with one or more signs of brainstem dysfunction. Best ED practice: brain MRI. (19) Orbitopathy after recent sinus surgery. Defined by monocular ductional deficits, clinical features of an orbitopathy, and recent sinus surgery. Best ED practice: orbit-based CT or MRI. RESULTS Patient Demographics There were 56 men and 44 women, ranging in age from 17 to 84 years (median 59.5 years). Only 1 patient was aged younger than 20 years; 5 patients were aged younger than 30 years. Encounters EMPs examined 100 patients, CNs examined 42 patients, and COs examined 97 patients. A faculty neuroophthalmologist examined 70 patients later in the outpatient neuro-ophthalmology clinic. All 100 patients had been examined either by the CO in consultation with a faculty neuro-ophthalmologist or by the faculty neuroophthalmologist alone in the outpatient clinic. Gold standard Diagnoses Cranial nerve palsies were diagnosed in 55% of patients. Most palsies involved a single cranial nerve as the only pertinent clinical abnormality (“isolated single cranial nerve palsies”). Isolated palsies of single third, fourth, and sixth cranial nerves were almost equally represented, most of them attributed to presumed ischemia of the extra-axial portion of the nerve. In 19% of the cohort, the single cranial nerve palsies were accompanied by nonophthalmic pertinent clinical abnormalities (“nonisolated palsies”) and were caused by intracranial cancer, inflammation, aneurysm clipping, carotid-cavernous fistula, high intracranial pressure, cerebrospinal fluid leak, or brainstem stroke. Only 3% of patients had multiple cranial nerve palsies on the same side, caused by cavernous sinus cancer, infection, or noninfectious inflammation. Decompensated phoria, which presented mostly as comitant esotropia, accounted for 14% of patients and was often idiopathic. Monocular diplopia, attributed to an optical aberration or uncertain cause, was Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution diagnosed in 10%. Skew deviation, a hypertropia caused by a brainstem lesion, made up 8% of the cohort. Myasthenia gravis, orbital myositis, giant cell arteritis, internuclear ophthalmoplegia, and orbitopathy after sinus surgery were infrequent diagnoses (Table 1). Provider Proficiency in Examination EMPs elicited no pertinent history related to diplopia in 35% of encounters. They extracted a history without any assessment of ocular versions or alignment in 6% of encounters, took a history and assessed ocular versions but not ocular alignment in 51% of encounters, and assessed ocular alignment by noting the positions of the eyes in a primary gaze position (straight-ahead gaze) in 7% of encounters. They assessed the plane of alignment in a primary gaze position with the cover test in only 1% of encounters and never assessed ocular alignment in eccentric gaze (Table 2). CNs failed to document a history pertinent to diplopia in only 2.4% of encounters. They performed an assessment of ocular versions without assessment of ocular alignment in 52.4% of encounters and added an assessment of ocular alignment by visualization in the primary gaze position in 14.2% of encounters. They performed cover testing in the primary gaze position in 31% of encounters, but never assessed ocular alignment in eccentric gaze positions. Provider Proficiency in Diagnosis EMPs documented no diagnosis in 56 (56%) encounters and entered an incorrect diagnosis in 32 (32%) encounters. In the remaining 12 (12%) encounters, they made the correct diagnosis but often documented it incompletely (Tables 3 and 4). Among the 12 patients in whom EMPs made the correct diagnosis, the diagnosis was often facilitated by the fact that the patients had obvious ductional deficits, ptosis, or misalignment. For example, in the 1 patient with a decompensated phoria from Wernicke encephalopathy, the EMP reached the correct diagnosis by noting that the patient had recently undergone bariatric surgery, not by assessing the ophthalmic features, which the CO documented as showing full ocular ductions and a comitant esotropia. In the patient with third and sixth nerve palsies on the same side, the patient’s