Are Strange Visual Symptoms a Sign of Alzheimer’s Disease?

woman straining to see through her glasses

Memory loss, getting lost in familiar places, forgetting how to complete routine tasks—these are all common signs of Alzheimer’s disease. New research, however, has found that in up to 15% of cases, the earliest signs of Alzheimer’s could be weird visual symptoms.

Posterior cortical atrophy, also known as Benson’s syndrome, is an unusual group of visuospatial problems. It is a very strong predictor of Alzheimer’s, according to the study, which was published in a 2024 issue of the Lancet Neurology. Researchers suggest these visual problems could be a red flag that can help with early diagnosis of Alzheimer’s disease.

In this blog, you’ll learn more about posterior cortical atrophy, the visual symptoms it causes, how common it is in people with Alzheimer’s, and what to do about it.

New research has found that in up to 15% of cases, the earliest signs of Alzheimer’s disease could be weird visual symptoms. Click To Tweet


Posterior cortical atrophy (PCA) is a neurodegenerative disorder that causes strange visual symptoms. A progressive condition, it is associated with worsening visuospatial and visuoperceptual processing.

Brain-imaging research shows that PCA causes brain cells in the back region of the brain to die. This results in brain shrinkage in the posterior region of the brain. This is a common brain pattern seen in early Alzheimer’s disease.

For example, at Amen Clinics, brain-imaging studies using SPECT scans on people with suspected Alzheimer’s disease show decreased activity in the parietal lobes, temporal lobes, and often in the posterior cingulate. This brain pattern can be seen on SPECT scans several years prior to the onset of memory loss symptoms.


Posterior cortical atrophy, or Benson’s syndrome, is associated with a wide range of visual symptoms, including:

  • Trouble judging distances
  • Difficulty distinguishing moving objects from stationary ones
  • Challenges with writing
  • Problems retrieving dropped objects
  • Difficulty recognizing people and objects
  • Having a hard time viewing multiple objects at once
  • Challenges with reading
  • Frequently bumping into things
  • Difficulty using tools and everyday objects
  • Trouble driving
  • Inability to tell right from left
  • Visual hallucinations

In the Lancet Neurology study, at the time of PCA diagnosis people experienced the following symptoms:

  • Constructional dyspraxia—an inability to copy or construct basic diagrams or figures: 61%
  • Space perception deficit—difficulties identifying the location of something they saw: 49%
  • Simultanagnosia—an inability to visually perceive more than one object at a time: 48%
  • New challenges with routine math calculations: 47%
  • New difficulty with reading: 43%

Other non-visual PCA symptoms include anxiety, confusion, and behavioral changes.

What makes this study so important is that the people typically did not have the hallmark symptoms of memory loss and cognitive impairment at the time of their PCA diagnosis. However, nearly 4 years later, on average, they began showing signs of memory deficits, cognitive decline, and other common symptoms of Alzheimer’s disease.


Being diagnosed with posterior cortical atrophy is a strong indicator of Alzheimer’s disease and other types of dementia. In the 2024 study in the Lancet Neurology, researchers analyzed data on 1,092 individuals from 16 countries.

In this study, 94% of people with PCA had neurodegeneration associated with Alzheimer’s. The other 6% had evidence of other dementia types, such as Lewy body disease and frontotemporal dementia.

Compare that to people with memory loss—only 70% of them are found to have Alzheimer’s pathology.

Studies suggest that as many as 5-15% of people with Alzheimer’s disease have PCA. Even so, it remains under-recognized in the medical community.


Increasingly, researchers are finding that Alzheimer’s is a lifestyle disease. Yes, there is a genetic component to Alzheimer’s, but your everyday habits greatly influence your risk for memory problems. Adopting brain-healthy habits can reduce your risk.

Here are 7 natural strategies to lower your risk for Alzheimer’s disease.

  1. Engage in physical activity on a regular basis. Exercise gets your heart pumping, which increases blood flow to the brain. Healthy blood flow levels in the brain are critical for a good memory. In fact, on SPECT, the top predictor of future Alzheimer’s disease is low overall blood flow in the brain.
  2. Learn something new every day. Increasing age is one of the biggest factors associated with Alzheimer’s disease. To counteract your advancing age, keep your brain active by learning new things. For example, take piano lessons, learn to speak Japanese, or take up pickleball.
  3. Reduce inflammation. Research shows that chronic inflammation is considered a key mechanism in Alzheimer’s disease. Eat an anti-inflammatory diet, which means reducing your intake of sugary sweets, refined grains, processed foods, cured meats, and sodas
  4. Avoid exposure to toxins. Smoking, drinking alcohol, taking drugs, and being exposed to environmental toxins contribute to the risk of Alzheimer’s disease. Reducing your exposure to these toxins can lower your chances of developing memory problems.
  1. Get adequate sleep. A growing body of research has linked a lack of quality sleep and insomnia with memory loss and Alzheimer’s disease. Make sleep a priority in your life. Develop a nighttime routine that promotes relaxation and stick to it.
  2. Treat mental health disorders. Decades of studies point to a connection between mental health conditions—such as ADD/ADHD, clinical depression, bipolar disorder, chronic stress, and post-traumatic stress disorder (PTSD)—and Alzheimer’s disease. This is one reason why it’s so critical to seek treatment for mental health problems.

What’s even more critical is to see a mental health professional who includes functional brain imaging, such as SPECT, as part of a comprehensive evaluation. Seeing how your brain functions can help determine the root cause of your issues, so you can get the most effective treatment.

  1. Investigate strange visual symptoms. If you’re experiencing unusual visual problems, be sure to seek medical help. Be aware that Benson’s syndrome, or PCA, is often misdiagnosed. In part, this is because people experiencing these visual symptoms frequently seek help from an eye doctor.

However, typical eye tests may show normal results, and optometrists and ophthalmologists may not consider brain dysfunction as a potential cause. If eye exams show normal results, but you’re having visual problems, consider making an appointment with a neurologist or brain health expert who uses functional brain imaging.

Memory loss, dementia, and other mental health issues can’t wait. At Amen Clinics, we’re here for you. We offer in-clinic brain scanning and appointments, as well as mental telehealth, clinical evaluations, and therapy for adults, teens, children, and couples. Find out more by speaking to a specialist today at 888-288-9834 or visit our contact page here.

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