Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which syndrome is characterized by ipsilateral ataxia, nystagmus, dysphagia, and contralateral limb sensory loss?

1. Lateral medullary syndrome

2. Wallenberg syndrome

3. Weber's syndrome

4. PICA syndrome

The correct answer is: Lateral medullary syndrome

The syndrome characterized by ipsilateral ataxia, nystagmus, dysphagia, and contralateral limb sensory loss is Lateral Medullary Syndrome, also known as Wallenberg Syndrome. This condition results from the occlusion of the posterior inferior cerebellar artery (PICA) that supplies the lateral part of the medulla oblongata. In this syndrome, the involvement of the medulla leads to several characteristic clinical features. The ipsilateral ataxia and nystagmus occur due to the disruption of cerebellar pathways and vestibular input from the affected side. Dysphagia arises from damage to the glossopharyngeal and vagus nerves, which are responsible for swallowing. The contralateral limb sensory loss results from the involvement of the spinothalamic tract, which crosses over in the spinal cord and carries pain and temperature sensation. Thus, individuals with this syndrome exhibit symptoms that align perfectly with the clinical description provided in the question. While other syndromes listed share some similar features, they do not encompass the full spectrum of symptoms presented, making Lateral Medullary Syndrome the correct diagnosis in this case.