Posterior cortical atrophy (PCA – also known as Benson’s syndrome) is a specific form of dementia that is considered a variant of Alzheimer’s disease. Over time, the disease is known to cause atrophy of the part of the brain known as the cerebral cortex. This atrophy of the posterior part of the brain results in the progressive disruption of complex visual processing.
PCA is a gradual, progressive degeneration of the cortex, the outer layer of the brain, in the back of the head. Researchers and scientists are currently unsure if PCA is a variant of Alzheimer’s disease or if PCA is a stand-alone disease. Many people who present with PCA have other signs or symptoms shared with Alzheimer’s disease (located elsewhere in the brain). Further, many of the brain changes look very similar to other diseases (including Creutzfeld-Jacob disease and/or Lewy body dementia). Onset of PCA occurs most often in people between the ages of 50 and 65.
Unlike Alzheimer’s disease (and other forms of dementia), someone with PCA does not necessarily have a noticeably reduced memory, though a person’s memory is sometimes affected during later stages of PCA. Additionally, also unlike some forms of dementia or other brain disorders or diseases, the symptoms of PCA often vary pretty extensively from person to person. The symptoms change as the brain degenerates.
Some of the common symptoms include the following:
- Trouble reading
- Difficulty in judging distance
- Trouble distinguishing between objects that are moving and standing still
- Frequent disorientation
- Issues in completing simple mathematical calculations
- Trouble spelling simple words
- Increased anxiety
Brain or Physical Changes
Often, in patients with PCA, the part of the brain that is affected shows neurofibrillary tangles and amyloid plaques, which is similar to what is found in patients with Alzheimer’s disease, only in a different area of the brain. For other people with PCA, the changes to the affected area of the brain look more like other diseases (such as Crutzfeld-Jacob disease or Lewy body dementia, for example). As the name suggests, with all cases of PCA, the outer layer of the brain (called the cortex) gradually and progressively degenerates over time.
Causes and/or Risk Factors
Unfortunately, scientists and researchers remain unsure of the cause of PCA at this time. Additionally, no known genetic mutations have been identified as linked to PCA.
Diagnosis, Treatment, and Care
It is common for a person with PCA to first receive a misdiagnosis, due to the rarity and unique presentation of this form of dementia. It is also common for people with PCA to first seek out the opinion of an ophthalmologist, since some of the first symptoms include trouble reading/processing and could be perceived (either by the individual or the friends/family of the individual) as an eye problem.