Motor neuron disease (MND) is one of 5 neurological disorders, that selectively affect motor neurons, the cells that control voluntary muscles of the body.

• Amyotrophic lateral sclerosis (ALS), which involves BOTH UMN and LMN degeneration
• Primary lateral sclerosis (PLS), which involves UMN degeneration only
• Progressive muscular atrophy (PMA), which involves LMN degeneration only
• Progressive bulbar palsy (PBP), which involves LMN degeneration in the bulbar region
• Pseudobulbar palsy, which involves UMN degeneration in the bulbar region

• Neurodegenerative in nature, and cause increasing disability and eventually, death

• In the USA and UK, the term MND is often used interchangeably with ALS
• Whilst MND refers to a specific set of diseases, there are numerous other diseases of motor neurons that are referred to as motor neuron disorders, e.g. spinal muscular atrophies