Frontotemporal lobar degeneration

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Frontotemporal lobar degeneration
Histology of frontotemporal lobar degeneration.jpg
Neuropathologic analysis of brain tissue from FTLD-TDP patients. Ubiquitin immunohistochemistry in cases of familial FTLD-TDP demonstrates staining of (a) neurites and neuronal cytoplasmic inclusions in the superficial cerebral neocortex, (b) neuronal cytoplasmic inclusions in hippocampal dentate granule cells, and (c) neuronal intranuclear inclusions in the cerebral neocortex (arrows). Scale bar; (a) and (b) 40 μm, (c) 25 μm, insert 6 μm.
Specialty Neurology, Psychiatry
Complications Brain death

Frontotemporal lobar degeneration (FTLD) is a pathological process that occurs in frontotemporal dementia. It is characterized by atrophy in the frontal lobe and temporal lobe of the brain, with sparing of the parietal and occipital lobes. [1] [2]

Contents

Common proteinopathies that are found in FTLD include the accumulation of tau proteins and TAR DNA-binding protein 43 (TDP-43). Mutations in the C9orf72 gene have been established as a major genetic contribution of FTLD, although defects in the granulin (GRN) and microtubule-associated proteins (MAPs) are also associated with it. [3]

Classification

There are 3 main histological subtypes found at post-mortem:

  • Type A presents with many small neurites and neuronal cytoplasmic inclusion bodies in the upper (superficial) cortical layers. Bar-like neuronal intranuclear inclusions can also be seen they are fewer in number.
  • Type B presents with many neuronal and glial cytoplasmic inclusions in both the upper (superficial) and lower (deep) cortical layers, and lower motor neurons. However neuronal intranuclear inclusions are rare or absent. This is often associated with ALS and C9ORF72 mutations (see next section).
  • Type C presents many long neuritic profiles found in the superficial cortical laminae, very few or no neuronal cytoplasmic inclusions, neuronal intranuclear inclusions or glial cytoplasmic inclusions. This is often associated with semantic dementia.
  • Type D presents with many neuronal intranuclear inclusions and dystrophic neurites, and an unusual absence of inclusions in the granule cell layer of the hippocampus. Type D is associated with VCP mutations.
  • Type E presents with neuronal granulofilamentous inclusions and abundant fine grains involving upper (superficial) and lower (deep) cortical layers. This has been associated with behavioral variant of frontotemporal dementia with a rapid clinical course. [5]

Two groups independently categorized the various forms of TDP-43 associated disorders. Both classifications were considered equally valid by the medical community, but the physicians and researchers in question have jointly proposed a compromise classification to avoid confusion. [6]

In December 2021 the structure of TDP-43 was resolved with cryo-EM [7] [8] but shortly after it was argued that in the context of FTLD-TDP the protein involved could be TMEM106B (which has been also resolved with cryo-EM), rather than of TDP-43. [9] [10]

Genetics

There have been numerous advances in descriptions of genetic causes of FTLD, and the related disease amyotrophic lateral sclerosis.

Mutations in all of the above genes cause a very small fraction of the FTLD spectrum. Most of the cases are sporadic (no known genetic cause).

Diagnosis

For diagnostic purposes, magnetic resonance imaging (MRI) and ([18F]fluorodeoxyglucose) positron emission tomography (FDG-PET) are applied. They measure either atrophy or reductions in glucose utilization.

The three clinical subtypes of frontotemporal lobar degeneration, frontotemporal dementia, semantic dementia and progressive nonfluent aphasia, are characterized by impairments in specific neural networks. [17] The first subtype, frontotemporal dementia, mainly affects a frontomedian network and impairs social cognition. Semantic dementia is mainly related to the inferior temporal poles and amygdalae; brain regions enabling conceptual knowledge, semantic information processing, and social cognition, whereas progressive nonfluent aphasia affects the entire left frontotemporal network for phonological and syntactical processing.[ citation needed ]

Treatment

There is no known treatment.

Society

United States Senator Pete Domenici (R-NM) suffered from FTLD, and the illness was the main reason for his October 4, 2007 announcement of retirement at the end of his term in office. [18] American film director, producer, and screenwriter Curtis Hanson died as a result of FTLD on September 20, 2016. [19] British journalist Ian Black died from the disease on January 22, 2023. [20]

