MRI research demonstrates ALS attacks multiple parts of the brain, not just
those responsible for movement

September 16, 2011: Edmonton – Recently published studies by a researcher
in the Faculty of Medicine & Dentistry demonstrate that ALS – known as Lou
Gehrig’s disease – damages neurons in parts of the brain responsible for
cognition and behaviour.

ALS, which stands for amyotrophic lateral
sclerosis, is a fatal neurodegenerative disease that eventually leaves patients
unable to move, breathe or swallow. Previous research has shown about 50 per
cent of patients with ALS also have mild cognitive and behavioural changes, but
between five and 15 per cent of patients can have severe changes resulting in
dementia. In Canada, between 2,500 and 3,000 people live with the disease. Most
die within two to five years of diagnosis.
Sanjay Kalra, a researcher in the
faculty’s Division of Neurology and a practising neurologist, has published two
papers this year in the American Journal of Neuroradiology providing evidence
that ALS affects more than just the motor cortex, the part of the brain
responsible for motor function.

“ALS was previously thought to be a
disease restricted to the motor system causing only weakness,” says Kalra, the
principal investigator in both peer-reviewed papers. “But a significant
proportion of people with ALS also have cognitive and behavioural changes. We
wanted to know how ALS was impacting other parts of the brain to cause these
symptoms.

“There is increasing evidence from pathological studies of ALS
patients post-mortem that not just the motor system is involved. Our research
supports this and demonstrates in those living with ALS, that the disease is
indeed attacking other parts of the brain. The cognitive and behavioural changes
we are seeing in patients are not reactive,” he says. “They are not happening
because someone is depressed or doesn’t have initiative because he is weak.
Those changes are happening because there are biological and chemical changes in
parts of the brain that are responsible for behaviour and cognition.”

Kalra uses magnetic resonance imaging (MRI) not to just look at pictures
of the brain, but also as a means of measuring the levels of various chemicals
in the brain. In his most recently published paper, he looked at two different
chemicals called NAA and mIns. NAA is known as a neural marker, which means it
is only found in neurons, while levels of mIns increase when there is abnormal
scarring in the brain.

“If NAA is decreased, it means neurons have died
or they are not working. Many papers have shown NAA to be decreased in regions
where you expect it to be decreased with ALS – the motor cortex. But our recent
study shows that these levels are also decreasing in areas of the brain
responsible for cognition and behaviour,” says Kalra.

His paper
published in early 2011 looked at decreasing levels of NAA in the cingulate
cortex – the first time MRI had been used to measure chemicals in this region of
the brain in ALS. And his most recently published paper, which came out late
this summer, was the first to demonstrate that NAA was decreasing and mIns was
increasing in the frontal lobe, even when there weren’t signs of cognitive or
behavioural issues in patients. The frontal lobe is considered the hub for
cognition and behaviour in the brain.

Kalra would like to continue his
research using MRI to track the changes in the brain of those who have ALS, and
to evaluate new drugs. Kalra is the leading researcher in Canada to use MRI to
study ALS. In November 2010, he was invited to give a presentation at Oxford
University, and earlier this year he collaborated with a number of international
researchers to write a commentary piece in Lancet Neurology about this growing
area of research.

He first became interested in studying ALS when he was
a neurology resident looking for a research project using MRI. He has continued
studying the disease ever since.

Funding for this research was provided
by the University Hospital Foundation, the MSI Foundation of Alberta, ALS
Society of Canada, ALS Association, and the Shelly Mrkonjic ALS Research
Fund.

For more information, please contact:
Raquel Maurier,
Communications Associate
780-492-5986 (office); 780-224-7751 (cell); raquel.maurier@ualberta.ca