Archives for December 2018

Recommended Reading – Diagnostic Errors in Initial Misdiagnosis of Optic Nerve Sheath Meningiomas

Recommended Reading – Diagnostic Errors in Initial Misdiagnosis of Optic Nerve Sheath Meningiomas

Diagnostic Errors in Initial Misdiagnosis of Optic Nerve Sheath Meningiomas
Pinar Kahraman-Koytak, MD; Beau B. Bruce, MD, PhD; Jason H. Peragallo, MD; Nancy J. Newman, MD; Valérie Biousse, MD.  JAMA Neurol. Published online December 17, 2018.

IMPORTANCE Diagnostic errors can lead to the initial misdiagnosis of optic nerve sheath meningiomas (ONSM), which can lead to vision loss.

OBJECTIVE To identify factors contributing to the initial misdiagnosis of ONSM.

DESIGN, SETTING, AND PARTICIPANTS We retrospectively reviewed 35 of 39 patients with unilateral ONSM (89.7%) who were seen in the tertiary neuro-ophthalmology practice at Emory University School of Medicine between January 2002 and March 2017. The Diagnosis Error Evaluation and Research taxonomy tool was applied to cases with missed/delayed Diagnoses.

EXPOSURES Evaluation in a neuro-ophthalmology clinic.

MAIN OUTCOMES AND MEASURES Identifying the cause of diagnostic errors for patients who initially received a misdiagnosis who were found to have ONSM.

RESULTS Of 35 patients with unilateral ONSM (30 women [85.7%]; mean [SD] age, 45.26 [15.73] years), 25 (71%) had a diagnosis delayed for a mean (SD) of 62.60 (89.26) months. The most common diagnostic error (19 of 25 [76%]) was clinician assessment failure (errors in hypothesis generation and weighing), followed by errors in diagnostic testing (15 of 25 [60%]). The most common initial misdiagnosis was optic neuritis (12 of 25 [48%]), followed by the failure to recognize optic neuropathy in patients with ocular disorders. Five patients who received a misdiagnosis (20%) underwent unnecessary lumbar puncture, 12 patients (48%) unnecessary laboratory tests, and 6 patients (24%) unnecessary steroid treatment. Among the 16 patients who initially received a misdiagnosis that was later correctly diagnosed at our institution, 11 (68.8%) had prior magnetic resonance imaging (MRI) results that were read as healthy; 5 (45.5%) showed ONSM but were misread by a non-neuroradiologist and 6 (54.5%) were performed incorrectly (no orbital sequence or contrast). Sixteen of the 25 patients (64%) had a poor visual outcome. 

CONCLUSIONS AND RELEVANCE Biased preestablished diagnoses, inaccurate funduscopic examinations, a failure to order the correct test (MRI brain/orbits with contrast), and a failure to correctly interpret MRI results were the most common sources of diagnostic errors and delayed diagnosis with worse visual outcomes and increased cost (more visits and tests). Easier access to neuro-ophthalmologists, improved diagnostic strategies, and education regarding neuroimaging should help prevent diagnostic errors.

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Neuro-ophthalmology Illustrated Chapter 3 – Visual Fields

1. What values indicate an unreliable Humphrey Visual Field?
2. What are the monocular VF defect patterns?
3. What are the bilateral VF defect patterns?
4. A lesion of Wilbrand’s Knee results in what visual field defect?
5. What is the visual field defect of a junctional scotoma?
6. Where is the lesion of a junctional scotoma?
7. What are the findings of a left optic tract lesion?
8. What are the findings of a temporal lobe lesion?
9. What are the findings of a parietal lobe lesion?
10. What are the findings of an occlusion of the posterior cerebral artery?
11. What field defects results from ischemia limited to of the tip of an occipital lobe?
12. What field defect results when a stroke affects the occipital lobe but spares the anterior portion of the occipital lobe?
13. What field defect results when a stroke only affects the anterior portion of the occipital lobe?
14. What are the findings of bilateral occipital lobe lesions?
15. In interpreting a visual field test, what questions should be asked?

Recommended Reading – Neuro-ophthalmological manifestations of Behçet’s disease

Recommended Reading – Neuro-ophthalmological manifestations of Behçet’s disease

Neuro-ophthalmological manifestations of Behçet’s disease
Ammr Alghamdi, Bahram Bodaghi, Chloé Comarmond, Anne Claire Desbois, Fanny Domont, Bertrand Wechsler, Raphael Depaz, Phuc Le Hoang, Patrice Cacoub, Valérie Touitou, David Saadoun
British Journal of Ophthalmology. 2018

Background The neuro-ophthalmological manifestations of Behcet’s disease (BD) are rare, and data regarding their characteristics and outcome are lacking.

