TY - CHAP M1 - Book, Section TI - Chapter 8. Neuropathology of Parkinsonian Syndrome A1 - Dickson, Dennis W. A2 - Watts, Ray L. A2 - Standaert, David G. A2 - Obeso, Jose A. PY - 2012 T2 - Movement Disorders, 3e AB - The common denominator of virtually all disorders associated with clinical parkinsonism is neuronal loss in the substantia nigra, particularly of dopaminergic neurons in the pars compacta (A9) that project to the striatum (Fig. 8–1). The exception to this concept is parkinsonism due to direct injury to the striatum, such as that seen in vascular parkinsonism, in which infarcts or hemorrhages are present in the basal ganglia, especially the globus pallidus, without necessarily affecting the substantia nigra.1 The ventrolateral tier of neurons appears to be the most vulnerable in many parkinsonian disorders, and these project heavily to the putamen.2 The more medial group of dopaminergic neurons (A10) send projections to the forebrain and medial temporal lobe and are less affected. The basis for selective vulnerability between A9 and A10 neurons has been explored with microarray expression studies, which show different patterns of gene expression in A9 and A10 neurons,3 but much remains to be learned how this translates into selective neuronal loss of A9 neurons in parkinsonian disorders. The dorsal tier of neurons may be most vulnerable to neuronal loss associated with aging.4 SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/10/12 UR - accessphysiotherapy.mhmedical.com/content.aspx?aid=55792190 ER -