Posterior cortical atrophy

Posterior cortical atrophy is a brain and nervous system syndrome that causes brain cells to die over time. It causes problems with eyesight and with processing visual information.

Common symptoms include trouble reading, judging distances and reaching for objects. People with the syndrome may not be able to recognize objects and familiar faces. They also may have trouble making calculations. Over time this condition may cause a decline in memory and thinking abilities, known as cognitive skills.

Posterior cortical atrophy causes the loss of brain cells in back of the brain. This is the region responsible for visual processing and spatial reasoning. This changes a person's ability to process visual and spatial information.

In more than 80% of cases, posterior cortical atrophy is due to Alzheimer's disease. However, it can be due to other neurological conditions such as Lewy body dementia or corticobasal degeneration.

Posterior cortical atrophy symptoms vary among people. Symptoms also can vary over time. They tend to gradually get worse. Common symptoms include having trouble with:

• Reading, spelling or math.
• Driving.
• Getting dressed.
• Telling the difference between objects that are moving and those that are still.
• Judging how far away objects are.
• Using everyday objects or tools.
• Identifying left from right.

Other common symptoms include:

• Anxiety.
• Confusion.
• Changes in behavior and personality.

Memory problems may occur later in the disease.

The most common cause of posterior cortical atrophy is a form of Alzheimer's disease that's not typical. It affects the back of the brain. Other less common causes include corticobasal degeneration, Lewy body dementia and Creutzfeldt-Jakob disease. Researchers are looking at potential gene variations that may be related to the condition.

Further study is needed to determine whether the risk factors for Alzheimer's disease may play a role in posterior cortical atrophy.

Because the first symptoms are often visual, posterior cortical atrophy can be misdiagnosed as a vision disorder. It's important to see a neurologist or a neuro-ophthalmologist who can correctly diagnose your condition. A neurologist is trained in brain and nervous system conditions. A neuro-ophthalmologist specializes in neurology and conditions related to vision.

To diagnose posterior cortical atrophy, a specialist will review your medical history and symptoms. This includes vision problems. The specialist also will conduct a physical exam and a neurological exam.

Several tests may help diagnose your condition. The tests also might rule out other conditions that may cause similar symptoms. The tests might include:

• Mental status and neuropsychological tests. You will be asked questions and will have tests to assess your cognitive skills. You also may be assessed for depression or other mental disorders.
• Blood tests. Your blood may be tested for vitamin deficiency, thyroid disorders and other conditions that may be causing your symptoms.
• Ophthalmology exam. A vision test can determine whether another condition such as a problem within your eyes is causing your vision symptoms.
• Magnetic resonance imaging (MRI). An MRI machine uses powerful radio waves and a magnetic field to create a 3D view of your brain. In this test, your health care provider can view changes in your brain that may be causing your symptoms.
• Fluorodeoxyglucose (FDG) PET imaging or single-photon emission computerized tomography (SPECT). In these tests, a small amount of radioactive material is injected into a vein. Images are taken using a large machine. You'll lie on a padded table that slides into the part of the machine that looks like a doughnut hole. PET provides visual images of brain activity. SPECT measures blood flow to regions of the brain.
• Spinal fluid test. This test involves removing a small amount of the fluid that cushions the brain and spinal cord. This test can measure amyloid and tau proteins that are the hallmark of Alzheimer's disease.

There are no treatments to cure or slow the progression of posterior cortical atrophy. Some research suggests that medicines used to slow the progression of Alzheimer's disease may help manage symptoms of posterior cortical atrophy. However, this hasn't been proved, and more research is needed.

Some therapies and medicines can help manage the condition. They may include:

• Medicines. Your health care provider may give you medicines to treat symptoms such as depression or anxiety.
• Physical, occupational or cognitive therapy. These therapies may help you regain or retain skills that are affected by posterior cortical atrophy.