Global hemianaesthesia: A parietal perceptual distortion suggesting non-organic illness

In two patients, lesions in the non-dominant parietal lobe were associated with global anaesthesia to all sensory modalities affecting the opposite half of the body. A striking inconsistency existed between the complaints of limb anaesthesia and the grossly preserved motor and postural control of the involved limb. The gross discrepancy between complaint and functional ability prompted early consideration of a "non-organic" diagnosis. It is suggested that this unusual sensory deficit may be due to distorted perception of somatosensory stimuli, representing another disorder of body schema associated with parietal lobe lesions. The diagnosis of non-organic illness may then be avoided by focusing on a search for parietal disease.