Lentiform nucleus

At a glance

English

Lentiform nucleus

Latin (TA2)

Nucleus lentiformis

System

Brain and spinal cord

Region

Head

Side

Paired, left and right

About the lentiform nucleus

The lentiform (or lenticular) nucleus is one of the basal nuclei. It takes its name from its shape: seen in a horizontal or coronal section it looks like a biconvex lens or wedge, broad on its lateral side and tapering to an edge medially. It is buried in the white matter of the hemisphere beneath the insula.

It is made of two parts. The larger, darker putamen forms the outer part, and the paler globus pallidus forms the inner part; a thin sheet of white matter, the lateral medullary lamina, separates them, and the medial medullary lamina further divides the globus pallidus into external and internal segments. The putamen and the caudate nucleus share their structure and connections and together form the striatum; strands of grey matter cross the anterior limb of the internal capsule to join them, giving the striped appearance behind the name.

Its relations are important on scans. Medially lies the internal capsule: its anterior limb separates the lentiform nucleus from the head of the caudate nucleus, and its posterior limb separates it from the thalamus. Laterally, in order, come the external capsule, the claustrum, the extreme capsule and the cortex of the insula. Below lie the anterior perforated substance and the anterior commissure.

Functionally the putamen receives most of the input from the motor and sensory cortex, and the globus pallidus sends the output to the thalamus. The lentiform nucleus is a common site of hypertensive haemorrhage from the thin lenticulostriate arteries, which also endangers the nearby internal capsule. Copper deposits in Wilson's disease, also called hepatolenticular degeneration, damage it.

Function and supply

Function

Part of the basal nuclei: the putamen receives cortical input and the globus pallidus sends output to the thalamus, helping to start wanted movements and suppress unwanted ones.

Blood supply

Mainly the lenticulostriate (lateral striate) branches of the middle cerebral artery, with the medial striate artery (recurrent artery of Heubner) from the anterior cerebral artery in front and the anterior choroidal artery to the medial pallidum.