Which of the following represents the site of lesion in Motor Neuron disease?
High-Yield Explanation
Amyotrolic lateral sclerosisis the most common type of motor neuron disease. Pathologic hallmark of this disease is the death of lower motor neurons (which consist of anterior horn cells in spinal cord and their brainstem homologues innervating bulbar muscles ) and upper motor neurons (which originate in the motor coex and descend pyramidal tract to synapse with lower motor neurons). Ref: Harrisons Principles of Internal Medicine 18th Edition/Chapter 374; Molecular Neurology By Stephen G. Waxman, Page 308