RT Book, Section A1 Greenberg, David A. A1 Aminoff, Michael J. A1 Simon, Roger P. SR Print(0) ID 1182391043 T1 Motor Disorders T2 Clinical Neurology, 11e YR 2021 FD 2021 PB McGraw-Hill Education PP New York, NY SN 9781260458350 LK neurology.mhmedical.com/content.aspx?aid=1182391043 RD 2024/03/28 AB Normal motor function depends on the transmission of signals from the brain to the brainstem or spinal cord by upper motor neurons, and from there to skeletal muscle by lower motor neurons (Figure 9-1). A lesion that involves this pathway anywhere along its length may impair motor function. Anatomic structures involved in the regulation or execution of motor activity include the pyramidal and extrapyramidal systems, cerebellum, and lower motor neurons in the cranial nerve nuclei of the brainstem and anterior horns of the spinal cord.