TORONTO, April 5 /CNW/ - A new study shows that patients in stroke
rehabilitation treated for their co-existing obstructive sleep apnea
(OSA) recovered better from stroke than those whose OSA was not
The study, published in the April edition of the journal Stroke, found "significant improvements" in functional and motor outcomes as
well as mood of stroke rehabilitation patients who received continuous
positive airway pressure (CPAP), a small mask placed over the patient's
nose during sleep that alleviates OSA.
"These new findings are important because functional and motor
impairments are often the most disabling features of stroke, limiting
people's mobility and participation in daily activities," says Dr.
Clodagh Ryan, lead author of the Toronto Rehab study. Dr. Ryan is
assistant director of Toronto Rehab's Sleep Research Laboratory and an
"If stroke patients get greater improvement in motor and functional
outcomes, such as the ability to walk, dress and bathe themselves
without assistance, they are going to be more independent and will
function better at home."
Stroke is a leading cause of disability in Canada. Only 10 per cent of
people who have a stroke recover completely. The rest are left with
permanent or long-lasting disability. The impact for stroke survivors,
and for their families, can be enormous.
OSA is a disorder that causes a person to stop breathing repeatedly
during sleep because of recurrent collapse of the throat. About five to
10 per cent of otherwise healthy people are believed to have OSA―but as
many as 70 per cent of stroke patients have the disorder. Stroke
patients with OSA have greater functional impairment and higher death
rates than stroke survivors without OSA.
The new study involved 44 inpatients in Toronto Rehab's stroke
rehabilitation service. All were diagnosed with OSA. Half of the
patients were treated with CPAP, while the other half did not receive
"The impact on patients' mobility, which is the major problem for most
of our stroke patients, was quite dramatic," says study co-author Dr.
Douglas Bradley, a Toronto Rehab senior investigator who heads the
hospital's Sleep Research Laboratory.
During the four-week trial, he says, patients treated with CPAP showed
"a markedly greater improvement in walking distance within six minutes,
a test used to determine walking ability, compared to those not treated
for sleep apnea."
Impaired motor function of the leg is a major limitation to stroke
recovery because it limits functional independence, the authors note.
CPAP usage "could improve functional independence and hasten return to
How CPAP treatment produced these benefits is not clear. It could be due
to increased brain blood flow and oxygen delivery, which alleviates
adverse cardiovascular effects of sleep apnea, and possibly through
enhanced 'neuroplasticity,' the authors suggest. Notably, CPAP
treatment had marginal, if any, effects on cognitive outcomes in the
The new study builds on previous research by Dr. Bradley that showed OSA
plays a role in inhibiting recovery from stroke. His earlier studies
found that stroke patients who have OSA spend much longer in
rehabilitation and do not recover as well physically compared to stroke
patients without the sleep disorder.
"With this study, we've moved forward to actually treat obstructive
sleep apnea in these patients, and the results are exciting," says Dr.
Bradley. "These findings have implications for people's independence
and quality of life, and for reducing the burden on caregivers and the
Although the findings are encouraging, several study limitations,
including the small sample size, make it difficult to know whether the
results apply to the general stroke population, the authors say. Also,
larger, longer-term trials are needed to determine whether such
improvements persist over longer periods.
The study's other authors are Drs. Mark Bayley and Robin Green of
Toronto Rehab, and Dr. Brian Murray of Sunnybrook Health Sciences
Centre. The authors all hold appointments at the University of Toronto,
and Drs. Ryan and Bradley also work at Toronto General Hospital,
University Health Network.
The study was supported by an operating grant from the Physicians'
Service Incorporated Foundation.
About Toronto Rehab
One of North America's leading rehabilitation sciences centres, Toronto
Rehab is revolutionizing rehabilitation by helping people overcome the
challenges of disabling injury, illness or age related health
conditions to live active, healthier more independent lives. Affiliated
with the University of Toronto as a teaching and research hospital,
Toronto Rehab integrates innovative patient care, groundbreaking
research and diverse education to build healthier communities and
advance the role of rehabilitation in the health system. Find out how
SOURCE Toronto Rehabilitation Institute
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