Brainstem syndromes, most of them with awkward names

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The midbrain syndromes

There is a significant overlap between the midbrain syndromes: Weber’s, Benedikt’s, Claude’s and Nothnagel’s.

Weber’s syndrome

Weber’s syndrome is a crossed midbrain syndrome. Other names for the syndrome are midbrain stroke syndrome and superior alternating hemiplegia.

It is typically caused by an ischemic or hemorrhagic stroke. The midbrain receives its blood supply from the vertebrobasilar circulation, from the branches of the basilar, posterior cerebral and superior cerebellar arteries. Weber’s syndrome caused by the stroke most often comes with signs of stroke in other parts of the vertebrobasilar system, rarely as an isolated syndrome. Other possible causes of Weber’s syndrome are tumors, aneurysms, and demyelination.

Isolated Weber’s syndrome is characterised by contralateral hemiparesis/hemiplegia and ipsilateral oculomotor nerve palsy. If nearby substantia nigra is affected by the lesion, the patient will present with contralateral parkinsonian signs. Contralateral ataxia will be present if the red nucleus is affected with the lesion. As said before, there is a large overlap between the midbrain syndromes. If contralateral hemiparesis dominates the clinical presentation and ataxia is discrete, the syndrome should be called Weber’s.

The pontine syndromes

Millard–Gubler syndrome

Millard–Gubler syndrome is a crossed brainstem syndrome. It is also known as ventral pontine syndrome and facial abducens hemiplegia syndrome. It is caused by a unilateral lesion of the ventral portion of the caudal pons.  The lesion affects fascicles of abducens and facial nerve, and uncrossed fibers of the corticospinal tract.

Symptoms and signs:

• Ipsilateral weakness of the abduction of the eye. There is no binocular gaze paresis because the abducens nucleus is not damaged.
• Ipsilateral peripheral facial paralysis
  • Ipsilateral loss of the corneal reflex
• Contralateral hemiparesis/hemiplegia
• Other contralateral neurological deficits are also possible, such as paresthesia and cerebellar ataxia

Etiology varies with patients age. In older patients the syndrome is most often caused by an ischemic or hemorrhagic stroke. In younger patients it is most often caused by tumor, demyelination or a viral infection.

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OSMCQs

Midbrain

References:

Munakomi S, M Das J. Weber Syndrome. [Updated 2022 Feb 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559158/

Sakuru R, Elnahry AG, Bollu PC. Millard Gubler Syndrome. [Updated 2022 Feb 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532907/

Inspiration, images, links and other material from:

https://en.wikipedia.org/wiki/Brainstem_stroke_syndrome