Neurodegenerative diseases are characterised by formation or presence of proteins with altered physiochemical properties. It is hypothesised that these abnormal proteins cause neuronal death leading to further complications.
Currently, there are no known cures for neurodegenerative diseases. There are two kinds of neurodegenerative diseases:
Ataxias : Causes problems with movements
Dementias : Causes problems with mental function.
What is dementia?
Dementias are a subset of neurodegenerative disorders.
Dementia is a umbrella term used to describe a multitude of conditions that cause a decline in an individual’s cognitive abilities such as their memory, linguistic skills, behavioral changes, problem solving, reasoning and thinking skills
Types of dementias
A few types of dementias that have been identified so far include
Alzheimer’s Disease
Vascular Dementia
Parkinson’s disease
Mixed Dementia
Huntington’s Disease
Lewy Body Dementia
Frontotemporal Dementia
Normal Pressure Hydrocephalus
Creutzfeldt-Jakob Disease
New Type of dementia:
The new type of dementia discovered is termed as LATE. LATE is an abbreviation for Limbic-predominant age-related TDP-43 Encephalopathy.
LATE has symptoms very similar to Alzheimer’s. Due to it’ tendency to cause memory loss and decline in thinking and reasoning skills.
Since, symptoms resemble so closely to that of Alzheimer’s it had been difficult for researchers to identify. Though, the symptoms of LATE closely resemble that of Alzheimer’s, LATE has a distinct patho-physiology.
LATE a late onset and symptoms show only at about 80 years or older.
Alzheimer’s is caused due to abnormal build up of amyloid plaques and clumps. Whereas, in LATE it was plaques and clumps of TDP-43 were observed in only three regions of the brain amygdala, hippocampus, and middle frontal gyrus
Significance of this discovery
Over the years, many different types of dementias have been identified. All with their own distinct pathologies and yet, present with a very similar set of symptoms.
It has been estimated that LATE may comprise about 17% cases of total cases diagnosed with Alzheimer’s currently. Due to new distinctions in pathologies drug trials could be better focused and current interventions improved for better efficacy.
Further Reading:
Robinson, J. L., Corrada, M. M., Kovacs, G. G., Dominique, M., Caswell, C., Xie, S. X., ... & Trojanowski, J. Q. (2018). Non-Alzheimer’s contributions to dementia and cognitive resilience in The 90+ Study. Acta neuropathologica, 136(3), 377-388.
Nelson, P. T., Dickson, D. W., Trojanowski, J. Q., Jack, C. R., Boyle, P. A., Arfanakis, K., ... & Coyle-Gilchrist, I. T. (2019). Limbic-predominant age-related TDP-43 encephalopathy (LATE): consensus working group report. Brain, 142(6), 1503-1527.