Prion Diseases: Types, Symptoms, Diagnosis, Treatment & Prevention

Overview

Prions are misfolded proteins that have the ability to transmit their misfolded shape onto normal variants of the same protein. Prion proteins are most abundantly in the brain. The functions of these normal proteins are still not completely understood while the abnormal ones can lead to brain damage that is usually rapidly progressive and always fatal.

Prion diseases occur when normal prion protein becomes abnormal and clump in the brain, causing brain damage. This abnormal accumulation of protein in the brain can cause memory impairment, personality changes, and difficulties with movement.

Types

  • Creutzfeldt–Jakob disease (CJD). Most cases of CJD are sporadic and tend to strike people around age 60. Acquired CJD is caused by exposure to infected tissue during a medical procedure, such as a cornea transplant. Symptoms of CJD quickly lead to severe disability and death.
  • Variant Creutzfeldt–Jakob disease (vCJD). This is an infectious type of the disease that is related to “mad cow disease.” Eating diseased meat may cause the disease in humans. The meat may cause normal human prion protein to develop abnormally. This type of the disease usually affects younger people.
  • Variably protease-sensitive prionopathy (VPSPr). This is similar to CJD but the protein is less sensitive to digestion. It is more likely to strike people around age 70 who have a family history of dementia.
  • Gerstmann-Sträussler-Scheinker disease (GSS). This is extremely rare but occurs at an earlier age, typically around age 40.
  • Kuru. This disease is seen in New Guinea. This is caused by eating human brain tissue contaminated with infectious prions.
  • Fatal insomnia (FI). This is a rare hereditary disorder that can cause difficulty in sleeping. There is also a sporadic form of the disease that is not inherited.

Symptoms

Symptoms of prion diseases include:

  • Confusion
  • Difficulty walking and changes in gait
  • Difficulty speaking
  • Fatigue
  • Hallucinations
  • Muscle stiffness
  • Rapidly developing dementia

Diagnosis

Your doctor may do a number of tests to help diagnose prion diseases such as CJD, or to rule out other diseases with similar symptoms. Based on your symptoms, your doctor may order one or more of these tests:

  • Blood tests
  • Electroencephalogram, which analyzes brain waves; this painless test requires placing electrodes on the scalp
  • MRI (magnetic resonance imaging) scans of the brain
  • Neurologic and visual exams to check for nerve damage and vision loss
  • Samples of fluid from the spinal cord (spinal tap, also called lumbar puncture)

Treatment

Unfortunately, prion diseases cannot be cured, but certain medicines may help slow their progress. Medical management focuses on keeping people with these diseases as safe and comfortable as possible, despite progressive and debilitating symptoms.

Antiepileptic drugs (AEDs) including diphenylhydantoin or carbamazepine can help with seizures, clonazepam can help with myoclonus. Social workers can also assist the family in managing the disease.

Prevention

If you have or may have CJD, do not donate organs or tissue, including corneal tissue.

Cleaning and sterilizing medical equipment properly may prevent the spread of the disease.

There are also newer regulations that govern the handling and feeding of cows, which may help prevent the spread of prion diseases.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.