Creutzfeldt-Jakob disease

Also called CJD, Prion disease

A rare, rapidly progressive brain disease. The speed is what distinguishes it: weeks to months, not years.

What it is

A rare and fatal degenerative brain disease caused by prions, misfolded proteins that cause other proteins to misfold.

Sporadic CJD, the commonest form, occurs with no identifiable cause, mainly in people over 60, affecting roughly one or two people per million per year.

Variant CJD, linked to eating beef products contaminated with BSE, caused a small number of deaths concentrated in the 1990s and 2000s and is now extremely rare.

Inherited forms account for around 10 to 15 per cent, and iatrogenic cases from contaminated surgical instruments, hormone treatments and grafts are now historical but drove significant changes in how instruments are handled.

**The clinically useful feature is speed.** Dementia that progresses over weeks to a few months, with prominent unsteadiness, jerking movements and visual disturbance, is not Alzheimer's disease. Rapidly progressive dementia should prompt urgent neurology referral, precisely because the far more likely causes on that timescale, encephalitis, autoimmune conditions, subdural haematoma, infection and metabolic problems, are treatable and must not be missed.

There is no treatment, and care is entirely about symptoms, dignity and support. Deterioration is fast, typically to death within months.

It is a notifiable condition and cases are referred to the National CJD Research and Surveillance Unit.

Signs you might notice

Rapidly progressive memory loss, confusion and personality change, over weeks to a few months.

Unsteadiness and poor coordination, often early and prominent.

Sudden jerky muscle movements, called myoclonus, sometimes triggered by startle.

Visual disturbance, including distorted vision and cortical blindness.

Depression, anxiety and withdrawal, sometimes preceding the cognitive changes.

Later: rigidity, mutism, and complete dependence.

Urgent: any dementia progressing over weeks rather than years. It needs urgent neurology assessment, mostly to exclude treatable causes.

Variant CJD, now very rare, presented differently and in younger people, with psychiatric symptoms and painful sensory disturbance first.

How it can affect day-to-day life

The pace is what families describe as unbearable: a person can go from working to needing total care within months, with no time to adjust or plan.

Because of that, everything has to be brought forward: advance care planning, lasting power of attorney, benefits, equipment and package of care. Waiting for the usual processes means missing the window entirely.

Fast-track continuing healthcare funding exists for rapidly deteriorating conditions and should be applied for immediately.

Myoclonus, agitation and pain all need active symptom control, and specialist palliative care involvement early makes a substantial difference.

Families frequently encounter fear and misinformation about infection risk. Ordinary contact, care and affection carry no risk; the precautions relate to surgical instruments and specific procedures.

The national surveillance unit provides expert advice and support to families and to local teams, and contacting them early is worthwhile.

Supporting someone well

Treat rapidly progressive cognitive decline as urgent, primarily to find a treatable cause.

Ask for urgent neurology referral, MRI, lumbar puncture and EEG.

Once diagnosed, bring everything forward: power of attorney, advance care planning, benefits, equipment, care package.

Apply for fast-track continuing healthcare funding immediately.

Involve specialist palliative care early for symptom control, particularly myoclonus, agitation and pain.

Contact the national surveillance unit for expert advice.

Reassure the family that ordinary care and contact is safe.

Ask for family support and bereavement support from the outset; this is an extremely fast loss.

Where to get help

A GP practice for urgent neurology referral.

The National CJD Research and Surveillance Unit, which advises clinicians and supports families.

Alzheimer's Society on 0333 150 3456 and Dementia UK for family support.

Marie Curie on 0800 090 2309 for end of life care and planning.