Northland was not the only region where patients were facing long waits.
In Taranaki and South Canterbury, people were waiting four months for an initial appointment - the maximum time Ministry of Health guidelines allow for first specialist assessments.
Taranaki District Health Board chief operating officer Wendy Langlands said some patients would have to wait up to four months for a first appointment to offer those with the highest clinical need to get treatment first.
Mr Woodhams said the waiting times for people to see a neurologist were unacceptable.
"In Palmerston North, we have reports of people waiting 15 months for a follow-up.
"Delays can mean that a person with MS cannot access the treatment they desperately need in a timely manner which may result in disease progression and disability."
Mr Woodhams believed the delays were caused by under-resourcing of the specialty because of a lack of funding.
"New Zealand only has 37 full-time equivalent neurologists employed in DHBs across the country. This figure is a disgrace," he said.
An article in the New Zealand Medical Journal in August 2015 found 74 full-time neurologists were needed to cope with demand at that time, with pressure only expected to increase.
The journal also found about half of the current workforce would hit retirement age by about 2027 but, on average, only one new New Zealand-trained neurologist was entering the country's workforce each year.
"As a result of these shortages, neurologists, MS nurses, and other staff are being placed under intolerable pressure to try and provide an adequate service," Mr Woodhams said.
"The latest evidence is that the sooner you are diagnosed and the sooner you get on to treatment, the more likely the drugs that are available in New Zealand for treating MS will be successful.
"Any undue delays in diagnosis - that means not just an appointment with the neurologist but access to MRIs, access to ophthalmology - is not desirable."
As at May 26, some MS patients in Canterbury were waiting more than six months for MRI results.
Acting chief of radiology Dr Mike Hurrell said the current waiting time had now fallen to 22.5 weeks for a routine MRI but urgent cases could be seen within 48 hours.
Clinical status guidelines meant even the least urgent MS patients should be seen within four weeks, according to the district's written response.
Dr Hurrell said a rapid increase in population and new funded drugs for MS which required an MRI to determine suitability had put pressure on radiology resources.
Pharmac now also required an annual review and MRI scan for MS patients on funded treatments which was only increasing the workload for neurologists, he said.
Association of Salaried Medical Specialists executive director Ian Powell said he was aware there was an undersupply of neurologist positions in the country's public hospitals.
"These are not so much advertised positions but positions not advertised leaving existing staff to cover.
"This means overstretched neurologists, delays in specialist assessments and delays in necessary follow-up treatment."
About Multiple Sclerosis:
- MS is a progressive disease of the central nervous system, for which there is no cure at present
- MS affects 2.3 million people worldwide
- About 4000 New Zealanders live with the disease
- More women than men have MS, with a global ratio of three women to one man
- Diagnosis of MS is generally between 20 and 40 years of age, although onset may be earlier
- MS attacks the nervous system. Symptoms can include sight loss, pain, fatigue, incontinence and disability.