immune-compromised state and obvious abduction deficit guided the EMP to the correct diagnosis. The single patient who was correctly diagnosed with giant cell arteritis by the EMPs was elderly and had a new headache. In their 42 encounters, CNs documented no diagnosis in 3 (7%) and an incorrect diagnosis in 10 (24%), including 5 patients with decompensated phoria, 3 with skew deviation, 3 with monocular diplopia, and 1 each with decompensated fourth nerve palsy and myasthenia gravis. In many cases, the mistakes came from not assessing ocular alignment in eccentric positions of gaze. For example, among the 5 patients with a decompensated phoria, correct diagnosis would have depended on noting comitant misalignment, a finding that can be discovered only by assessing ocular alignment in eccentric gaze positions. In the 3 patients with skew deviation, mistakes likely occurred from failure to establish that the pattern of misalignment did not fit a cranial nerve palsy or that there were signs of brainstem dysfunction, such as nystagmus. The single patient with a decompensated fourth nerve palsy had full ocular ductions, so the diagnosis depended on establishing the typical pattern of misalignment, which again required assessment of alignment in eccentric positions of gaze. The mistakes in the 3 patients with monocular diplopia likely occurred because CNs did not elicit a pertinent history or perform monocular occlusion. TABLE 1. Gold standard diagnoses in 100 patients Diagnosis No. of Patients Isolated single cranial nerve palsy Third Fourth Sixth Nonisolated single cranial nerve palsy Third Fourth Sixth Decompensated phoria Monocular diplopia Skew deviation Myasthenia gravis Multiple cranial nerve palsies Orbital myositis Giant cell arteritis Internuclear ophthalmoplegia Orbitopathy after sinus surgery Total Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 33 12 9 12 19 5 1 13 14 10 8 4 3 3 3 2 1 100 Provider Proficiency in the Ordering of Diagnostic Studies Nearly all diagnostic studies were brain CTs or MRIs. CTs were ordered without contrast. All MRI studies were ordered with contrast. EMPs did not meet the testing standard recommended by neuro-ophthalmologists in 54% of encounters. CNs did not meet that standard in 28.6% of encounters (Table 5). EMPs ordered 14 unindicated and 20 incorrect imaging studies before their consultants arrived. Unindicated studies were mostly noncontrast CTs. Incorrect studies were noncontrast CTs instead of the preferred MRIs or vascular imaging studies. In 1 of those patients, who had a pupilsparing third nerve palsy without prominent headache, CTA later ordered by the CO disclosed an unruptured posterior communicating aneurysm. EMPs omitted the ordering of 47 studies, probably because they deferred that task to their consultants. e233 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution TABLE 2. Provider proficiency in examination of diplopia Examination Proficiency Grades 1 2 3 4 5 6 Tasks Executed No history taken History taken but ocular versions not examined History taken + ocular versions examined History + ocular versions + ocular alignment examined by visualization History + ocular versions + ocular alignment by cover test performed in primary gaze position History + ocular versions + ocular alignment by cover test performed in primary and eccentric gaze positions Total encounters CNs ordered 6 unindicated studies. They also ordered 2 incorrect studies—MRIs in patients with isolated third nerve palsy, where a vascular imaging study rather than an MRI was preferred to rule out intracranial aneurysm. They omitted 8 indicated studies, which occurred in patients with isolated third nerve 3, “nonisolated” sixth nerve palsy, multiple cranial nerve palsies, myasthenia gravis, complicated decompensated phoria, and giant cell arteritis (See Supplemental Digital Content, Text E1, http://links.lww.com/ WNO/A463). DISCUSSION The objective of this study was to use standards recommended by neuro-ophthalmologists (14–28) as a basis for judging the performance of EMPs and CNs in the evaluation of diplopia in the ED of an academic medical center. We chose a cohort size of 100 