Weber's syndrome, also known as midbrain stroke syndrome or superior alternating hemiplegia, is a form of

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

that affects the medial portion of the midbrain. It involves oculomotor fascicles in the interpeduncular cisterns and cerebral peduncle so it characterizes the presence of an ipsilateral lower motor neuron type oculomotor nerve palsy and contralateral

hemiparesis Hemiparesis, also called unilateral paresis, is the weakness of one entire side of the body (''wikt:hemi-#Prefix, hemi-'' means "half"). Hemiplegia, in its most severe form, is the complete paralysis of one entire side of the body. Either hemipar ...

or hemiplegia.

Cause

It is mainly caused by a

midbrain The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

infarction Infarction is tissue death (necrosis) due to Ischemia, inadequate blood supply to the affected area. It may be caused by Thrombosis, artery blockages, rupture, mechanical compression, or vasoconstriction. The resulting lesion is referred to as a ...

as a result of occlusion of a branch of

posterior cerebral artery The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, as well as the medial and inferior aspects of the temporal lobe of the human brain. The two arteries originate from the d ...

most commonly or the paramedian branches of basilar bifurcation perforating arteries. This lesion is usually unilateral and affects several structures in the midbrain including:

Diagnosis

Clinical findings mainly eyeball is down and out ipsilateral lateral squint. Ptosis present as the levator palpebrae superioris nerve supply is disrupted. Pupil dilated and fixed. Contralateral hemiplegia CT scan or MRI might help in delineating the cause or the vessel or region of brain involved in stroke.

Management

History

It carries the name of Sir Hermann David Weber, a German-born physician working in London, who described the condition in 1863. It is unrelated to

Sturge–Weber syndrome Sturge–Weber syndrome, sometimes referred to as encephalotrigeminal angiomatosis, is a rare congenital neurocutaneous disorder (also known as phakomatoses). It is often associated with port-wine stains of the face, glaucoma, seizures, intellect ...

, Klippel–Trénaunay–Weber syndrome or Osler–Weber–Rendu syndrome. These conditions are named for his son Frederick Parkes Weber.

References

External links