Incidence and Etiologies of Acquired Third Nerve Palsy Using a Population-Based Method

Not Just Down and Out: Oculomotor Nerve Pathologic Spectrum

The purpose of this article is to understand the complex pathologic spectrum of oculomotor nerve palsy. We review the detailed anatomy and function of the oculomotor nerve and demonstrate how the location of a lesion can drive the differential diagnosis. Lastly, we review atypical presentations of oculomotor nerve palsy to include oculomotor synkinesis and oculomotor nerve hyperactivity. Radiologists must be aware of the typical and atypical presentations of CN III palsy to accurately localize lesions as well as avoid premature exclusion of CN III pathology.

Evaluation of Surgical Clipping and Endovascular Coiling on Oculomotor Nerve Palsy Caused by Internal Carotid Artery Aneurysm

Objectives: Internal carotid artery (ICA) aneurysm often leads to oculomotor nerve palsy (ONP) that impairs eye movement. Currently, microsurgical clipping and endovascular coiling are the two major options to treat ONP. The purpose of the current study is to compare the clinical outcomes of the two methods in patients with ONP caused by ICA aneurysm. Patients and Methods: In the present study, we assessed the prognostic factors and recovery outcomes of a total of 90 ICA aneurysm-induced ONP patients, where 50 of them were treated with microsurgical clipping and 40 of them were treated with endovascular coiling. Within the endovascular coiling group, 20 of the patients were treated with balloon-assisted coiling and the other 20 were treated with stent-assisted coiling. Results: Overall, we achieved a 59% (53 out of 90) full recovery rate. Both surgical clipping and endovascular coiling treatment methods achieved similar recovery outcomes in the tested patients. However, within the endovascular coiling group, balloon-assisted coiling treatment demonstrated a significantly higher full recovery rate (17 out of 20) compared to stent-assisted coiling treatment (eight out of 20). Conclusion: In general, no significant difference was identified between the surgical and coiling treatments, and both procedures were considered as beneficial for ICA aneurysm-induced ONP.

Idiopathic unilateral oculomotor nerve palsy: A case report

Cranial nerve III palsy, also known as oculomotor nerve palsy, may result from various causes; however, the etiology remains unknown in some instances. The aim of this case report is to present the authors' experience with two cases of idiopathic cranial nerve III palsy, together with a review of the literature. Case 1 is a 78-year-old woman and case 2 is a 75-year-old man, both having no history of trauma and no vascular risk factors. They presented to the authors' hospital with diplopia and palpebral ptosis and were diagnosed with idiopathic unilateral cranial nerve III palsy. They received oral steroids for treatment. One patient recovered completely within 3 months, while the other patient did not recover regardless of long-term follow-up. Idiopathic cranial nerve III palsy can occur in otherwise healthy individuals and often recover in several months. Careful examinations to rule out other causes and then steroid treatment should be considered after early diagnosis.

Chameleons, red herrings, and false localizing signs in neurocritical care

False localizing signs (FLS) and other misleading neurological signs have long been an intractable aspect of neurocritical care. Because they suggest an incorrect location or etiology of the pathological lesion, they have often led to misdiagnosis and mismanagement of the patient. Here, we reviewed the existing literature to provide an updated, comprehensive descriptive review of these difficult to diagnose signs in neurocritical care. For each sign presented, we discuss the non-false localizing presentation of symptoms, the common FLS or misleading presentation, etiology/pathogenesis of the sign, and diagnosis, as well as any other clinically relevant considerations. Within cranial neuropathies, we cover cranial nerves III, IV, V, VI, VII, VIII, as well as multiple cranial nerve involvement of IX, X, and XII. FLS ophthalmologic symptoms indicate diagnostically challenging neurological deficits, and here we discuss downbeat nystagmus, ping-pong-gaze, one-and-a-half syndrome, and wall-eyed bilateral nuclear ophthalmoplegia (WEBINO). Cranial herniation syndromes are integral to any discussion of FLS and here we cover Kernohan's notch phenomenon, pseudo-Dandy Walker malformation, and uncal herniation. FLS in the spinal cord have also been relatively well documented, but in addition to compressive lesions, we also discuss newer findings in radiculopathy and disc herniation. Finally, pulmonary syndromes may sometimes be overlooked in discussions of neurological signs but are critically important to recognize and manage in neurocritical care, and here we discuss Cheyne-Stokes respiration, cluster breathing, central neurogenic hyperventilation, ataxic breathing, Ondine's curse, and hypercapnia. Though some of these signs may be rare, the framework for diagnosing and treating them must continue to evolve with our growing understanding of their etiology and varied presentations.

