Autoimmune encephalitis mimicking Creutzfeldt-Jakob disease

Abstract

We present a patient with rapidly progressive dementia (RPD) clinically suspicious for prion disease who met clinical criteria for probable and proposed MRI criteria for definite sporadic Creutzfeldt-Jakob disease (sCJD) but was found to have autoimmune encephalitis (AE). 1,2Case report A 69-year-old man with a history of smoking and tremor presented with RPD. During the prior 3 weeks, he lost his job and became increasingly confused, with worsening tremor and difficulty ambulating. At admission, he was oriented to self and setting, had poor recent and remote memory, and could not follow complex commands. There was moderate expressive aphasia with frequent paraphasic errors. Diffuse paratonia, a right parietal drift, tremor of the hands, poor coordination of rapid alternating movements, and brisk right deep tendon stretch reflexes were noted. He listed to the right when walking.Testing revealed hyponatremia (133 mEq/L) and CSF studies showed 1 leukocyte, protein 68 mg/dL, and glucose 91 mg/dL, without evidence of infection. CSF 14-3-3 and tau protein assay results were pending during hospitalization.Admission diffusion-weighted image (DWI) brain MRI demonstrated hyperintense cortical ribboning throughout the left hemisphere with corresponding hypointensity on apparent diffusion coefficient (ADC) mapping, sparing bilateral caudate nuclei and putamen ( figure, A and B). Admission EEG was low voltage with slight left hemispheric slowing in the delta/theta range, without periodic sharp-wave complexes commonly associated with prion disease.On day 6 the patient followed no commands, and had right facial myoclonus, right hemineglect, and severe ataxia.Antithyroperoxidase antibody level was 528 WHO units/mL blood. CT demonstrated a thyroid nodule and a 4-mm right upper lung nodule with 1 prominent hilar lymph node. Whole-body FDG-PET on day 8 demonstrated increased uptake in the left posterior cingulate Practical ImplicationsIn patients presenting with rapidly progressive dementia, brain FDG-PET imaging may be helpful in distinguishing patients with autoimmune encephalitis from those with CreutzfeldtJakob disease.

Autoimmune encephalitis mimicking sporadic Creutzfeldt–Jakob disease: A retrospective study

“…In contrast to a previous study with a mean patient age of 69 years and a male to female ratio of 8:7 (Geschwind et al, 2008), our patients were younger (P = 0.01) and maledominated. According to many case studies, men are more susceptible to VGKC autoimmune encephalitis (Rosenfeld et al, 2012;Fermo et al, 2014;Irani et al, 2011). The age difference may be due to racial differences or may reflect an underestimate of morbidities among elderly patients, who have neurodegenerative diseases more frequently than younger patients.…”

“…Heterogeneity in the imaging data of patients with AE is associated with autoantibody type, in which autoantibodies against intracellular antigens are associated with mesiotemporal abnormalities, whereas autoantibodies against surface antigens are more often associated with either normal findings or abnormalities outside the mesiotemporal region (Rosenfeld et al, 2012), as in our patients. Increased uptake in the left posterior cingulate gyrus, posterior frontal cortex, occipital cortex, thalamus, and precuneus in a patient with the neuronal VGKC antibody suggests an autoimmune process (Fermo et al, 2014). PET imaging of LGI-1 encephalitis reveals altered glucose metabolism, which may be partially relevant to disease stage, but there is a lack of large-scale longitudinal PET investigations due to its cost-effectiveness and radiation exposure.…”

The importance of recognizing faciobrachial dystonic seizures in rapidly progressive dementias

“… 6 Even brain MRI, in which abnormal hyperintensity on FLAIR and (diffusion-weighted image) DWI in cortical gyri (cortical ribboning), caudate, putamen or thalamus is considered a very accurate method for diagnosing CJD, has been reported to misdiagnose cases of VGKC encephalitis as CJD. 4 , 5 , 20 Despite the limitation of ancillary testing, a recent test called real-time quacking induced conversion (RT-QuIC) is a very promising premortem diagnostic test. 21 …”

A Creutzfeldt‐Jakob disease case misdiagnosed with acute cerebral infarction and review of the literature

“…One study showed that a serial MRI scan within the disease course is necessary for reaching the diagnosis of CJD 5 . Cortical DWI hyperintensity with normal ADC mapping has been reported in autoimmune encephalitis(AE), which is a key neuroimaging clue to distinct AE from sCJD 6 . A PET‐CT scan is useful for improving diagnostic accuracy by showing a hypometabolic pattern in CJD patients 7 .…”