Samir Alkabie1, Madison Gray2, Jonathan Lau3, Lillian Barra4, Jennifer Mandzia5, Qi Zhang2, Adrian Budhram6
1Department of Neurology, Lenox Hill Hospital, Northwell Health, 2Department of Pathology and Laboratory Medicine, 3Department of Clinical Neurological Sciences, Western University, London Health Sciences Centre, 4Department of Medicine, Division of Rheumatology, Western University, St. Joseph's Health Care, 5Department of Clinical Neurological Sciences, 6Department of Clinical Neurological Sciences and Department of Pathology and Laboratory Medicine, London Health Sciences Centre
Objective:
To present an illustrative pathology-proven case of primary angiitis of the central nervous system (PACNS) with striking left hemispheric predominance, which was compatible with a diagnosis of unilateral PACNS.
Background:
Unilateral PACNS is highly unique with characteristic clinical and neuroimaging features of chronic focal-onset seizures and unilateral predominance, respectively. We herein highlight how to recognize this rare clinico-radiologic syndrome, which may be under-recognized with only few cases published in the literature.
Design/Methods:
Case report.
Results:
A 48-year-old woman was referred with an 18-year history of focal-onset seizures. She also reported years-long slowly progressive right-sided weakness that was corroborated on examination. Brain MRIs dating back 15 years showed multifocal left-hemispheric T2-fluid-attenuated inversion recovery (FLAIR)-hyperintense lesions with patchy enhancement and microhemorrhages, as well as a left cerebellar infarct. No diffusion restriction was observed. Only two non-specific white matter lesions were seen contralaterally, indicating largely unihemispheric disease. Differential diagnosis included unilateral primary angiitis of the central nervous system (PACNS), Rasmussen’s encephalitis, and myelin oligodendrocyte glycoprotein (MOG)-antibody-associated disease. Serum and CSF testing for autoimmune, infectious and malignant etiologies, as well as whole body FDG-PET, whole-exome genetic sequencing and MR vessel-wall imaging were non-diagnostic. Brain biopsy revealed intramural fibrinoid necrosis with perivascular hemorrhage and transmural inflammation mediated by CD4 and CD8-positive T-lymphocytes and CD68-positive histiocytes, loss of myelinated axons, and vascular thrombosis, compatible with vasculitis, and the patient was diagnosed with unilateral PACNS. Treatment with mycophenolate mofetil has been initiated.
Conclusions:
Unilateral PACNS is a rare unihemispheric disease characterized by an indolent course of neurological deficits and focal-onset seizures, recognition of which is critical to accurate diagnosis.