What Causes Agnosia?
Agnosia is a condition where one does not have any awareness or reaction to a specific stimulus. The term refers to a lack of emotional response to stimuli which are unfamiliar or unexpected. A form of mental retardation characterized by the inability to recognize faces, hear sounds, see objects and read language. There are two types of agnosias: semantic (a failure to identify words) and non-semantic (failure to respond emotionally). Semantic agnosias are caused by damage to the right hemisphere of the brain while non-semantic agnosias are caused by damage to the left hemisphere.
Agnosia is often associated with epilepsy, but it may also result from other neurological disorders such as stroke, head trauma, traumatic brain injury and even exposure to certain drugs. Agnosic patients are usually unable to perform simple tasks such as reading a newspaper without assistance. They may also experience difficulty learning new things, especially if they have had little or no previous exposure to these subjects.
Symptoms of Agnosia
The symptoms of agnosia vary depending on the type and severity of the disorder. Some common signs include:
Lack of recognition when faced with familiar objects, people or situations. For example, a patient might fail to recognize their name upon seeing it printed out on a piece of paper.
Patients may lack an emotional response when faced with certain situations or stimuli. For example, they may not blink when someone near them cries out in pain.
Patients may also experience a general difficulty learning new things and may have problems converning verbal instructions into physical actions.
Agnosic patients become stressed and anxious when placed in situations where they are unable to recognize familiar faces, places or objects.
Treatments for Agnosia
Unfortunately, there is no cure for agnosia and most patients live the remainder of their lives making use of whatever abilities they still retain. Alternative treatments may include:
Ensuring the safety of agnoic patients by keeping them under constant supervision. This may involve keeping them at home or placing them in a secure facility.
Helping the patient to complete daily activities such as cooking, cleaning, shopping and other routine activities.
Helping the patient to perform basic activities of daily living such as bathing, dressing and using the bathroom.
Helping the patient to communicate with others and recognize familiar faces.
Ensuring the patient takes their medication on a regular basis and receives proper medical care.
Agnosia is a medical condition that causes patients to lose all or some of their senses. It is most commonly caused by brain damage resulting from oxygen deprivation, infection, toxin exposure, disease or severe head injury. There are two main forms of agnosia: semantic and non-semantic.
Semantic agnosia refers to a loss of the ability to identify specific categories of words such as animals, tools or foods. Non-semantic agnosia refers to a loss of the ability to feel emotions in response to certain situations or stimuli.
Dementia is a broad term used to describe a general loss of cognitive functioning and memory. It can be caused by trauma, illness, infection, toxin exposure or genetic disposition. Symptoms may include: personality changes, difficulty communicating, impaired judgement, confusion, disorientation and memory loss.
There are many different types of dementia with varying degrees of severity.
Dementia is a general term used to describe a loss of cognitive functioning and memory. It may be caused by trauma, infection, illness, toxin exposure or genetic disposition.
Cognitive Dysfunction or Cognitive Decline
The most common type of dementia is known as cognitive dysfunction. This refers to a general loss in cognitive functioning including memory, reasoning and attention span. It is a slow, progressive condition that worsens overtime and does not have a cure.
Sources & references used in this article:
Visual agnosia by MJ Farah – 2004 – books.google.com
Agnosia, apraxia, aphasia: Their value in cerebral localization by JM Nielsen – 1946 – pure.mpg.de
Perception and action in ‘visual form agnosia’ by AD Milner, DI Perrett, RS Johnston, PJ Benson… – Brain, 1991 – academic.oup.com