However, more recent imaging and histopathological studies suggest that cortical demyelination plays a crucial role in MS pathogenesis and cognitive dysfunction. Historically, MS was classified as an inflammatory disease targeting white matter, with diagnostics and therapeutics focused on this mechanism of pathology. Currently, brain biopsy is the only method to definitively determine pathologic subtypes, but studies are underway to find blood, cerebrospinal fluid, and MRI biomarkers. 9 Further research is needed to understand how these different pathologic subtypes affect prognosis and response to treatments. 7 Predominant factors driving neurodegeneration include mitochondrial dysfunction due to defective oxidative phosphorylation and nitric oxide production, resulting in a chronic state of virtual hypoxia due to unmet energy demands, 8 and age-dependent iron accumulation in myelin and oligodendrocytes leading to oxidative tissue damage. Instead, progressive MS is characterized by neurodegeneration of the white and grey matter resulting in brain and spinal cord atrophy on a background of mild-moderate inflammation. In progressive MS, inflammation is a less defining pathological hallmark. The exact cause of inflammation remains unclear, but an autoimmune response directed against CNS antigens is suspected. Histologic examination reveals foci of severe demyelination, decreased axonal and oligodendrocyte numbers, and glial scarring. It remains unclear whether this altered incidence represents an environmental influence (eg, vitamin D deficiency), genetic difference, variable surveillance, or other, as yet unidentified, differences.Д®arly in the disease course, MS involves recurrent bouts of CNS inflammation that results in damage to both the myelin sheath surrounding axons as well as the axons themselves.

The prevalence of MS varies by location and generally increases the further one travels from the equator in either hemisphere. 1 Although MS is more frequently seen in white than African American and Hispanic populations, the latter groups overall have poorer disease outcomes in that they accumulate disability more quickly, suggesting more destructive tissue injury in these groups.

5,6 Initial symptoms typically occur between 20 and 50 years of age, and women have about 3 times increased likelihood of developing MS compared with men. MS affects approximately 1 million individuals in the US and 2.5 million worldwide. 3 Patients with PPMS tend to be older, have fewer abnormalities on brain MRI, and generally respond less effectively to standard MS therapies. About 10% to 15% of patients have gradually worsening manifestations from the onset without clinical relapses, known as primary progressive MS (PPMS). Relapses can be seen during the early stages of SPMS, but are uncommon as the disease further progresses. 2 After tissue damage accumulates over many years and reaches a critical threshold, about two-thirds of the patients transition to secondary progressive MS (SPMS), where pre-existing neurologic deficits gradually worsen over time. Approximately 85% of patients present with a relapsing-remitting MS (RRMS) disease course at onset, where symptoms appear for several days to weeks, after which they usually resolve spontaneously. Nonetheless, they provide an organized framework for diagnosis and long-term management. Since these classifications were based upon clinical characteristics, they are empiric and do not reflect specific biologic pathophysiology. Complementary approaches such as symptom management and healthy lifestyle practices also have an important role in MS care. Therapies that target inflammation and slow progression of disease are available therefore, early diagnosis and treatment are important in limiting the impact of this potentially devastating disease. 1 As symptoms of MS are extremely variable and often quite subtle, diagnosis and management have been greatly enhanced by the use of magnetic resonance imaging (MRI). Direct MS-related healthcare costs are estimated to be more than $10 billion annually in the United States. MS is one of the most common causes of non-traumatic disability among young and middle-aged adults. Multiple Sclerosis (MS) is a chronic inflammatory, demyelinating, and neurodegenerative disorder of the central nervous system (CNS) that affects the white and grey matter of the brain, spinal cord, and optic nerve.

Bac cooling tower serial number age