Solitary Sign of Third Nerve Palsy in a Conscious Patient With Epidural Hemorrhage

Epidural hematoma is a life-threatening complication of head injury, which often occurs as a result of blunt trauma to the skull. Unregulated hematoma expansion in any setting results in elevated intracranial pressure and may contribute to the compression of the oculomotor nerve among several other adversities culminating in various long-lasting complications in the future. In this case report, we present the findings of a rare, insightful case of a 47-year-old Southeast Asian male with no established prior medical history apart from being a victim of blunt trauma attributable to a fall four days before presenting to the emergency department with abrupt onset of diplopia and drooping of the left eyelid. The initial physical examination helped to establish a diagnosis of third nerve palsy. A non-contrast CT of the head was conducted, and its findings revealed the presence of a right temporal-parietal-occipital epidural hemorrhage, with no mass impact on the cerebral hemisphere. The patient later underwent a successful left temporoparietal craniotomy, during which 100-125 ml of blood was drained out. Post-surgery, a near-full reduction of ptosis was recorded at the end of the first week. This case report summarizes this ingenious depiction of a partial third nerve palsy presenting as the sole sign of the epidural hemorrhage in a cognizant patient.

Clinical Prediction Score for Early Neuroimaging in Acquired Isolated Oculomotor Nerve Palsy

Purpose

An immediate neuroimaging investigation in patients with isolated oculomotor nerve palsy (ONP) remains controversial. We aimed to develop a clinical prediction score to determine whether or not acquired isolated ONP patients require prompt imaging.

Methods

A retrospective study was performed. Demographic data and clinical presentations were collected to determine predictive factors favored for early brain imaging using multivariate logistic regression analysis.

Results

Ninety-seven eyes of 96 patients diagnosed with isolated ONP were included. Forty-one eyes (42.3%) were caused by ischemia, while the other 56 eyes (57.7%) were caused by non-ischemic etiologies, namely aneurysm (n = 22), trauma (n = 18), inflammation (n = 5), tumor (n = 4), and others (n = 7). Eighty-two eyes (84.5%) had undergone neuroimaging study due to initially suspected non-ischemic causes. Only 36 (43.9%) revealed concordant diagnosis. The potential clinical predictors favored for neuroimaging using multivariate logistic regression analysis were age 10‒50 years (adjusted odds ratio [aOR] 9.01, 95% CI: 1.25‒64.8), age 51‒70 years (aOR 1.71, 95% CI: 0.46‒6.35), history of head trauma (aOR 7.14, 95% CI: 1.19‒42.9), absence of vascular risk factors (aOR 3.85, 95% CI: 1.23‒12.1), and poor pupillary response (aOR 6.96, 95% CI: 1.99‒24.3). The predictor scores with an area under the ROC curve of 0.852 were 4, 1, 4, 3, and 4, respectively. The optimum cut-point was 3 for a sensitivity of 96% and specificity of 44%.

Conclusion

Patients with acquired isolated ONP should be considered early neuroimaging studies when they are younger than 50 years old, have a history of head trauma, have no history of vascular risk factors, or have poor pupillary reaction.

Approach to patient with diplopia

This article presents an overview of the most important points a neurologist must remember when dealing with a patient complaining of diplopia. Patients with monocular diplopia and those with full ocular motility and comitant misalignment should be referred to an ophthalmologist and do not require further testing. Patients with recent onset of binocular diplopia who have associated "brainstem" symptoms should have an urgent brain MRI. All patients with 3rd cranial nerve palsy require urgent brain CTA to rule out compressive aneurysmal lesion. Management of patients over 50 years of age with microvascular risk factors with new onset of 6th nerve palsy is controversial: some image these patients at presentation while others choose a short period of observation as most of these patients would have a microvascular etiology for the 6th nerve palsy which should improve spontaneous in 2-3 months. All others with 6th nerve palsy require brain MRI with contrast. Patients with 4th palsy with hyperdeviation that worsens in downgaze should have an MRI with contrast and all others referred to an ophthalmologist. If there is more than one cranial nerve palsy, urgent neuroimaging should be performed with attention to cavernous sinus and superior orbital fissure. Ocular myasthenia should be suspected in patients with eye misalignment that does not fit a pattern for any cranial nerve palsy. Orbital pathology (most commonly thyroid eye disease) can result in restriction of ocular motility and has specific clinical signs associated with it.

