Parsonage-Turner Syndrome (medical marijuana help?)

Hello recently my dad has been diagnosed with Parsonage Turner Syndrome (brought on by the Shingles) also known as brachial neuritis or neuralgic amyotrophy, is a peripheral nerve disorder that causes severe pain - If you have brachial neuritis, the nerves that control your shoulder, arm, and hand become inflamed. These nerves run from your spinal cord along your neck and shoulder into your arm and form what's known as the brachial plexus. ... Brachial neuritis — In his case its involving the shoulder and arm. This pain is followed in days to weeks by weakness. He has pretty much lost the use of his left arm. He is in severe pain 24-7.
 

I'm seeking any info that might help him. Thank you.


nerve.wustl.edu/nd_parsonage.php