CHAPTER XXXV 



The extrapyramidal motor system 



RICHARD JUNGi 

 ROLF HASSLERi 



University of Freiburg, Freiburg im Breisgau, West Germany 



CHAPTER CONTENTS 



Introduction 



Scope of Subject 



Development of Concept of Extrapyramidal System 

 Survey of Clinical Extrapyramidal Syndromes 

 Anatomy of Extrapyramidal Motor System 

 Afferent Pathways 

 Efferent Pathways 



Strionigral system (caudate portion) 



Putaminonigral connections 



Striopallidoreticular system 



Pallidofugal paths 



Striopallidocortical systems 



Red nucleus 



Normal and Pathological Physiology of Extrapyramidal 

 Structures; Effects of Stimulation and Ablation in 

 Animals and of Lesion in Man 

 Telencephalic Structures 



Striatum: animal experiments 



Striatum: studies in man 



Pallidum : animal experiments 



Pallidum ; studies in man 

 Diencephalic Structures 



Nucleus subthalamicus : animal experiments 



Nucleus subthalamicus: human studies 



Centrum medianum 



Other thalamic nuclei belonging to extrapyramidal system 

 Mesencephalic Structures 



Nucleus niger 



Nucleus ruber 

 Statokinetic and Locomotor Structures in Brain Stem 



Neuronal mechanisms of rotatory movements around 

 longitudinal axis 



Neuronal mechanisms of upward movements 



Neuronal mechanisms of downward movements 



Neuronal mechanisms of ipsiversive turning movements 



Neuronal mechanisms of contraversive turning movements 

 Cortical Extrapyramidal Areas in Relation to Subcortical 



Extrapyramidal Centers 

 Extrapyramidal Efferent Mechanisms and their Interrela- 

 tions with Cortical and Cerebellar Systems 



' The first part of this chapter (p. 864 to p. 901) was written 

 by Professor Hassler, the second part (p. 901 to p. 922) by 



Physiological Correlations and Functional Significance 

 Role in Posture and Locomotion 



Postural mechanisms as conceived by Magnus school; 



optovestibular regulation 

 Hess' experiments on statokinetic regulation and their 

 dynamic interpretation in terms of teleokinetic and 

 ereismatic motility 

 Upright posture in man and its ontogenetic development 

 Motor performances of human anencephali 

 Decerebration phenomena 

 Startle Reaction 

 Tremor 



Hyperkineses in General 



Extrapyramidal System and Spinal Reflex Activity 

 Relation of Extrapyramidal Mechanisms to Thalamoreticular 

 System : Sleep and Arousal, Motor Patterns of Attention 

 Relation of Extrapyramidal Functions to Instinctive Behavior 

 Experiments on basal ganglia of birds 

 Instinctive behavior and basal ganglia in lishes 

 Mammalian behavior studies in relation to extrapyramidal 

 centers 

 Endocrine Influences on Extrapyramidal Mechanisms 

 Electrophysiology of Basal Ganglia 

 Conclusions 



Different Organization of Extrapyramidal System in Man 



and Animals 

 Mechanism of Extrapyramidal Disorders 

 Pathological Manifestations and Normal Function of Extra- 

 pyramidal Structures 

 Lower Centers of Statokinetic Regulation in Brain Stem 

 Extrapyramidal Cortical Areas 

 Afferent Mechanisms 



Efferent Mechanisms and Cooperation with Motor Cortex 

 and Cerebellum 



INTRODUCTION 



Scope of Subject 



A neurophysiological synopsis of the extrapyramidal 

 motor system is difficult for several reasons. First, the 



Professor Jung. The introduction and conclusion were also pre- 

 pared by Professor Jung. The German text of Professor Hassler's 

 portion was translated by Dr. Johannes P. Gangloff, whose 

 great care is gratefully acknowledged by the authors. 



863 



