Balo's concentric sclerosis

Balo's concentric sclerosis (BCS) is a rare and unusual variant of multiple sclerosis (MS). It is characterized by concentric layers of demyelination, a process in which the protective covering of nerve fibers in the central nervous system is damaged. This condition was first described by Josef Balo, a Hungarian pathologist, in 1928.

Epidemiology

BCS is extremely rare, with fewer than 100 cases reported worldwide. It is more common in Asian populations and affects both adults and children. The age of onset is typically between 20 and 40 years, but cases have been reported in individuals as young as 3 and as old as 70.

Pathophysiology

The hallmark of BCS is the presence of concentric rings of demyelination and remyelination in the brain, giving a characteristic "onion bulb" appearance on magnetic resonance imaging (MRI). The exact cause of this pattern is unknown, but it is thought to be due to waves of inflammation and demyelination followed by periods of remyelination.

Clinical Presentation

The clinical presentation of BCS is variable and can mimic other forms of MS. Symptoms may include motor and sensory disturbances, visual problems, cognitive impairment, and seizures. In some cases, the disease can progress rapidly and lead to severe disability or death, while in others it follows a more benign course.

Diagnosis

Diagnosis of BCS is based on clinical presentation, MRI findings, and sometimes brain biopsy. The concentric rings of demyelination seen on MRI are highly suggestive of BCS, but they are not always present and their absence does not rule out the diagnosis.

Treatment

There is no specific treatment for BCS. Management is largely supportive and may include corticosteroids to reduce inflammation, physical therapy to manage symptoms, and medications to control seizures. Some patients may benefit from disease-modifying therapies used in MS, but the evidence is limited.

Prognosis

The prognosis of BCS is variable. Some patients experience a single episode and recover completely, while others have a progressive course leading to severe disability or death. Early diagnosis and treatment may improve the prognosis.

See Also

• Multiple sclerosis
• Demyelinating diseases
• Neurology