parietal lobe signs
Last reviewed 07/2021
The parietal lobe is the principal sensory area of the cerebral cortex. The manifestations of damage may be specific to the dominant or non-dominant hemisphere, or it may be general:
Disease of either dominant or non-dominant hemisphere post-central gyral sensory cortex produces contralateral disturbance of cortical sensation:
- impairment of postural sensation and sensation of passive movement
- impairment of tactile sensation - accurate localisation of light touch, two point discrimination
- agraphism, astereognosis
- sensory and visual inattention
Dominant hemisphere lesions:
- involving Wernicke's speech area - receptive dysphasia
- Gerstmann's syndrome
- dyslexia
Non-dominant lesions:
- neglect of contralateral limb, even if densely hemiplegic
- denial of weakness - anosognosia
- spatial neglect
- disappreciation of three dimensional sense - dressing dyspraxia, constructional dyspraxia
- geographical agnosia - e.g. unable to find defined places
Involving the optic radiation deep in the parietal lobe:
- lower homonymous quadrantanopia