Only a brain biopsy or an examination of brain tissue after death during autopsy can confirm (diagnose) the presence of Creutzfeldt-Jakob disease (CJD). However, doctors often can make an accurate diagnosis based on the patient's medical and personal history, a neurological exam, and certain diagnostic tests.

A neurologist will carry out the tests to rule out other conditions with similar symptoms, such as Alzheimer's disease, Parkinson's disease or a brain tumor.

The neurological exam is likely to reveal characteristic symptoms as: Tests to help detect CJD:
  • Electroencephalogram (EEG). Using electrodes placed on the scalp, this test measures the brain's electrical activity. People with CJD and vCJD show a characteristically abnormal pattern.
  • Magnetic resonance imaging (MRI) . It uses radio waves and a magnetic field to create cross-sectional images of the head and body. It is especially useful in diagnosing brain disorders.
  • Spinal fluid tests. Cerebral spinal fluid surrounds and cushions the brain and spinal cord. In a test called a lumbar puncture (also known as a spinal tap) doctors use a needle to withdraw a small amount of this fluid for testing. The presence of a particular protein in spinal fluid is often an indication of CJD or vCJD.
  • Tonsil biopsy. Scientists have learned that tissue from the tonsils tends to harbor evidence of vCJD. Examination of a sample of tonsil tissue may help diagnose vCJD. However, this method seems less reliable for other forms of CJD.
  • Genetic test. This is a simple blood test to see if there is a mutation (fault) in the gene that produces normal protein. A positive result may indicate inherited prion disease.
  • Brain biopsy. It is done under general anesthetic. A surgeon drills a tiny hole into the skull and removes a small piece of brain tissue using a very thin needle.

    As a brain biopsy carries the risk of causing brain damage or seizures, it is only performed in a few cases, where there is a concern that the patient does not have CJD but some other treatable condition.
Written by Stephanie Brunner