patients to generate a realistic portrayal yet allow a detailed analysis of each patient. The distribution of gold standard diagnoses was similar to that of earlier reports (1–3). Provider performance errors were largely attributable to incomplete examinations and lack of familiarity with certain conditions that cause diplopia. Those issues led to correct diagnoses in only 12% of encounters by EMPs and in 69% of encounters by CNs. Where EMPs made the correct diagnoses, a thorough ocular motility examination was not necessary, as patients had either obvious ductional deficits or nonophthalmic features that were strong clues. As expected, CNs performed more complete examinations than did EMPs, but they never documented ocular alignment in eccentric gaze positions, making it difficult to discern the pattern of misalignment. That deficiency contributed to their missing the diagnosis of decompensated phoria and skew deviation. Both types of providers often missed the diagnosis of monocular diplopia, which applied to 10% of our cohort. A simple maneuver to establish persistence of diplopia with either eye covered would have yielded the correct diagnosis. e234 Emergency Medicine Physician Encounters (%) 35 6 51 7 (35) (6) (51) (7) Consultant Neurologist Encounters (%) 1 (2.4) 0 (0) 22 (52.4) 6 (14.2) 1 (1) 13 (31.0) 0 (0) 0 (0) 100 42 Diagnostic errors may have contributed to the ordering of unindicated or incorrect imaging studies. For EMPs, those errors consisted mostly of noncontrast CTs ordered before consultants arrived. The 14 unindicated studies occurred in adults with isolated fourth or sixth nerve palsies, uncomplicated decompensated phoria, monocular diplopia, and myasthenia gravis (23,26–28). The 20 incorrect studies occurred in patients with isolated third nerve palsies, where CTA or MRA rather than CT is indicated to exclude an aneurysm (14,15,21,28), in patients with multiple cranial nerve palsies or a single cranial nerve palsy accompanied by features that strongly suggested a nonischemic intracranial cause, where MRI is more sensitive than CT (14,15,21,28), in patients with skew deviation, where MRI is preferred over CT, and in patients with congestive orbital features, where an orbit-based CT is more sensitive than a brain-based CT (14,15,21,28). The ordering of unindicated and incorrect studies by the EMPs might be explained by the desire to speed up the evaluation in advance of consultation by the specialists. But a noncontrast CT, the “up front” study they always chose, is not helpful in the diagnosis of diplopia, which is almost never caused by abnormalities visible on that study. The EMPs may also have been heeding recommendations set forth in widely consulted emergency medicine texts and journal review articles (30–34). Although appropriate history taking is emphasized in those sources, the recommended physical examination of the eyes in diplopic patients is focused on the testing of ocular versions without measurements of alignment (30–34). One widely used textbook (33) provides an excellent diagnostic algorithm that proceeds stepwise through ruling out monocular diplopia by occluding each eye, looking for signs of orbitopathy, identifying single isolated cranial nerve palsies, multiple cranial nerve palsies, signs of brainstem dysfunction, and signs of neuromuscular disorders, but it does not describe how to go about making those diagnoses. The algorithm emphasizes differentiating between ischemic and compressive (aneurysmal) causes of isolated third nerve palsy and appropriately Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution TABLE 3. Provider proficiency in diagnosis of diplopia Diagnosis Proficiency Grades 1 2 3 4 Definition of Grades Emergency Medicine Physician Encounters (%) Consultant Neurologist Encounters (%) 88 (88) 13 (31.0) 9 (9) 7 (16.6) 1 (1) 9 (21.4) 2 (2) 13 (31.0) 100 42 No documented diagnosis or incorrect diagnosis Incompletely documented, correct diagnosis Completely documented, correct, but not favored diagnosis Completely documented, correct, and favored diagnosis Total encounters recommends no imaging for presumed ischemic palsies and MRA or CTA for presumed