|
Multiple sclerosis (MS) is a condition where the CNS of a person present a special kind of distributed glial scars (sclerosis) 〔Dutta R, Trapp BD. "Pathology and definition of multiple sclerosis, Rev Prat. 2006 Jun 30;56(12):1293-8.〕 which are a remaining of a previous inflammatory demyelination. MS pathophysiology is complex and still under investigation and there is no agreement about its scope. Some authors consider it a pathological entity, while others consider it a clinical entity. From a pathological point of view, the demyelinating lesions can be classified as encephalomyelitis, and sometimes the disease is known as encephalomyelitis disseminata. There are two phases for how an unknown underlying condition may cause damage in MS: First some MRI-abnormal areas with hidden damage appear in the brain and spine (NAWM, NAGM, DAWM). Second, there are leaks in the blood–brain barrier where immune cells infiltrate causing the known demyelination and axon destruction.〔Tallantyre EC1, Bø L, Al-Rawashdeh O, Owens T, Polman CH, Lowe JS, Evangelou N. "Clinico-pathological evidence that axonal loss underlies disability in progressive multiple sclerosis. ''Acta Neuropathol.'' 2010 May;119(5):601-15. doi: 10.1007/s00401-009-0618-9. Epub 2009 Dec 5.〕 Some clusters of activated microglia, transection of axons and myelin degeneration is present before the BBB breaks down and the immune attack begins〔Bsibsi M, Holtman IR, Gerritsen WH, Eggen BJ, Boddeke E, van der Valk P, van Noort JM, Amor S. Alpha-B-Crystallin Induces an Immune-Regulatory and Antiviral Microglial Response in Preactive Multiple Sclerosis Lesions, J Neuropathol Exp Neurol. 2013 Sep 13, PMID 24042199〕 Pathophysiology is a convergence of pathology with physiology. Pathology is the medical discipline that describes conditions typically observed during a disease state; whereas physiology is the biological discipline that describes processes or mechanisms operating within an organism. Referring to MS, the physiology refers to the different processes that lead to the development of the lesions and the pathology refers to the condition associated with the lesions. ==Pathology== (詳細はsclerosis) in the central nervous system. These sclerosis are the remainings of previous demyelinating lesions in the CNS white matter of a patient (encephalomyelitis) showing special characteristics, like for example confluent instead of perivenous demyelination. Multiple sclerosis differs from other idiopathic inflammatory demyelinating diseases in its confluent subpial cortical lesions, being a hallmark exclusively present in MS patients, Normally the WM lesions appear along to other kind of damage such as NAWM (normal appearing white matter) and grey matter lesions, but MS main findings take place inside the white matter, and lesions appear mainly in a peri-ventricular distribution (lesions clustered around the ventricles of the brain), but apart from the usually known white matter demyelination, also the cortex and deep gray matter (GM) nuclei are affected, together with diffuse injury of the normal-appearing white matter. MS is active even during remission periods. GM atrophy is independent of the MS lesions and is associated with physical disability, fatigue, and cognitive impairment in MS At least five characteristics are present in CNS tissues of MS patients: Inflammation beyond classical white matter lesions, intrathecal Ig production with oligoclonal bands, an environment fostering immune cell persistence, Follicle-like aggregates in the meninges and a disruption of the blood–brain barrier also outside of active lesions. The scars that give the name to the condition are produced by the astrocyte cells healing old lesions. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pathophysiology of multiple sclerosis」の詳細全文を読む スポンサード リンク
|