TY - CHAP M1 - Book, Section TI - Motor Neuron Disease A1 - Berkowitz, Aaron L. PY - 2016 T2 - Clinical Neurology and Neuroanatomy: A Localization-Based Approach AB - This chapter discusses a group of diseases that affect motor neurons in isolation, collectively referred to as motor neuron disease. Motor neuron disease can affect upper motor neurons (motor neurons of the central nervous system), lower motor neurons (motor neurons of the peripheral nervous system), or both (Table 28–1). The primary symptom of motor neuron disease is weakness. The distribution of weakness, associated signs (upper motor neuron vs lower motor neuron vs both; see “Upper Motor Neuron Lesions Versus Lower Motor Neuron Lesions” in Ch. 4), and pace of progression differ depending on the disease. Just as there are upper and lower motor neurons for the muscles of the extremities, the motor cranial nerves contain lower motor neurons under the control of upper motor neuron cortical input (corticobulbar tract). The muscles of the face, larynx, and pharynx (bulbar muscles) are affected in many motor neuron diseases. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - neurology.mhmedical.com/content.aspx?aid=1174549355 ER -