Balo concentric sclerosis
Encyclopedia
Balo concentric sclerosis is one of the borderline forms of multiple sclerosis.
Balo 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.
It is also common that the clinic course is primary progressive, but a relapsing-remitting course has been reported.
It seems that the course gets better with prednisone therapy, although evidence of this is anecdotal and such conclusions are difficult to accept given that there are cases where patients spontaneously recover whether the patient was on steroid therapy or not.
According with Dr. Lucchinetti investigations, in Balo's concentric sclerosis, the rings may be caused by a physiological hypoxia (similar to that caused by some toxins or viruses) in the lesion, which is in turn countered by expression of stress proteins at the border. This expression and counter-expression forms rings of preserved tissue within the lesion and rings of demyelinated tissue just beyond where the previous attack had induced the protective stress proteins. Hence, subsequent attacks form concentric rings.
Ultimately, this expanding lesion causes the progressive picture typically seen. However, in some patients, the pathology underlying the disease appears to burn out and hence the disease may halt, hence the patients who spontaneously recover. The mechanisms triggering attacks and recovery remain uncertain.
Recently, a mathematical model for concentric sclerosis has been proposed. Authors review the previous pathogenic theories, discuss the link between concentric sclerosis and Liesegang's periodic precipitation phenomenon
and propose a new mechanism based on self-organization.
Balo concentric sclerosis is a demyelinating disease similar to standard multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
, but with the particularity that the demyelinated tissues form concentric layers. Scientists used to believe that the prognosis was similar to Marburg multiple sclerosis
Marburg multiple sclerosis
Marburg multiple sclerosis, also known as fulminant multiple sclerosis, is considered one of the multiple sclerosis borderline diseases, which is a collection of diseases classified by some as MS variants and by others as different diseases. Other diseases in this group are Neuromyelitis optica ,...
, but now they know that patients can survive, or even have spontaneous remission and asymptomatic cases.
It is also common that the clinic course is primary progressive, but a relapsing-remitting course has been reported.
It seems that the course gets better with prednisone therapy, although evidence of this is anecdotal and such conclusions are difficult to accept given that there are cases where patients spontaneously recover whether the patient was on steroid therapy or not.
Pathophysiology
The lesions of the Balo sclerosis belong to the MS lesion pattern III (distal oligodendrogliopathy).According with Dr. Lucchinetti investigations, in Balo's concentric sclerosis, the rings may be caused by a physiological hypoxia (similar to that caused by some toxins or viruses) in the lesion, which is in turn countered by expression of stress proteins at the border. This expression and counter-expression forms rings of preserved tissue within the lesion and rings of demyelinated tissue just beyond where the previous attack had induced the protective stress proteins. Hence, subsequent attacks form concentric rings.
Ultimately, this expanding lesion causes the progressive picture typically seen. However, in some patients, the pathology underlying the disease appears to burn out and hence the disease may halt, hence the patients who spontaneously recover. The mechanisms triggering attacks and recovery remain uncertain.
Recently, a mathematical model for concentric sclerosis has been proposed. Authors review the previous pathogenic theories, discuss the link between concentric sclerosis and Liesegang's periodic precipitation phenomenon
Liesegang rings
Liesegang rings are a phenomenon seen in many, if not most, chemical systems undergoing a precipitation reaction, under certain conditions of concentration and in the absence of convection.-History:...
and propose a new mechanism based on self-organization.