Superior alternating hemiplegia (Weber's syndrome)- Case report

and importance: Weber's syndrome is a rare type of brain stem stroke syndrome that is characterized by ipsilateral oculomotor nerve palsy and contralateral hemiparesis. The most common etiology is a midbrain infarction caused by occlusion of the paramedian branches of the posterior cerebral artery or the perforating branches of the basilar bifurcation. Although there are many multiple brainstem strokes, it is uncommon to see this syndrome.

Here we present a case of a 62-year-old male hypertensive patient who presented with a one-week history of cognitive dysfunction, left hemiparesis, right eye ptosis, and right medial gaze palsy (oculomotor nerve palsy). Diffusion MRI showed milimetric diffusion restriction in the right side of the mesencephalon, consistent with an acute infarct. Based on the clinical and radiological findings, a diagnosis of Weber's syndrome was made. The patient was treated with antiplatelet and Piracetam along with strict blood pressure control. There was a massive improvement in the patient's condition on the follow-up visit three weeks later.

Weber's syndrome is a rare brainstem stroke due to midbrain infarction and is characterized by crossing hemiplegia consisting of ipsilateral occulomotor nerve palsy and contralateral limb weakness due to damage to the corticospinal tract. Despite it being a brainstem stroke infarct, it carries a good prognosis if it is early treated along with strict control of the risk factors such as hypertension in this case. Our case had massive clinical improvement within three weeks of medical treatment and risk factor control.

This case highlights the classic rare syndrome of brainstem stroke presenting with crossing hemiparesis due to midbrain infarction. This syndrome has a favorable prognosis.