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Recommended Reading – The clinical evaluation of infantile nystagmus: What to do first and why

August 15, 2018 By

Recommended Reading – The clinical evaluation of infantile nystagmus: What to do first and why

The clinical evaluation of infantile nystagmus: What to do first and why.
Morgan Bertsch, Michael Floyd, Taylor Keohea, Wanda Pfeifer, and Arlene V. Dracka Ophthalmic Genet. 2017 ; 38(1): 22–33.
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA

Abstract Introduction—Infantile nystagmus has many causes, some life threating. We determined the most common diagnoses in order to develop a testing algorithm.

Methods—Retrospective chart review. Exclusion criteria were no nystagmus, acquired after 6 months, or lack of examination. Data collected: pediatric eye examination findings, ancillary testing, order of testing, referral, and final diagnoses. Final diagnosis was defined as meeting published clinical criteria and/or confirmed by diagnostic testing. Patients with a diagnosis not meeting the definition were “unknown.” Patients with incomplete testing were “incomplete.” Patients with multiple plausible etiologies were “multifactorial.” Patients with negative complete workup were “motor.”

Results—284 charts were identified; 202 met inclusion criteria. The 3 most common causes were Albinism(19%), Leber Congenital Amaurosis(LCA)(14%) and Non-LCA retinal dystrophy (13%). Anatomic retinal disorders comprised 10%, motor another 10%. The most common first test was MRI (74/202) with a diagnostic yield of 16%. For 28 MRI-first patients, nystagmus alone was the indication; for 46 MRI-first patients other neurologic signs were present. 0/28 nystagmus-only patients had a diagnostic MRI while 14/46 (30%) with neurologic signs did. Yield of ERG as first test was 56%, OCT 55%, and molecular genetic testing 47%. 90% of patients had an etiology identified.

Conclusion—The most common causes of infantile nystagmus were retinal disorders (56%), however, the most common first test was brain MRI. For patients without other neurologic stigmata complete pediatric eye examination, ERG, OCT and molecular genetic testing had a higher yield than MRI scan. If MRI is not diagnostic, a complete ophthalmologic workup should be pursued.

Full Article https://drive.google.com/open?id=1h76ziIrxB6TpINMsPF1mcsWvvAvVkaj3

 

Recommended Reading – Mystery Case: A young woman with isolated upbeating nystagmus.

August 8, 2018 By

Recommended Reading – Mystery Case: A young woman with isolated upbeating nystagmus.
Charlene Ong, Kevin Patel, Erik Musiek, Gregory Van Stavern.
Neurology 2015; 84 (4) RESIDENT AND FELLOW SECTION
http://n.neurology.org/content/84/4/e17.full

ARTICLE
A 15-week pregnant 21-year-old woman initially presented with nausea, vomiting, and abdominal pain. The patient admitted to decreased oral intake over the past 4 weeks, including her prescribed prenatal vitamins. She was hypokalemic with elevated transaminases and gallstone pancreatitis was confirmed by imaging. Prior to cholecystectomy, fetal heart tones were lost and intrauterine fetal demise occurred. The patient underwent dilation and evacuation as well as cholecystectomy. She was discharged home but returned within 1 week with persistent nausea and vomiting. She had no neurologic complaints at the time. Basic metabolic panel on admission was unremarkable. On hospital day 2, she developed oscillopsia. Her examination was remarkable for large amplitude upbeating nystagmus (UBN) in primary position. She had gaze-evoked UBN in all other directions. The amplitude of the UBN increased on upgaze and dampened on downgaze. Smooth pursuit was impaired in all directions and saccades were dysmetric (video https://www.youtube.com/watch?v=b8j3LcwY2ZM).

Extraocular movements were intact with no evidence of ophthalmoplegia. Pupils were equal and reactive, and fundus examination was normal. Reflexes were present and symmetric, and gait was normal. The patient had no deficits on mental status examination. She was oriented to name, date, place, and situation and had no difficulty with complex commands, calculations, or short-term or long-term memory. Language was similarly intact. She demonstrated no ataxia or other focal abnormalities on examination.

Questions for consideration:
1. What is the differential diagnosis with this history and examination?
2. What is the next step in management for this patient? What tests would you order?

Recommended Reading – IMAGES IN CLINICAL MEDICINE Orbital Varix

August 1, 2018 By

Recommended Reading – IMAGES IN CLINICAL MEDICINE Orbital Varix
Kiang L, Kahana A. N Engl J Med 2015; 372:e9v

A 63-year-old man was referred to our clinic with a 13-year history of intermittent vision loss, binocular diplopia, and blepharoptosis of the left eye during bending or straining that had worsened over the previous year. Other than uneventful cataract surgery, the patient had no clinically significant ocular history, and prior computed tomographic (CT) scans of the head and orbit did not identify any abnormality. An orbital vascular anomaly was suspected. A CT scan of the head was obtained while the patient performed the Valsalva maneuver, revealing the expansile orbital mass. On presentation to us, the patient’s visual acuity was 20/20 in the right eye and 20/50 in the left eye, with a relative afferent pupillary defect in the left eye. There was no proptosis on examination (Panel A).

Visual-field testing revealed severe constriction.

A Valsalva maneuver induced 6 mm of proptosis in the left eye, with anterior superior globe displacement and blepharoptosis (Panel B, and video).

   Orbital Varix. (00:19)

Proptosis quickly reversed on relaxation. CT of the orbit while the patient waw at at rest was unremarkable (Panels C and D show the axial and coronal views, respectively),

but a Valsalva maneuver revealed an orbital mass causing anterior superior globe displacement (Panels E and F).

An orbital angiogram confirmed the presence of an expansile orbital mass (Fig. 2 in the Supplementary Appendix).

Although the differential diagnosis of an orbital mass is broad and includes lymphoma, metastatic tumors, and inflammatory masses, the clinical findings and imaging studies in this patient were pathognomonic of an orbital vascular anomaly and were most consistent with a distensible venous anomaly (i.e., varix). In the confines of the orbit, an expansile mass can cause intermittent orbital compartment syndrome and compressive optic neuropathy. The patient underwent successful endovascular and transorbital sclerosing treatment. The postoperative visual acuity was 20/30 in the left eye, with a stable visual field.

 

Recommended Reading Cavernous Sinus Thrombosis

July 25, 2018 By

From:  MRI in the Evaluation of Acute Visual Syndromes.
Mukhi SV, Lincoln CM. Topics in Magnetic Resonance Imaging 24 (6):309-24. 2015
https://drive.google.com/open?id=1ayqCxDRn0E_Own4NkKoWbC2zqvfAc2X8

The prevalent use of antibiotics has decreased the overall incidence of CST. CST still carries significant mortality, commonly reported as approximately 30%, with more than 50% of the cases resulting in morbidity secondary to cranial neuropathies. CST is subclassified as aseptic or infectious in etiology. Aseptic causes include surgery or trauma. Infectious CST is typically a complication of a facial, orbital, odontogenic, or paranasal sinus infection. Sinusitis is the most common cause of CST, whereas odontogenic sources have been reported in up to 10% of the cases.3,33–39

The CS is a paired structure on either side of the sella, pituitary gland, and sphenoid sinus. It is composed of two layers of dura that are split to create a septate venous channel. The internal carotid artery (ICA) is the most medial structure and cranial nerves III, IV, and first and second branches of cranial nerve V are located in the lateral wall of the dura. Cranial nerve VI courses at the medial aspect of the ICA. Anteriorly, the CS is bordered by the SOF and OA. The posterior margin of the CS is immediately lateral to the dorsum sella and bordered by Meckel cave medially and the petrous apex posteroinferiorly.33,40,41

CST most commonly occurs secondary to the spread of infection by emissary veins as well as by direct extension. Emissary veins throughout the skull base are valve less and have bidirectional flow, accounting for the ease of contiguous spread.41 Spread of infection also occurs by the propagation of thrombus and/or septic embolism. It is postulated that bacteria stimulate the formation of thrombus by the release of a procoagulant substance and through toxins that cause tissue damage.38 In otitis media, infection spreads via the sigmoid sinus and along the internal carotid artery plexus. Staphylococcus aureus (70%) and Streptococcus sp (22%) are the important organisms responsible for infection of the CS. In patients with uncontrolled diabetes and immunocompromise, fungal infection can also be responsible, particularly mucormycosis.38,41

Tuberculosis has also been reported to cause both unilateral and bilateral CST; cavernous sinus tuberculoma may occur in the absence of pulmonary findings. Lymphomatous infiltration of the CS has been reported in both pediatric and adult patients.4

CST typically presents with orbital swelling, proptosis, chemosis, fever, and ophthalmoplegia. Visual impairment in CST has been reported in 7% to 22% of the cases, with blindness reported in 8% to 15% of the cases. As the disease progresses, decreased light perception and visual loss ensue. In a case report by Chen et al, CST-induced blindness suggested involvement of the bilateral retina and optic nerves. The postulated mechanisms accounting for visual impairment and blindness in CST include venous infarction of the retina and retinal ischemia caused by occlusion of either an ophthalmic artery branch or the central retinal artery, or by mechanical pressure at the OA.39