Big Data Research in Neuro-Ophthalmology: Promises and Pitfalls

BACKGROUND

Big data clinical research involves application of large data sets to the study of disease. It is of interest to neuro-ophthalmologists but also may be a challenge because of the relative rarity of many of the diseases treated.

EVIDENCE ACQUISITION

Evidence for this review was gathered from the authors' experiences performing analysis of large data sets and review of the literature.

RESULTS

Big data sets are heterogeneous, and include prospective surveys, medical administrative and claims data and registries compiled from medical records. High-quality studies must pay careful attention to aspects of data set selection, including potential bias, and data management issues, such as missing data, variable definition, and statistical modeling to generate appropriate conclusions. There are many studies of neuro-ophthalmic diseases that use big data approaches.

CONCLUSIONS

Big data clinical research studies complement other research methodologies to advance our understanding of human disease. A rigorous and careful approach to data set selection, data management, data analysis, and data interpretation characterizes high-quality studies.

The Incidence and Etiologies of Third Cranial Nerve Palsy in Koreans: A 10-year Nationwide Cohort Study

PURPOSE

This study aimed to determine the incidence, prevalence, and etiologies of third cranial nerve (CN3) palsy in Koreans.

METHODS

Data were collected from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database of South Korea and analyzed. Incident CN3 palsy subjects in the cohort population were defined as cases occurring after the initial 4-year or longer washout period. The incidence and prevalence were analyzed by sex, age group, and year. The etiologies of CN3 palsy were evaluated using comorbidities.

RESULTS

Of 1,108,253 subjects, 387 patients were newly diagnosed with CN3 palsy between 2006 and 2015. The incidence of CN3 palsy was 3.71 per 100,000 person-years (95% confidence interval, 3.35-4.09). The incidence of CN3 palsy increased with age and accelerated after the age of 60 years. The mean male-to-female incidence ratio was 1.16. The main cause was presumed to be vascular disease (52.7%), followed by idiopathic causes (25.8%), intracranial neoplasm (7.8%), unruptured cerebral aneurysm (5.4%), and trauma (5.2%).

CONCLUSIONS

The incidence of CN3 palsy in Koreans increased with age and peaked between 75 and 79 years. The main cause of CN3 palsy was vascular disease.

The oculomotor neurovascular conflict: Literature review and proposal of management

BACKGROUND

The Oculomotor nerve (OCN) lies in a close relationship with large arteries inside the basal cisterns. Therefore, it may be compressed by vascular malformations or aneurysms. Nevertheless, the compression is not always related to pathologic conditions. Indeed, some cases of neurovascular conflicts of the OCN have been described in the literature.

METHODS

A case of neurovascular conflict of the OCN resolved after steroid treatment is reported. Additionally, a systematic literature review of those cases was performed.

RESULTS

OCN palsy due to a neurovascular conflict has been described as acute or chronic persistent palsy, or with an intermittent presentation. Symptoms result from compression, although asymptomatic compression is not uncommon. Surgical treatment, pharmacological treatment, and observation have been reported as options in the literature. Microvascular decompression was employed effectively in some cases of OCN neurovascular conflict. Nevertheless, other cases were treated successfully with steroids (persistent presentation) and carbamazepine (intermittent presentation). A management algorithm based on the results of the literature review is proposed.

CONCLUSIONS

Treatment options for OCN neurovascular conflicts and their results are heterogeneous. Based on the literature review, the pharmacological treatment seems to be the most appropriate first-line approach, reserving surgery for refractory cases. Collecting clinical information about new cases will allow defining treatment standards for this rare condition.

Oculomotor Nerve Palsy in the Emergency Department: A Complication of Epidural Injection

BACKGROUND

Epidural injections are routinely used for management of radicular pain and are prevalent nonsurgical interventions for chronic low back pain. Pneumocephalus is a rare complication that may occur as a result of inadvertent dural puncture with an epidural needle. Pneumocephalus-induced cranial nerve deficit is also rare, with only a few reported cases.

