The lesions responsible for conscious hemiasomatognosia have been ascribed to various anatomical sites in the brain, but this is still a disputable subject. This communication describes 11 cases of conscious hemiasomatognosia, with vascular lesions in the thalamus or the upper brainstem and discusses pathophysiological mechanisms causing conscious hemiasomatognosia. The cases included 6 males and 5 females aged 36 to 76 yr. Five cases had hemorrhagic lesions and 6 cases had ischemic lesions which were verifed by CT. Seven cases had localized thalamic lesions only, 2 cases had thalamic lesion and adjacent lesions of the thalamus, and 2 cases had upper brainstem lesions. Neurological examination revealed the disturbance of deep sensation and hemiparesis in all cases, but neither cortical symptoms nor anosognosia were noted. Among these cases, 6 cases complained of a sensation of a 'lost extremity' within 2 weeks after the attack, whereas the remaining subjects complained on later days. All cases revealed the symptoms in the presence of the slight disturbance of consciousness, or immediately after sleeping. The 'lost limbs' corresponded to the paralyzed extremities of the patient, although the degree of the paralysis was variable. Six cases 'lost' only upper extremities, 1 case 'lost' only lower extremities and 4 cases 'lost' both upper and lower extremities. When improvement in the disturbance of deep sensation occurred every patient stopped complaining about these abnormal experiences. In order to verify the lesion responsible for the conscious hemiasomatognosia, we had superimposed the lesion of each patient obtained from CT film of the comparable level. The superimposed CT findings revealed a common lesion in the thalamus, namely thalamic VPL nuclei in each side. The authors conclude that the conscious hemiasomatognosia is a unique type of the disturbance of the body schema which is caused by the combination of two conditions; severe disturbance of deep sensation due to thalamic VPL lesions or lesions of medial leminiscus, and the alteration of the level of consciousness.
|Number of pages||9|
|Publication status||Published - 1982|
ASJC Scopus subject areas
- Clinical Neurology