Easy as it is to recognize a typical case of amyotrophic lateral sclerosis, the diagnosis of an atypical form of this morbid condition is often difficult. Pathologically evidenced by degeneration of the system of the motor ganglion cells of the cortex, medulla and spinal cord, a typical case of amyotrophic lateral sclerosis manifests itself clinically by a combination of atrophies of the muscles innervated by the bulbar and spinal nerves and spasticity of the extremities, especially the lower. The atrophies are the result of degeneration of the motor cells of the medulla and spinal cord; the spasticity is the result of degeneration of the motor cells of the cortex and the consequent degeneration of the pyramidal tracts.
As has been emphasized on several occasions,1 the clinical picture of amyotrophic lateral sclerosis may be a manifestation of involvement of only a part of the system of the motor cells. For
GEORGE B. HASSIN. AMYOTROPHIC LATERAL SCLEROSISANATOMIC AND PATHOLOGIC CONSIDERATIONS. Arch NeurPsych. 1940;43(4):765–777. doi:10.1001/archneurpsyc.1940.02280040152009