The lentiform nucleus is a descriptive collective term for both the putamen and globus pallidus, which are divided by a thin layer of white matter, the lateral medullary lamina. Embryologically and functionally, the caudate nucleus and putamen form a unit, the striatum. The substantia nigra and subthalamic nucleus originate from the mesencephalon and diencephalon, respectively, and are not considered a part of the basal ganglia in this review. For the purpose of this review, the term “basal ganglia” is used in the strictest sense (the telencephalic basal ganglia) and refers to the corpus striatum (comprising the caudate nucleus, putamen and globus pallidus). The components of the basal ganglia and the method of naming depend on which aspect (biochemical, embryological or functional) of these complex structures is considered. The terminology can be confusing because of the variety of names and definitions, complex interconnections and interactions. Thalamic lesions can cause chronic pain, sensory loss, amnesia, dystonia and other disorders. The thalamus is a complex hub receiving subcortical sensory and motor input that projects to both the cortex and striatum.
Basal ganglia pathologies typically cause movement disorders, but their role extends beyond the extrapyramidal system to memory, emotion and other cognitive functions. They are involved in the regulation of autonomic, motor, sensory, limbic and endocrine functions, and consequently, their metabolic demand exceeds that of the cerebral cortex in the resting state. The basal ganglia and thalami are paired grey matter structures, embedded deep in the brain hemispheres and are often referred to as the “central grey matter”.
0 kommentar(er)
