Hippocampal sclerosis is a slowly progressive disorder that typically affects elderly. There is focal involvement of the CA1 and subicular sectors of the hippocampus, with neuronal loss and reactive gliosis. The neuronal loss is disproportionate to the accumulation of neurofibrillatry tangle pathology.
It was considered to be of a vascular etiology, but there is evidence to support a neurodegenerative origin with the discovery of TDP-43 pathology.
Is hippocampal sclerosis a form of frontotemporal lobar degeneration? What is your opinion?
We found hippocampal sclerosis to be much more comon than we expected in elderly patients with autopsy-proven FTD. The phenomenology was also distinct from accepted prototypical presentations of FTD in younger patients, although this was based on retrospective assessment of poor-quality clinical records. See PMID:20978901. I have open mind but wonder about a two-hit model (ie second process in elderly with FTD).
It was histologically proven hippocampal sclerosis (HS) in our study and was found in patients with both TDP and tau pathology causing their FTLD. I am arguing that HS is commoner in this group than would have been expected (43% - but note HS can be found in 50% of other elderly dementia PM series and up to 20% of unselected elderly PM series - see PMID:22950047) . I am anot arguing that HS is a form of FTLD: by definition it is not. I retain an open mind about possible common factors realted to HS and FTLD but the figures in other PM series encourage caution.
I understand the difficulties in terminology use of Hippocampal Sclerosis in neurodegeneration vs epilepsy. The ILAE has just very recently published an intl consensus classification of HS in TLE patients, specifying the different patterns of segmental pyramidal cell loss, although referring and discussing its different use in dementia. Wouldn't it make sense to negotiate better differentiation of HS terminology under both conditions to prevent any further confusion ?
Hippocampal sclerosis (HS) is defined as selective neuronal loss abs gliosis of hippocampus.
HS is an independent pathologic explanation for dementia, the so called HS dementia(HSD).
So HSD is different from HS associated with FTLD-u- specifically it is more common in the elderly and it is associated with marked neuronal and synaptic loss and with greater reactive gliosis. Corpora amylacea tended to be more frequent in HSD than FTLD - u-, but thers is no difference in frequency of argrophilic grains.
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India