Complex sentence: ALS is characterised by muscle spasticity, rapidly progressive weakness due to muscle atrophy, and difficulty in speaking (dysarthria), swallowing (dysphagia), and breathing (dyspnea).
Split into simpler sentences: ALS is characterised by muscle spasticity, rapidly progressive weakness due to muscle atrophy. This results in difficulty speaking (dysarthria), swallowing (dysphagia), and breathing (dyspnea).