Agnosia

(Redirected from Auditory agnosia)
Jump to navigation Jump to search

WikiDoc Resources for Agnosia

Articles

Most recent articles on Agnosia

Most cited articles on Agnosia

Review articles on Agnosia

Articles on Agnosia in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Agnosia

Images of Agnosia

Photos of Agnosia

Podcasts & MP3s on Agnosia

Videos on Agnosia

Evidence Based Medicine

Cochrane Collaboration on Agnosia

Bandolier on Agnosia

TRIP on Agnosia

Clinical Trials

Ongoing Trials on Agnosia at Clinical Trials.gov

Trial results on Agnosia

Clinical Trials on Agnosia at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Agnosia

NICE Guidance on Agnosia

NHS PRODIGY Guidance

FDA on Agnosia

CDC on Agnosia

Books

Books on Agnosia

News

Agnosia in the news

Be alerted to news on Agnosia

News trends on Agnosia

Commentary

Blogs on Agnosia

Definitions

Definitions of Agnosia

Patient Resources / Community

Patient resources on Agnosia

Discussion groups on Agnosia

Patient Handouts on Agnosia

Directions to Hospitals Treating Agnosia

Risk calculators and risk factors for Agnosia

Healthcare Provider Resources

Symptoms of Agnosia

Causes & Risk Factors for Agnosia

Diagnostic studies for Agnosia

Treatment of Agnosia

Continuing Medical Education (CME)

CME Programs on Agnosia

International

Agnosia en Espanol

Agnosia en Francais

Business

Agnosia in the Marketplace

Patents on Agnosia

Experimental / Informatics

List of terms related to Agnosia

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

Template:DiseaseDisorder infobox

Overview

Agnosia (a-gnosis, "non-knowledge", or loss of knowledge) is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the temporal lobe.

Historical Perspective

Classification

Types

  • Visual agnosia is associated with lesions of the left occipital lobe and temporal lobes. Many are the inability to recognize objects. Subtypes:
    • Form agnosia: Patients perceive only parts of details, not the whole object.
    • Finger agnosia is the inability to distinguish the fingers on the hand. It is present in lesions of the dominant parietal lobe, and is a component of Gerstmann syndrome.
    • Simultanagnosia: Patients can recognize objects or details in their visual field, but only one at a time. They cannot make out the scene they belong to or make out a whole image out of the details. They literally cannot see the forest for the trees. Simultanagnosia is a common symptom of Balint's syndrome.
    • Associative agnosia: Patients can describe visual scenes and classes of objects but still fail to recognize them. He may, for example, know that a fork is something you eat with but may mistake it for a spoon. Patients suffering from associative agnosia are able to reproduce an image through copying.
    • Apperceptive agnosia: Patients are unable to distinguish visual shapes and so have trouble recognizing, copying, or discriminating between different visual stimuli. Unlike patients suffering from associative agnosia, those with apperceptive agnosia are unable to copy images.
    • Mirror agnosia: Patients cannot recognize objects or activity on either their left or right field of view. Impairment can vary from mild inattention to complete inability to perform spatial reasoning with regard to the afflicted side. The disorder takes its name from an experiment in which a patient was shown objects reflected in a mirror and saw them, but was unable to find them when prompted.
    • Semantic agnosia:
    • Agnosic alexia: Inability to recognize text.
    • Color agnosia: There is a distinction between color perception versus color recognition. Central achromatopsia and color blindness refer to deficiency in color perception.
    • Prosopagnosia also known as faceblindness and facial agnosia: Patients cannot consciously recognize familiar faces, sometimes even including their own. This is often misperceived as an inability to remember names. People with PA frequently (but not always) also suffer from topographical agnosia (poor sense of direction, get lost easily), automobilia agnosia (an inability to recognize cars), expressive agnosia (an inability to perceive people's moods from their facial expressions), verbal agnosia (see below) and possibly dyscalculia (poor with numbers).
  • Auditory agnosia refers to similar symptoms for sounds. This term is sometimes used with the limited reference to environmental, nonverbal auditory cues, as separate from verbal agnosia There is a weakly defined link between these terms and CAPD/APD (originally Central Auditory Processing Disorder, the term Auditory Processing Disorder is now preferred).
    • Verbal auditory agnosia or Pure word deafness or simply word deafness: agnosia connected to verbal information. Patients may hear the sounds of the words, but they don't understand what they mean or can't recognize them as words.
    • Amusia or Receptive amusia is agnosia for music. It involves loss of the ability to recognize musical notes, rhythms, and intervals and the inability to experience music as musical.
    • Cortical deafness refers to people who do not respond to any auditory information but whose hearing is intact.
    • Phonagnosia is the inability to recognize familiar voices, even though the hearer can understand the words used.
  • Somatosensory agnosia or Astereognosia is connected to tactile sense - that is, touch. Patient finds it difficult to recognize objects by touch based on its texture, size and weight. However, they may be able to describe it verbally or recognize same kind of objects from pictures or draw pictures of them. Thought to be connected to lesions or damage in somatosensory cortex.

Pathophysiology

Causes

Agnosia can result from strokes, dementia, or other neurological disorders. It may also be trauma-induced by a head injury, or hereditary. Until the 1990s, it was not believed to be genetic, but that view has changed.

Differentiating Agnosia from Other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications, and Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Laboratory Findings

Imaging Findings

Other Diagnostic Studies

Treatment

For all practical purposes, there is no direct cure. Patients may improve if information is presented in other modalities than the damaged one. In some cases, occupational therapy or speech therapy can improve agnosia, depending on its etiology.

Medical Therapy

Surgery

Prevention

See also

External links

  • Types and brain areas
  • "Total Recall: Memory Requires More than the Sum of Its Parts". Retrieved 2007-06-05. at Scientific American

Referencecs

Template:Skin and subcutaneous tissue symptoms and signs Template:Nervous and musculoskeletal system symptoms and signs Template:Urinary system symptoms and signs Template:Cognition, perception, emotional state and behaviour symptoms and signs Template:Speech and voice symptoms and signs Template:General symptoms and signs

de:Agnosie gl:Agnosia it:Agnosia he:אגנוזיה nl:Agnosie no:Agnosi sr:Агнозија fi:Agnosia sv:Agnosi uk:Агнозія

Template:WH Template:WS