Would mri of brain and emg being normal rule out als or ms 33 yr old male.

Probably: If you have MS, I would expect there to be some sign of it on your MRI of the brain. Likewise, if you had ALS I would expect there to be some evidence for it on EMG testing, as you mention. Since nothing is "black and white" with these two diagnoses, I would discuss the results and your concerns with your neurologist. Take care, and stay well!

Never say never: Yes, it is quite unlikely you have either ALS or MS, considering your test results. Hasn't the person who ordered these tests for you discussed this? In medicine, few things are certain, but it is time to consider less serious causes of your symptoms. Muscle twitching is very common, and is often caused by benign conditions, such as exercise regimen changes.

Reassuring: Sounds like your main issue involves headaches, and spasms. You should be comforted by normal testing, but if still uncertain, or symptomatic, take some time for a clinical conference with your doctor.