Changes in Motor Unit Loss and Axonal Regeneration Rate in Sporadic and Familiar Amyotrophic Lateral Sclerosis (ALS) – Possible different Pathogenetic Mechanisms?

Amyotrophic Lateral Sclerosis (ALS) is a fatal, neurodegenerative disorder affecting upper and lower motor neurons; it’s the commonest of the motor unit (MU) diseases in Europe and North America, characterized by a broad spectrum of clinical presentations [1, 2]. Striking asymmetry and selective involvement of individual groups of muscles, especially of hand and forearm, are typical early features of the disease. On average, delay from onset of symptoms to diagnosis is about 14 months and expected survival commonly ranges from months to a few years [3].