Objective To report prevalence, main characteristics and outcome of neuro-ophthalmological manifestations in BD.

Patients and methods This is a retrospective monocentric study of 217 patients diagnosed with neuro-Behçet’s disease (NBD), of whom 29 (13.3%) patients presented with neuro-ophthalmological manifestations (55% of men and mean±SD age of 26±8 years). All patients underwent a detailed ophthalmological examination and were followed up in the internal medicine and the ophthalmology departments.

Results Neuro-ophthalmological manifestations were the first presentation of BD in 45% of patients and developed later in the course of the disease in 55% of patients. They are divided into parenchymal (PM) and non-parenchymal (NPM)-related manifestations in, respectively, 13 patients (45%) and 16 patients (55%). PM included papillitis in seven patients (53.8%), retrobulbar optic neuritis in four patients (30.8%) and third cranial nerve palsy in two patients (15.4%). NPM included papilloedema related to cerebral venous thrombosis in all 16 patients, of whom 6 patients (37.5%) had sixth cranial nerve palsy. At initial examination, 93.1% of patients had visual alterations, including mainly decreased visual acuity visual field defects and/or diplopia. All patients were treated with corticosteroids and 79% of patients received immunosuppressive agents. After treatment, the visual outcome improved or stabilised in 66.7% of patients while it worsened in 33.3. The mean±SD logarithm of the minimum angle of resolution visual acuity improved from 0.4±0.3 at diagnosis to 0.2±0.3 after therapy. 10.3% and 3.4% of patients were legally blind at diagnosis and after therapy, respectively.

Conclusion Neuro-ophthalmological manifestations of BD represented 13% of NBD. They could be potentially severe and disabling. Prompt treatment is the key factor in improving visual outcome.


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Neuro-ophthalmology Illustrated Chapter 2 Fundus Examination

1. What drops should be used to dilate the pupils for examination?
2. How long does dilation with usually last?
3. Why is it always better to dilate both eyes rather than one eye?
4. Is glaucoma a contraindication for pupillary dilation?
5. What are 5 causes of an abnormal red reflex?
6. What are 14 examples of systemic disorders in which examination of the fundus may be abnormal even without visual symptoms?

Recommended Reading – Teaching Video NeuroImages: Oculopalatal myoclonus

Recommended Reading – Teaching Video NeuroImages: Oculopalatal myoclonus

Teaching Video NeuroImages: Oculopalatal myoclonus
A possible consequence of brainstem injury
Neurology. November 27, 2018; 91 (22) RESIDENT & FELLOW SECTION

A 61-year-old man with previous left cerebellar infarct complained of double vision and dizziness several months postinfarct. Infarct is shown in the figure. Examination showed rotatory nystagmus in all directions of gaze, worse on left gaze (video 1). Oral examination showed palatal tremor (video 2). Oculopalatal tremor (OPT) is thought to result from interruption of connections between the red nucleus (midbrain), dentate nucleus (cerebellum), and inferior olive (medulla).1,2 The most common cause is brainstem infarction or hemorrhage,1 but it has also been observed with multiple sclerosis and other inflammatory entities. OPT usually becomes apparent several months after the injury. Treatment may include gabapentin, memantine, benzodiazepines, and valproic acid.

Figure: Brain MRI, fluid-attenuated inversion recovery
Image shows the patient’s infarct, involving the caudal portion of the left cerebellar hemisphere. Area of involvement corresponds to posterior inferior cerebellar artery territory.

Video 1: Rotatory nystagmus toward the left in all directions of gaze but worse on left and upward gaze. Rotatory nystagmus improved in amplitude and frequency with low dose clonazepam.

Video 2: Video shows rhythmic contractions of the soft palate.

1. Tilikete C, Desestret V. Hypertrophic olivary degeneration and palatal or oculopalatal tremor. Front Neurol 2017;8:302.Google Scholar
2.Borruat FX. Oculopalatal tremor: current concepts and new observations, Curr Opin Neurol 2013;26:67–73.

Neuro-ophthalmology Illustrated Chapter 1 – Examination 6

25. Do metabolic causes of coma usually result in large or small pupils?
26. What is ocular bobbing?
27. What is the likely location of a lesion with ocular bobbing?
28. What is ocular dipping?