<s>[INST] 55 year old W/F with symptoms of sudden loss of balance feeling foggy, sleepy and then going into a deep sleep sometimes lasting 1-2 hours. When wake up feels better but mind not as clear for a while. MRI shows T1 and flair signal hyperintensities int he corona radiate and subcortical white matter likely mild ischemic gliotic change or possible demyelination . I never know when this is going to occur and has happened at non specific times for 4 days in a row. [/INST] Hello, Is there any family history of multiple sclerosis? Possible causes are like B12 deficiency or MS or multi infarcts etc. Until examination is done it is difficult to say what it is. Balance problems may be due to muscle weakness or joint problems or neurodegenerative or neurovascular problems. Use bit B12 tablets once a day for one month. Please consult with your neurophysician he will examine and treat you accordingly. Take care. Hope I have answered your question. Let me know if I can assist you further.  </s>