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Neurodegeneration and mirror image agnosia
Sadanandavalli Retnaswami Chandra1, Thomas Gregor Issac2
1Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
North American Journal of Medical Sciences
|October 16, 2014
Summary
Patients with dementia experiencing mirror image agnosia, a specific type of visual agnosia, often show right parietal lobe dysfunction. This suggests early disruption in visual processing circuits.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Neurology
Background:
- Visual agnosias, including prosopagnosia, have been documented since the 19th century.
- Difficulty recognizing reflected self-images, distinct from general cognitive decline, poses diagnostic challenges, sometimes mistaken for psychosis.
Purpose of the Study:
- Investigate patients with dementia exhibiting difficulties in identifying reflected self-images.
- Assess recognition of reflected objects, animals, relatives, and self.
- Correlate these deficits with neuropsychological and radiological findings.
Main Methods:
- Studied five dementia patients with difficulties recognizing reflected images.
- Utilized a mirror (45 cm × 45 cm) positioned 30 cm in front of the participants.
Main Results:
- Mirror image agnosia was observed in patients with moderate-stage posterior dementias.
- These patients demonstrated neuropsychological and radiological evidence of right parietal dysfunction.
Conclusions:
- Real-time interpretation of reflected self-images likely relies on specific data-linking circuits within the right parietal lobe.
- These critical circuits may be affected early in the progression of certain dementias.
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