So, if you have an intermittant disability, you can't possibly need a carer?
That's bullshit. I don't have seizures every day - but when I do, I am unconcious and therefore need a carer. sometimes I can go 3 weeks without a seizure, sometimes I can have 3 in one day. Doesn't mean I'm not disabled.
And how many people will hold a job open for you to WORK and be in PAID EMPLOYMENT if your condition is intermittant, and therefore so is your time off sick - it can't be planned for, it might be every few weeks, it might be 6 times in a week, it might be literally an hour before your shift starts, it might be in the middle of your shift, necessitating a hospital visit or a return home to bed - and therefore leaving work short-handed.
It's practically impossible to get an employer to take you on under those circumstances.
An intermittant disability is no less disabling just because it isn't present 24/7.