I understand your concern for your mother. Currently, there are no approved medications that can stop the progression of semantic dementia or regenerate lost brain cells. Donepezil is sometimes prescribed to help manage cognitive symptoms, but it does not cure or halt the underlying disease. While research into brain cell regeneration is active, no such drugs are clinically available yet. Management currently focuses on speech-language therapy and supportive care to maintain her quality of life. I highly recommend discussing her treatment plan with her neurologist, as medications like Donepezil can sometimes be less effective or even worsen symptoms in frontotemporal dementia variants.