Tim Lynch, consultant neurologist at Beaumont and the Mater hospitals, says the "underdevelopment" of clinical services is denying Parkinson's patients' opportunities to improve their quality of life.
"My clinic is booked up until 2006, with a waiting list of nine to ten months, and my colleagues also have waiting lists of up to 12 months," he said.
There is no definitive diagnostic test for Parkinson's disease and a diagnosis, based on a patient's medical history and neurological examination, can take an hour and a half.
"It is causing people anxiety and concern about what they have getting tremors is very worrying and while GPS do a great job people want to be seen by those with specific training," he said.
There are 14 neurologists in Ireland, a ratio of one per 250,000 people. While two new appointments are expected soon, Mr Lynch says a trebling of numbers is needed to reach a target of at least one neurologist per 100,000 people.
"It's been very, very slow moving we need desperately to increase the numbers of neurologists," he said. "It is one of the sins of omission of the Department of Health."
The consultant also revealed that many patients who could benefit substantially from neuro-surgical intervention (deep brain stimulation surgery or DBSS) are not taking up treatment because they must travel abroad for it.
"It's particularly frustrating. These surgeries could be done in Ireland to develop our care and expertise for the treatment of Parkinson's," said Mr Lynch.
About 20 patients from Ireland have travelled to France, Germany or England over the last two years months to undergo DBSS.
"DBSS improves the quality of life of patients substantially and probably not infrequently people who would benefit don't get surgery due to the logistics involved," he said.
A Beaumont hospital spokesman said a proposal to provide DBSS was made to the Eastern Regional Health Authority last year but still "awaited approval". The Health Service Executive, meanwhile, said it is "moving to develop services for patients in all areas as quickly as possible".
Mr Lynch was speaking at a conference organised by the Conway Institute at UCD entitled 'Neurodegeneration Ireland'.