In excruciating pain haven't slept all for 7mos had early menopause, brain/body burning and dementia how is 1 diagnosed with sporadic fatal insomnia?

Sorry you have been: Waiting for an answer and having so much difficulty sleeping and dealing with pain. Sleep deprivation can lead to serious psychological and physical issues. I would encourage you to contact a psychologist who practices clinical hypnosis. It can be used for insomnia and for pain management. It can help regardless of what the diagnosis turns out to be. In the meantime it will help you get some sleep.

SFI: Sporadic fatal insomnia is a rare prion disease related to familial fatal insomnia. It involves a characteristic change in sleep pattern, autonomic hyperactivation, and motor abnormalities. Polysomnography (sleep study), genetic analysis, and a pet scan may aid in diagnosis. If you are concerned, you should see a neurologist who specializes in degenerative disorders.