Pulvinar - Dorsal Thalamus

Pulvinar

The pulvinar occupies the caudal third of the thalamus and is divided into several nuclei. Its functional significance is not understood. Since it does not receive any extrathalamic input, it must be viewed as an integration nucleus. Afferent fibers from the lateral geniculate nucleus (collaterals of the optic fibers) and probably also fibers from the medial geniculate nucleus enter the pulvinar.

There are reciprocal fiber connections be-tween the pulvinar and the cortex of the parietal lobe and the dorsal temporal lobe. Hence, the pulvinar is not only integrated into the optic and acoustic systems but is also connected with the cortical areas important for language and symbolic thinking.

Clinical Note: Injury (or electrical stimula-tion) of the pulvinar causes speech disorder in humans.