What are the most common symptoms of motor neuron disease?

Motor neuron disease: There are two relatively early signs of motor neuron disease (abnormal nerve function in the muscles rather than the spinal cord). First, your reflexes (like a tap on the knee to watch it jerk) become very weak or absent. The second is that you get twitching, jerks, of fasciulations in the muscle. These are episodic, brief, painless, twitches of the muscle that you can see under the skin.

Weakness: Motor neuron diseases affect the nerves that send the impulse to muscles to initiate movement. Examples of motor neuron diseases include lou gerig's disease(als) and spinal muscular atrophy. Symptoms may include limb weakness, difficulty swallowing, and difficulty breathing. Some types may also affect eye movement and facial expression.