Professional and Linguistic Assessments Board (PLAB) Practice Exam

What does a patient with Brown-Sequard syndrome demonstrate on examination?

1. Contralateral loss of proprioception

2. Contralateral loss of pain sensation

3. Loss of all sensory modalities

4. Bilateral spasticity

The correct answer is: Contralateral loss of pain sensation

A patient with Brown-Sequard syndrome exhibits a characteristic pattern of neurological deficits due to hemisection of the spinal cord, usually resulting from trauma or tumors. One of the hallmark features of this syndrome is the contralateral loss of pain and temperature sensation, which occurs because the spinothalamic tract, responsible for transmitting these sensations, crosses over to the opposite side of the body shortly after entering the spinal cord. This cross-over means that if one side of the spinal cord is damaged (such as in Brown-Sequard syndrome), the patient will experience a loss of pain and temperature sensations on the opposite side of the body. In contrast, the patient will have ipsilateral loss of proprioception and fine touch, since these modalities ascend on the same side and cross over at a higher level in the brainstem. Therefore, the correct identification of the contralateral loss of pain sensation as a feature of Brown-Sequard syndrome aligns with the neuroanatomical pathways affected by the condition. The other options do not accurately reflect the clinical presentation associated with Brown-Sequard syndrome. The loss of all sensory modalities would be indicative of more extensive spinal cord injury or involvement, which is not specific to this syndrome, while bilateral spasticity is