Master Wallenberg Syndrome (PICA Syndrome) with Picmonic for Medicine

Wallenberg Syndrome, also called Lateral Medullary Syndrome, arises from compromise to the posterior inferior cerebellar artery, or PICA.

Because of the territory irrigated by PICA, the region affected in a stroke of this artery is the lateral medulla. As such, the affected structures are the vestibular nuclei, the trigeminal nuclei, the spinothalamic tract, the nucleus ambiguus, the inferior cerebellar peduncle, and the descending sympathetic fibers

The compromise of the vestibular nuclei in lateral medullary syndrome can cause vertigo.

The compromise of the vestibular nuclei in lateral medullary syndrome can cause nystagmus.

Compromise of the vestibular nuclei can cause nausea and vomiting.

The compromise of the trigeminal nuclei causes loss of pain and temperature sensations in the ipsilateral side of the face.

Compromise of the spinothalamic tract causes loss of pain and temperature sensation in the contralateral side of the trunk and extremities.

Because the nucleus ambiguus houses motor neurons for cranial nerves IX and X, its compromise can cause dysphagia.

Because the nucleus ambiguus houses motor neurons for cranial nerves IX and X, its compromise can cause dysarthria and dysphonia.

When the nucleus ambiguus is affected, there is a loss of the gag reflex.

When the descending sympathetic fibers are affected in Wallenberg Syndrome, Ipsilateral Horner Syndrome is seen.

Damage to the inferior cerebellar peduncle causes ipsilateral ataxia and dysmetria. It also causes dysdiadochokinesia, the inability to perform rapid, alternating muscle movements such as closing and opening the fists.