[Unusual thalamo-mesencephalic infarction: clinico-radiological correlations]

Mesencephalic infarcts usually produce clinical features that allow the lesion to be located with precision, although they do not always match the patterns included in the classical syndromes reported in the literature, as occurs in the case we describe here.

We report the case of a 73-year-old female with no cardiovascular risk factors, who presented a sudden clinical picture of instability, diplopia, palpebral ptosis and mild hypersomnia. On examining the patient the following manifestations were observed: compromise of the right common oculomotor nerve, up and down vertical gaze palsy, dysmetry of the right limbs and mild long tract signs in the left limbs. Magnetic resonance imaging of the brain revealed right thalamo-mesencephalic infarction in the paramedian territory, which became bilateral in the upper mesencephalon. The aetiological study showed only a carotid atheromatosis.

Cerebellar compromise ipsilateral to a lesion in the common oculomotor nerve in mesencephalic infarcts is a very uncommon clinical variant. The pathogenetic heterogeneity of infarctions involving the mesencephalon makes it necessary to carry out an extensive aetiological study. Magnetic resonance imaging of the brain is an essential tool for understanding the clinical picture and the anatomical structures involved in cases of infrequent cerebral infarction.