Pathophysiology and diagnostic criteria of multiple sclerosis that has changed as the evolution of technology

Abstract

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, causing demyelination and neurodegeneration in most patients. Clinical symptoms of MS vary. In recently diagnosed or benign course patients, the incidence of cognitive impairment ranges from 20–40% of RRMS. Secondary progressive course is more common ; roughly 50–60% of patients are affected. The Brief International Cognitive Assessment for MS (BICAMS) battery includes tests of mental processing speed and memory. BICAMS has been recently internationally validated and can be useful in Japan. Diagnostic criteria of MS has been changing as the evolution of technology. Poser criteria were diagnostic criteria for MS. They had replaced the older Schumacher criteria ; defining Laboratory supported definite MS, showing oligoclonal bands. McDonald criteria intended to replace these two criteria. McDonald criteria were revised first in 2005 to clarify exactly what an “attack”, “dissemination” and a “positive MRI” mean. Later they were revised again in 2017 as follows : patients with a typical clinically isolated syndrome and clinical or MRI demonstration of dissemination in space, the presence of CSF–specific oligoclonal bands allows a diagnosis of multiple sclerosis. Informed consent is needed in decisions involving high risk. Patients should nonetheless be informed about the benefits and risks of the treatments, and they are free to refuse it. Shared decision making is appropriate for situations in which 2 or more medically reasonable choices exist, regardless of whether the degree of risk is high or low.