A "recruitment crisis" in neurology is affecting patient care, MSPs have heard.
Professor Malcolm Macleod, clinical lead for neurology at NHS Forth Valley, said use of locums caused "chaos".
Giving evidence to Holyrood's Health and Sport Committee, he said the health board recently recieved no applications for a consultant neurology post.
He said: "I'd like to have five applicants for every job so I could choose the very best and just now I'd take anyone who'll apply and make it through to interview.
"And I don't think that's good for patients with neurological diseases in Scotland."
He said there were many reasons behind the recruitment issues, including consultants in Scotland no longer being in line for higher awards, unlike England, and a 15-20% real terms drop in salaries across the health service in the past seven years.
Mr Macleod, Professor of Neurology at Edinburgh University, said junior doctors were leaving to go into finance "because they don't see it as a career for someone like them".
He said Forth Valley health board, like others, was behind on some waiting times for neurology and in a bid to treat urgent referrals would see patients before clinics began.
He said waiting for neurological assessment could cause anxiety but locums were not helpful.
He said: "I detest this bringing in activity from outside. I think it's driven by a desire for boards to meet their waiting time targets but it is very disruptive.
"We had people coming in doing clinics over the weekend and we audited what happened and the rate at which they requested investigation was much higher than our in-house neurologists, the rate of complaints was much higher, the rate of return appointments made was much lower and the chaos that ensued was much, much, much higher.
"It would have been quicker if I had seen those 100 patients than it was to clean up the mess afterwards."
The committee also heard from Tanith Muller, vice-chair of the Neurological Alliance of Scotland, who said use of locums to address the "recruitment crisis" can be unhelpful.
She said health boards brought in locum neurologists who do not know the local support services for conditions such as Parkinson's or multiple sclerosis, leaving patients "struggling" following diagnosis.