Introduction[edit | edit source]
Tauopathies are a heterogeneous group of neurodegenerative diseases characterised by abnormal metabolism of misfolded tau proteins (tau prions). Tau proteins stabilise parts of the cell called “microtubules”. Misfolding leads to intracellular accumulation and formation of neurofibrillary tangles (NFT) which are defective and no longer stabilising the microtubules. . Tau proteins are abundant in neurones of the central nervous system and are less common elsewhere.
- Tau prions replication begins spontaneously in the frontal lobes.
- Tauopathy is a term that encompasses both the loss-of-function effects on the microtubules and the gain-of-function effects of the toxic tau species.
- There are currently no disease-modifying therapies for the treatment of tauopathies.
Pathophysiology[edit | edit source]
Tauopathies are the result of aggregation and precipitation of misfolded tau proteins that normally stabilise neural microtubules. These aggregates form neurofibrillary tangles that in turn lead to neuronal toxicity and degeneration. Neurofibrillary tangles (NFTs) are abnormal cytoplasmic accumulations of tau proteins, found in neuronal and glial cells of the central nervous system.
Traditionally it was believed that each tauopathy was associated with a specific clinical syndrome, however recent clinicopathological studies have demonstrated that this is not the case, and the clinical syndromes associated with these pathologically defined disorders are heterogeneous.
This 2 minute video is a good animation of NFTs.
Examples[edit | edit source]
The term primary tauopathy refers to disorders in which tau protein deposition is the predominant feature. Diseases characterized by tau pathologies considered as having another and diverse driving force are also called secondary tauopathies. 
Examples of tauopathies include:
- Progressive supranuclear palsy
- Frontotemporal lobar degeneration
- Alzheimer disease (considered a secondary tauopathy)
- Chronic traumatic encephalopathy
- Parkinsonism linked to chromosome 17
Diagnosis[edit | edit source]
Definitive diagnosis is based in specific neuropathological features. Clinically, they present with Parkinson-plus or dementia, both usually present in later stages. There is a significant clinical overlap between the different tauopathies. This heterogeneity and the clinical and neuropathological overlap are not understood at present time.
References[edit | edit source]
- Radiopedia Tauopathy Available: https://radiopaedia.org/articles/tauopathy?lang=gb(accessed 17.3.2022)
- IND Tauopathies Available:https://ind.ucsf.edu/research/tauopathies (accessed 17.3.2022)
- The dementia society Tauopathy Available:http://dementia-wellbeing.org/tag/tauopathy/ (accessed 17.3.2022)
- Science direct Tauopathy Available: https://www.sciencedirect.com/topics/neuroscience/tauopathy(accessed 17.3.2022)
- Orr ME, Sullivan AC, Frost B. A brief overview of tauopathy: causes, consequences, and therapeutic strategies. Trends in pharmacological sciences. 2017 Jul 1;38(7):637-48.Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5476494/(accessed 17.3.2022)
- Whitwell JL, Josephs KA. Tauopathies. InMagnetic Resonance Imaging in Movement Disorders: A Guide for Clinicians and Scientists 2006 Jan 1 (pp. 147-166). Cambridge University Press. Available:https://mayoclinic.pure.elsevier.com/en/publications/tauopathies (accessed 17.3.2022)
- Pharmacology Animation NFT and tau protein Available: https://www.youtube.com/watch?v=bRJ70hvHW0Y(accessed 17.3.2022)
- Kovacs GG. Tauopathies. Handbook of clinical neurology. 2018 Jan 1;145:355-68. Available:https://www.sciencedirect.com/science/article/abs/pii/B9780128023952000250 (accessed 17.3.2022)
- Simões R, Litvan I. Tauopathies. Available: https://www.sciencedirect.com/science/article/pii/B9780123741059002148(accessed 17.3.2022)