CASE REPORT

We report a case of a 61-year-old woman with a chief complaint of diplopia after she underwent epidural injection for chronic lumbar pain. Her examination was remarkable for a partial right oculomotor nerve palsy. We obtained a computed tomography brain scan, which revealed pneumocephalus. She was managed conservatively and reported complete symptom resolution after 2 weeks. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Pneumocephalus is an uncommon complication of epidural spinal injections. Emergency physicians should include this on the differential for a patient presenting with cranial nerve deficit after this procedure.

Pupil-Involving Oculomotor Nerve Palsy Following Tonsillectomy and Adenoidectomy

Ocular complications of adenotonsillectomy are rare. The authors describe a 6-year-old boy who developed mydrasis and limitations of supraduction and infraduction after adenotonsillectomy. This was attributed to the hemorrhagic compression of the nerve in the cavernous sinus. This is the first report of pupil-involving oculomotor nerve palsy following adenotonsillectomy. [J Pediatr Ophthalmol Strabismus. 2019;56:e76-e78.].

Imaging of Nontraumatic Orbital and Neuro-ophthalmological Emergencies

Emergency department (ED) visits for eye and vision-related concerns are common. In most cases, accurate diagnosis is made using clinical history and physical exam findings without the need for emergent imaging. When orbital imaging is performed in the ED, it is often in patients with orbital trauma where CT is used to assess for orbital fractures and associated injuries. However, CT or MR imaging can also be critical to appropriately diagnose and manage certain ED patients with nontraumatic eye and vision-related conditions. The purpose of this article is to review the imaging findings and differential diagnoses for nontraumatic orbital and neuro-ophthalmological emergencies from a practical, clinical perspective, based on a patient's typical presenting symptoms. The more commonly imaged clinical indications will be discussed including periorbital swelling, proptosis, eye pain, diplopia, and visual disturbances. In addition, rare but easily overlooked and clinically important diagnoses for the emergency radiologist to recognize will be highlighted.

Don't Miss This! Red Flags in the Pediatric Eye Exam: Pupils

The pupillary exam in the pediatric population is a vital part of any clinician's workup. In the right clinical setting, pupillary abnormalities such as anisocoria, light-near dissociation, an afferent pupillary defect, and paradoxic pupillary constriction in the dark can be red flags that trigger further examination and workup. Through both careful physical examination and detailed history-taking and observation, potentially vision- and life-threatening conditions can be detected.

Diplopia-Related Ambulatory and Emergency Department Visits in the United States, 2003-2012

Importance

Diplopia is believed to be a common eye-related symptom. However, to date, there are no available population-based estimates, which are necessary to understand the impact of this disabling symptom on the health care system and to identify steps to optimize patient care.

Objective

To describe diplopia presentations in US ambulatory and emergency department (ED) settings.

Design, Setting, and Participants

Ambulatory and ED visits in the United States by patients with diplopia were analyzed in this prespecified secondary analysis of National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey data collected for a 10-year period (2003-2012). Data were analyzed for the present study from October 6, 2016 to August 18, 2017.

Main Outcomes and Measures

Numbers of ambulatory and ED diplopia presentations were estimated using weighted sample data. Weighted proportions of patient and clinician (ie, ophthalmologists, general practitioners, and specialty physicians) characteristics, diagnoses, and imaging use were calculated.

