MRI study of Baló’s concentric sclerosis before and after corticosteroid therapy

Baló Concentric Sclerosis Mimicking Encephalitis with Seizures and Progressive Aphasia in a 26-Year-Old Woman: A Challenging Diagnostic Dilemma

Introduction

Baló's concentric sclerosis (BCS) is a rare subtype of multiple sclerosis characterized by inflammatory demyelination within the central nervous system.

Case Presentation

This case report presents a challenging diagnostic scenario involving a 26-year-old woman diagnosed with BCS. Despite treatment, her condition did not ameliorate, and magnetic resonance imaging (MRI) findings remained unchanged. A subsequent stereotactic biopsy revealed tumefactive Balo disease, highlighting the intricate diagnostic and therapeutic issues surrounding BCS.

Conclusion

The juxtacortical location of the BCS lesion, as observed in our case, suggests an unfavourable prognosis due to treatment-resistant seizures.

Baló's concentric sclerosis - A rare entity within the spectrum of demyelinating diseases

Baló's concentric sclerosis (BCS) is a rare, inflammatory demyelinating disease of the central nervous system (CNS). Historically, BCS was thought to be uniformly fatal and diagnosis was based on postmortem findings. With advances in modern neuroimaging, BCS is currently defined by the presence of concentric layered patterns composed of alternating rings of varying intensity. They are best appreciated on gadolinium-enhanced T1-weighted sequences and predominantly occur in the supratentorial cerebral white matter with sparing of cortical U-fibers. The lamellar pattern of the lesions likely reflects bands of demyelination and relative myelin preservation with minimal axonal loss. While BCS falls within the spectrum of atypical demyelinating diseases, there is ongoing debate over whether BCS is a phenotypical variant of multiple sclerosis (MS) or a separate entity. Corticosteroids comprise first-line therapy but there is ongoing controversy regarding appropriate maintenance therapy. First-line MS disease-modifying therapies such as interferon beta-1a are appropriate for patients who fulfill diagnostic criteria for relapsing-remitting MS. Fingolimod should likely be avoided as Baló-like lesions have been reported during its administration or after withdrawal. Monoclonal antibodies such as natalizumab and rituximab are potentially effective at reducing BCS relapses, but alemtuzumab may be relatively ineffective because humoral immunity does not play a central role in BCS pathogenesis.