Professional and Linguistic Assessments Board (PLAB) Practice Exam

What syndrome is indicated by saddle anesthesia and loss of bowel control?

1. Cerebellar syndrome

2. Cauda equina syndrome

3. Thalamic syndrome

4. Subclavian steal syndrome

The correct answer is: Cauda equina syndrome

The presence of saddle anesthesia and loss of bowel control aligns with the clinical presentation of cauda equina syndrome. This syndrome occurs when there is compression of the cauda equina, which is a bundle of nerve roots located at the lower end of the spinal cord. The symptoms arise due to disruption of nerve function in this area, leading to loss of sensation in the saddle region (the area that would come into contact with a saddle) and loss of bowel and bladder control. Saddle anesthesia typically presents as a peculiar sensory loss affecting the buttocks, perineum, and inner thighs, indicating the involvement of the nerves responsible for these sensory modalities. Additionally, bowel and bladder dysfunction suggest that nerve roots that control these functions are affected. Together, these symptoms are classic indicators of cauda equina syndrome, which necessitates urgent medical intervention to prevent permanent neurological damage. Other options do not share this combination of symptoms. Cerebellar syndrome primarily involves issues of coordination and balance due to cerebellar dysfunction, while thalamic syndrome is usually characterized by sensory alterations rather than specific localized sensory loss and bowel dysfunction. Subclavian steal syndrome involves vascular complications and does not relate to nerve root compression or resulting neurological deficits. Thus, cauda equina syndrome