Chemosis, periorbital edema, and proptosis have been attributed to venous congestion.38 Papilledema as a result of raised intracranial pressure from a CST has been described as well.42 Palsies of III, IV, and VI cranial nerves secondary to compression result in impaired EOM motility. Intracranial extension of infection may result in meningitis, encephalitis, brain abscess, pituitary infection, epidural and subdural empyema, and coma/death.33,38,42

MRI is the radiologic examination of choice, and the CS should be imaged in its entirety. MRI demonstrates the contents of the CSs more effectively compared with CT.40 Imaging protocols should extend from the OA to the prepontine cistern. Routine T2, fluid-attenuated inversion recovery, and pre- and post-contrast T1 weighted images of the entire brain should be included. Postcontrast T1 weighted, 3-mm thick images should be obtained in the axial and coronal planes with at least one plane imaged utilizing a fat-saturation technique. Thin-section, postcontrast axial images may be acquired by three-dimensional spoiled gradient techniques. In addition, thin-section, three-dimensional, heavily T2 weighted images allow visualization of individual cranial nerves in the CS and adjacent cisterns.43 Pula et al describe the use of three-dimensional constructive interference in steady state to show smaller structures within the CS, making it the ideal choice to study cranial neuropathies in the CS.44

Alterations in signal intensity, size, and contour of the CS are subtle signs of thrombosis. A filling defect with enhancement of the peripheral margins of the CS suggests a clot within it (Fig. 4). Subacute thrombus exhibits high signal intensity on all pulse sequences, whereas acute thrombosis may appear more isointense. Indirect signs that may suggest the diagnosis are dilation of the superior ophthalmic veins, exophthalmos, and increased dural enhancement along the lateral border of CS and ipsilateral tentorium. Appropriate clinical symptoms, adjacent sinusitis, and orbital or odontogenic infection confirm the diagnosis and etiology.33,38,41,43

FIGURE 4. (A) Twenty-year-old man with invasive fungal sinusitis in setting of relapsed acute lymphocytic leukemia. Axial postcontrast image of the orbit and CS demonstrates filling defect in the left CS (arrow).
(B and C) Twenty-three-year old man with leukemia and rapidly progressive right-sided cranial neuropathy involving III, IV, and VI. Axial pre- (B) and post (C) contrast T1 images shows filling defect in the right CS with absence of the right cavernous carotid artery flow void (arrows).

CST therapy relies on mobilization of the varied disciplines of neurology, neurosurgery, otolaryngology, and infectious disease. Aggressive antibiotic therapy and surgical debridement of the primary site of infection and surrounding areas of involvement are the mainstay of treatment. The use of steroid therapy to reduce orbital edema and cranial nerve inflammation is controversial. Anticoagulant therapy has shown some benefit when initiated early.33,38,43

Recommended Reading – Neuroimaging: Carotid Cavernous Fistula CT Angiogram Findings

July 18, 2018 By

CTisus  Published on Feb 10, 2017

These first five CTA images of the head demonstrate filling of the left cavernous sinus in the arterial phase and asymmetric enlargement and filling of the left superior ophthalmic vein.  These findings are consistent with a carotid cavernous fistula. The diagnostic angiogram was performed to evaluate the supply and drainage of the fistula. No aneurysm was identified. The fistula was supplied most prominently from the bilateral external carotid arteries and showed prominent retrograde drainage into the dilated left superior ophthalmic vein. These fistulas may present with unilateral or bilateral proptosis and chemosis and if severe may cause vision loss. This patient was treated with transvenous coil embolization and demonstrated no evidence of fistula on two month follow-up imaging.

Video https://www.youtube.com/watch?v=gkhd36dssqA

Reference
CT is us is created and maintained by The Advanced Medical Imaging Laboratory (AMIL). AMIL is a multidisciplinary team dedicated to research, education, and the advancement of patient care using medical imaging with a focus on spiral CT and 3D imaging. The AMIL is headed by Elliot K. Fishman, M.D.

http://www.ctisus.com

 

Recommended Reading – Teaching NeuroImages: Ocular bruit in carotid-cavernous sinus fistula

July 10, 2018 By

Teaching NeuroImages: Ocular bruit in carotid-cavernous sinus fistula
Jeong-Yoon Choi, Seol-Hee Baek, Jin-Man Jung, Do-Young Kwon, Moon Ho Park
Neurology. August 12, 2014; 83 (7) RESIDENT AND FELLOW SECTION

