New and effective anti-migraine drugs aren't publicly funded in New Zealand, costing those with chronic migraine nearly 300 dollars a month

An Otago University survey suggests almost half of those with the disease meet the criteria for severe disability.

Some report paralysis on one side of the body and loss of coherent speech.

Neurologist Rosamund Hill says the medicine's publicly funded in Australia.

She says it's feasible for Pharmac to identify those at the worst end of the spectrum, and how these drugs would significantly change their lives.