Alexia, agraphia, acalculia, amusia

1. Big picture

These are higher cortical disorders. The key exam idea is that the patient does not lose the basic motor, sensory, visual, or auditory function, but loses a learned symbolic function:

• Alexia = acquired inability to read.

• Agraphia = acquired inability to write.

• Acalculia = acquired inability to calculate.

• Amusia = acquired disturbance of musical perception or musical performance.

They are important because they help localize lesions in the dominant parietal lobe, occipital lobe, temporal lobe, and connecting pathways. In the exam, they are often tested together with aphasia, apraxia, agnosia, and especially Gerstmann syndrome.