The Flail Limb Syndrome

The authors aim to compile and clarify the clinical and electrophysiologic features of flail limb syndrome (FLS), a rare lower motor neuron disorder distinct from classic amyotrophic lateral sclerosis (ALS). They highlight the syndrome's characteristics, including its male predominance, slower progression to respiratory failure, and the variability of upper motor neuron signs, while noting the lower frequency of associated genetic mutations compared to classic ALS. The study emphasizes the importance of a two-year period of regional stability for accurate diagnosis and prognosis.