INSTRUCTION

Examine this patient's cranial nerves.

SALIENT FEATURES

History

· Severe nausea, vomiting, nystagmus (involvement of the lower vestibular nuclei).· Limb ataxia (involvement of the inferior cerebellar peduncle).· Intractable hiccups, dysphagia (ninth and tenth cranial nerve involvement)

Examination

· Nystagmus.· Ipsilateral involvement of fifth, sixth, seventh and eighth cranial nerves.· Bulbar palsy: impaired gag, sluggish palatal movements.· Homer's syndrome.Proceed as follows:Tell the examiner that you would like to check for the following:· Cerebellar signs on the same side.· Pain and temperature sensory loss on the opposite side (dissociated sensory loss).Remember. The main features of this syndrome are ipsilateral Homer's syndrome and contralateralloss of pain and temperaturesensation.

DIAGNOSIS

This patient has lateral medullary syndrome (lesion) due to a stroke (aetiology) and has dysphagia (functional status).

ADVANCED-LEVEL QUESTIONS

Which vessel is occluded?

Any of the following five vessels:· Posterior inferior cerebellar artery.· Vertebral artery.· Superior, middle or inferior lateral medullary arteries.

How may these patients present?

With sudden onset of vertigo, vomiting and ipsilateral ataxia, with contralateral loss of pain and temperature sensations

Where is the lesion in lateral medullary syndrome?

The syndrome results from infarction of a wedge-shaped area of the lateral aspect of the medulla and inferior surface of thecerebellum. The deficits are caused by involvement of one side of the nucleus ambiguus, trigeminal nucleus, vestibular nuclei,cerebellar peduncle, spinothalamic tract and autonomic fibres.

What is the medial medullary syndrome?

It is caused by occlusion of the lower basilar artery or vertebral artery. Ipsilateral lesions result in paralysis and wasting of thetongue. Contralateral lesions result in hemiplegia and loss of vibration and joint position sense.

Mention a few other eponymous syndromes with crossed hemiplegias.

· Weber's syndrome: contralateral hemiplegia with ipsilateral lower motor neuron lesion of the oculomotor nerve. The lesion is inthe midbrain.· Millard-Gubler syndrome: contralateral hemiplegia with lower motor neuron lesion of the abducens nerve. The lesion is in thepons.· Foville's syndrome: as Millard-Gubler syndrome with gaze palsy.

What is Benedikt's syndrome?

It causes cerebellar signs on the side opposite the third nerve palsy (which is pro-duced by damage to the nucleus itself or to thenerve fascicle). It is due to a midbrain vascular lesion causing damage to the red nucleus, interrupting the dentatorubrotha-lamictract from the opposite cerebellum.Auguste L.J. Millard (1830-1915) and Adolphe Marie Gubler (1821-1879), Parisian physicians.Achille L.E Foville (1799-1878), a Parisian neurologist.A. Wallenburg (1862-1949), a German neurologist, described this syndrome in 1895.