Onset and spreading patterns of upper and lower motor neuron symptoms in ALS

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal rapidly progressive adult-onset neurodegenerative disorder characterized by the progressive degeneration of upper and lower motor neurons. It has been debated whether „dying forward“ mechanisms originating in the primary motor cortex and/or „dying back“ phenomena starting in the lower motor neurons occur in ALS since the disease has first been described by Jean Martin Charcot in 1874.