Neuro-ophthalmic Manifestations of Wernicke Encephalopathy

Abstract

Wernicke encephalopathy (WE) is a life-threatening but reversible syndrome resulting from acute thiamine deficiency that is frequently overlooked and underdiagnosed. It is classically characterized by a triad of ocular dysfunction, ataxia, and altered mental status. However, less than 1/3 patients have the complete triad, so it is crucial to have a high index of suspicion. Awareness of the early signs of WE is essential to prevent clinical progression, as patients with the full triad already have a profoundly thiamine-deficient state. This review highlights the neuro-ophthalmic manifestations of WE to guide the clinician in identifying the condition. In addition, we provide an update regarding the clinical characteristics, pathophysiology, neuroimaging and laboratory findings, treatment options, and prognosis of WE.

Keywords: Wernicke-Korsakoff Syndrome; ocular findings; review; thiamine deficiency.

Figure 1

Fundus changes in Wernicke encephalopathy. At initial presentation (A), there is bilateral optic disc edema with peripapillary and scattered retinal hemorrhages. At one week (B) and two weeks (C) following thiamine supplementation, there is significant interval improvement. At three weeks (D) following treatment, there is complete resolution of the optic disc edema and retinal hemorrhages except one residual hemorrhage along the inferotemporal arcade of the left eye. Both optic discs became pale with final best-corrected visual acuity of 20/600 in each eye. Reprinted from J Formos Med Assoc, 112(3), Yeh WY, Lian LM, Chang A, Cheng CK. Thiamine-deficient optic neuropathy associated with Wernicke’s encephalopathy in patients with chronic diarrhea, 165–170, Copyright (2013), with permission from Elsevier.

Figure 2

The metabolic pathways in which thiamine plays a critical role. Note: Adapted from Thomson AD, Cook CC, Touquet R, Henry JA. The royal college of physician’s report on alcohol: guidelines for managing Wernicke’s encephalopathy in the accident and emergency department. Alcohol Alcohol. 2002;37(6):513–521 by permission of Oxford University Press.

Figure 3

Brain MRI findings in Wernicke encephalopathy. Axial views. (A) Precontrast T1 scan is unremarkable. (B) Postcontrast T1 scan demonstrates enhancement of the mammillary bodies. (C) T2 FLAIR image reveals hyperintensity of the periaqueductal gray. (D) Diffusion-weighted imaging shows hyperintense signal in the medial thalami. (E) ADC map shows mild diffusion restriction, consistent with cytotoxic edema.