Section 6. Brain, Spinal Cord, and Nerve Disorders

Chapter 91. Movement Disorders

Topics: Introduction | Myoclonus | Tremor | Parkinson's Disease | Progressive Supranuclear Palsy | Shy-Drager Syndrome | Tics | Chorea and Athetosis | Huntington's Disease | Dystonia | Coordination Disorders

Introduction

Every body movement, from raising a hand to smiling, involves a complex interaction between the central nervous system (brain and spinal cord), nerves, and muscles. Damage to or malfunction of any of these components may result in a movement disorder.

Different types of movement disorders can develop, depending on the nature and location of the malfunction or damage. For example, damage to the connections between the brain and spinal cord can cause weakness or paralysis of the muscles involved in voluntary movements and can exaggerate reflexes. Damage to the basal ganglia (collections of nerve cells located at the base of the cerebrum, deep within the brain) can cause involuntary or decreased movements but not weakness or changes in reflexes. Damage to the cerebellum causes incoordination. Some movement disorders, such as hiccups, are temporary, usually causing little inconvenience. Others, such as Parkinson's disease, are serious and progressive, impairing the ability to walk, speak, use the hands, and stand.

See the sidebar Hiccups: Spasms of the Diaphragm.