Eventually, yes. Lbd is not the same as alzheimers. However, there also is no cure, and it is progressive - either slow or rapid. So, it is terminal but an average life expectancy after DX is 5-7 yrs. The worst of it is that the symptoms are quite difficult to manage and few families can avoid residential care. Here's a link: http://www.Lbda.Org/content/role-palliative-and-hospice-care-in-lbd. Hope you find help!
Dementia is fatal. Dementia including both lewy body dementia and alzheimers disease are progressive fatal illnesses. However, they progress over a number of years. I diagnosed someone with very very early lewy body disease and he and his wife travelled the country for 5 years before he even had significant symptoms beyond the hallucinations. Medications enabled him to stabilize his symptoms for 7 years, .