- 1Front of the brainThinking, planning, personality and mood
- 2Side of the brainMemory and finding words
- 3Deep centre, the thalamusSleep and body rhythms
- 4Back of the brainSight
- 5CerebellumBalance and coordination
A simplified picture. Prion disease can affect many areas, and which come first differs by person and by type of disease.
The word sporadic is doing one job here. It means no cause has been found: nothing was inherited, and nothing was caught or passed on. For most families this is the first thing they want to be sure of.
How common is it, and who gets it?
Sporadic CJD accounts for about 85 of every 100 cases of prion disease. Even so it is rare. About 1 to 2 people in a million are affected each year, and the same rate is reported in the United Kingdom, Canada and the United States.
Most people are over 50 when it starts. The average age at the first symptoms is in the late 60s, and about 9 in 10 of those diagnosed are between 45 and 85. It is very unusual under the age of 30.
What are the first signs?
The early changes are often small and easy to put down to something else. Memory lapses, confusion and changes in mood or personality are common at the start. So are problems with balance and walking, slurred speech, dizziness and trouble with vision such as double vision. Sudden jerky movements of the limbs can appear early too.
What marks this illness out is the speed. Symptoms get worse over weeks and a few months. Because of that, doctors look at CJD when a dementia is moving quickly, which is explained on our page about rapidly progressive dementia. There is a fuller list on our symptoms page.
How is it found?
There is no single test that settles it. A neurologist builds the picture from the pattern of symptoms and how fast they change, a scan of the brain by MRI, a recording of the brain’s electrical activity called an EEG, and tests on the fluid around the spinal cord. One of those fluid tests, RT-QuIC, looks directly for misfolded prion protein and is now widely used. A certain answer comes from examining brain tissue, which in practice usually means after death. How the tests fit together is set out in how it is diagnosed.
What treatment and care are there?
No medicine stops the disease or slows it down. What does help is good care for each symptom as it comes, and that can be a great deal.
Jerky movements, pain, anxiety, poor sleep and difficulty swallowing can all be treated. Nursing support, equipment at home, help with feeding and a palliative care team brought in early all make a real difference to comfort. Most people live for months to about a year after symptoms begin. What to expect goes through this stage by stage, including who to ask for help.
Research on lowering prion protein is moving, though nothing has yet been shown to change the course of the illness in people. Studies open to join are listed under current trials, and the science is summarised in our research page on sporadic CJD.
Who should I ask about my own situation?
This page cannot tell you what is happening to a particular person. A neurologist is the right person for symptoms, scans and test results, and the team caring for the person can refer you to palliative care at any point. A clinical account of the same material is in sporadic CJD: more detail.