Interestingly, GDNF appears selectively to promote survival of dopaninergic neurons, those which typically degenerate in Parkinson's disease. Large numbers of previous drug trials have proven negative. This discouraging picture is changing dramatically, and, for the first time, therapies that hold true promise are appearing. Most relevant are glutamate antagonists, exemplified by riluzole, and the use of neurotrophic factors such as insulin-like growth factor I and brainderived neurotrophic factor. Additionally, antioxidants and nonsteroidal anti-inflammatory agents such as aspirin may piay an important role.
Some medications have possible or proven neuroprotective properties.
Supportive measures continue to be important. It is likely that ALS has a multifactorial etiopathogenesis and may be more heterogeneous than previously recognized. As a result, it is unlikely that a single therapy will ever prove to be of major benefit, and efforts must be directed toward combination therapies. Impacting on therapy is the fact that the different manifestations From the Neuromuscular Diseases Unit, The Vancouver Ceneral Hospital, and the University of British Columbia, Vancouver, British Columbia. Vancouver, BC, V5Z lM9 Canada.