Ablation of the 'somatosensory area I' of the cerebral coex leads to :
D i.e. Loss of tactile localization & two point discrimination Functions & Lesions Somatosensory area I (SI) Primary somatosensory area (SI) is Brodmann's area 1, 2, 3 situated in postcentral gyrus. Ablation of SI would lead to coical pattern of sensory loss. Lesion in this area produce contralateral impairment of: - TouchQ - Sterognosis - Pressure - Barognosis - Proprioception - Cutaneographia - Two point discrimationQ Spinal cord lesion Brainstem lesion Thalamic lesion Coical lesion Five patterns are seen depending Loss of pain & temperature Hemisensory loss of Patients is able to recognize all upon whether there is: on ipsitateral face and all modalitiesQ sensation but localizes them - Complete transaction opposite side of bodyQ. poorly - Hemisection (Lateral medullary - Loss of two point - Central cord section syndrome)Q discriminationQ - Posterior column section sensation) - Sensory inattention
Total loss of pain sensation
Total loss of touch sensation
Loss of tactile localization but not of two point discrimination
Loss of tactile localization and two point discrimination