- Etiology & Localization
- Caused by a lesion in the dominant parietal lobe, specifically the angular gyrus.
- In the angular gyrus, which integrates visual sensory information for pattern recognition
- Common etiologies: Ischemic stroke (Middle Cerebral Artery territory), tumor, or other focal damage.
- Clinical Tetrad (Classic Features)
- Agraphia: Inability to write.
- Acalculia: Inability to perform mathematical calculations.
- Finger Agnosia: Inability to identify, name, or orient one’s own fingers.
- Left-Right Disorientation: Inability to distinguish left from right.
- Associated Findings
- May also present with alexia (inability to read) and aphasia (e.g., receptive aphasia) due to the proximity of the lesion to Wernicke’s area and the visual cortex pathways.
- Diagnostics
- Primarily a clinical diagnosis based on the presence of the tetrad.
- Neuroimaging (CT or MRI of the brain) is essential to identify the underlying structural lesion (e.g., stroke, mass).