Balo concentric sclerosis

Baló's concentric sclerosis
Typical aspects of Baló's concentric sclerosis. (a) Original case of Baló; several anastomoses are located in the lower half of the lesion. (b) Lesion centered by a veinule showing ring fragmentation in a constrained area. (c) Lesion. (d) Progress of the pathologic process from a center located in a constrained area, showing formation of bands. Loyez staining (myelin in black, destroyed areas in white); scale bars: 1 cm.
Specialty	Neurology

Baló's concentric sclerosis is a disease in which the white matter of the brain appears damaged in concentric layers, leaving the axis cylinder intact.^[1] It was described by József Mátyás Baló who initially named it "leuko-encephalitis periaxialis concentrica" from the previous definition,^[2] and it is currently considered one of the borderline forms of multiple sclerosis.

Baló's concentric sclerosis is a demyelinating disease similar to standard multiple sclerosis, but with the particularity that the demyelinated tissues form concentric layers. Scientists used to believe that the prognosis was similar to Marburg multiple sclerosis, but now they know that patients can survive, or even have spontaneous remission and asymptomatic cases.^[3]

The concentric ring appearance is not specific to Baló's MS. Concentric lesions have also been reported in patients with neuromyelitis optica, standard MS, progressive multifocal leukoencephalopathy, cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, concomitant active hepatitis C and human herpes virus 6.^[4]