RT Book, Section A1 Xia, Yaqin A2 South-Paul, Jeannette E. A2 Matheny, Samuel C. A2 Lewis, Evelyn L. SR Print(0) ID 1106851725 T1 Movement Disorders T2 CURRENT Diagnosis & Treatment: Family Medicine, 4e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071827454 LK accessmedicine.mhmedical.com/content.aspx?aid=1106851725 RD 2024/03/29 AB Movement disorders (MDs) are a broad spectrum of motor and nonmotor disturbances arising from the dysfunction of subcortical motor control circuitry, including basal ganglia and thalamus, as well as other parts of the nervous system, involving the cortex, cerebellum, central, and peripheral autonomic nervous system. Patients suffering from MDs have normal muscle strength and sensation, but their normal voluntary motor activities are influenced or impaired by involuntary movement, alteration in muscle tone or posture, and loss of coordination or regulation—either facilitation or inhibition—of pyramidal motor activities as a result of malfunction. MDs can be classified into the following categories on the basis of their clinical manifestations: tremor, chorea and choreoathetosis, dystonia, myoclonus, tics, and ataxia. MDs include less movement (hypokinesia or akinesia), or excessive movement (hyperkinesias), or both (Table 44-1).