THE first breakthrough in the treatment of Motor Neurone Disease, the devastating disorder which killed Cyril Cusack and champion jockey John Harty, is being greeted with cautious optimism by Irish sufferers.
"The reaction varies from one family to the next," says Ms Eithne Frost, director of the Irish Motor Neurone Disease Association. "There is elation on the part of some patients and a quite cynical reaction by others. The drug increases life expectancy by how much and with what quality?"
Clinical trials have shown that on average three months is added to the lives of those taking Rilutek, a drug manufactured by Rhone Poulenc Rorer which was last week granted marketing authorisation by the European Commission for use in all of the EU's 15 member states. But Dr Orla Hardiman, a neurologist at University College Dublin who has been treating many of the 240 Irish sufferers with the new drug, says this is only an average figure. The extended life expectancy could be much better for certain sub groups of patients, she believes.
Rilutek will not be licensed for use in the Republic before the end of July, but many of the 260 Irish MND sufferers have already been using the drug on a "named basis" on compassionate grounds for the past year or so. They will be allowed to continue using the drug, although newly diagnosed patients who would like to take Rilutek will have to wait until the drug is licensed here.
MND, also known as "Lou Gehrig's Disease" and as amyotrophic lateral sclerosis (ALS) affects the motor neurons of the brain and spinal cord. Among its first signs are slurring of speech, difficulty grasping objects and loss of balance. Eventually, sufferers lose the ability to dress and feed themselves, sit up, walk and even speak. Yet because MND does not affect sensory neurons, the senses of sight hearing, smell, taste and touch remain. Nor are intellect and memory affected.
Death occurs within three to five years of the first symptoms, usually as a result of damage to the motor neurons that control breathing.
While Rilutek is no miracle cure, Dr Hardiman says that if such positive results, had been seen for a cancer drug, they would be regarded as exciting. The most important aspect of the breakthrough, however is that finally researchers have discovered a mechanism by which MND works and can be halted and this could lead to even better treatment for the disease, she adds.
Although researchers have not yet discovered the exact cause of MND, one of the leading theories involves glutamate, the brain's most abundant excitatory neuro-transmitter. It is thought that people with MND have an abnormally high concentration of glutamate in their nervous systems which can damage motor neurons and may contribute to the development and progression of MND.