ARTICLE
A 57-year-old man who had a traffic accident 1 month previously presented with left ocular pain, double vision, and left eye proptosis with ptosis and conjunctival hemorrhage. Fundus showed dilated veins with no hemorrhages or disc edema. Left ocular motility showed complete external ophthalmoplegia (figure 1). There was prominent ocular bruit in his left eye (audio file on the Neurology® Web site at Neurology.org). MRI and magnetic resonance angiography showed a dilated left superior ophthalmic vein and an extravasation into cavernous sinus (figure 2). With chemosis, ophthalmoplegia, and retro-orbital pain, the auscultation of orbital bruit can make a correct and prompt diagnosis in the patient with carotid-cavernous sinus fistula.1


Figure 1 Physical examination
(A) Left eye with conjunctival injection and ptosis.
(B) Left eye proptosis.
(C) Fundus shows dilated veins with no hemorrhages or disc edema.
(D) Ocular motility shows complete external ophthalmoplegia in left eye and partial limitation of abduction in right eye.


Figure 2 Brain MRI and magnetic resonance angiography findings
(A) magnetic resonance angiography
(B) show a dilated left superior ophthalmic vein (black arrowhead) and a extravasation into cavernous sinus (white arrow).

Audio. Auscultation of ocular bruit.

(audio.mp3)
It was recorded using the JABES electronic stethoscope (GS tech., Korea) and WavePad Sound Editor (NCH software, Australia).

AUTHOR CONTRIBUTIONS Dr. Choi: participated in conceptualization of the manuscript, drafted the manuscript. Dr. Baek: participated in analysis of results and conceptualization of the manuscript. Dr. Jung: selected appropriate images and revised the manuscript for intellectual content. Dr. Kwon: participated in analysis of results and revised the manuscript for intellectual content. Dr. Park: drafted the manuscript and figure legend and revised the manuscript for intellectual content.

STUDY FUNDING No targeted funding reported.
DISCLOSURE The authors report no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures.
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Supplemental data at Neurology.org
Download teaching slides: Neurology.org
© 2014 American Academy of Neurology

REFERENCE 1. Ling JD, Chao D, Al Zubidi N, Lee AG. Big red flags in neuro-ophthalmology. Can J Ophthalmol2013;48:3–7.

 

Teaching NeuroImages: The half-split man

June 30, 2018 By

Teaching NeuroImages: The half-split man
Makoto Takahashi, Akiko Shinya, Hisao Kitazono, Teruhiko Sekiguchi, Akira Inaba, Satoshi Orimo. Neurology. September 13, 2016; 87 (11) RESIDENT AND FELLOW SECTION

ARTICLE
A 51-year-old man was admitted with left lateral medullary infarction due to vertebral artery dissection (figure 1). Neurologic examination revealed nystagmus, dissociated sensory disturbance, and no evidence of paralysis. Miosis and ptosis were observed on the ipsilateral side, but hypohidrosis was not apparent. Thermography revealed a bilateral discrepancy in body temperature, as if the patient were split down the middle (figure 2). Asymmetric skin temperature can occur among patients with Wallenberg syndrome associated with Horner syndrome due to a disturbance of the descending sympathetic tract that causes ipsilateral hypohidrosis and increased cutaneous blood flow.1

Figure 1 MRI and magnetic resonance angiography of the medulla and the vertebral artery
Diffusion-weighted and T2-weighted images show an acute infarction of the left lateral medulla (A, B). Magnetic resonance angiography and black-blood MRI show dissection of the left vertebral artery (C, D).

Figure 2 Thermography findings
Thermography images show the bilateral discrepancy in body temperature (in °C), as though the patient were split down the middle of his body.

AUTHOR CONTRIBUTIONS Dr. Takahashi: study concept, interpretation of data, and drafting the manuscript. Dr. Shinya: revision of the manuscript for intellectual content. Dr. Sekiguchi: study supervision. Dr. Kitazono: study supervision. Dr. Inaba: study supervision. Dr. Orimo: revision of the manuscript for intellectual content and study supervision.

STUDY FUNDING No targeted funding reported.

DISCLOSURE The authors report no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures.

Footnotes Download teaching slides: Neurology.org

REFERENCE
1. Korpelainen JT, Sotaniemi KA, Myllylä VV. Asymmetrical skin temperature in ischemic stroke. Stroke 1995;26:1543–1547.

 

Teaching Video NeuroImages: Is it III alone, or III and IV?