nonischemic palsies. It does not, however, acknowledge that the distinction between these ischemic and nonischemic (including aneurysmal) causes of third nerve palsies is unreliable on clinical grounds alone. It recommends MRI acutely on all isolated fourth and sixth nerve palsies but does not consider the option of deferring imaging in vasculopathic adults with sixth nerve palsy and in patients with decompensated fourth nerve palsies. In addition, the value of distinguishing comitant from incomitant misalignment is not described. The concept of a decompensated esophoria is not discussed in the source material directed at EMPs or neurology trainees. One source (34) appropriately recommends that brain imaging be deferred in older patients with sixth nerve palsy suspected of having an ischemic cause and suggests CT or MRI in anyone who has “associated symptoms and signs” that point to “brainstem or cavernous sinus involvement.” The same source (33) suggests urgent imaging in patients with third nerve palsy only if the pupil is involved and the patient also has a “thunderclap” headache. Notably, in one patient in this study with an isolated pupil-sparing third nerve palsy and only mild headache, EMPs incorrectly ordered a CT. CTA later ordered by the CO disclosed an unruptured cerebral aneurysm at the appropriate location to cause the palsy. The errors on the part of CNs are less explainable because diplopia is an issue more commonly addressed by these specialists, who have access to more detailed guidance (14–17,25–27). The American Academy of Neurology (AAN) website guidelines for neurology trainees suggest that they be familiar with the diagnosis of ocular motor palsies, internuclear ophthalmoplegia, and skew deviation, but do not specify what is to be done (35). On the other hand, comprehensive essays on the evaluation of diplopia are found in the AAN’s continuing education review series TABLE 4. Provider diagnostic proficiency according to gold standard diagnoses Correct Diagnoses Gold Standard Isolated third nerve palsy Nonisolated third nerve palsy Isolated fourth nerve palsy Nonisolated fourth nerve palsy Isolated sixth nerve palsy Nonisolated sixth nerve palsy Decompensated phoria Monocular diplopia Skew deviation Myasthenia gravis Multiple cranial nerve palsies Orbital myositis Giant cell arteritis Internuclear ophthalmoplegia Orbitopathy after sinus surgery Total Emergency Medicine Physicians Consultant Neurologists 3/12* 1/5 0/9 1/1 2/12 2/13 1/14 0/10 0/8 0/4 1/3 0/3 1/3 0/2 0/1 12/100 4/4* N/A† 3/4 N/A† 3/3 4/4 3/8 4/7 2/5 2/3 2/2 N/A† 2/2 N/A† N/A† 29/42 *Numerator indicates number of correct diagnoses, denominator indicates number of encounters. † N/A indicates that the consultant neurologists had no encounters with patients carrying this diagnosis. Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 e235 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Gold Standard Diagnosis (No. of Patients) Unindicated Incorrect CNs EMPs Studies Studies Adhere to Adhere to Ophthalmologist Ordered by Ordered by Testing Best ED Best ED Best ED EMPs EMPs Practice Practice Practice Recommendations* Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Isolated cranial nerve 3 CTA or 5/12† 2/4† palsy (12) MRA Nonisolated cranial nerve MRI‡ 0/5 N/A 3 palsy (5) Isolated cranial nerve 4 palsy (9) MRI 1/4 1/1 Nondecompensated, nonischemic profile (4) Nondecompensated, No 0/2 0/1 ischemic profile (2) imaging Decompensated (3) No 1/3 2/2 imaging Nonisolated cranial nerve MRI 0/1 N/A 4 palsy (1) Isolated cranial nerve 6 palsy (12) Nonischemic profile (2) MRI 0/2 N/A Ischemic profile (10) No 6/10 2/3 imaging MRI 4/13 3/4 Nonisolated cranial nerve 6 palsy (13) Decompensated phoria (14) Uncomplicated profile No 4/6 3/4 (6) imaging Complicated profile (8) CT or MRI 5/8 3/4 Monocular diplopia (10) No 8/10 6/7 imaging Skew deviation (8) MRI 0/8 5/5 Myasthenia gravis (4) ARAB 1/4 2/3 Multiple cranial nerve palsies (3) MRI 1/3 1/2 Indicated Studies Omitted by EMPs Unindicated Incorrect Studies Indicated Studies Ordered by Ordered by Studies Omitted CNs by CNs CNs 7 CTA or MRA 0 3 CT 7 CTA or MRA 0 2 MRI 2 CTA or MRA 