Frontotemporal dementia
668318
224817968
2008-07-10T15:33:28Z
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/* Genetics */
{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = Frontotemporal_degeneration.png |
Caption = A [[human brain]] showing [[frontotemporal lobar degeneration]] causing frontotemporal dementia. |
DiseasesDB = 10034 |
ICD10 = |
ICD9 = {{ICD9|331.19}} |
ICDO = |
OMIM = 600274 |
MedlinePlus = |
eMedicineSubj = |
eMedicineTopic = |
MeshID = D003704 |
}}
'''Frontotemporal dementia (FTD)''' is a clinical [[syndrome]] caused by degeneration of the [[frontal lobe]] of the [[brain]] and may extend back to the [[temporal lobe]]. It is one of three syndromes caused by [[frontotemporal lobar degeneration]].
==Signs and symptoms==
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 [[lethargy]] 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 Apathetic patients may become socially withdrawn and stay in bed all day or no longer take care of themselves.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.
Language skills can be affected in a number of ways with two broad patterns. Some patients remain fluent with normal phonology and syntax but increasing difficulty with naming and word comprehension, known as [[semantic dementia]] in which there is atrophy of the anterior temporal lobes, typically with a asymmetric pattern. Other patients, by contrast, present with a breakdown in speech fluency due to articulation difficulty, phonological and/or syntactic errors but preservation of word comprehension, referred to as [[progressive nonfluent aphasia]].
In addition to the characteristic cognitive dysfunction, a number of [[primitive reflexes]] known as [[frontal release signs]] are often able to be elicited. Usually the first of these [[frontal release signs]] to appear is the [[palmomental reflex]] which appears relatively early in the disease course whereas the [[palmar grasp]] reflex and [[rooting reflex]] appear late in the disease course.
FTD can occur 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.<ref name="titleThe effects of executive and behavioral dysfunction on the course of ALS -- Olney et al. 65 (11): 1774 -- Neurology">{{cite web |url=http://www.neurology.org/cgi/content/abstract/65/11/1774 |title=The effects of executive and behavioral dysfunction on the course of ALS -- Olney et al. 65 (11): 1774 -- Neurology |accessdate=2008-04-09 |format= |work=}}</ref>
==Pathology==
A number of case series have now been published looking at the pathological basis of frontotemporal dementia. As with other syndromes associated with [[FTLD]], a number of different pathologies are associated with FTD:
* [[Pick's disease]] (3-repeat Tau inclusions)
* Other tau-positive pathology including FTDP-17, corticobasal degeneration, progressive supranuclear palsy
* [[FTLD]] with ubiquitin positive, tau- and alpha-synuclein negative inclusions with and without motor neuron degeneration (recently characterized by nuclear and cytoplasmic staining of TDP-43 protein)
* [[Dementia]] lacking distinctive [[histology]]
* In rare cases, patients with clinical FTD were found to have changes consistent with [[Alzheimer's disease]] on [[autopsy]]
* Evidence suggests that FTD selectively impairs [[spindle neuron]]s, a type of neuron which has only been found in the brains of humans, great apes, and whales
==Imaging==
Structural MRI scans often reveal frontal lobe and/or anterior temporal lobe atrophy but in early cases the scan may seem normal. Atrophy is often be asymmetric. 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.). FDG-PET scans classically show frontal and/or anterior temporal hypometabolism, which helps differentiate from Alzheimer's disease. The PET scan in Alzheimer's disease classically shows biparietal hypometabolism.
==Genetics==
A higher proportion of FTD cases seem to have a familial component (perhaps more so than Alzheimer's disease). Two known mutations are associated with familial FTD: tau-positive frontotemporal dementia with parkinsonism (FTDP-17) with mutations in the MAPT gene on chromosome 17, and tau-negative frontotemporal lobar degeneration with ubiquintin-positive inclusions (FTLD-U; positive for TDP-43) with progranulin mutations (also on chromosome 17). However, it is estimated that each of these two genes only accounts for about 5-10% of all cases of FTD, thus other genes or heritable components are likely responsible for the high degree of heritability in FTD.
==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.).
Because FTD often occurs in younger people (i.e. in their 40's or 50's), it can severely affect families. 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.
