When Perception Fails: Agnosia and Stroke

by | Apr 26, 2024

Discover the link between agnosia and stroke with our specialized stroke clinic in Singapore. Dr. Manish Taneja, our stroke specialist, provides comprehensive assessment and personalized treatment plans to address agnosia symptoms caused by stroke, aiding in recovery and improving quality of life.

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Understanding Agnosia

Agnosia and stroke are often connected because these two issues can go hand in hand. Agnosia is a neurological sensory disorder that causes people to struggle to process sensory information, leading to hardship in identifying objects, people, smells, shapes, or sounds. While stroke and agnosia are distinct conditions, they do have some overlap as a stroke can trigger agnosia because a stroke can impact parts of the brain used for the processing of sensory information. Agnosia is a rare disorder with less than 1% of the population experiencing it, but it has huge impacts on people who do suffer from it, and it generally occurs in people who have undergone brain damage from causes like stroke, tumors, or traumatic brain injury.

Agnosia refers to several conditions that cause a person’s brain to be unable to recognize something that their senses can detect. What this means is that someone’s senses work fine, but they struggle to process what they are perceiving, leading to deficits in recognizing certain things. Agnosia makes it hard to recognize certain stimuli, which can lead people to struggle to make sense of their surroundings. For instance, a person may not process that a moving object is moving or cannot recognize the face of their spouse.


Agnosia vs. Aphasia

Both agnosia and aphasia are neurological conditions that can impact how sufferers interact with the world, but they each impact different areas of life. Agnosia leads to issues identifying sensory items like sounds, people, or objects, but aphasia is struggling to process language, both spoken and written. Both conditions can be caused by brain damage from triggers such as a stroke, brain tumors, infections, and neurological or degenerative diseases.  Thus, these diseases have a good deal of overlap but have different symptoms.


Symptoms and Causes of Agnosia

Agnosia can be caused by a number of factors, which are usually related to injuries in the brain. These injuries can include stroke, concussions, traumatic brain injuries, concussions, dementia, tumors, and aneurysms. These are some of the most prevalent causes but are certainly not the only causes.

When looking for agnosia symptoms, a range of symptoms may be prevalent because agnosia can impact different sensory areas. Agnosia has two main forms, apperceptive and associative. Apperceptive means that people have working senses but are unable to process the information their brains receive. Associative agnosia means that a person senses and processes information but is unable to make sense of or recognize what they pick up on.

The symptoms of agnosia can include any struggle to identify or process information despite having functioning sensory input. Any one of the five senses can be impacted, and people with this condition may notice that they can’t engage in the world in ways that they used to.


Types of Agnosia

Agnosia is an umbrella term that can cover a range of experiences people may go through when they have agnosia. Some people may experience just one type while other people may experience multiple types. The type of agnosia is impacted by factors like how and where the brain was damaged.

For example, one person with this condition may experience visual agnosia, and visual agnosia can include:

  • Autopagnosia: struggling to recognize body parts
  • Alexia: Being unable to read but still seeing words and being able to write or speak
  • Environmental agnosia: being unable to tell where one is
  • Form agnosia: being able to identify the form of an object but not knowing what the object actually is
  • Cortical blindness: your brain cannot process images input by your eyes

These are not all the visual types of agnosia that people can experience, but they show the huge impacts that agnosia can have and the wide range of sensory input that agnosia influences. For example, you might not even be able to recognize your own dog. 

People often also experience a range of auditory processing disturbances, such as being unable to recognize sounds despite hearing working fine. They may also have phonagnosia and be able to recognize voices without knowing what the voice is saying. Other agnosia can include tactile agnosia like amorphognosia where people don’t know the shape or size of something they are feeling or taste and olfactory agnosia where they may not be able to recognize tastes or smells. Any sense can be impacted by agnosia


Diagnosis of Agnosia

Agnosia diagnosis is completed by noting a patient’s symptoms and often using some diagnostic tests such as:

  • A CT (computer tomography) scan
  • EEG (electroencephalogram)
  • MRI (magnetic resonance imaging)
  • Evoked potentials test

Professionals may also use some other tests depending on potential underlying causes that may be indicated. Thus, seeing a professional is vital to get a proper diagnosis.