Results

In total, 804 647 (95% CI, 662 075-947 218) ambulatory and 49 790 (95% CI, 38 318-61 262) diplopia-related ED visits occurred annually; 12.3% of ambulatory visits were primarily for acute- or subacute-onset diplopia. Mean (SD) patient age was 62.1 (20.3) years for ambulatory vs 48.1 (22.3) years for diplopia-related ED visits. Most visits primarily for diplopia were by patients 50 years or older (ambulatory, 79.1% [95% CI, 72.9%-84.2%]; ED, 51.8% [95% CI, 41.0%-62.4%]) who were white (ambulatory, 81.7% [95% CI, 74.8%-87.0%]; ED, 86.1% [95% CI, 77.8%-91.6%]) women (ambulatory, 51.1% [95% CI, 44.1-58.1]; ED, 52.8% [95% CI, 41.6%-63.7%]). Most diplopia-related ambulatory visits were conducted by ophthalmologists (70.4% [95% CI, 62.2%-77.5%]) even when symptoms were acute or subacute (89.0% [95% CI, 81.0%-93.9%]). The most common diagnosis in both settings was diplopia (International Classification of Diseases, Ninth Revision, Clinical Modification code 368.2). None of the 10 most frequent diagnoses was life threatening in the ambulatory setting, but approximately 16% of diplopia-related ED visits resulted in a stroke or transient ischemic attack diagnosis. Computed tomography or magnetic resonance imaging was ordered in 6.2% (95% CI, 2.8%-12.9%) of ambulatory and 59.7% (95% CI, 38.6%-77.7%) of ED visits, primarily for diplopia.

Conclusions and Relevance

Approximately 850 000 diplopia visits occur in the United States annually; 95% were outpatient visits, and diagnoses were rarely serious in the ambulatory setting but potentially life threatening in 16% of diplopia-related ED visits. Given the low probability of a serious neurologic diagnosis in the ambulatory setting and higher probability in an ED, future cohort studies are needed to define the association of various diagnostic practice patterns, such as imaging, with patient outcomes.

Prognosis Factor in Oculomotor Schwannoma: A Case of Endoscopic Endonasal Approach and Systematic Review of the Literature

BACKGROUND

We report the first case of oculomotor nerve (ON) schwannoma treatment through an endonasal endoscopic approach. We also review the literature to determine prognosis factors of ON function after treatment.

METHODS

A complete MEDLINE search was undertaken for all articles reporting data for oculomotor schwannoma. We divided the patient population into 2 groups; Group I: patients who conserved or recovered good ON function and Group II: patients with either new, worsening, or unchanged third-nerve palsy at the last available follow-up. We conducted a comparative statistical analysis of data between the 2 groups.

RESULTS

We identified 55 reported cases of ON schwannoma, all of whom were treated with open transcranial surgery, stereotactic radiosurgery, or observation. There were 22 patients in group I and 33 in group II. At admission, 29 patients had complete oculomotor nerve palsy (34.7% in group I and 67.7% in group II; P = 0.02). Surgical treatment was performed in 36 cases. Radiosurgery was performed in 3 cases. Among patients with good preoperative ON function, 34.6% worsened at last follow-up (26.6% after surgery and 50% with observation; P = 0.03). In total, 31% of patients with total or near-total palsy at admission had an improvement of their ON function (all after surgical resection; P = 0.05).

CONCLUSIONS

ON function at admission and surgical resection of schwannoma appears to be a predictive factor of favorable prognosis regardless of location and tumor size. The endonasal endoscopic approach can be used to biopsy tumors in cases in which open surgery is considered too risky, such as cavernous sinus schwannomas.

Traumatic orbital third nerve palsy

We present a case series of three patients who developed acute traumatic orbital third nerve palsies. To our knowledge, reported cases have mainly been localised to the intracranial course of the nerve and often associated with visual impairment. Those in which the orbit is the site of injury are rare. Our case series highlights the importance of careful preoperative assessment of patients with orbital trauma (particularly when there is a coexisting fracture) and the need to assess ocular movements and pupillary reactions to distinguish between a neurogenic and soft tissue injury. Early diagnosis is helpful in deciding on the timing of the operation and enables patients to be given appropriate counselling to make sure that their expectations are realistic.

National Study of Ocular Hospitalizations in Medicare Beneficiaries

PURPOSE

To study the characteristics of Medicare beneficiaries hospitalized for ophthalmic conditions.

DESIGN

Cross-sectional study.

METHODS

The 2015 National Medicare 100% Inpatient Limited Dataset was analyzed to identify all patients with either an admitting or primary diagnosis for an ophthalmic condition using ICD-9-CM codes. All other hospitalized Medicare patients served for comparison. Comorbidities were calculated using the Elixhauser Comorbidity Index. Multivariable logistic regression was used to determine odds of primary ophthalmic hospitalization after controlling for patient characteristics and medical comorbidities.

