Brainstem stroke syndromes

Brainstem stroke syndromes, also known as crossed brainstem syndromes, refer to a group of syndromes that occur secondary to lesions, most commonly infarcts, of the brainstem.

Epidemiology

Although many different brainstem stroke syndromes have been classically described, the majority appear extremely rarely in the literature and are mainly for historical interest only . The most common brainstem stroke syndrome seems to be the lateral medullary syndrome (Wallenberg syndrome) .

Clinical presentation

Each brainstem stroke syndrome has a characteristic clinical picture according to the involved area, however, generally, there is ipsilateral cranial nerve palsy and contralateral hemiplegia/hemiparesis and/or hemisensory loss .

The rule of 4 of the brainstem is a useful and simple clinical tool to aid in the anatomical localization of signs and symptoms in a brainstem stroke .

Pathology

Etiology

These syndromes are classically caused by ischemic strokes that occur secondary to occlusion of small perforating arteries of the posterior circulation, however many have also been described secondary to hemorrhage, neoplasm, and demyelination .

Classification

Brainstem stroke syndromes are most commonly classified anatomically.

Midbrain
Pons
Medulla oblongata