Agnosia

Agnosia is a rare disorder that makes you lose the ability to recognize objects, faces, voices, or places previously known. It is specific for a given sensory modality. 

There are three main types of agnosia: 

• Visual: This is the most common type of agnosia, in which you are not able to recognize objects or faces. It includes:
  

  • Prosopagnosia, that is, the inability to identify faces even though the person is known 

  • Agnostic Alexia, that is, the inability to recognize written pieces (including letters and words)

  • Colour Agnosia, that is, the inability to discriminate between colours and therefore cannot name the colour

  • Object Agnosia, that is, the inability to name objects

  • Simultanagnosia, that is, the inability to recognize a whole image although individual details are recognized

• Auditory: People with auditory agnosia are unable to recognize sounds and language to varying degrees, depending on the severity of the disease. It includes:
  

  • Auditory/verbal information agnosia, that is, the inability to hear words

  • Auditory agnosia, that is, the inability to hear environmental sounds such as a car starting or a dog barking

  • Receptive amu​sia, that is, the inability to hear music

• Tactile: This type of agnosia is the inability to identify objects by touch.
  

Agnosia can result from: 

• Strokes 
  

• Brain injury 
  

• Dementia
  

• Tumour
  

• Developmental disorders
  

• Overexposure to environmental toxins
  

• Other neurological conditions

When to seek expert advise

If you or a loved one is facing similar symptoms, it is recommended that you consult with your doctor immediately. You can obtain additional information and expert medical advice from the ​​​Section of Neurology at The Aga Khan University Hospital.

Imagery