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.
Frontotemporal dementia (frontotemporal lobar degeneration) is an umbrella term for a diverse group of uncommon disorders that primarily affect the frontal and temporal lobes of the brain – the areas generally associated with personality, behavior and language.
In frontotemporal dementia, portions of these lobes atrophy or shrink. Signs and symptoms vary, depending upon the portion of the brain affected. Some people with frontotemporal dementia undergo dramatic changes in their personality and become socially inappropriate, impulsive or emotionally indifferent, while others lose the ability to use and understand language.
Frontotemporal dementia is often misdiagnosed as a psychiatric problem or as Alzheimer’s disease. But frontotemporal dementia tends to occur at a younger age than does Alzheimer’s disease, typically between the ages of 40 and 70.
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
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.
Frontotemporal Dementia Facts
As many as seven million Americans may be afflicted with a form of dementia. Frontotemporal Dementia may account for 2-5 percent or 140,000 – 350,000 cases of dementia and for as many as 25 percent of pre-senile dementias.
FTD occurs predominantly after age 40 and usually before age 65, with equal incidence in men and women. In nearly half of the patients, a family history of dementia exists in a first degree relative (parent or sibling), suggesting a genetic component in these cases. Additionally, a form of dementia found in persons with motor neuron disease (amyotrophic lateral sclerosis, commonly known as “Lou Gehrig’s Disease”) may be associated with FTD.
Frontotemporal Dementia Symptoms
Initial symptoms of FTD are primarily changes in personality and behavior. In addition to the symptoms described below, FTD patients often present two seemingly opposite behavioral profiles in the early and middle stages of the disease. Some individuals are overactive, restless, distractible and disinhibited. Others are apathetic, inert, aspontaneous and emotionally blunted. These differences in outward activity disappear in the late stages of the disease.
Major symptoms of FTD are:
– Dramatic change in personal and social conduct. The individual may lack initiative, seem unconcerned, and neglect domestic, financial and occupational responsibilities.
– Loss of empathy toward others.
– Patients may show shallow affect (flat facial expression or lack of emotional response). Or they may be inappropriately jocular and sing, dance, clap or recite phrases repeatedly.
– Rigid and inflexible thinking and impaired judgment.
– Loss of insight into personal and social misconduct, such as small sexual or moral transgressions.
– Stereotyped (i.e., repetitive) or compulsive behavior. For example, the person with FTD may become compulsive about rituals of hygiene and dress while at the same time neglecting proper hygiene. They may echo what others say, wander restlessly over a fixed route, or adhere to a fixed daily schedule.
– Hypochondriasis, including bizarre somatic complaints.
– Excessive eating or gluttony, food fads (especially a craving for sweet foods) and even excessive alcohol consumption. (The tendency of FTD patients to consume alcohol often leads to a misdiagnosis of alcohol-related dementia.) The person may refuse to eat, however, due to a behavioral pattern called “negativism” or to inability to use motor skills needed for eating.
– Decreased motor skills in later stages.
– Change in sleep patterns, with prolonged sleepiness shown, especially in those that present more apathetic behaviors.
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.
The researchers reported support from the UK National Institute for Health Research, the UK Medical Research Council, the Newcastle NIHR Biomedical Research Centre in Ageing and Age Related Diseases, the Alzheimer’s Society and Alzheimer’s Research Trust. The journal said the researchers did not make any financial disclosures.
Differences Between FTD and Other Dementias
FTD differs markedly in several ways when compared to other dementias, especially Alzheimer’s disease:
– FTD is characterized by cerebral atrophy in the frontal and anterior temporal lobes of the brain, while Alzheimer’s affects the hippocampal, posterior temporal and parietal regions.
– The neurofibrillary tangles, senile plaques and Lewy bodies present in the brains of Alzheimer’s and other dementia patients are absent. (Pick bodies are also usually absent.)
– Alzheimer’s patients experience severe memory loss. While FTD patients exhibit memory disturbances, they remain oriented to time and place and recall information about the present and past.
– FTD patients, even in late stages of the disease, retain visuo-spatial orientation, and they negotiate and locate their surroundings accurately.
– Intellectual failure in FTD is distinctly different from that of Alzheimer’s patients. Results of intelligence tests are normal in those with FTD until the point in the disease when disinterest results in lower scores.
– Life expectancy is slightly longer for FTD.
Primary source: Archives of Neurology
Source reference: Baborie A, et al “Frontotemporal dementia in elderly individuals” Arch Neurol 2012; DOI: