Baló's concentric sclerosis (BCS) is a rare inflammatory demyelinating disorder characterised by a pathologic appearance of concentric layers of demyelinated and partially myelinated fibres, with a distinctive "onion bulb" pattern on magnetic resonance imaging (MRI). Due to its rarity and overlapping features with multiple sclerosis and neuromyelitis optica spectrum disorder (NMOSD), diagnosis is challenging. We report the case of a 60-year-old male with hypertension who presented with acute bilateral painless vision loss, absent pupillary light reflex, and marked photophobia. Initial brain and orbital MRI were normal, but cervical spine MRI revealed a demyelinating lesion from C5 to C6. Cerebrospinal fluid (CSF) showed type 1 oligoclonal bands and negative anti-aquaporin 4 and anti-myelin oligodendrocyte glycoprotein antibodies. The patient was initially diagnosed with seronegative NMOSD and treated with intravenous methylprednisolone without improvement. One month later, he developed spastic dysarthria and dysphagia; brain MRI showed a right pre-Rolandic lesion with concentric rings associated with the previously reported demyelinated lesion in the cervical spinal cord and other demyelinated lesions in the brainstem. CSF analysis during relapse revealed hyperproteinorrhachia and mild hypoglycorrhachia without infectious or autoimmune markers. Plasmapheresis led to the resolution of bulbar symptoms. Given clinical relapse and lesion progression, rituximab therapy was initiated, achieving clinical stability. This case illustrates the diagnostic complexity of BCS, the importance of integrating imaging and immunological findings, and the potential role of B-cell-depleting therapy in preventing new relapses.

Balo concentric sclerosis (BCS) is a rare and aggressive variant of multiple sclerosis (MS), characterized by unique alternating concentric layers of demyelinated and preserved myelin on neuroimaging. We present a case of a 34-year-old male patient with progressive right-sided weakness, whose MRI brain findings confirmed BCS. The patient demonstrated rapid clinical improvement with early initiation of high-dose corticosteroids. The Expanded Disability Status Scale (EDSS) score improved from 6 to 1 within one month, underscoring the importance of timely intervention. Early recognition and prompt treatment are critical to improving outcomes in BCS, as delays can lead to irreversible neurological damage. This case highlights the significant role of early high-dose corticosteroid therapy in achieving clinical improvement and preventing long-term disability.

Balo concentric sclerosis (BCS) is a rare demyelinating disease. This study aims to follow up on patients initially diagnosed with BCS and MS or presented with BCS in the context of MS. This study was conducted at an MS clinic center in Isfahan, monitoring 2600 MS patients, among which 10 cases were related to BCS. These 10 patients were assessed clinically and radiologically during 2013-2024, with consecutive MRIs and periodic clinical examinations. Among the 10 patients, BCS was either the inaugural presentation of MS or occurred in the context of the disease. The most common Symptoms included limb weakness and paresthesia. All patients exhibited characteristic onion-like lesions in the periventricular white matter, with two showing tumefactive demyelination. CSF analysis was abnormal in all patients, revealing positive oligoclonal bands (OCB), which were categorized as type 2 in all patients. Treatment mainly involved rituximab, which indicated plausible results. Our study highlights the variability in BCS clinical presentations and supports its classification as a variant of MS due to overlapping characteristics. Additionally, our findings contribute to understanding BCS's distinct clinical and radiologic profiles and emphasize the importance of further investigation into its pathophysiology and treatment.

Balo Concentric Sclerosis (BCS) is a rare neurological demyelinating disorder similar to Multiple Sclerosis. Both present with progressive neurological debility but differences on brain imaging help with distinction. The lack of prevalence and general diagnostic information about BCS makes it an underdiagnosed disease which can sometimes delay treatment. This case of BCS was initially treated as an infectious brain mass, leading to unnecessary interventions. Early recognition and differentiation from other neurological conditions are crucial for appropriate management and prognosis. We hope that by presenting this case, we can aid in creating diagnostic criteria and promote awareness of this chronic debilitating disease.