Related Brain Diseases
Since 1990, CurePSP has helped thousands of people with PSP, CBD and related brain diseases. While progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) remain the prime focus of our organization, the Board of Directors, at the June 2009 meeting, expanded the mission of CurePSP to include multiple system atrophy (MSA), argyrophilic grain disease (AGD), lytico-bodig (LyB), Guadelupean tauopathy (GT), and pallidal degeneration (PaD).
Those living with MSA and AGD will primarily benefit through our expanded education program, while lytico-bodig and Guadelupean tauopathy have been added to the Foundation's research mission.
The mission expansions of the outreach and education an research programs enable CurePSP to serve more patients and families with PSP, CBD and related disorders.
- Argyrophilic Grain Disease (AGD)
Argyrophilic grain disease (aka Braaks Disease) is a neuro-degenerative brain disease which is not fully characterised. A sporadic late-onset form of dementia characterised by a neuro-degenerative process, which mainly affects limbic structures (amygdala, hippocampus and mediobasal temporal/entorhinal cortex).
It is named after silver-staining (argyrophilic) grains or coiled bodies within the cytoplasm of neurons that consist mainly of tau protein isoforms with four microtubule-binding repeates (4-R tau).
Symptoms include:
Reduction of short-term memory, disorders of word finding, disorders of reading and writing, disorientation, behavioural disturbances (personality changes, emotional disorders with aggression and ill-temper) may precede or follow memory failure. Clinically it is hard to distinguish from late-onset AD.
The age of onset is around 70 years old. The duration of the disease is between 4 and 8 years.
Causes and Risk Factors
The disease is caused by neuron degeneration which is likely associated with dysfunction of tau protein. Grains are composed of abnormally phosphorylated tau protein with 4 repeats. Recent studies indicate that tau protein dysfunction in AGD in contrast to other 4-R-tauopathies (progressive supranuclear palsy, corticobasal degeneration).
Genetics
The disease arises irrespective of the genetic background regarding tau H1 or H2 haplotypes, at the opposite of PSP and CBD (Miserez A. R. et al, 2003). Lack of relationship with apolipoprotein E4.
Frequency
1 to 5% of AD patients (Togo T. et al, 2002).
Diagnostic procedures
It is almost impossible to distinguish from late-onset Alzheimer’s disease. The diagnosis is almost entirely made by post-mortem examination. AGD lesions are found in about 5% of Alzheimer’s disease (Togo T. et al, 2002).
(Source: European Commission financed project "Rare forms of dementia". And Alzheimer's Europe (http://www.alzheimer-europe.org/Dementia/Other-forms-of-dementia/Neuro-Degenerative-Diseases/Argyrophilic-Grain-Disease-AGD) information.
- lytico-bodig (LyB)
- Guadelupean tauopathy (GT)
- pallidal degeneration (PaD)
