Prosopagnosia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 3, 2016
StartDiseasesProsopagnosia

Prosopagnosia is a disorder that causes problems with facial recognition. Also referred to as face-blindness, prosopagnosia makes it difficult to differentiate between or remember faces, including those of familiar individuals like friends and family members. It can also affect visual processing of details or items other than the face. It is a form of agnosia.

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Definition & Facts

Prosopagnosia is a term developed from the Latin words for face and not knowing. It describes a medical condition where individuals are unable to recognize or identify differences between faces. Prosopagnosia can be caused by injury or disease, a condition referred to as acquired prosopagnosia.

It is also believed that some are born with prosopagnosia in which case it is termed congenital prosopagnosia. The condition is believed to be linked to issues with the right fusiform gyrus, a particular fold in the brain believed to control visual processing and memory. Damage or improper development of this part of the brain has been linked to difficulty identifying faces. 

Symptoms & Complaints

The symptoms and complaints associated with prosopagnosia can vary in severity from case to case. The primary symptom is an inability to recognize faces. Symptoms can range from difficulty recognizing faces to a complete inability to distinguish between facial features even when there is a dramatic difference in their appearances. This difficulty in recognizing faces extends to familiar individuals as well, including those seen daily.

Many people with the disorder even have issues with self-recognition. Individuals with prosopagnosia may have trouble identifying people they know, may not be able to assess a person's age or gender based on their facial features, and they may have trouble recognizing emotional expressions. 

Additionally, some individuals report other recognition issues beyond those associated with the face. An inability to recognize landmarks or familiar surroundings is often noted. The issue may also extend to the ability to recognize objects or animals.

Another common prosopagnosia complaint is difficulty remembering information about people. Facial recognition is tied to memory storage, putting individuals with prosopagnosia at a disadvantage in terms of remembering information about people they meet.

Prosopagnosia may also occur with vision issues, including loss of vision on one side or trouble with color perception. Depression and social anxiety are also common complaints although they may stem from complications caused by the condition rather than the underlying mechanisms of the condition.

Causes

Prosopagnosia can be caused by a variety of issues, including genetic factors, traumatic brain injury, and brain diseases. In all known cases, portions of the brain are affected which result in the inability to recognize faces and other recognition processing disorders. Prosopagnosia will either be congenital, meaning it occurred at birth, or it will be acquired, meaning it was caused later in life.

In congenital cases, there has been some indication that it is hereditary in nature. In these cases, the diagnosis usually comes earlier in life, although it is possible not to be diagnosed until puberty. Congenital prosopagnosia is thought to be caused by abnormal development of certain portions of the brain including the right fusiform gyrus. It can also occur as a developmental issue and has been linked to autism and Asperger syndrome.

Acquired cases can be caused by brain injuries, cancers, exposure to certain environmental toxicants, and some diseases. Any condition that causes brain damage, lesions, or other injuries to key sections of the brain responsible for processing visual data and storing visual memories can result in prosopagnosia. Some common issues that have been linked to acquired prosopagnosia include:

Diagnosis & Tests

Prosopagnosia is generally diagnosed based on individual self-reporting and facial recognition testing. Self-reporting is more common with individuals who have acquired prosopagnosia because they have a point of reference in terms of their ability to recognize faces. Those with the congenital version of the disease may be less aware of their condition.

If facial recognition or visual processing issues are suspected, various testing is available to aid in confirming prosopagnosia. There are several versions of prosopagnosia assessments, but there is little standardization between the tests. Some of the testing options include:

The focus of tests like these is to determine if individuals can recognize familiar faces, remember aspects of faces they’ve seen, or routinely experience issues with visual processing and recognition. The reliability of tests like these has been called into question from time to time, simply because most only look for one form of prosopagnosia and an individual could pass one test and fail another.

Current research is focused on determining if prosopagnosia can be identified by studying portions of the brains of those with the disorder. This is accomplished using diagnostic imaging techniques but has yet to be perfected. 

Imaging studies may be conducted to assess brain damage such as magnetic resonance imaging (MRI) scans and computed tomography (CT) scans.

Treatment & Therapy

There is currently no proven treatment for prosopagnosia. Too little is known about the exact cause, and no current methods are known for resolving the issues in the brain rather they were caused during development or by damage. In some cases, treatment may be directed at the suspected underlying cause. For example, individuals experiencing prosopagnosia related to a brain tumor or growth may experience some relief as the cancer is treated.

For those who have congenital prosopagnosia or acquired the condition through injury or trauma, there is no cure. Generally, those diagnosed with prosopagnosia are treated with therapies designed to help them cope with the effects of the disorder. 

The primary therapy for prosopagnosia is to learn to use other recognition strategies to compensate for the lack of facial recognition. Recognizing someone based on their clothing, the way they sound, their shape, or on the context of the situation are some common strategies. This can aid an individual with prosopagnosia in their social interactions but still puts them at a severe disadvantage when things change. The very nature of the condition can make social interactions and relationships challenging. 

Prevention & Prophylaxis

There are no known means of preventing congenital prosopagnosia. The limits of current medical technology make it impossible to determine if a child will be born with the disease. Although the risk is increased when other members of the child’s family have also had congenital prosopagnosia, it can occur even if no one else in the family has ever had it.

General prevention of brain damage and stroke decreases the risk of acquiring prosopagnosia, but no specific methodology is currently known to be an effective prophylaxis. Preventative methods for reducing the risk of brain damage and stroke can include adopting appropriate safety protocols when engaging in contact sports and riding in motor vehicles and engaging in regular exercise and healthy diet to reduce the risk of cardiovascular disease that leads to stroke.