Ischaemic Stroke

NOTE: THESE SUMMARIES ARE OF HISTORICAL INTEREST ONLY AS THE COCHRANE REVIEWS ARE OUTDATED

STUDIES

With a loss of blood flow to the brain an ischaemic stroke can occur, causing permanent damage to nerves and brain cells. Stroke is divided into two broad subgroups: ischaemic (impairment of blood flow), and haemorrhagic (bleeding within the brain).

If the arteries become clogged up with fatty deposits, blood clots and platelets (a condition called atherosclerosis), circulation of blood to the legs can be decreased. Atherosclerosis causes narrowing of the blood vessels carrying blood from the heart to the body tissues and the increased likelihood of blood clots (thromboemboli) forming. Fragments can break off to block narrower blood vessels – which can result in a stroke. Ischaemic strokes are more common , accounting for over three quarters of strokes. On average, fewer patients with ischaemic stroke than haemorrhagic stroke die within the first year (23% versus 62%) and treatment differs for the two types.

Stroke is the leading medical cause of adult disability and people who survive a stroke often lose quality of life and independence. Some people have to go into long-term institutional care because of neurological impairments, such as motor, sensory or cognitive deficits, and inability to function. Stroke is a major burden for the individual, family and carers. By five to six months after a stroke it is really becoming clear what the neurological and functional outcomes are to be as spontaneous recovery slows down.

We present some of the evidence from Cochrane systematic reviews about complementary and alternative treatments related to treatment following an ischaemic stroke. This evidence comes from carefully researched reviews of information about clinical trials done to evaluate medical treatments. Studies are only included in these reviews if they meet pre-defined criteria.

DAN SHEN AGENTS AFTER AN ISCHAEMIC STROKE

Dan Shen agents are well accepted by Chinese doctors and they are one of the most frequently used Chinese herbal medicines in the treatment of acute ischaemic stroke, heart disease and major (systemic) blood flow disorders. In stroke, the intent is to improve the local brain blood circulation and limit the nerve and brain cell damage caused by an acute lack of blood flow.

Dan Shen agents are given as tablets or injections, often mixed with other traditional Chinese herbal medicines (as Compound Dan Shen agents). The main botanical family in Dan Shen (red sage) is Radix Salviae Miltiorrhizae. Compound Dan Shen agents also contain other Chinese herbal medicines such as Ligni dalbergiae odoriferae, Sanqi, and Bingpian to promote the curative effects and decrease the adverse effects of Dan Shen. The Compound Dan Shen dropping pill is one of these.

What the synthesised research says

Compound Dan Shen injection and Compound Dan Shen dropping pill may improve neurological impairment caused by an acute ischaemic stroke. This conclusion is based on the results of three trials that looked for an improvement in neurological deficit at the end of treatment. This is too few trials with too few participants to have a clear measure of any benefit.

The methodological quality of the included trials was not scientifically rigorous enough to know whether Dan Shen agents help people with stroke and there were too few patients to draw reliable conclusions. The most important thing to people after a stroke is their ability to go about activities of daily living rather than their neurological deficits; which was not measured in these trials. The follow up was also short, approximately one month, even though spontaneous recovery does not plateau until some 5 to 6 months.

How it was tested

The researchers made a thorough search of the medical literature and found only three controlled trials with 304 acute ischaemic stroke patients. All the trials were conducted in China. The average age of patients, more men than women, was between 56 and 62 years.

Two trials combined Compound Dan Shen injection with snake venom in the treatment group and only used snake venom in the control group over 28 days of treatment; all patients also received routine treatment. The doses of snake venom and Compound Dan Shen injection were 0.25 to 0.75 U and 20 ml respectively.

Oral Compound Dan Shen dropping pill was used in one study. It was given three times daily for 28 days. There was no evidence of a difference of effect between this form of Dan Shen and injection with snake venom. 

