Motor Neuron Disease

Cross references:   Motor Nerve Organization     Motor Neuron Evolution     
Muscle Innervation    Medial Motor Column   

Motor neuron disease (Wiki) 
    "There are five recognized subtypes of motor neuron diseases. They are distinguished by the nerve cells affected, upper motor neuron (UMN) and lower motor neuron (LMN), and the symptoms that result from this damage: 

Type UMN degeneration LMN degeneration
Amyotrophic lateral sclerosis (ALS) yes yes
Primary lateral sclerosis (PLS) yes no
Progressive muscular atrophy (PMA) no yes
Progressive bulbar palsy (PBP) no yes – bulbar region
Pseudobulbar palsy yes – bulbar region no

The term "bulbar region" in the above table refers to the mouth, face, and throat.

The disease spinal muscular atrophy (SMA) as well as various other spinal muscular atrophies are classified as motor neuron diseases by the disease terminology classification system Medical Subject Headings (MeSH) but not by the tenth International Statistical Classification of Diseases and Related Health Problems (ICD-10) published in 1992; hence, they are not discussed in this article."