RESULTS

For 2015, there were a total of 13 152 Medicare patients with ocular hospitalizations compared to 6 621 005 patients with nonophthalmic events. Most ophthalmic patients were emergent admissions (73.19%) with routine discharges (75.50%) and low rates of inpatient mortality (0.62%). The top admitting diagnoses for nontraumatic and traumatic eye conditions were diplopia (11.69%) and closed fracture of the orbital floor (3.76%), respectively. Patients admitted for eye conditions were more likely to be younger, to be African American, and to have hypertension, valvular heart disease, diabetes, hypothyroidism, AIDS, lymphoma, solid tumor without metastasis, rheumatologic diseases, alcohol and drug abuse, psychoses, and depression compared to the general Medicare inpatient population.

CONCLUSIONS

Most inpatient admissions for US Medicare beneficiaries with primary ophthalmic diagnoses were for nontraumatic disorders of the eye and adnexa. Ophthalmic admissions were on average shorter in duration and had lower rates of inpatient mortality compared to nonophthalmic admissions. Patients admitted for eye conditions were more likely to have comorbidities such as hypertension, diabetes, and depression compared to the general Medicare inpatient population.

Acute Oculomotor Nerve Palsy Caused by Compression from an Aberrant Posterior Communicating Artery

Oculomotor nerve palsy (ONP) is a rare neurological deficit associated with numerous underlying pathologies. Of these, aneurysm of the posterior communicating artery (PCOM) has been described due to the intimate association with the third cranial nerve in the basal cistern. Less described are other vascular abnormalities and their contribution to ONP. We describe a case of ONP thought to result from a PCOM aneurysm, per the associated magnetic resonance imaging (MRI) scan, yet found intraoperatively to be caused by a congenital vascular aberrancy. This is the first case, to our knowledge, of this presentation.

The aetiologies of the unilateral oculomotor nerve palsy: a review of the literature

Oculomotor nerve palsy (ONP) is an important and common clinical diagnosis. Its main features are diplopia and ptosis. Its aetiologies are various and complex. A number of different conditions have been reported to cause ONP, such as diabetes mellitus, aneurysm, tumours, painful ophthalmoplegia, pituitary lesions, cavernous sinus lesions, central nervous system infections, and subarachnoid haemorrhage. A patients needs to undergo several tests in order to establish the correct underlying pathology. In this review, we have summarized the aetiologies of the unilateral ONP, and discussed their relative clinical features, pathogenesis, diagnostic criteria, treatment options, and prognosis. We searched PubMed for papers related to ONP and its aetiologies, and selected the publications, which seemed appropriate.

Quantitative analysis of pupillometry in isolated third nerve palsy

OBJECTIVES

To objectively assess pupillary involvement according to various etiologies of acquired isolated third nerve palsy using automated pupillometry, and evaluate the efficacy of digital pupillometry in discriminating compressive lesions from microvascular ischemic third nerve palsy.

DESIGN

Retrospective, observational case series.

METHODS

A total of 171 subjects were included in this study, consisting of 60 subjects with presumed microvascular ischemic third nerve palsy, 51 with non-ischemic third nerve palsy, and 60 controls whose pupillary light responses were measured using a dynamic automated pupillometer. Subjects with non-ischemic third nerve palsy were divided into subgroups according to their etiology; inflammatory and compressive groups including tumor and aneurysm. Pupillometry parameters including minimum and maximum pupil diameters, constriction latency and ratio, maximum and average constriction velocities and dilation velocity were noted. The diagnostic ability of pupillometry parameters for discriminating compressive vs microvascular ischemic third nerve palsy was evaluated. The inter-eye difference of the involved eye and the uninvolved fellow eye was calculated to adjust for individual variability.

RESULTS

Among all parameters, reduced pupillary constriction ratio was the most specific parameter for detecting non-ischemic third nerve palsy, as a large inter-eye difference beyond the normative range of controls was found in 0% of ischemic, 20% of inflammatory and 60% of compressive third nerve palsy. With the diagnostic criteria using inter-eye differences of 1) minimum pupil diameter > 0.45 mm, or 2) pupillary constriction ratio < -7.5% compared to the fellow eye, the sensitivity and specificity for diagnosing compressive third nerve palsy were 95% and 88%, respectively. In the compressive group, positive correlations were found between the degree of external ophthalmoplegia and constriction ratio (r = 0.615, p<0.001), average constriction velocity (r = 0.591, p = 0.001) and maximum constriction velocity (r = 0.582, p = 0.001).

