Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which syndrome results from damage to the PICA and presents with specific neurological deficits?

1. Vertebrobasilar insufficiency

2. Lateral medullary syndrome

3. Wallenberg syndrome

4. Weber's syndrome

The correct answer is: Wallenberg syndrome

Wallenberg syndrome, also known as lateral medullary syndrome, arises from an infarction in the territory supplied by the posterior inferior cerebellar artery (PICA). This specific artery supplies the lateral part of the medulla oblongata, and damage to it can lead to a characteristic set of neurological deficits. Patients with Wallenberg syndrome typically present with symptoms such as dysphagia, dysarthria, and ataxia due to involvement of the brainstem nuclei and cerebellar pathways. There may also be sensory deficits on the opposite side of the body due to disruption of the spinothalamic tract, along with autonomic symptoms like Horner's syndrome (ptosis, miosis, and anhidrosis) on the same side as the lesion due to sympathetic fiber involvement. The neurological manifestations are distinct and result from the specific vascular territory affected by PICA occlusion. This delineation helps to identify Wallenberg syndrome as a unique clinical syndrome in the context of cerebrovascular accidents, differentiating it from other vascular events like vertebrobasilar insufficiency or Weber's syndrome, which are associated with damage to different vascular territories and exhibit different symptomatology.