The role of local thyroid hormone perturbation in hippocampal sclerosis dementia—commentary on a multi-modality study

Dementia is a common condition and its prevalence is expected to increase further in the coming decades due to population ageing. It is estimated that 35.6 million people were living with dementia worldwide in 2010, with numbers expected to rise to 65.7 million in 2030 and 115.4 million in 2050 (1). Dementia affects not only the individuals and families living with the condition but also the social-economy system. The global economic burden is estimated to be more than $800 billion and expected to rise further still (2). Currently, no effective disease-modifying or preventive measures have been identified. Several stakeholders, including governments of 80 countries, have committed to prioritise research in this area and allocate resources with the aim to reduce the global burden of dementia (3). Alzheimer disease, vascular dementia, dementia with Lewy bodies and frontotemporal dementia are among the most common types of dementia; caused by a complex interplay between genetics, environment and lifestyle (4). AD has a strong genetic component with more than 20 risk alleles being identified and the heritability rate of the different dementia subtypes ranges from 40 to 80 % (4).