Which brand and form of B 12 should I use?

I have a neurological condition (see below if you want the details). A public hospital doctor prescribed a monthly intramuscularly injection of 1000mcg cyanocobalamin B 12. I have taken 4 injections in 4 months with no effect.

I believe B 12 would really help, but the dosage I am receiving just isn't enough and now I want to take B 12 on my own account. Can someone tell which brand and which form of B 12 I should take?

For your reference I came cross two products:

1. B-12 Methylcobalamin 1000mcg Sublingual (by Natural Factors), 90 tablets for $10 (http://www.vitaminlife.com/product-exec/product_id/40363/nm/B-12+Methylcobalamin+1000mcg+Sublingual). It claims to be more potent than injection. Could this be true?

2. Vitamin B 12 Patch (8 Patches) for $24 (http://www.amazon.com/dp/B002GUFCAU/ref=asc_df_B002GUFCAU959873?smid=A2FQNJZGIT5DKQ&tag=dealtmp5017-20&linkCode=asn&creative=380341&creativeASIN=B002GUFCAU).

I appreciate other ideas that may help my condition.

[My condition: Early this year, I woke up and found the feeling, but not appearance, of facial imbalance, with the left feeling down and the right feeling up. When I closed my eyes, the left side was dark while the right side was "bright". I believe my nerve was damaged after using a screwdriver with my right hand a lot for several days (first pain in my right shoulder and later the facial nerve was also affected), although the doctors I saw wouldn't buy this. To make the story short, I tried lots of things and the condition has much improved, about 70% I would say.]

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