What Is Wallenberg Syndrome?

Posterior inferior cerebellar artery (PICA) is one of the major arterial trunks that supply blood to the brainstem. When there is a stroke in this area, involving PICA, it is referred to as Wallenberg syndrome.

Risk factors of PICA stroke:

- Hypertension

- Diabetes

- Smoking

- High cholesterol

Clinical features:

Brainstem features

- Dysphagia (difficulty swallowing) - due to involvement of nucleus ambiguus.

- Hoarseness of voice - due to involvement of nucleus ambiguus.

- Nystagmus - rapid involuntary movement of eyes usually in the horizontal plane due to involvement of vestibular nucleus.

- Vertigo - due to involvement of the vestibular apparatus or vestibular nucleus.

Lateral medullary syndrome:

- Ipsilateral loss of pain and temperature sensation from the face and contralateral side of the body.

- Ipsilateral Horner’s syndrome - ptosis (drooping eyelid), miosis (small pupil), anhidrosis (absence of sweating) - due to involvement of descending sympathetic pathway.

- Ipsilateral paralysis/weakness of the sternocleidomastoid muscle and trapezius muscle. Ipsilateral palate deviates away from the lesion towards the normal side.

Cerebellar features:

- Nystagmus - Rapid involuntary movement of the eyes, may be horizontal, vertical, or rotatory.

- Ataxia - difficulty with coordination and balance, staggering gait, dysmetria (difficulty judging distance and direction of intended movements).

- Intention tremors - involuntary shaking or trembling that occurs when a person tries to move a body part purposefully.