The Impact of Agnosia on Stroke Survivors

There’s no doubt that agnosia can have a momentous impact on stroke survivors because this condition can make it hard to accurately perceive and interact with the world. Surviving a stroke, even in the best of circumstances, is a major obstacle in many people’s lives, and other effects like agnosia only add to the stress and hardships stroke survivors face. People with agnosia may feel hopeless and distressed over their situations, and they may feel as though their minds are betraying them.

While there is no guaranteed cure for agnosia, there are treatments that can help patients learn to cope and improve their overall condition. Medication, surgery, and rehabilitation or therapy are all options doctors may pursue to help patients deal with their condition. A doctor can help you better understand your options and make the best decisions for your needs.


Empowering Stroke Patients with Agnosia

For patients who have experienced a stroke and are trying to manage the effects of agnosia, having a proper stroke management plan and getting the proper diagnosis can make a significant impact on treatment outcomes. With the right doctor, stroke and agnosia patients can get the care they need to improve their quality of life and promote overall health. To learn more about stroke and agnosia treatment, contact us, and we will be glad to address any concerns you may have and get you on the path to improved well-being.

Aphasia and Stroke

Understand the complexities of aphasia and its impact on stroke survivors from our specialized stroke clinic in Singapore.

Consult a Stroke Specialist in Singapore


Dr. Manish Taneja, is an expert in endovascular and image guided neurointerventional procedures of brain and spine. He has special interest in treatment of brain aneurysms, stroke and vascular malformations. Come in for a further evaluation and arrange an appointment today with our stroke specialist.


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Stroke Resources

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Imagine heart attacks where the blood flow to your heart is blocked. Similarly, a stroke occurs when the blood flow to your brain is interrupted becoming a “brain attack”. When blood supply does not reach a certain part, brain cells begin to die. Different types of stroke include ischemic strokes (blockage of blood vessel due to blood clot) or a mini stroke, a TIA (transient ischemic attack), with no permanent damage yet serious. Stroke also occurs when a blood vessel in the brain pops causing bleeding in the brain.

Certain areas of the brain can be affected by stroke and some symptoms of a stroke including cardiovascular disease, diabetes, and high blood sugar levels increase the risk of stroke whereas an active lifestyle or controlling high cholesterol reduces the risk. How well do you know stroke? Find tips to prevent and manage stroke, the differences in stroke screening tests, and the newer technology and treatments available. Come in for an easy consultation and further evaluation with our stroke specialist in Singapore at the Supreme Vascular and Interventional Clinic.

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Did you experience the worst headache of your life? Could it be a brain aneurysm that ruptures, which means bleeding in the brain? Thoughts could be racing through your mind. Then what is the difference between unruptured (a weak or thin spot on an artery in the brain that balloons) or ruptured brain aneurysm? If you’re wondering, then the Supreme Vascular and Interventional Clinic is here to help. It’s important to look out for the tell-tale brain aneurysm symptoms, signs, causes, and risk factors.

Dr. Manish Taneja has been performing brain aneurysm treatments since 1995 from surgical clipping to latest minimally invasive procedures. Each patient is unique as is the size and location of the aneurysm. Your brain has different conditions to treat the aneurysm and artery vessel walls of a blood vessel in the brain. This calls for personalised brain aneurysm treatment depending on your symptoms, family, history, medication, and more. A simple CT scan could be just what the doctor ordered and the first step in early detection and prevention of a brain aneurysm. Come in for an easy consultation with our brain aneurysm specialist in Singapore to be on your health radar.

Other Health Conditions

The Supreme Vascular and Interventional Clinic is your “go-to” facility for various neurological conditions and treatments. To arrange an appointment with Dr. Manish Taneja, our neurointervention specialist, contact us. You can also call us at (+65) 6904 8084 for a consultation.