Which of the following sensation is preserved on the side of the lesion in Brown-Sequard syndrome: September 2005

Ans. C: Temperature The hemisection of the cord results in a lesion of each of the three main neural systems: The principal UMN pathway of the coicospinal tract One or both dorsal columns The spinothalamic tracts As a result of the injury to these three main brain pathways the patient will present with three lesions: The coicospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the UMN). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense) as well as loss of all sensation of fine touch on the ipsilateral side. The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion.