If your reflex problems are bilateral, they could be completely normal, which is why your neuro is not too concerned. They can also vary from time to time. Your neuro is simply being thorough and trying to alleviate the fears of someone who is scared (I'm sure he's aware of it) and doing a follow-up on you. Your muscle twitches would be a lower motor neuron problem and your EMG was clean, so they're not due to ALS. In my opinion, another EMG would be a waste of time and money at this time.