UBC Reports | Vol. 47 | No. 07 | April
5, 2001
On the track of a killer
Dr. Andrew Eisen is hot on the trail of a disease that paralyses its
victims
by Hilary Thomson staff writer
The disease is mysterious.
It appears in clusters in unlikely places that range from a
California football
team to a South Pacific island.
Long believed to be a disease of the spine, it may actually be a disease of the
brain.
It has no cure yet patients are known to have a remarkably positive outlook.
The disease is amyotrophic lateral sclerosis (ALS). It has been the
fascination of Dr. Andrew Eisen for more than 30 years.
"Working with this disease is like unravelling a detective story," says Eisen,
the director of Vancouver's ALS Clinic and head of UBC's Dept. of
Neurology. "It's baffling and simple at the same time."
Eisen originally studied neurosurgery before going on to neurology. He obtained
his medical degree at the University of Leeds in England and completed his
residency in Neurology at the Montreal Neurological Institute. He was appointed
to staff there in 1968, and later taught at Montreal's McGill
University.
By that time, he was captivated with understanding human motor function and
with ALS, also known as Lou Gehrig's Disease after the U.S.
baseball player who died of the illness in 1936.
Eisen joined UBC in 1980 to direct the Neuromuscular Disease Unit and
the ALS Clinic -- both located at Vancouver Hospital. An internationally
recognized expert, his patients come from all over North America.
"If you are lucky and your neurologist is on the ball you'll be referred
to Dr. Eisen," says Sue Lewis-O'Halloran, president of B.C.'s ALS
Society. "He's reputed to be the top ALS diagnostician in the world -- and
this disease is hard to diagnose."
Monitoring almost one-third of the 3,000 Canadians with the disease, the ALS
clinic is the only one in B.C. and the largest in Canada. Its
database tracks an illness that is rapidly progressive and fatal.
Early symptoms often include difficulty swallowing or slurred
speech, tripping and falling and loss of power in hands and arms. Complete
paralysis can occur at any time within two to five years of diagnosis. About 20
per cent of those diagnosed live for more than five years and up to 10 per cent
survive more than 10 years.
The disease attacks the motor neurons that transmit electrical impulses from
the brain to voluntary muscles throughout the body. Over time, muscles lose
strength and cease to function. Brain activity remains healthy but support is
required to move, breathe, eat and communicate.
Most people with ALS are between 50 and 75 years old. Between ages 40-50
twice as many men as women get the disease. After 50 years of age the incidence
is equal but increases for women over 75 years.
As the baby boomer population ages, pressure to understand this disease and its
cause is increasing.
"There are many theories and just as many questions," says Eisen.
"We're now
exploring the idea that the disease starts in the brain and then kills cells
in the spinal cord."
Mysterious aspects of the disease include the fact that although old cells
appear to be more vulnerable to the disease, accounting for its late onset,
it does not seem to be a degenerative disease. Many patients are fit rather
than frail.
Also, only the motor cells in the brain and spinal cord are
affected.
It is a human disease only, not known in other primates. And two
groups of muscles,
those operating eyes and the bladder, are untouched by the disease.
"This is an important clue about the origin of ALS," says Eisen. "These
two areas are not directly connected to the brain. Since they are
unaffected it supports the theory that ALS is a brain
disease."
Eisen has used cortical magnetic stimulation to better understand how and where
ALS might affect the brain. The painless technique uses a
magnetic stimulator to assess the function of the motor pathways.
Eisen's research has earned him the prestigious 1999 Forbes
Norris award, an international recognition sponsored by the Motor Neuron
Disease/ALS Association of England and Wales. In 1998, he was
also named a distinguished researcher by the American Association of
Electrodiagnostic Medicine and was the recipient of the Distinguished Medical
Research Lecture at UBC.
"The level of funding for ALS in Canada is not good with about six to
seven new grants awarded annually," says Eisen. "We hope the situation may
improve through the new Canadian Institutes of Health Research."
But tracing the disease to its source is only part of the detective work.
Another is finding the cause of the malfunction.
Researchers have explored environmental factors such as the presence
in water of lead, mercury, aluminum or calcium. These elements are found in
areas where there is high incidence of the disease, such as the South Pacific
island of Guam, in western New Guinea and on the Kii peninsula in Japan.
Other clusters for the disease include patients serving in the merchant navy
in Halifax in the 1950s. Three members of the San Francisco `49ers football
team were also diagnosed. The cause or mechanics of the clustering
is not known
and it is very difficult to prove that they are
statistically significant,
says Eisen.
Family history of ALS is very rare -- less than five per
cent of patients
have family members with the disease. Mutations in at least two
genes have been
discovered in relation to ALS and one of those occurs in about 20 per
cent of familial ALS.
"A single genetic factor is unlikely," says Eisen. "It may be a multi-gene
problem connected with aging genes, but I suspect the answer may come from a
whole different source -- one we haven't even explored."
Diagnosing patients who have a fatal disease with no known cause isn't easy.
"Breaking the news is the hardest part," says Eisen who recommends compassion
and understanding as an antidote to burnout. "The diagnosis may take 10 minutes
but I usually spend hours with the family -- it's very draining
emotionally."
Although there are few therapeutic options and limited time for treatment
because of the disease's rapid progression, Eisen finds that ALS
patients are a joy to work with and surprise him with their positive outlook.
"This man is so determined to find answers for these patients,"
says Lewis-O'Halloran.
"Now there's hope because of people like him."
Patients at the ALS clinic were part of the initial trial for the only
drug yet developed for the disease, Rilutek. It had some modest
effects. Interventions such as providing stomach tubes and
non-invasive ventilation allow patients to stay at home comfortably.
Future therapy will likely explore the effectiveness of infusing
human stem cells -- the precursor cells that produce the wide variety of mature
cells -- into the motor cortex and spinal cord of ALS patients. The goal
is to replace damaged and dying motor neurons.
Eisen also shares his knowledge with undergraduates and over his 30-plus-year
career he has worked with almost 100 fellows and residents. He has some
concerns about teaching, however.
"There are pressures on students having to cover too much ground
today. It's
not possible to match the necessary time with the advances that
have taken place."
A soft-spoken man, Eisen offsets the demands of
his work with
many activities, including photography. In the hallway leading to
his office
hang pictures that document travels to exotic locales. Iguanas,
rhinos and domed
sepulchres all have been captured by his lens.
He is also a runner, skier, golfer and opera buff, but
does not hesitate
to cite his long and sustaining marriage as a primary source of balance and
renewal.
For students contemplating a career in neurology he has some advice.
"Neurology is a spectacular specialty. It is a continuous detective story
involving the workings of the brain and mind and muscles. ALS and all
neurodegenerative diseases are not going away -- if I were to start my career
now I would look at molecular biology and genetics of ALS."
Next year Eisen will preside at the World Congress of Neuromuscular Diseases
being held in Vancouver. It will be a concentration of global experts all
seeking to solve the mysteries of ALS. It is doubtful that Canada could
find a better representative.
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