Frontotemporal dementia

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A human brain showing frontotemporal lobar degeneration causing frontotemporal dementia.
A human brain showing frontotemporal lobar degeneration causing frontotemporal dementia.
Frontotemporal dementia
Classification & external resources
ICD-9 331.19

Frontotemporal dementia (FTD) is one of three clinical syndromes associated with frontotemporal lobar degeneration. FTD selectively affects the frontal lobe of the brain and may extend backward to the temporal lobe.

Symptoms can be classified (roughly) into two groups which underlie the functions of the frontal lobe: behavioural symptoms (and/or personality change) and symptoms related to problems with executive function.

Behavioural symptoms include apathy and aspontaneity or oppositely disinhibition. Apathetic patients may become socially withdrawn and stay in bed all day or no longer take care of themselves. Disinhibited patients can make inappropriate (sometimes sexual) comments or perform inappropriate acts. Patients with FTD can sometimes get into trouble with the police because of inappropriate behaviour such as stealing.

Executive function is the cognitive skill of planning and organizing - patients become unable to perform skills that require complex planning or sequencing.

Frontotemporal dementia occurs in patients with motor neurone disease (also known in the US as Lou Gehrig's disease or amyotrophic lateral sclerosis) in a small number of cases. The prognosis for people with MND is worse when combined with FTD, shortening survival by about a year.[1]

Because FTD often occurs in people who are young (i.e. in their 40's or 50's) the effects on families can be severe. Patients often still have children living in the home. Financially, it can be devastating as the disease strikes at the time of life that are often the top wage earning years.

Contents

[edit] Pathology

A number of case series have now been published looking at the pathological basis of frontotemporal dementia. As with other types of FTLD a number of different pathologies are associated with the clinical syndrome of FTD:

  • Pick's disease (3-repeat Tau inclusions)
  • Other tau-positive pathology
  • Ubiquitin positive, tau-negative inclusions (now known to contain the protein TDP-43)
  • Dementia lacking distinctive histology

[edit] Imaging

Structural MRI scans often reveal frontal lobe and/or temporal lobe atrophy but in early cases the scan may seem normal. Registration of images at different time points (e.g. one year apart) can show evidence of atrophy in two cross-sectional images that may be reported as normal. This is a useful diagnostic technique. However, many research groups are currently looking at ways of making an early diagnosis of FTD using other techniques (magnetic resonance spectroscopy, functional imaging, cortical thickness measurements etc.).

[edit] Genetics

Many cases of FTD are genetic (and much more so than Alzheimer's disease). Reports suggest between 30 and 50% of cases have a heritable component. In many cases it is associated with Parkinsonism and hence the term FTDP was coined. As many cases are associated with a mutation in the MAPT gene on chromosome 17 this syndrome has the name FTDP-17. Mutations in another gene on chromosome 17 (progranulin) have been recently described that also cause the clinical syndrome of FTD.

[edit] Management

There is no known curative treatment for FTD. Supportive care is essential. Management of behavioural symptoms may be necessary (e.g. SSRIs for depression; atypical neuroleptics etc.).

[edit] Further reading

[edit] References

  • Neary D, Snowden JS, Gustafson L, Passant U, Stuss D, Black S, Freedman M, Kertesz A, Robert PH, Albert M, Boone K, Miller BL, Cummings J, Benson DF. "Frontotemporal lobar degeneration: a consensus on clinical diagnostic criteria." 'Neurology' (1998) 51(6):1546-54. Available: [2]
  • Neary D, Snowden JS, Mann DM. "Classification and description of frontotemporal dementias." Ann N Y Acad Sci (2000) 920:46-51. Available: [3]
  • Kramer JH, Jurik J, Sha SJ, Rankin KP, Rosen HJ, Johnson JK, Miller BL. "Distinctive neuropsychological patterns in frontotemporal dementia, semantic dementia, and Alzheimer disease." Cogn Behav Neurol. (2003) 16(4):211-8. Available: [4]
  • Rosen HJ, Gorno-Tempini ML, Goldman WP, Perry RJ, Schuff N, Weiner M, Feiwell R, Kramer JH, Miller BL. "Patterns of brain atrophy in frontotemporal dementia and semantic dementia." Neurology (2002) 58(2):198-208. Available: [5]
  • Miller BL, Seeley WW, Mychack P, Rosen HJ, Mena I, Boone K. "Neuroanatomy of the self: Evidence from patients with frontotemporal dementia." Neurology (2001) 57:817-821. Available: [6]
  • Diehl J, Ernst J, Krapp S, Forstl H, Nedopil N, Kurz A. (2006) [Misdemeanor in frontotemporal dementia] Fortschr Neurol Psychiatr. 74(4):203-10. [PMID 16671160]

[edit] See also

[edit] External links

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