Familial Fatal Insomnia (FFI)

Overview

• FFI is a rare genetic disorder causing insomnia and psychiatric symptoms, leading to death.
• Typically affects adults in their 30s but can appear in teenagers.
• No cure; patients usually die within 1-2 years after symptoms appear.

Symptoms

• Difficulty in falling or staying asleep.
• Altered brain activity and sleep cycles.
• Dreamlike perceptions even when awake, hallucinations, seeing double.
• Progressive symptoms: Problems with balancing, walking, experiencing dreams throughout the day.

Diagnosis Challenges

• Symptoms can mislead diagnosis (e.g., hallucinations may suggest schizophrenia).
• Extremely rare with only a few dozen cases documented.

Pathophysiology

• Deterioration of the thalamus, a relay center in the brain involved in sleep regulation.
• The thalamus monitors sensory information and helps reduce awareness as you sleep.

Genetic Basis

• FFI is a prion disease caused by mutations in the PRNP gene.
• The prion protein mutation leads to neural degeneration.
• Only one variant of the PRNP gene leads to thalamus deterioration found in FFI.
• Similar to Creutzfeldt-Jakob disease, which affects different brain regions.

Prion Protein Function

• The exact role of the prion protein in normal conditions is unclear.
• Found in humans, mammals, and birds, suggesting an evolutionary purpose.
• Experiments in mice show conflicting results about its role in memory and brain protection.
  • Less prion protein may lead to less long-term potentiation (memory theory).
  • More prion protein could enhance synaptic transmission.
  • Could protect neural tissue from damage, shown in stroke experiments.

Research Implications

• Understanding the prion protein may unlock insights into memory and brain aging.
• Could inform treatment for common diseases like Alzheimer's and MS.

Conclusion

• Further research is needed to understand prion proteins and their functions.
• Could lead to treatments helping those with FFI and similar conditions.

Acknowledgment

• Thanks to SciShow Psych and its community patrons for supporting this research.
• Interested viewers can contribute at patreon.com/scishow.