CONCLUSIONS

Abnormal pupillary constriction ratio was highly specific for detecting compressive third nerve palsy, although the sensitivity was not high. Digital pupillometry demonstrated relatively good performance for discriminating compressive lesions from microvascular ischemic third nerve palsy.

Bilateral Cavernous Carotid Aneurysms: Atypical Presentation of a Rare Cause of Mass Effect. A Case Report and a Review of the Literature

Bilateral cavernous carotid aneurysms (CCAs) represent a rare medical condition that can mimic other disorders. We present a rare case of bilateral CCAs simulating an ocular myasthenia. A 76-year-old woman presented with a history of fluctuating bilateral diplopia and unilateral ptosis, which led to the suspicion of ocular myasthenia. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain showed the presence of large bilateral aneurysms of the carotid cavernous tract. After an unsuccessful attempt with steroid therapy, the patient underwent endovascular treatment, with mild improvement. Bilateral CCAs can cause pupil sparing third nerve palsies and other cranial neuropathies which can mimic signs and symptoms of disorders of the neuromuscular junction. Therefore, the possibility of a vascular lesion simulating ocular myasthenia should be considered especially in older patients.

Approach to a Patient with Diplopia in the Emergency Department

BACKGROUND

Diplopia can be the result of benign or life-threatening etiologies. It is imperative for the emergency physician to be proficient at assessing diplopia and recognize when urgent referral or neuroimaging is required.

OBJECTIVE

The first part of this review highlights a simple framework to arrive at the appropriate disposition of diplopic patients presenting to the emergency department (ED). The second part of this review provides more detail and further management strategies.

DISCUSSION

ED strategies for assessment of diplopia are discussed. Management strategies, such as when to image, what modality of imaging to use, and urgency of referral, are discussed in detail.

CONCLUSIONS

Unenhanced plain computed tomography (CT) of the head or orbits is largely not useful in the work-up of diplopia. Magnetic resonance imaging is preferred for ocular motor nerve palsies. Due to limited resources in the ED, patients with isolated fourth and sixth nerve palsies with the absence of other neurological signs on examination should be referred to Neurology or Ophthalmology for further work-up. All patients presenting with an acute isolated third nerve palsy should be imaged with CT and CT angiography of the brain to rule out a compressive aneurysm. Contrast-enhanced CT imaging of the brain and orbits would be indicated in suspected orbital apex syndrome or a retro-orbital mass, thyroid eye disease, or ocular trauma. CT and CT venogram should be considered in cases of suspected cavernous sinus thrombosis. In any patient over the age of 60 years presenting with recent (1 month) history of diplopia, inflammatory markers should be obtained to rule out giant cell arteritis.

Binocular diplopia in a tertiary hospital: Aetiology, diagnosis and treatment

OBJECTIVE

To study the causes, diagnosis and treatment in a case series of binocular diplopia.

MATERIAL AND METHOD

A retrospective chart review was performed on patients seen in the Diplopia Unit of a tertiary centre during a one-year period. Diplopia was classified as: acute≤1 month since onset; subacute (1-6 months); and chronic (>6 months). Resolution of diplopia was classified as: spontaneous if it disappeared without treatment, partial if the course was intermittent, and non-spontaneous if treatment was required. It was considered a good outcome when diplopia disappeared completely (with or without treatment), or when diplopia was intermittent without significantly affecting the quality of life.

RESULTS

A total of 60 cases were included. The mean age was 58.65 years (60% female). An acute or subacute presentation was observed in 60% of the patients. The mean onset of diplopia was 82.97 weeks. The most frequent aetiology was ischaemic (45%). The most frequent diagnosis was sixth nerve palsy (38.3%), followed by decompensated strabismus (30%). Neuroimaging showed structural lesions in 17.7% of the patients. There was a spontaneous resolution in 28.3% of the cases, and there was a good outcome with disappearance of the diplopia in 53.3% at the end of the study.

CONCLUSIONS

The most frequent causes of binocular diplopia were cranial nerve palsies, especially the sixth cranial nerve, followed by decompensated strabismus. Structural lesions in imaging tests were more than expected. Only one third of patients had a spontaneous resolution, and half of them did not have a good outcome despite of treatment.