Symptoms

Human prion diseases have different names according to the signs and symptoms presented by the patient:  

Creutzfeldt-Jakob disease is the most common, and accounts for 90% of cases. Symptoms begin within days or weeks in previously healthy middle aged people. Death usually occurs around 6 months after the onset of symptoms.  The most frequent initial symptoms (in order of progression) are:  

• Cognitive problems; affecting memory, perception and problem solving.
• Movement coordination and gait disorders.  
• Motor disorders or stiffness.
• Involuntary muscle tremors or twitching (myoclonus).
• Visual disturbances.  
• The patient loses their connection with their environment, and cannot speak or move.  

Fatal insomnia (familial or sporadic): most cases are due to a genetic mutation. Symptoms usually start around the age of 40-50. Progression is rapid, and patients die within 18 months of the onset of symptoms.  

• Disturbance of biological cycles.  
• Sleep disturbances ranging from daytime tiredness to non-restful sleep at night, interrupted by movements or sleep talking (somniloquy).
• Cognitive problems.
• Difficulties walking.
• Sweating disturbances, palpitations, fever, changes in blood pressure (dysautonomia).  
• Brief, rapid involuntary movements (myoclonus).
• Changes in the voice.  

Gerstmann-Sträussler-Scheinker disease or octapeptide insertion disease. This is a less common prion disease.  At the beginning a slower course predominates:

• Gait disturbance.
• Cognitive dysfunction.