Neuromyelitis optica spectrum disorders may be misdiagnosed as Wernicke's encephalopathy

Wernicke Encephalopathy: Typical and Atypical Findings in Alcoholics and Non-Alcoholics and Correlation with Clinical Symptoms

PURPOSE

Clinical diagnosis of Wernicke encephalopathy (WE) can be challenging due to incomplete presentation of the classical triad. The aim was to provide an update on the relevance of standard MRI and to put typical and atypical imaging findings into context with clinical features.

METHODS

In this two-center retrospective observational study, the local radiology information system was searched for consecutive patients with clinical or imaging suspicion of WE. Two independent raters evaluated T2-weighted imaging (WI), fluid-attenuation inversion recovery (FLAIR), diffusion WI (DWI), T2*WI and/or susceptibility WI (SWI), and contrast-enhanced (CE)-T1WI, and noted the involvement of typical (i.e., mammillary bodies (MB), periaqueductal grey (PAG), thalamus, hypothalamus, tectal plate) and atypical (all others) lesion sites. Unusual signal patterns like hemorrhages were also documented. Reported clinical features together with the diagnostic criteria of the latest guidelines of the European Federation of Neurological Societies (EFNS) were used to test for relationships with MRI biomarkers.

RESULTS

47 patients with clinically confirmed WE were included (Jan '99-Apr '23; mean age, 53 yrs; 70% males). Interrater reliability for imaging findings was substantial (κ = 0.71), with lowest agreements for T2WI (κ = 0.85) compared to all other sequences and for PAG (κ = 0.65) compared to all other typical regions. In consensus, 77% (n = 36/47) of WE cases were rated MRI positive, with FLAIR (n = 36/47, 77%) showing the strongest relation (χ2 = 47.0; P < 0.001) compared to all other sequences. Microbleeds in the MB were detected in four out of ten patients who received SWI, not visible on corresponding T2*WI. Atypical findings were observed in 23% (n = 11/47) of cases, always alongside typical findings, in both alcoholics (n = 9/44, 21%) and non-alcoholics (n = 2/3, 67%). Isolated involvement of structures, explicitly PAG (n = 4/36; 11%) or MB (n = 1/36; 3%), was present but observed less frequently than combined lesions (n = 31/36; 86%). A cut-off width of 2.5 mm for the PAG on 2D axial FLAIR was established between cases and age- and sex-matched controls. An independent association was demonstrated only between short-term memory loss and changes in the MB (OR = 2.2 [95% CI: 1.1-4.5]; P = 0.024). In retrospect, EFNS criteria were positive (≥ 2 out of 4) in every case, but its count (range, 2-4) showed no significant (P = 0.427) relationship with signal changes on standard MRI.

CONCLUSION

The proposed sequence protocol (FLAIR, DWI, SWI and T1WI + CE) yielded good detection rates for neuroradiological findings in WE, with SWI showing microbleeds in the MB with superior detectability. However, false negative results in about a quarter of cases underline the importance of neurological alertness for the diagnosis. Awareness of atypical MRI findings should be raised, not only in non-alcoholics. There is limited correlation between clinical signs and standard MRI biomarkers.

Neuromyelitis Optica Spectrum Disorder Resembling Wernicke's Encephalopathy: A Case Report and Review of the Literature

We describe a case of Neuromyelitis Optica Spectrum Disorder (NMOSD) mimicking Wernicke's Encephalopathy (WE) to highlight an atypical presentation of NMOSD. A 39-year-old female presented with subacute encephalopathy and progressive ophthalmoplegia. Her MRI revealed T2 hyperintensities involving the mammillary bodies, periaqueductal grey matter, medial thalami, third ventricle, and area postrema. Whole blood thiamine levels were elevated and she did not improve with IV thiamine. CSF was notable for lymphocytic pleocytosis and elevated protein. She tested positive for serum Aquaporin-4 (AQP4) antibody. Subsequent imaging revealed multilevel lesions in the cervical and thoracic spinal cord. Her CSF GFAP antibody also came back positive. She steadily and significantly improved after high-dose IV steroids and plasmapheresis. She later started on chronic rituximab therapy. This represents a unique case of NMOSD presenting with the classical clinical and imaging features of WE, as opposed to the typical presenting symptoms of NMOSD. As such, demyelinating disorders should be considered when there is concern for diencephalic and midline pathologies, particularly without classic WE risk factors. Conversely, clinicians should be aware of secondary nutritional complications arising from severe area postrema syndrome.

Area postrema syndrome as initial manifestation in neuromyelitis optica spectrum disorder patients: A retrospective study

BACKGROUND

Area postrema syndrome (APS) is recognized as a core feature in neuromyelitis optica (NMO) diagnosis. Isolated APS can occur at NMO onset and frequently results in a delay of diagnosis, along with devastating secondary neurologic deficits. To date, few studies have characterized APS-onset neuromyelitis optica spectrum disorder (APSO-NMOSD).

OBJECTIVE

We aimed to describe the clinical and radiologic features of patients with APSO-NMOSD who are initially misdiagnosed in a cohort of patients from Zhengzhou, China.

MATERIALS AND METHODS

We identified 15 patients who presented with APS as an initial manifestation, based on the 2015 international consensus diagnostic criteria for NMOSD, and reviewed their demographic, clinical, laboratory, and magnetic resonance imaging (MRI) data.

RESULT

Fifteen patients (3 men, 12 women) aged 14-50 years old were included in our study. All patients presented with APS that included intractable nausea, vomiting, or hiccups (INVH) as the initial manifestation; many experienced a delay in diagnosis. Serum AQP4 was positive in eleven patients and myelin oligodendrocyte glycoprotein (MOG) in one patient. All patients had a linear medullary lesion or a linear medulla-spinal lesion on sagittal MRI. An "inverted V sign" on axial medulla oblongata images, representing a lesion involving the area postrema, was noted in seven patients in this study.

CONCLUSIONS

APS can occur as a sole and initial manifestation of NMOSD, often leading to misdiagnosis in the early process of disease. Identifying patients with an "inverted V" sign and a linear medullary lesion upon MRI examination can help to quickly identify APS patients and avoid further diagnostic delays.

Classical Triad and Periventricular Lesions Do Not Necessarily Indicate Wernicke's Encephalopathy: A Case Report and Review of the Literature

The classical triad—ophthalmoplegia, cerebellar dysfunction, and altered mental state—in addition to bilateral symmetrical periventricular lesions are actually common to see, and clinicians tend to associate that with Wernicke's encephalopathy (WE). The diagnosis is strengthened with a likely deficiency of thiamine. We herein describe a malnourished patient with clinical triad and hyperintensities in the circumventricular regions, and she turned out to have neuromyelitis optica spectrum disorder (NMOSD) after many twists and turns. Despite totally different pathogenic mechanisms, NMOSD can mimic WE, sometimes even exhibiting radiological features similar to that of WE, thereby complicating the diagnosis. Our case highlights how similar these two diseases could be and the importance of differential diagnosis in clinical practice, which are so far rarely reported. Some clinical and radiological differences of these two diseases are summarized to help establish a prompt diagnosis.

Pattern Recognition of the Multiple Sclerosis Syndrome

During recent decades, the autoimmune disease neuromyelitis optica spectrum disorder (NMOSD), once broadly classified under the umbrella of multiple sclerosis (MS), has been extended to include autoimmune inflammatory conditions of the central nervous system (CNS), which are now diagnosable with serum serological tests. These antibody-mediated inflammatory diseases of the CNS share a clinical presentation to MS. A number of practical learning points emerge in this review, which is geared toward the pattern recognition of optic neuritis, transverse myelitis, brainstem/cerebellar and hemispheric tumefactive demyelinating lesion (TDL)-associated MS, aquaporin-4-antibody and myelin oligodendrocyte glycoprotein (MOG)-antibody NMOSD, overlap syndrome, and some yet-to-be-defined/classified demyelinating disease, all unspecifically labeled under MS syndrome. The goal of this review is to increase clinicians’ awareness of the clinical nuances of the autoimmune conditions for MS and NMSOD, and to highlight highly suggestive patterns of clinical, paraclinical or imaging presentations in order to improve differentiation. With overlay in clinical manifestations between MS and NMOSD, magnetic resonance imaging (MRI) of the brain, orbits and spinal cord, serology, and most importantly, high index of suspicion based on pattern recognition, will help lead to the final diagnosis.

Neuroimaging of chronic alcohol misuse

Alcohol is one of the most commonly abused substances worldwide. It results in a wide range of diseases and disorders affecting many organ systems. Alcohol-related nutritional deficiencies and electrolyte disturbance leave chronic abusers at risk of a range of demyelinating conditions to which the radiologist and clinician should always be alert. These include Wernicke's encephalopathy, Korsakoff's syndrome, Marchiafava-Bignami disease and osmotic demyelination. Cerebral volume loss is also a commonly encountered neuroimaging phenomenon in chronic alcohol abusers. Neuroimaging with CT and MR, with a focus on FLAIR and diffusion-weighted MR sequences, play an important role in the diagnosis and often monitoring of these conditions. We present an educational review of these entities in terms of their clinical features, neuropathology and imaging features along with a case example of each condition.