Frontotemporal Dementia Seen in ElderlyPosted by WBHI on Apr 23, 2012 in Sooner Than You Think, Think Outside The Box
by Michael Smith for MedPage Today
Frontotemporal lobar degeneration, though not common, does exist in elderly patients and has different characteristics than the presenile-onset disease, researchers reported.
Over a 25-year period, so-called elderly FTLD accounted for 3.2% of dementia cases among older patients seen at a regional neuroscience center in England, according to Atik Baborie, MD, of the Walton Centre for Neurology and Neurosurgery in Liverpool, England, and colleagues.
These patients were more likely to have memory loss and hippocampal sclerosis than patients with the presenile disease and less likely to have atrophy of the frontal and temporal lobes, Baborie and colleagues reported online in Archives of Neurology.
The condition appeared to be clinically under-recognized and should be considered when patients present with an “atypical Alzheimer disease” phenotype, the researchers argued.
While FTLD is a common cause of dementia in the presenile period, its role in older patients has not been clear, Baborie and colleagues noted. Indeed, they added, one of the diagnostic features that has been cited is an age at onset of less than 65.
For this study, the researchers retrospectively analyzed case notes, as well as neuropathological findings, in 11 cases of FTLD in patients 65 and older and 19 cases in younger patients, all identified at autopsy from 1979 through 2004.
- Case notes showed that behavioral features, such as disinhibition, progressive loss of insight, and emotional lability, were similar in both groups and were consistent with orbitofrontal and basofrontal involvement.
- One major difference was that symptomatic memory loss was seen in 91% (10 of 11) of the elderly patients, but only 36% (7 of 19) of those with presenile-onset disease.
- The pattern of histological subtypes was similar in both groups.
- Hippocampal sclerosis was seen in 82% of the elderly patients and just 37% of those in the presenile group, and was significantly more severe in those 65 and over (P<0.05).
- On the other hand, severe atrophy of the frontal and temporal lobes was less common in elderly patients — 45% and 27%, respectively — compared with 63% and 78% in the younger group.
Baborie and colleagues also reported that the average age at onset among the elderly patients was 73.5, compared with 49 in the younger group, and disease duration was 57.7 months, compared with 84 months.
Many of the elderly patients had signs and symptoms that were difficult to distinguish from Alzheimer’s disease with anteretrograde memory loss, but none had Alzheimer-type pathology on autopsy, the researchers reported.
They cautioned that the retrospective nature of the analysis means it needs to be “treated with caution,” but argued that evidence suggests the elderly form of FTLD, while comparatively rare, is a clinical entity with distinct features.