Magnetic resonance imaging in the assessment of brain involvement in alcoholic and nonalcoholic Wernicke's encephalopathy

Abstract

Aim: To present the typical and atypical magnetic resonance (MR) imaging findings of alcoholic and non-alcoholic Wernicke's encephalopathy.

Methods: This study included 7 patients with Wernicke's encephalopathy (2 men, 5 women; mean age, 52.3 years) that underwent brain MR examination between January 2012 and March 2016 in a single institution. Three patients were alcoholics and 4 patients were non-alcoholics. MR protocol included a T2-weighted sequence, a fluid attenuation inversion recovery (FLAIR) sequence, a diffusion-weighted sequence (b = 0 and 1000 s/mm²), and a contrast-enhanced MR sequence. All MR images were retrospectively reviewed at baseline and follow-up by two radiologists.

Results: All patients with Wernicke's encephalopathy had bilateral areas showing high signal intensity on both T2-weighted and FLAIR MR images in the typical sites (i.e., the periaqueductal region and the tectal plate). Signal intensity abnormalities in the atypical sites (i.e., the cerebellum and the cerebellar vermis) were seen in 4 patients, all of which had no history of alcohol abuse. Six patients had areas with restricted diffusion in the typical and atypical sites. Four patients had areas showing contrast-enhancement in the typical and atypical sites. Follow-up MR imaging within 6 mo after therapy (intravenous administration of thiamine) was performed in 4 patients, and demonstrated a complete resolution of all the signal intensities abnormalities previously seen in all patients.

Conclusion: MR imaging is valuable in the diagnosis of Wernicke's encephalopathy particularly in patients presenting with atypical clinical symptoms, or with no history of alcohol abuse.

Keywords: Brain; Magnetic resonance imaging; Neurodegenerative disorder; Wernicke’s encephalopathy.

Figure 1

Magnetic resonance images in a patient with alcoholic Wernicke’s encephalopathy. A: Axial T2-weighted image shows symmetrical high signal intensity lesions in the medial thalami; B: Axial fluid-attenuated inversion recovery (FLAIR) image shows symmetrical high signal intensity lesions in the medial thalami; C: Axial FLAIR image shows symmetrical high signal intensity lesions in the periaqueductal area; D: Axial FLAIR image shows symmetrical high signal intensity lesions around the mammillary bodies.

Figure 2

Magnetic resonance images in a patient with nonalcoholic Wernicke’s encephalopathy. A: Axial FLAIR image shows a high signal intensity lesion in the left cerebellar hemisphere; B: Axial FLAIR image shows a high signal intensity lesion in the cerebellar vermis; C: Axial DWI shows an high signal intensity lesion in the left cerebellar hemisphere; D: Axial DWI shows a high signal intensity lesion in the cerebellar vermis. FLAIR: Fluid-attenuated inversion recovery; DWI: Diffusion-weighted imaging.

Figure 3

Axial diffusion weighted image magnetic resonance images in a patient with alcoholic Wernicke’s encephalopathy in the acute phase. A: Diffusion weighted image shows restricted diffusion in the periaqueductal grey matter; B: Diffusion weighted image shows restricted diffusion around the mammillary bodies.

Figure 4

Axial T1-weighted magnetic resonance images after contrast material administration in a patient with alcoholic Wernicke’s encephalopathy. A: Enhanced axial T1-weighted image shows contrast-enhancement of the periaqueductal grey matter; B: Enhanced axial T1-weighted image shows contrast-enhancement around the mammillary bodies.

Figure 5

Magnetic resonance images in a patient affected by alcoholic Wernicke’s encephalopathy. A-D: MR images before intravenous administration of thiamine therapy; E-H: MR images after intravenous administration of thiamine therapy. Axial FLAIR images (A,B) and DWI images (C,D) show signal abnormalities in the periaqueductal area and in the medial thalami. Axial FLAIR (E,F) and DWI (G,H) follow-up MR images, after intravenous administration of thiamine therapy, show resolution of the signal abnormalities previously observed. MR: Magnetic resonance; FLAIR: Fluid-attenuated inversion recovery; DWI: Diffusion weighted image.