The timing of the start of treatment after stroke onset was not reported. No deaths were reported within the first two weeks of treatment or during the following 21 to 28 days. This suggests the strokes were not severe.

Side effects and general cautions

Only one study reported on adverse events. Thirty-one people experienced drowsiness in the first week, which disappeared in the second week of Chinese medicine. Nine patients showed an abnormal drop in the number of platelets in their blood (thrombocytopenia) in the second week; which improved after stopping the Chinese medicine. The low blood platelets, which may interfere with blood clotting, could also have been caused by the snake venom.

Possible adverse events that have been reported with Dan Shen agents include nausea, vomiting, allergic reaction, rapid heart beat (tachycardia), bleeding in the damaged tissue area (infarct) and some unexplained organ abnormalities (for example liver, heart, lungs and the blood).

Source

Wu B, Liu M, Zhang S. Dan Shen agents for acute ischaemic stroke. Cochrane Database of Systematic Reviews 2007, Issue 2. Art. No.: CD004295. DOI: 10.1002/14651858.CD004295.pub3.

GINKGO BILOBA AFTER AN ISCHAEMIC STROKE

With a loss of blood flow to the brain an ischaemic stroke can occur, causing permanent damage to nerves and brain cells. Stroke is the leading medical cause of adult disability and people who survive a stroke often lose quality life and independence. Some have to go into long-term institutional care because of neurological impairments (motor, sensory or cognitive deficits) and inability to function. Stroke is a major burden for the individual, family and carers.

Ginkgo biloba extract is well accepted by doctors in China for traditional Chinese herbal treatment of acute stroke associated with loss of blood flow to parts of the brain (ischaemic stroke) to improve health outcomes. Ginkgo biloba extract is made from the dried leaves of the Ginkgo (maidenhair) tree and contains several biologically active substances. The extract increases cerebral and local tissue blood flow (cerebral microcirculation).

What the synthesised research says

One trial, which was well conducted to limit external influences on the results (biases), measured neurological deficit and did not show a clear benefit with Ginkgo biloba compared with non-active treatment (placebo). This places doubt on how beneficial Ginkgo biloba is.

An improvement in neurological impairment was reported with Ginkgo biloba in nine

trials that had important methodological limitations. The review authors conclude that there is no clear evidence to support the routine use of Ginkgo biloba extract to promote recovery after stroke. High-quality and large-scale randomised controlled trials are needed to test its efficacy.

How it was tested

The researchers made a thorough search of the medical literature and found 10 controlled trials. The 792 participants in these trials received either Ginkgo biloba extract (injection or tablet), placebo, or no additional treatment with their normal supportive care. Treatment began within the first two days to some time later, or was not stated, after onset of stroke. Ginkgo biloba was given as tablets in six trials, at 120 mg to 240 mg per day for 20 to 28 days and as intravenous injections or drips over 14 to 30 days in four other trials.

Side effects and general cautions

No major side effects were reported in the three trials that looked for them. Nor were adverse events evident in other identified studies that did not follow the same strict methodological design.

The most commonly reported side effects with Ginkgo biloba are mild stomach and intestinal problems such as constipation, indigestion and diarrhoea, and headaches. Serious side effects are rare but include excessive bleeding problems. This means that people who are already taking blood thinners (anti-clotting or anticoagulant and antiplatelet medications) to prevent strokes and heart attacks should consult a doctor before taking Gingko biloba. People who have seizures are also advised to seek medical advice about using this herb. 

It is likely that only people with mild strokes were included in these trials and functional ability was not measured. Ability to carry our daily activities of living are important to people as well as neurological impairments.

Source

Zeng X, Lui M, Yang Y, Li Y, Asplund K. Ginkgo biloba for acute ischaemic stroke. The Cochrane Database of Systematic Reviews 2005, Issue 4.

