Posterior cortical atrophy, which is also called Benson's syndrome, is a rare, degenerative brain and nervous system disorder that results in gradually declining vision. Common symptoms include difficulties with reading, judging distances, and recognizing objects and familiar faces. This condition may eventually cause the cognitive skills to decline. Posterior cortical atrophy may be associated with Alzheimer's disease, Lewy body dementia or other neurological conditions.
As a neurological condition, it is a form of dementia which is usually considered an atypical variant of Alzheimer's disease. The disease causes atrophy of the posterior part of the cerebral cortex, resulting in the progressive disruption of complex visual processing.
Because the posterior region of the brain is responsible for visual processing, visual functions are impaired in PCA patients. The atrophy is progressive; early symptoms include difficulty reading, blurred vision, increased sensitivity to bright light or shiny surfaces, double vision, issues with depth perception, and trouble navigating through space. Additional symptoms include a disorder of movement planning, an impaired ability to read and an object recognition disorder.
As neuro-degeneration spreads, more severe symptoms emerge, including the inability to recognize familiar people objects and places and sometimes visual hallucinations. In addition, patients may experience difficulty making guiding movements towards objects and may experience a decline in literacy skills. Furthermore, if neural death spreads into other anterior cortical regions, symptoms similar to Alzheimer’s disease, such as memory loss, may result. Apart from that, anxiety and depression are also common in PCA patients.
Similar to the Alzheimer’s disease, the causes of PCA are unknown, and no obvious genetic mutations have been shown to be linked to the condition. It is also not known if the risk factors for Alzheimer’s disease are also risk factors for PCA.
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.
As the disease progresses, word finding, day-to-day memory and general cognitive functions may become affected, and people develop the symptoms of typical Alzheimer's disease. In the later stages of the disease, people may experience jerking movements of their limbs and even seizures.