Not sure you can if you are not a neuromuscular doctor. But, I have a 27 year old son who has thought he has ALS since the ice bucket challenge last summer of 2014. It s 7 months hence now, many doctors, MRI s of brain and spine, EMG s, and no diagnosis except maybe Parsonage-Turner Syndrome. Main symptoms: twitching left arm, triceps, biceps, burning pain in brachial plexus (that is why they thought PTS), some left palm atrophy. No clinical weakness, reflexes, etc., blood tests, OK. Just typical stuff on MRI s. He has an obsessive tendency and is seeing a clinical psychologist and on Lexipro since 1/6/15. He is not convinced even after meeting with Dr. Jon Glass, an ALS specialist in Atlanta where he lives, that he doesn t have ALS. My husband and I are terrified but try to reassure him. Glass said he would re-evaluate in 4 months - June 2015 but he doesn t THINK it is ALS .