Neuroimaging 'HINTS' of the Lateral Medullary Syndrome

Photo Essay Section Editor: Timothy J. McCulley, MD Neuroimaging "HINTS" of the Lateral Medullary Syndrome Ali S. Saber Tehrani, MD, Jeffrey R. DeSanto, MD, Jorge C. Kattah, MD FIG. 1. Neuroimaging of lateral medullary syndrome. A. Vocal cord paralysis (arrows) on CT angiogram. B. Conjugate eye deviation indicative of slow phase of nystagmus or ocular lateropulsion. C. Palate deviation (arrow). D. Target sign on T2 magnetic resonance imaging due to clot in V4 segment of vertebral artery. These findings were seen in a patient with an initial false negative diffusion-weighted imaging study. Departments of Neurology (ASST, JCK) and Radiology (JD), University of Illinois College of Medicine at Peoria, Peoria, Illinois. A. S. Saber Tehrani: Illinois Neurological Institute. J. C. Kattah: BMBF (IFBLMU 01EO0901, Brain-Net- 01GI0505). GN Otometrics, Taastrup, Denmark loaned ICS impulse video-oculography device to our team for research purposes. National Institute On Deafness and Other Communication Disorders Grant #1U01DC013778-01A1. The authors report no conflicts of interest. Address correspondence to Ali S. Saber Tehrani, MD, 530 NE Glen Oak Avenue, Peoria, IL 61637; E-mail: [e-mail] Saber Tehrani et al: J Neuro-Ophthalmol 2017; 37: 403-404 Abstract: A series of neuroimaging studies illustrates many of the key findings of the lateral medullary syndrome. Journal of Neuro-Ophthalmology 2017;37:403-404 doi: 10.1097/WNO.0000000000000530 © 2017 by North American Neuro-Ophthalmology Society L ateral medullary syndrome (LMS) often presents with subtle clinical findings. It is estimated that approximately 35% of posterior fossa strokes initially are not 403 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay diagnosed in the emergency department (1). In addition, the false negative rate in detecting acute (,24 hours after symptom onset) stroke with diffusion-weighted imaging (DWI) is 15% (2). Yet, a variety of other findings may be detected on neuroimaging, and they may precede DWI abnormalities. These include vocal cord paralysis, "target sign" (clot in V4 segment of vertebral artery), palate deviation, and conjugate eye deviation indicative of the slow phase of nystagmus or ocular lateropulsion (Fig. 1). 404 Detection of these findings can help the clinician arrive at the correct diagnosis of LMS. REFERENCES 1. Kerber KA, Brown DL, Lisabeth LD, Smith MA, Morgenstern LB. Stroke among patients with dizziness, vertigo, and imbalance in the emergency department: a population-based study. Stroke. 2006;37:2484-2487. 2. Saber Tehrani AS, Kattah JC, Mantokoudis G, Pula JH, Nair D, Blitz A, Ying S, Hanley DF, Zee DS, Newman-Toker DE. Small strokes causing severe vertigo: frequency of false-negative MRIs and nonlacunar mechanisms. Neurology. 2014;83:169-173. Saber Tehrani et al: J Neuro-Ophthalmol 2017; 37: 403-404 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.