Isolated hemiataxia as a manifestation of mesencephalic lacunar infarction
Introduction. Lesions of the dento-rubro-thalamo-cortical pathway may cause homolateral or contralateral hemi- ataxia, depending on whether they are found above or below the decussation which occurs at the level of the inferior colliculus. Most mesencephalic infarctions causing hemiataxia also show oculomotor involvement with nuclear or fascicular lesions of the third cranial nerves. This was not seen in the case we report. Clinical case. We describe the case of a diabetic patient with a permanent right appendicular hemiataxia, without oculomotor involvement, caused by a lacunar infarct shown on MR imaging which was situated in the antero-external part of the left superior mesencephalum. Conclusions. This case helps to clarify the topography of the thalamic radiations of the mesencephalic calotte, including the decussated superior dento-rubro-thalamic pathway to the red nucleus. Involvement of this, situated in the mesencephalic lateral vascular territory causes contralateral hemiataxia.
Caso clínico Se describe el caso de un paciente diabético con cuadro permanente de hemiataxia apendicular derecha, sin afectación oculomotora, producida por un infarto lacunar demostrado mediante RM y situado en la porción anteroexterna del mesencéfalo superior izquierdo.
Conclusiones Este caso contribuye a aclarar la topografía de las radiaciones talámicas de la calota mesencefálica, entre las que se incluye la vía dentorrubrotalámica superior al núcleo rojo y ya decusada, cuya afectación, localizada en el territorio vascular lateral mesencefálico, produce hemiataxia contralateral
