Balo Disease is also known as Balo disease, encephalitis periaxialis concentrica, leukoencephalitis periaxialis concentric and concentric sclerosis are rare and progressive variants of multiple sclerosis. It usually first appears in adulthood, but childhood cases have also been reported. While multiple sclerosis typically is a disease that waxes and wanes, Balo Disease is different in that it tends to be rapidly progressive. Symptoms may include headache, seizures, gradual paralysis, involuntary muscle spasms, and cognitive loss. The alternative names for Balo Disease, concentric sclerosis or Balo concentric sclerosis, refer to the fact that Balo Disease is characterized by bands of intact myelin (the sheath of fatty substances surrounding nerve fibers), alternating with rings of loss of myelin (demyelination), in various parts of the brain and brain stem. The symptoms of Balo Disease vary, according to the areas of the brain that are affected. Symptoms may progress rapidly over several weeks or more slowly over two to three years.
Balo’s disease is a rare demyelinating disorder of the central nervous system (CNS) in which the myelin (the fatty substance covering nerve fibers) is damaged. Balo’s disease shares feature with other demyelinating diseases and are generally regarded as a rare variant of multiple sclerosis (MS). The term “concentric sclerosis” comes from a pattern of concentric (circular) areas of damaged myelin alternating with areas of relatively undamaged myelin in various parts of the brain and spinal cord. This pattern can be seen in magnetic resonance imaging (MRI).
Attacks from Balo’s disease can proceed rapidly over weeks or months, without remission (a rapidly progressive course); a relapsing course (periods of symptoms followed by improvement or disappearance of symptoms) can also occur, or a person may experience a single attack (monophasic course).
Symptoms
Most cases are characterized by the gradual onset of symptoms that might be found in the more common type of MS, including muscle spasms and paralysis. Other neurological symptoms develop depending on the areas of the brain that are affected and may include intellectual impairment and/or physiological abnormalities. However, in its most serious form, Balo Disease may also suggest the presence of infectious disease, starting with a high fever and painful headaches.
Causes
The cause of MS and its variants remains unknown. However, some studies indicate that autoimmune factors may play a role in the development of Balo Disease. Autoimmune disorders are caused when the body’s natural defenses against “foreign” or invading organisms (e.g., antibodies) begin to attack healthy tissue for unknown reasons.
Diagnosis
Lesions under MRI are distinctive due to their natural concentric shape.
Under a lumbar puncture CSF test, Baló’s concentric sclerosis, as well as patients with pattern III lesions, were recently shown to be mostly negative for CSF-restricted oligoclonal bands. Also, pattern III patients tend to be negative under the MRZ-reaction (measles, rubeola, and zoster viruses)
Pediatric cases
Baló’s concentric sclerosis in children has been reported to behave differently from adults
Lesions in autopsy and biopsy
A report comparing 1H-magnetic resonance spectroscopy, magnetization transfer, and diffusion tensor imaging with histopathology in a patient with Baló’s concentric sclerosis, found that inflammation was traced by fractional anisotropy and increased lactate. In contrast, the magnetization transfer ratio and the diffusion coefficient show a loss of tissue in the rings of the lesion.[rx]
Lesions under MRI
The features of the MRI and the characteristics of the lesion can be correlated when a biopsy has been taken, providing a way to standardize the future MRI diagnosis[rx]
Baló’s concentric sclerosis lesions can be distinguished from normal lesions on MRI showing alternating hypointense and hyperintense layers[rx]
Baló’s concentric lesions can be viewed using myelin water imaging techniques. This is a special MRI sequence that shows the myelin’s percentage of water content.[rx]
Pattern III lesions, including Baló lesions, have a specific initiation pattern under MRI (MRILIP) consisting in showing Gadolinium enhancement before FLAIR MRI appearance.[rx]
Under 7-Tesla MRI Ball lesions show a center vein, like in MS
References