==See also==
*[[Frontotemporal lobar degeneration]]
*[[Pick's disease]]
*[[Semantic dementia]]
*[[Progressive nonfluent aphasia]]
*[[Alzheimer's disease]]
*[[Corticobasal degeneration]]
== References ==
<references/>
* {{cite journal |author=Neary D, Snowden JS, Gustafson L, ''et al'' |title=Frontotemporal lobar degeneration: a consensus on clinical diagnostic criteria |journal=Neurology |volume=51 |issue=6 |pages=1546–54 |year=1998 |pmid=9855500 |doi=}}
* {{cite journal |author=Hodges JR, Patterson K, Oxbury S, Funnell E |title=Semantic dementia: progressive fluent aphasia with temporal lobe atrophy|journal=Brain |volume=115 |issue=6 |pages=1783–806 |year=1992 |pmid=1486461 |doi=}}
* {{cite journal |author=Neary D, Snowden JS, Mann DM |title=Classification and description of frontotemporal dementias |journal=Ann. N. Y. Acad. Sci. |volume=920 |issue= |pages=46–51 |year=2000 |pmid=11193176 |doi= |url=http://www.annalsnyas.org/cgi/pmidlookup?view=long&pmid=11193176}}
* {{cite journal |author=Kramer JH, Jurik J, Sha SJ, ''et al'' |title=Distinctive neuropsychological patterns in frontotemporal dementia, semantic dementia, and Alzheimer disease |journal=Cogn Behav Neurol |volume=16 |issue=4 |pages=211–8 |year=2003 |pmid=14665820 |doi= |url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=1543-3633&volume=16&issue=4&spage=211}}
* {{cite journal |author=Rosen HJ, Gorno-Tempini ML, Goldman WP, ''et al'' |title=Patterns of brain atrophy in frontotemporal dementia and semantic dementia |journal=Neurology |volume=58 |issue=2 |pages=198–208 |year=2002 |pmid=11805245 |doi= |url=http://www.neurology.org/cgi/pmidlookup?view=long&pmid=11805245}}
* {{cite journal |author=Miller BL, Seeley WW, Mychack P, Rosen HJ, Mena I, Boone K |title=Neuroanatomy of the self: evidence from patients with frontotemporal dementia |journal=Neurology |volume=57 |issue=5 |pages=817–21 |year=2001 |pmid=11552010 |doi= |url=http://www.neurology.org/cgi/pmidlookup?view=long&pmid=11552010}}
* {{cite journal |author=Diehl J, Ernst J, Krapp S, Förstl H, Nedopil N, Kurz A |title=[Misdemeanor in frontotemporal dementia] |language=German |journal=Fortschr Neurol Psychiatr |volume=74 |issue=4 |pages=203–10 |year=2006 |pmid=16671160 |doi=}}
* {{cite journal |author=Seeley WW, Carlin DA, Allman JM, ''et al'' |title=Early frontotemporal dementia targets neurons unique to apes and humans |journal=Ann. Neurol. |volume=60 |issue=6 |pages=660–7 |year=2006 |pmid=17187353 |doi=10.1002/ana.21055}}
* {{cite journal |author=Hodges JR, Davies R, Xuereb J, Kril J, Halliday G |title=Survival in frontotemporal dementia |journal=Neurology |volume=61|issue=6 |pages=349–354 |year=2003 |pmid=12913196}}
* {{cite journal |author=Hodges JR, Davies R, Xuereb J, Casey B, Broe M, Bak T, Kril J, Halliday G |title=Clinicopathological correlates in frontotemporal dementia |journal=Ann. Neurol. |volume=56|issue=3 |pages=349–354 |year=2004 |pmid=15349867 |doi=10.1002/ana.20203}}
* {{cite journal |author=Mioshi E, Kipps C, Dawson K. Mitchell J, Graham A, Hodges JR|title=Activities of daily living in frontotemporal dementia |journal=Neurology |volume=68 |pages=2077–2084 |year=2007 |pmid=17562828 |doi=10.1212/01.wnl.0000264897.13722.53}}
== Further reading ==
<!-- This section is for books and other offline resources, not external links to websites -->
* Radin, Lisa. "What If It's Not Alzheimer's: A Caregiver's Guide to Dementia." Prometheus Books. 2003.
* Hodges, John R. The Frontotemporal Dementia Syndromes. Cambridge University Press. 2007 ISBN 978-0-521-85477-1
==External links==
* [http://www.ftd-picks.org/ The Association for Frontotemporal Dementias]
* [http://ci.columbia.edu/c1182/web/sect_5/c1182_s5_4.html Columbia University Update]
* [http://www.neurology.org/cgi/collection/frontotemporal_dementia A collection of articles about Frontotemporal dementia in the journal ''Neurology'']
*[http://memory.ucsf.edu/Education/Disease/ftd.html FTD Info] at the UCSF Memory and Aging Center
*[http://www.ftd2008.org Conference 6th International Conference on Frontotemporal Dementia] in Rotterdam, September 2008
*[http://www.nytimes.com/2008/04/08/health/08brai.html ''New York Times'' article 4/8/2008 suggesting that scientist Anne Adams and composer Maurice Ravel had frontotemporal dementia]
*[http://www.ftdrg.org/ FRONTIER - Frontotemporal Dementia Research Group - at POWMRI, Sydney, Australia]
{{Mental and behavioural disorders}}
[[Category:Neurology]]
[[Category:Cognitive disorders]]
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