A Case of Cerebral Amyloid Angiopathy-Related Inflammation With the Rare Apolipoprotein ε2/ε2 Genotype.

Yin-Yan Xu,Xi-Ling Chen,Shuai Chen,Jie-Wen Zhang,Jian-Hua Zhao

doi:10.3389/fneur.2019.00547

Abstract

Cerebral amyloid angiopathy (CAA)-related inflammation (CAA-RI) is a rare CAA variant characterized by acute or subacute encephalopathy, headache, epilepsy, or focal neurological deficits. Radiologically, CAA-RI presents with widespread white matter lesions on brain magnetic resonance imaging (MRI) in addition to the hemorrhagic imaging features of CAA. Previous studies have found that the apolipoprotein E (ApoE) ε4 allele and ε4/ε4 genotype were over-represented in CAA-RI. The role of the ApoE ε2 allele in CAA-RI, however, is largely unknown, partly due to the rarity of the ε2/ε2 genotype in the general population. The authors report the first case of CAA-RI with the rare ApoE ε2/ε2 genotype. The patient presented with mild clinical symptoms but striking neuroimaging abnormalities. The response to small-dose glucocorticoids was satisfactory. Because ApoE ε2 promotes amyloid β accumulation and fibrinoid necrosis in the cerebral vasculature, the ε2/ε2 genotype, similar to ε4/ε4, may also be a precipitating factor for CAA-RI. To clarify the role of ApoE ε2 in CAA-RI, studies with large sample sizes investigating whether ε2 is more common in patients with CAA-RI than in those with CAA only are warranted.

Highlights

It was not a novel pathological finding that inflammation exists within or surrounding amyloid vessels in cerebral amyloid angiopathy (CAA) [1]
According to the different combinations of codon 112 and 158 of the fourth exon of the apolipoprotein E (ApoE) gene, the patient was found to harbor the rare ε2/ε2 genotype. This case of Cerebral amyloid angiopathy (CAA)-RI presented with mild cognitive impairment without headache, epilepsy, or other focal neurological deficits
The diagnosis of CAA-related inflammation (CAA-RI) in this patient was made without biopsy

Summary

BACKGROUND

It was not a novel pathological finding that inflammation exists within or surrounding amyloid vessels in cerebral amyloid angiopathy (CAA) [1]. A 69-years-old Chinese female farmer was admitted to the department of neurology due to cognitive decline and drooling during the previous month She had difficulty remembering recent events, and the involuntary drooling was especially obvious during sleep. Mild urinary incontinence developed; no dizziness, headache, fever, limb numbness, or weakness were reported She had a 20-years history of hypertension with irregular use of reserpine, and her blood pressure was not well-controlled. Initial brain magnetic resonance imaging (MRI) revealed multiple, asymmetrical subcortical white matter lesions, with U-fiber involved These lesions were hyperintense on T2-weighted imaging, fluid attenuated inversion-recovery (FLAIR) and apparent diffusion coefficient (ADC) sequences, and were isointense on diffusion-weighted imaging (DWI) sequence. On follow-up brain MRI, diffuse white matter lesions largely improved with microbleeds unchanged (Figure 1), and prednisone was discontinued 1 month later. According to the different combinations of codon 112 and 158 of the fourth exon of the ApoE gene, the patient was found to harbor the rare ε2/ε2 genotype

DISCUSSION

Findings

ETHICS STATEMENT