Posterior cortical atrophy
Posterior cortical atrophy | |
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Other names | Biparietal Alzheimer disease |
Lobes of the human brain | |
Specialty | Neurology |
Posterior cortical atrophy (PCA), also called Benson's syndrome, is a rare form of
PCA usually affects people at an earlier age than typical cases of Alzheimer's disease, with initial symptoms often experienced in people in their mid-fifties or early sixties.[4] This was the case with writer Terry Pratchett (1948–2015), who went public in 2007 about being diagnosed with PCA.[7] In rare cases, PCA can be caused by dementia with Lewy bodies and Creutzfeldt–Jakob disease.[6][4]
Symptoms
The main symptom resulting from posterior cortical atrophy is a decrease in
As
Connection to Alzheimer's disease
Studies have shown that PCA may be a variant of
Over time, however, atrophy in PCA may spread to regions that are commonly damaged in AD, leading to shared AD symptoms such as deficits in memory, language, learning, and cognition.[11][12][15][16] Although PCA has an earlier onset, a diagnosis with Alzheimer's is often made, suggesting that the degeneration has simply migrated anteriorly to other cortical brain regions.[8][11]
There is no standard definition of PCA and no established diagnostic criteria, so it is not possible to know how many people have the condition. Some studies have found that about 5 percent of people diagnosed with Alzheimer's disease have PCA. However, because PCA often goes unrecognized, the true percentage may be as high as 15 percent. Researchers and physicians are working to establish a standard definition and diagnostic criteria for PCA.[18]
PCA may also be correlated with
Diagnosis
The cause of PCA is unknown, and there are no fully accepted diagnostic criteria for the disease.[2][10] This is partially due to the gradual onset of PCA symptoms, their variety, the rare nature of the disease, and the younger age of onset typically 50–60 years.[20] In 2012, the first international conference on PCA was held in Vancouver, Canada. Continued research and testing will hopefully result in accepted and standardized criteria for diagnosis.[10]
PCA is often initially misdiagnosed as an anxiety disorder or depression. It has been suggested that depression or anxiety may result from the symptoms of decreased visual function, and the progressive nature of the disease. Early visual impairments have often led to a referral to an ophthalmologist, which can result in unnecessary cataract surgery.[20]
Due to the lack of
For some people with PCA, neuroimaging may not give a clear diagnosis; therefore, careful observation in relation to PCA symptoms can also assist in the diagnosis.[20] The variation and lack of organized clinical testing has led to continued difficulties and delays in the diagnosis of PCA.[10]
Treatment
Specific and accepted treatment for PCA has yet to be discovered; this may be due to the rarity and variations of the disease.[10][25] At times people with PCA are treated with AD treatments, such as cholinesterase inhibitors: donepezil, rivastigmine, galantamine, and also memantine.[10] Antidepressant drugs have also provided some positive effects.[20]
Other treatments such as occupational therapy, or help with adapting to visual changes may help.[10][20] People with PCA and their caregivers are likely to have different needs than the more typical cases of Alzheimer's disease, and may benefit from specialized support groups, or other groups for young people with dementia. No study to date has been definitive to provide accepted conclusive analysis on treatment options.[20]
References
- PMID 30707187.
- ^ a b c "Visual variant of Alzheimer's disease - EyeWiki". eyewiki.aao.org. Retrieved 2017-11-07.
- PMID 14617709.
- ^ a b c "Posterior Cortical Atrophy". UCSF Memory and Aging Center. University of California, San Francisco. Retrieved 2011-10-22.
- PMID 3390033.
- ^ a b "Posterior Cortical Atrophy". Martinos Center for Biomedical Imaging. Harvard University. 2009-01-19. Retrieved 2011-10-22.
- Alzheimer's Research Trust. 2011-07-29. Archived from the originalon 2013-01-14. Retrieved 2011-07-29.
- ^ S2CID 12291848.
- ^ PMID 22265212.
- ^ S2CID 45579994.
- ^ S2CID 46582748.
- ^ S2CID 16404876.
- PMID 21951958.
- PMID 22265212.
- ^ S2CID 20617012.
- ^ PMID 9425534.
- PMID 21951958.
- ^ "Posterior Cortical Atrophy | Signs, Symptoms, & Diagnosis". Dementia. Retrieved 2016-07-25.
- PMID 15374033.
- ^ PMID 22265212.
- ^ Croisile, MD. Bernard; Alexis Brice (September 2004). "Benson's syndrome or Posterior Cortical Atrophy" (PDF). Orphanet Encyclopedia. Archived from the original (PDF) on 12 November 2013. Retrieved 11 November 2013.
- PMID 21497228.
- S2CID 14187936.
- PMID 22099855.
- S2CID 45491962.
External links
- Posterior Cortical Atrophy support from the Dementia Research Centre