June 20, 2018 By

Teaching Video NeuroImages: Is it III alone, or III and IV?
Stephen G. Reich
Neurology May 22, 2007; 68 (21)
RESIDENT AND FELLOW SECTION http://n.neurology.org/content/68/21/E34

Series editor: Mitchell S.V. Elkind MD, MS, Section Editor

The most important questions, when confronted with an oculomotor (III) palsy are:  
1) Is the pupil spared?
2) Is it complete aside from pupil sparing? and
3) Is it in isolation?

A “no” answer to any makes a benign, ischemic III palsy less likely.1

In the presence of a III palsy, the traditional method of testing the trochlear nerve (IV) at the bedside by asking the patient to depress the adducted eye cannot be performed. Instead, the patient should be instructed to abduct the eye and then look down; if IV is intact, there will be intorsion.2

Confirming that IV is intact in the presence of a III palsy is important because the combination of an oculomotor and trochlear palsy suggests a lesion in the cavernous sinus.

A 56-year-old man presented with a complete, pupil-sparing right oculomotor palsy (video E-1). The evaluation was negative, and the palsy resolved within 1 month.
Video
The video demonstrates a pupil-sparing but otherwise complete right oculomotor palsy.
There is ptosis. The eye is down, out, and unable to adduct, depress, or elevate. With attempted down gaze, there is intorsion, confirming that IV is intact. Although not demonstrated in the video, this primary action of IV should be tested by first having the patient abduct and then attempt to depress the eye. Intorsion is best appreciated by observing a medial conjunctival vessel.

ACKNOWLEDGMENT The author thanks Dr. Neil Miller for assistance.

Footnotes Disclosure: The author reports no conflicts of interest.

REFERENCES
1. Trobe JD. Isolated third nerve palsies. Sem Neurol 1986;6:135–141.
2. Ansons AM, Davis H. Diagnosis and management of ocular motility disorders. 3rd ed. Oxford: Blackwell Science Ltd, 2001:359–360.

 

 

Pearls and oy-sters of localization in ophthalmoparesis

June 13, 2018 By

Pearls and oy-sters of localization in ophthalmoparesis
Teresa Buracchio, Janet C. Rucker
Neurology. December 11, 2007; 69 (24) RESIDENT AND FELLOW SECTION

Abstract
Ocular misalignment and ophthalmoparesis result in the symptom of binocular diplopia. In the evaluation of diplopia, localization of the ocular motility disorder is the main objective. This requires a systematic approach and knowledge of the ocular motor pathways and actions of the extraocular muscles. This article reviews the components of the ocular motor pathway and presents helpful tools for localization and common sources of error in the assessment of ophthalmoparesis.

Teaching Video NeuroImages: Alternating skew deviation with abducting hypertropia following superior colliculus infarction

June 7, 2018 By

Teaching Video NeuroImages: Alternating skew deviation with abducting hypertropia following superior colliculus infarction
Damien Biotti, Marianne Barbieux and David Brassat
Neurology. March 01, 2016; 86 (9) RESIDENT AND FELLOW SECTION

A 63-year-old patient was admitted with acute ataxia and binocular oblique diplopia. Neuro-ophthalmologic examination revealed abducting hypertropia on lateral gaze, better seen during upgaze, mimicking bilateral inferior oblique palsy (Figure A, video). There was no ocular cyclotorsion. Brain MRI revealed focal ischemic lesions in the right cerebellar hemisphere and left superior colliculus (Figure B). The diagnosis of alternating abducting hypertrophic skew deviation was made. This rare type of skew deviation is related to central otolithic dysfunction. Similar cases have been described with cerebellar, pretectal, or cervico-medullary junction lesions.1,2 Orthoptic management can help and patients can slowly improve over months.


Figure  Ocular motor examination and MR images
(A) Ocular motor examination (right gaze, straight gaze, left gaze).
(B) Diffusion-weighted imaging (left) and apparent diffusion coefficient images (right) reveal a focal and acute ischemic stroke.

AUTHOR CONTRIBUTIONS D. Biotti: principal author, corresponding author. M. Barbieux: contributor, neurologic management. D. Brassat: contributor.

STUDY FUNDING No targeted funding reported.

DISCLOSURE The authors report no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures.

Footnotes
  ● Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
● Supplemental data at Neurology.org
  ● Download teaching slides: Neurology.org

REFERENCES
1. Versino M, Hurko O, Zee D. Disorders of binocular control of eye movements in patients with cerebellar dysfunction. Brain 1996;119:1933–1950.
2. Hamed LM, Maria BL, Quisling RG, Mickle JP. Alternating skew on lateral gaze: neuroanatomic pathway and relationship to superior oblique overaction. Ophthalmology 1993;100:281–286.