3 MRI 0 2 CT 5 MRI N/A N/A N/A 2 MRI 0 1 CT 3 MRI 0 0 0 0 1 CT, 1 CTA 0 0 1 MRI/MRV 0 0 1 MRI 1 CT, 1 CTA 0 0 0 0 0 1 MRI 0 0 1 MRI N/A N/A N/A 2 MRI 2 MRI 0 4 CT 0 0 2 MRI 0 N/A 1 MRI N/A 0 N/A 0 1 CTA, 7 MRI 0 4 CT 9 MRI 0 0 1 MRI 0 1 CT, 1 CTA 0 0 1 MRI 0 0 1 MRI/MRV 0 0 2 CT 0 0 3 CT or MRI 0 0 1 MRI/MRV 0 0 1 CT or MRI 0 1 CTA, 2 MRI 2 ARAB, 3 EMG 0 1 MRI, 1 CTA 0 8 CT 0 8 MRI 3 ARAB 0 1 MRI 0 0 0 1 ARAB 1 CT 2 MRI 0 0 1 MRI 1 MRI Original Contribution e236 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. TABLE 5. Provider adherence to best ED practice in diagnostic testing Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Gold Standard Diagnosis (No. of Patients) Orbital myositis (3) Giant cell arteritis (3) Internuclear ophthalmoplegia (2) Orbitopathy after sinus surgery (1) Total Unindicated Incorrect CNs EMPs Studies Studies Adhere to Adhere to Ophthalmologist Ordered by Ordered by Testing Best ED Best ED Best ED EMPs EMPs Practice Practice Practice Recommendations* CT or MRI orbit ESR/CRP 1/3 N/A 1/3 0/2 MRI 2/2 N/A CT or MRI orbit 1/1 N/A 41/100 30/42 2 MRI orbit 2 ESR/CRP, 3 temporal artery biopsy 1 CTA 0 Indicated Studies Omitted by EMPs Unindicated Incorrect Indicated Studies Studies Ordered by Ordered by Studies Omitted by CNs CNs CNs 0 1 CT 2 CT or MRI orbit N/A N/A N/A 0 0 2 ESR/CRP 1 CTA 0 2 esr/CRP 0 0 0 N/A N/A N/A 0 0 0 N/A N/A N/A 9 CT, 4 CTA, 1 MRI 20 CT 2 MRI 1 CT or MRI, 2 CTA or MRA, 2 MRI, 1 ARAB, 2 ESR/CRP 3 CT or MRI, 2 CT or MRI 1 CTA, 3 MRI, 2 orbit, 7 CTA or MRA, MRI/MRV 30 MRI, 3 ARAB, 2 ESR/CRP *Includes recommendations from consulting ophthalmologists and neuro-ophthalmology fellows (CO) and backed up by faculty neuro-ophthalmologists. † Column numerators indicate the number of encounters in which providers adhered to the best practice; denominators indicate the total number of encounters for each provider. ‡ All MRIs were ordered with contrast administration. The total number of tests may exceed the total number of patients for some diagnoses because providers were given credit for adhering to the best practice if they did not order additional studies on a patient who had already received the best ED practice test; the total number of tests may be fewer than the total number of patients for some diagnoses because some patients may not have received the best ED practice test. ARAB, acetylcholine receptor antibody; CN, consulting neurologists; CRP, C-reactive protein; EMG, electromyography; EMP, emergency medicine physicians; ESR, erythrocyte sedimentation rate. Original Contribution e237 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. (Continued ) Original Contribution called Lifelong Learning in Neurology (15,16), and in widely used textbooks (24) and websites like MedLink Neurology (22–24). Even so, CNs omitted cover testing and ordered unindicated studies in patients with isolated fourth and sixth nerve palsies, where strong ischemic profiles should have permitted deferral of imaging, and in patients with monocular diplopia, uncomplicated decompensated phoria, myasthenia gravis, and giant cell arteritis, where imaging is not indicated. They incorrectly ordered MRIs on patients who had isolated third nerve palsies, where vascular imaging is preferred to rule out aneurysm. Provider ordering errors come at a substantial cost. Using our institutional charges of $2,090 for noncontrast CT, $3,386 for CTA, $6,009 for MRI, and $3,178 for MRV, the total charges were $119,950 for the 42 unindicated and incorrect studies ordered by EMPs and CNs. We acknowledge that there is some controversy even within the neuro-ophthalmic community as to whether MRI should be ordered or deferred in patients with newonset isolated fourth and sixth nerve palsies. If we deduct the charges associated with unindicated ED imaging in those cases in calculating the unnecessary expenditures, the residual charges are $89,261. For comparison, the charges for 100 consultant visits, based on our institutional charge of $250 per encounter, are $25,000. EMPs often seemed to delegate the evaluation of diplopic patients to their consultants. Away from an academic medical center, where consultants