The History of the Basal Ganglia: The Contribution of Karl Friedrich Burdach

It took many centuries for the basal ganglia (BG) to be recognized as specific brain entities involved in the control of psychomotor behavior. Andreas Vesalius (1514-1564) was the first to delineate this set of structures, but he did not name them nor payany attention to their functional significance. This was left to the English physician Thomas Willis (1621-1675), who used the term corpus striatum (striated or chamfered body) to designate the largest BG constituent, which he considered a major sensorimotor integration center. Willis’s pioneering description influenced markedly some 18th and 19th centuries scholars, particularly the German physician and anatomist Karl Friedrich Burdach (1776-1847). Burdach’s insightful studies of the human brain are summarized in a three-volume treatise entitled Vom Baue und Leben des Gehirns (1819-1826). This landmark opus provides a description of the BGwhose originality has largely been overlooked. Burdach’s careful investigation allowed him to differentiate the caudate nucleus from the putamen, which he respectively termed Streifenhügel (elongated hillock) and Schale (shell). He also called the putamen Linsenkern (lens-shaped nucleus), a term that he admittedly borrowed from his compatriot Johann Christian Reil (1759-1813). He further identified a paler structure (blasser Klumpen) within the inner portion of the lentiform nucleus that he called globus pallidus, and correctly identified its inner and outer segments (innern und ?ussern Theil). He aptly pointed out that the major BG nuclei are separated from one another by fibers fascicles that he termed inner and ?ussre Capsel (internal and external capsules). Burdach also referred to the substantia nigra (schwarzgraue Schicht or stratum nigrum) and claustrum (Vormauer), but gave full credit to the French anatomist Félix Vicq-d’Azyr (1748-1794) for their discovery. Although Burdach did not comment much on BG function, his anatomical description was sufficiently cogent to be still in use two centuries after its inception.

Reduced striatal volumes in Parkinson’s disease:a magnetic resonance imaging study

Background:The presence and extent of structural changes in the brain as a consequence of Parkinson’s disease(PD)is still poorly understood.Methods:High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were examined.Putamen,caudate,and intracranial volumes were manually traced in the axial plane of 3D reconstructed images.Striatal nuclei volumes were normalized to intracranial volume for statistical comparison.Disease status was assessed using the Unified Parkinson’s Disease Rating Scale and Hoehn and Yahr scale.Cognitive status was assessed using global status tests and detailed neuropsychological testing.Results:Both caudate and putamen volumes were smaller in PD brains compared to controls after adjusting for age and gender.Caudate volumes were reduced by 11%(p=0.001)and putamen volumes by 8.1%(p=0.025).PD striatal volumes were not found to be significantly correlated with cognitive or motor decline.Conclusion:Small,but significant reductions in the volume of both the caudate and putamen occur in PD brains.These reductions are independent of the effects of age and gender,however the relation of these reductions to the functional loss of dopamine,which is characteristic of PD,remains unclear.