ELECTRICAL STIMULATION TO PREVENT OR TREAT SHOULDER PAIN AFTER A STROKE

People have a stroke when blood flow in the brain is impaired because of a blocked artery (ischaemic) or, less often, when there is bleeding in the brain (haemorrhagic stroke). To have shoulder pain is common after stroke, which adds to the difficulties caused by the stroke and interferes with functional recovery during rehabilitation. The painful shoulder can cause weakness, loss of muscle tone and loss of feeling.  Nearly three quarters of patients with one side paralysed after the stroke suffer from shoulder pain on that side (hemiplegic shoulder pain) during the twelve months.

During rehabilitation in the immediate period after a stroke, people may be given physiotherapy that is based around daily tasks. Local electrical stimulation of the skin can be used as part of the therapy to prevent and treat pain.

Electrical stimulation can be administered in two different ways.

Functional electrical stimulation causes contraction of muscles in a body region, in this instance the shoulder. Contraction of the muscle is organised and can build muscle strength to facilitate the recovery of limb function, reduce spasms (spasticity) and align the bone joint.

TENS (transcutaneous electrical nerve stimulation) is often used to relieve pain. The electrical stimulation masks pain by giving lower intensity, higher frequency stimulation to nerves in the skin without causing muscle contraction. However, the treatment effects of the techniques may overlap.

Methods of stimulation in between the two have been described, which includes ‘high intensity TENS.

What the synthesised research says

Electrical stimulation of muscles improves shoulder stiffness so that the therapist can move the stroke-affected arm more easily. This conclusion was based on three trials (146 people who experienced stiffness, 86% of the total number of participants in the trials). One trial used high intensity TENS, which was particularly effective.

There is currently no evidence to confirm or refute that electrical stimulation reduces shoulder pain. Two trials (84 people with shoulder pain, 49% of the total in the trials) recorded people’s experience of shoulder pain. There was no clear change in pain.

The results suggested that when partial dislocation or a sprain (subluxation) contributes to the shoulder pain, electrical stimulation may give them greater pain free movement, although their background level of pain is not affected. Partial dislocation may also have been reduced in two trials.

Electrical stimulation did not improve upper arm spasticity or motor recovery. This conclusion was based on only three studies (110 people with loss of shoulder function, 65% of the total number in the trials).

This number of trials is too few, with insufficient numbers of participants, to have a clear measure of benefits.

How it was tested

The researchers made a thorough search of the medical literature and found four randomised controlled trials that met set criteria. A total of 170 people who had lost motor function in an arm because of a stroke were randomized to receive conventional physiotherapy according to need with or without electrical stimulation. Most participants were over 60 years of age, but between 45 and 84 years.

Most people had an ischaemic stroke, confirmed by CT scan (computerized tomography), from less than 2 days to nearly 9 months before the trial commenced. They received an average of 12 to 112 sessions of therapy in a 4 to 12 week program. The design of the trial and electrical stimulation technique, whether or not it was intended to cause muscle contractions, varied considerably between trials.

Side effects and general cautions

There did not appear to be any negative effects of electrical stimulation at the shoulder and no adverse effects were reported.

Shoulder discomfort after a stroke is not always caused by muscle and bone (mechanical) problems; local electrical stimulation would not be expected to work with other non-mechanical causes.

It is not possible to reach a broad conclusion from this review about the use of functional electrical stimulation designed to cause muscle contraction in improving upper limb function. The search criteria used selected trials that looked at treatment effects on pain. The ability of a person to rate pain may be particularly difficult after a stroke and trials measured impairment of function rather than disability.

The number of participants in each study was small and the methods used were often inadequate.

Trials which had electrical stimulation as only one part of a multiple intervention package were not included, for example stimulation and arm support together versus control. People with previous shoulder problems were usually excluded from trials.

Source

Price CIM, Pandyan AD. Electrical stimulation for preventing and treating post-stroke shoulder pain. The Cochrane Database of Systematic Reviews 2000, Issue 4. Art. No.: CD001698. DOI: 10.1002/14651858.CD001698.