See also

References

  1. Whitwell, Jennifer L.; Anderson, Valerie M.; Scahill, Rachael I.; Rossor, Martin N.; Fox, Nick C. (2004). "Longitudinal Patterns of Regional Change on Volumetric MRI in Frontotemporal Lobar Degeneration". Dementia and Geriatric Cognitive Disorders. 17 (4): 307–310. doi:10.1159/000077160. ISSN   1420-8008. PMID   15178942.
  2. Lu, Po H.; Mendez, Mario F.; Lee, Grace J.; Leow, Alex D.; Lee, Hyun-Woo; Shapira, Jill; Jimenez, Elvira; Boeve, Bradley B.; Caselli, Richard J.; Graff-Radford, Neill R.; Jack, Clifford R.; Kramer, Joel H.; Miller, Bruce L.; Bartzokis, George; Thompson, Paul M. (2013-01-09). "Patterns of Brain Atrophy in Clinical Variants of Frontotemporal Lobar Degeneration". Dementia and Geriatric Cognitive Disorders. 35 (1–2): 34–50. doi:10.1159/000345523. ISSN   1420-8008. PMC   3609420 . PMID   23306166.
  3. van der Zee, Julie; Van Broeckhoven, Christine (7 January 2014). "Dementia in 2013: Frontotemporal lobar degeneration—building on breakthroughs". Nature Reviews Neurology. 10 (2): 70–72. doi:10.1038/nrneurol.2013.270. PMID   24394289.
  4. Kumar, Vinay; Abbas, Abul K.; Aster, Jon C. (2018). Robbins basic pathology (Tenth ed.). Philadelphia, Pennsylvania. p. 877. ISBN   9780323353175.{{cite book}}: CS1 maint: location missing publisher (link)
  5. Lee, Edward B.; et al. (Jan 2017). "Expansion of the classification of FTLD-TDP: distinct pathology associated with rapidly progressive frontotemporal degeneration". Acta Neuropathol. 134 (1): 65–78. doi:10.1007/s00401-017-1679-9. PMC   5521959 . PMID   28130640.
  6. Ian R. A. Mackenzie; Manuela Neumann; Atik Baborie; Deepak M. Sampathu; Daniel Du Plessis; Evelyn Jaros; Robert H. Perry; John Q. Trojanowski; David M. A. Mann & Virginia M. Y. Lee (July 2011). "A harmonized classification system for FTLD-TDP pathology". Acta Neuropathol. 122 (1): 111–113. doi:10.1007/s00401-011-0845-8. PMC   3285143 . PMID   21644037.
  7. Arseni, Diana; Hasegawa, Masato; Murzin, Alexey G.; Kametani, Fuyuki; Arai, Makoto; Yoshida, Mari; Ryskeldi-Falcon, Benjamin (2022-01-06). "Structure of pathological TDP-43 filaments from ALS with FTLD". Nature. 601 (7891): 139–143. Bibcode:2022Natur.601..139A. doi:10.1038/s41586-021-04199-3. ISSN   0028-0836. PMC   7612255 . PMID   34880495.
  8. "An ALS Protein, Revealed". www.science.org. Retrieved 2022-04-04.
  9. Jiang, Yi Xiao; Cao, Qin; Sawaya, Michael R.; Abskharon, Romany; Ge, Peng; DeTure, Michael; Dickson, Dennis W.; Fu, Janine Y.; Ogorzalek Loo, Rachel R.; Loo, Joseph A.; Eisenberg, David S. (2022-03-28). "Amyloid fibrils in disease FTLD-TDP are composed of TMEM106B not TDP-43". Nature. 605 (7909): 304–309. doi:10.1038/s41586-022-04670-9. ISSN   1476-4687. PMC   9844993 . PMID   35344984. S2CID   247777613.
  10. "Frontotemporal Dementia: Not the Protein We Thought". www.science.org. Retrieved 2022-04-04.
  11. Goedert, M.; et al. (1989). "Cloning and sequencing of the cDNA encoding an isoform of microtubule-associated protein tau containing four tandem repeats: differential expression of tau protein mRNAs in human brain". The EMBO Journal. 8 (2): 393–9. doi:10.1002/j.1460-2075.1989.tb03390.x. PMC   400819 . PMID   2498079.
  12. Cruts, M.; et al. (2006). "Null mutations in progranulin cause ubiquitin-positive frontotemporal dementia linked to chromosome 17q21". Nature. 442 (7105): 920–4. Bibcode:2006Natur.442..920C. doi:10.1038/nature05017. PMID   16862115. S2CID   4423699.
  13. Kimonis, V.E.; et al. (2008). "VCP disease associated with myopathy, Paget disease of bone and frontotemporal dementia: review of a unique disorder" (PDF). Biochim Biophys Acta. 1782 (12): 744–8. doi:10.1016/j.bbadis.2008.09.003. PMID   18845250.
  14. Darwich, N.F., Phan J.M.; et al. (2020). "Autosomal dominant VCP hypomorph mutation impairs disaggregation of PHF-tau". Science. 370 (6519): eaay8826. doi:10.1126/science.aay8826. PMC   7818661 . PMID   33004675.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. Borroni, B.; et al. (2010). "TARDBP mutations in frontotemporal lobar degeneration: frequency, clinical features, and disease course". Rejuvenation Res. 13 (5): 509–17. doi:10.1089/rej.2010.1017. PMID   20645878.
  16. Dejesus-Hernandez, M.; et al. (2011). "Expanded GGGGCC Hexanucleotide Repeat in Noncoding Region of C9ORF72 Causes Chromosome 9p-Linked FTD and ALS". Neuron. 72 (2): 245–56. doi:10.1016/j.neuron.2011.09.011. PMC   3202986 . PMID   21944778.
  17. Schroeter ML, Raczka KK, Neumann J, von Cramon DY (2007). "Towards a nosology for frontotemporal lobar degenerations–A meta-analysis involving 267 subjects". NeuroImage. 36 (3): 497–510. doi:10.1016/j.neuroimage.2007.03.024. PMID   17478101. S2CID   130161.
  18. Blakeslee, Sandra (2008-04-08). "A Disease That Allowed Torrents of Creativity". The New York Times. ISSN   0362-4331 . Retrieved 2024-01-05.
  19. Kenneally, Tim (2016-09-21). "Curtis Hanson Suffered From Rare Illness, His Partner Reveals". TheWrap. Retrieved 2023-12-25.
  20. "Ian Black, former Guardian Middle East editor, dies aged 69".

Bibliography

Further reading