MEDICINE

Senility in retreat

JOHN BARBER November 24 1986
MEDICINE

Senility in retreat

JOHN BARBER November 24 1986

Senility in retreat

MEDICINE

Their recovery had all the drama of a biblical miracle, but the victims were suffering from an ailment identified only this century—the devastating condition known as Alzheimer’s disease. And they were aided not by divine intervention but by a few pills in what could be an important breakthrough in treatment of the debilitating condition. Dr. William Summers of the University of California at Los Angeles gave 17 patients the experimental drug tetrahydroaminoacridine (THA), and 16 of them experienced significant recoveries. One man, who was so incapacitated that he could barely speak, not only talked but even took up golf again. Another, less severely affected by the disease, resumed parttime work. Others who took the pills remembered their own names and recognized their families for the first time since slipping into senility. Although the testing was limited, no other treatment has ever shown such promise. “If this is validated,” said Summers, “I think we will have our first viable treatment for Alzheimer’s.”

Summers’s findings, which were published in last week’s edition of The New England Journal of Medicine, are the outgrowth of a crucial 1983 discovery of how Alzheimer’s affects the brain. At the time, researchers found that the disease impaired the brain’s ability to make acetylcholine, one of several chemicals known as neurotransmitters, which help carry messages between nerve endings in the brain. Since then, they have experimented with several compounds designed to replace the missing acetylcholine and some have shown promise. But none of them has produced results comparable to those achieved with THA, which, according to Summers, helps the acetylcholine that remains in the body to work more effectively.

But Summers emphasized that the drug cannot be considered a cure for Alzheimer’s disease. Indeed, an editorial in the Journal calle'd the THA treatment “ultimately flawed” because it attacks a symptom—the depletion of acetylcholine —rather than the cause of the disease, the stillunknown process that destroys the brain cells producing the chemical. Summers said that although the drug could prove highly effective in reversing and preventing memory loss, the disease will continue to progress “underneath the medication.” He added, “I expect that toward the end there

will be more or less a sudden collapse.” One leading Canadian Alzheimer’s researcher, Dr. Arthur Dalton of Toronto’s Surrey Place Centre, a provincial government facility for the developmentally handicapped, said that the announcement “gives no reason for optimism at this time.” Still, Dalton

In its first trial, the experimental drug THA proved almost miraculously effective against Alzheimer's disease

noted that the replacement of missing chemicals has proven successful with other diseases, especially Parkinson’s disease, which can be controlled with the chemical levodopa. He speculated that, because Alzheimer’s leads to the depletion of several other chemical transmitters in addition to acetylcholine, doctors may one day be able to

suppress or reverse its symptoms with a combination of chemicals including THA.

The announcement highlighted the success of a nationwide effort in the United States to find a cure for Alzheimer’s, which is believed to affect five to 10 per cent of people over 65. In the past three years, Washington has committed $207 million to Alzheimer’s research, compared to only $600,000 in Canada over the same period. One result, according to Dalton, is that Canada may lose its leading role in Alzheimer’s research, and several Canadian scientists are leaving the country. Dalton himself will be out of Canada for at least a year to conduct a major Alzheimer’s study at the Institute for Basic Research in New York.

In the meantime, Summers’s THA research is at an impasse. The drug was first discovered in 1909, and no firm currently holds a patent on its use. The extensive tests necessary to have it licensed for general use are costly, and no company has expressed a willingness to finance them. But if the U.S. research drive continues at its current pace, it is almost certain that that difficulty will be swept away, and that at least some future victims will be granted a reprieve.

—JOHN BARBER in Toronto