I was diagnosed back in Jan '09 aged 34. My sister, who is asymptomatic discovered that I was eligible for Disability Living Allowance (DLA) here in the U.K. (I live in Worcestershire). Basically anybody in the U.K. with symptomatic AMN is eligible for DLA it just depends on how restricted your mobility is as to how much money you will receive, it is broken down into two components and both are assessment led.
The problem is that at the moment this system is in the process of being replaced by the new Personal Independence Payment (PIP). I say problem because the government has been very ambiguous about the whole situation and what it means for us and other people that are living within the spectrum of disability.
As far as any other governmental help goes you can apply for cost free modifications to your home - say bathroom hand rails and that kind of thing. Application for a drivers Blue Badge is handled by your local council - again you shouldn't have any problems getting one of these. If your partner is eventually awarded the higher rate of the DLA mobility component you will be eligible for a new car through the car Mobility scheme.
I hope this has helped you out, if there is anything else I can help you with I can give you my Email address.