Anatomy of the parietal lobe and signs of its lesion

1. Big picture

The parietal lobe is the cortical area mainly responsible for somatic sensation, sensory integration, body schema, spatial orientation, attention, praxis, and some language-related symbolic functions.

For the exam, the examiner usually wants you to connect anatomy → clinical signs → hemisphere dominance:

• Postcentral gyrus lesion → contralateral sensory loss.

• Dominant inferior parietal lesion → Gerstmann syndrome, apraxia, alexia/agraphia, anomic aphasia.

• Non-dominant parietal lesion → neglect, anosognosia, dressing/constructional apraxia.

• Parietal optic radiation lesion → contralateral lower quadrantanopia.

• Irritative lesion → sensory Jacksonian seizures.

The parietal lobe is not just a “sensory lobe.” It is a sensory-association and orientation lobe.