麻豆传媒

WASHINGTON, Jan. 14 -- Restless legs syndrome patients may respond to an hour a day -- five seconds a minute -- of periodic pneumatic compression, researchers here said.

One-third of RLS patients in a randomized controlled trial who had an hour a day of compression therapy had complete resolution of their symptoms (P=0.007), Christopher J. Lettieri, M.D., and Arn H. Eliasson, M.D., both of Walter Reed Army Medical Center, reported in the January issue of CHEST.

Inflation of the compression may be an effective adjunctive or alternative therapy, the researchers said.

The specific pathophysiology of RLS is unknown, but it is regarded to be a central nervous system disorder resulting from the dysfunction of dopaminergic and opioidergic neurotransmission mediated by the metabolism of iron.

However, the researchers said it may be a peripheral disorder, because chronic venous insufficiency has been shown to have a common association with RLS.

They said tissue hypoxia and ischemia may lead to peripheral neuronal dysfunction.

Vascular compression by pneumatic compression may improve local perfusion by enhancing venous and lymphatic drainage and relieving mild and otherwise subclinical ischemia, the researchers said. It may also stimulate the release of endothelial mediators that decrease symptoms of RLS, which include difficulty sleeping, fatigue, mood changes, and social withdrawal.

Existing pharmacologic treatments for RLS include dopamine agonists, benzodiazepines, opioids, and anti-epileptics. The researchers noted, however, that success rates of these drugs are variable and the side effects can be intolerable.

So to evaluate the efficacy of compression, the researchers conducted a prospective, randomized, placebo-controlled trial of 35 patients, the majority of them with moderate to severe symptoms of RLS at baseline.

Of those patients, 21 received therapeutic and 14 received placebo pneumatic compression devices that were identical in appearance, weight, and noise generation.

The devices inflated leg wraps for five seconds of each minute. The only difference was that the real devices generated 40 cm H2O of air pressure with each inflation cycle. Sham devices only generated a 3- to 4-cm H2O rise in pressure.

Patients wore the device for an hour each day for four weeks and were asked to keep a log of their symptoms and therapy.

The researchers found that devices effectively improved the symptoms associated with RLS. Eight participants (38.1%) using the real devices experienced a complete resolution of symptoms, compared with none of those using sham devices (P=0.007).

Specific findings included the following:

• Restless Legs Severity Score improved from 14.1 ± 3.9 to 8.4 ± 3.4 (P < 0.006) and Johns Hopkins Restless Legs Scale improved from 2.2 ± 0.5 to 1.2 ± 0.7 (P < 0.01).
• All quality of life domains improved more with therapeutic than sham devices (social function 14% versus 1%, respectively, P < 0.03; daytime function 21% versus 6%, respectively, P < 0.02; sleep quality 16% vs 8%, respectively, P < 0.05; emotional well-being 17% vs 10%, respectively, P < 0.15).
• Both Epworth sleepiness scale (6.5 ± 4.0 versus 11.3 ± 3.9, respectively, P < 0.04) and fatigue (4.1 ±2.1 versus 6.9 ±2.0, respectively, P < 0.01) improved more with therapeutic devices than sham devices.

Those using compression who had more severe symptoms at baseline had a greater reduction in symptoms, and those who had more severe disease at baseline had lower severity scores at the end of therapy, they added.

There was a placebo effect, but using compression resulted in significantly greater improvements in disease severity, quality of life scores, and other symptom improvements.

The researchers said that compression may be impractical because they require patients to be immobile for an hour each day.

They noted that most patients have symptoms in the evening when they may be relaxing, thus minimizing the ambulatory limitations for the patient.

They suggested the devices could be used in patients who are refractory to treatment or intolerant of pharmacologic side effects.

The study may have been limited by reliance on patients' self-reported logs, and further validation studies are needed before the therapy is ready for wide-spread use.

Aircast LLC, manufacturer of VenaFlow system pneumatic compression devices, supplied the treatment and sham devices for the study. The researchers reported no conflicts of interest.

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