An insight into the neuroanatomy of the basal ganglia in the cerebral hemisphere

The basal ganglia, or nuclei, are cluster of gray matter masses located within the white matter of the cerebral hemispheres. The anatomy and relationships of the basal ganglia can be confusing due to the varying terms and definitions used to describe this region. Understanding their anatomy is important because of their diverse connections and relationships with motor and cognitive functions. This anatomy must be clearly defined so that clinicians can identify any disorders affecting them. This short article aims to provide a simplified, concise, and up-to-date overview of the basal ganglia of the cerebrum. The basal ganglia are 4 pairs in number in the cerebrum; caudate nucleus, lentiform nucleus, claustrum and amygdala, plus two more associated with the midbrain called the subthalamic nuclei above the midbrain and substantia nigra within the midbrain. The basal ganglia of the cerebrum are closely connected to surrounding structures including the cerebral cortex, the substantia nigra of the midbrain, and the thalamus. The striatum, consisting of the caudate nucleus and the putamen of the lentiform nucleus, represents the primary input to the basal ganglia, while output information emerges mostly from the inner part of the lenticular nucleus called the pallidum. The basal ganglia are supplied with blood mainly by the middle cerebral artery via the lenticulostriate arteries, which are prone to hemorrhagic stroke in cases of uncontrolled hypertension.