may not be available in the ED, this practice may incur costs of unnecessary hospitalization, inconvenience, and delays in diagnosis. In this study, a delay in diagnosis might have been especially precarious in the patient with the isolated third nerve palsy from an unruptured cerebral aneurysm. Based on our study, we suggest the following targeted approach to teaching EMPs and CNs: (1) Elicit monocular diplopia (2) Separate “comitant” from “incomitant” misalignment (3) Separate “isolated” from “nonisolated” cranial nerve palsies (4) Separate presumptive “ischemic” from presumptive “nonischemic” isolated cranial nerve palsies (5) Order appropriate vascular imaging for isolated third nerve palsy (6) Distinguish the features of skew deviation, internuclear ophthalmoplegia, myasthenia gravis, orbitopathy, and carotid-cavernous fistula (7) Know about “decompensated phoria” (8) Know about “decompensated” fourth nerve palsy (9) Know when to consider giant cell arteritis as a cause of diplopia The conclusions from this study must be tempered by its weaknesses. The performance of the medical providers was judged by standards set by neuro-ophthalmologists that are unrealistically high for EMPs, but probably appropriate for e238 neurology trainees. Some of the evaluation guidelines are controversial, including acute imaging in the evaluation of isolated sixth nerve palsy and decompensated phoria, and the distinction between presumed “ischemic” and presumed “nonischemic” profiles. In addition, some patients who were staffed by the attending neuro-ophthalmologist were not examined in person in the ED. Our detailed review of medical records may not have revealed all the management elements, including discussions between EMPs and their consultants, most of which were probably undocumented. The ophthalmic abnormalities documented by the COs did not always permit a straight-forward diagnosis, so even they occasionally ordered unindicated studies. Finally, judging the performance of EMPs in an academic medical center might seem artificial because these providers typically turn over the evaluation of diplopia to consultants. However, failing to record any relevant history in 35% of patients is hard to excuse, even if EMPs were expecting to have the help of specialists. On the other hand, given the breadth of preparedness expected of EMPs, the fact that diplopia is a relatively uncommon complaint, and that a thorough evaluation requires skill and experience, an incomplete diagnostic evaluation by EMPs is not surprising. The expectations from neurology trainees should be higher. Despite these limitations, we believe that we have drawn an accurate image of the evaluation of diplopic patients in an academic center ED. We found that the teamwork approach to patient care ultimately led to satisfactory outcomes but that there were many missteps along the way. Uncovering those missteps suggests a focused approach to teaching EMPs and CNs that could improve quality and reduce costs. STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: Y. Feng, P. Commiskey, T. Deveney, L. B. De Lott, and J. D. Trobe; b. Acquisition of data: Y. Feng, P. Commiskey, T. Deveney, L. B. De Lott, and J. D. Trobe; c. Analysis and interpretation of data: Y. Feng, P. Commiskey, T. Deveney, L. B. De Lott, and J. D. Trobe. Category 2: a. Drafting the manuscript: Y. Feng, P. Commiskey, T. Deveney, L. B. De Lott, and J. D. Trobe; b. Revising it for intellectual content: J. D. Trobe. Category 3: a. Final approval of the completed manuscript: Y. Feng, P. Commiskey, T. Deveney, L. B. De Lott, and J. D. Trobe. ACKNOWLEDGMENTS Two physicians trained in emergency medicine, who did not participate in the study, reviewed its methods, results, and conclusions. Their feedback was incorporated into the final article. REFERENCES 1. Nazerian P, Vanni S, Tarocchi C, Portaccio E, Vannucci N, Para O, Giannazzo G, Gigli C, Grifoni S. Causes of diplopia in the emergency department: diagnostic accuracy of clinical Feng et al: J Neuro-Ophthalmol 2022; 42: e230-e239 Copyright © North American Neuro-Ophthalmology Society. 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