Hi Suki,
This is not the answer you want to hear ! But if you were from an EU country you would not have a problem, you would be able to use GP's etc !
The fact that your hubby has a condition that needs monitoring you would be wiser to contact BUPA or possibly HSA for cover before he goes.......a neurologist is high ranking and even us locals would wait months to see one on the NHS.
So better to be safe than sorry !
Good Luck, Nance