Using pharmacological medications for unilateral spatial neglect (USN) after stroke

Review question

Which pharmacological intervention (use of any type of medication) is more efficacious and safe for improving the ability of people with stroke to recognize their paralyzed limb after stroke, and what guidance can be provided to clinicians in their clinical practice?

Background

USN (difficulty recognizing the left or right side of the body and space) has been associated with poor independence and long stays in hospitals and rehabilitation centers, all of which predispose people with stroke to the risk of falls and to semi permanent or permanent wheelchair use, which can reduce their quality of life. Furthermore, this condition decreases the ability of people to return to work. Pharmacological medication for USN, such as dopamine and noradrenergic agonists or pro-cholinergic treatment, could have a positive effect in improving independence for people after stroke. This review aims to answer this question.

Study characteristics

Adults over 18 years of age, regardless of gender and ethnicity, with USN after stroke diagnosis measured by clinical examination or radiographically by computed tomography or magnetic resonance imaging, regardless of whether they were evaluated by any paper-and-pencil tests. We considered including people diagnosed with any type of stroke (ie, ischemic or hemorrhagic) from the acute phase (the first 24 to 72 hours) until one year after the stroke.

Key results

We identified two studies involving 30 participants up to April 2015. We are uncertain as to whether comparison of different pharmacological interventions (rivastigmine, transdermal nicotine)showed an important effect on (1) the ability of people to recognize their paralyzed limb, and (2) independence in daily life functions after stroke, because results were imprecise and included studies did not report most of the predefined outcomes (ie, falls, balance, depression or anxiety, poststroke fatigue, and quality of life).

Quality of the evidence

We considered the quality of included studies to be reasonable. Given the small sample size and methodological limitations (participants were assigned in a successive manner in one study), no conclusions can be drawn regarding the effectiveness of pharmacological medications in USN after stroke.

Conclusions and future research

The quality of the evidence obtained from available randomized controlled trials was very low. The effectiveness and safety of pharmacological interventions for USN after stroke are therefore uncertain. Additional large randomized controlled trials are needed to evaluate these treatments.

Authors' conclusions: 

The quality of the evidence from available RCTs was very low. The effectiveness and safety of pharmacological interventions for USN after stroke are therefore uncertain. Additional large RCTs are needed to evaluate these treatments.

Read the full abstract...
Background: 

Unilateral spatial neglect (USN) is characterized by the inability to report or respond to people or objects presented on the side contralateral to the lesioned side of the brain and has been associated with poor functional outcomes and long stays in hospitals and rehabilitation centers. Pharmacological interventions (medical interventions only, use of drugs to improve the health condition), such as dopamine and noradrenergic agonists or pro-cholinergic treatment, have been used in people affected by USN after stroke, and effects of these treatments could provide new insights for health professionals and policy makers.

Objectives: 

To evaluate the effectiveness and safety of pharmacological interventions for USN after stroke.

Search strategy: 

We searched the Cochrane Stroke Group Trials Register (April 2015), the Cochrane Central Register of Controlled Trials (April 2015), MEDLINE (1946 to April 2015), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to April 2015), EMBASE (1980 to April 2015), PsycINFO (1806 to April 2015) and Latin American Caribbean Health Sciences Literature (LILACS) (1982 to April 2015). We also searched trials and research registers, screened reference lists, and contacted study authors and pharmaceutical companies (April 2015).

Selection criteria: 

We included randomized controlled trials (RCTs) and quasi-randomized controlled trials (quasi-RCTs) of pharmacological interventions for USN after stroke.

Data collection and analysis: 

Two review authors independently assessed risk of bias in the included studies and extracted data.

Main results: 

We included in the review two studies with a total of 30 randomly assigned participants. We rated the quality of the evidence as very low as the result of study limitations, small numbers of events, and small sample sizes, with imprecision in the confidence interval (CI). We were not able to perform meta-analysis because of heterogeneity related to the different interventions evaluated between included studies. Very low-quality evidence from one trial (20 participants) comparing effects of rivastigmine plus rehabilitation versus rehabilitation on overall USN at discharge showed the following: Barrage (mean difference (MD) 0.30, 95% confidence interval (CI) -0.18 to 0.78); Letter Cancellation (MD 10.60, 95% CI 2.07 to 19.13); Sentence Reading (MD 0.20, 95% CI -0.69 to 1.09), and the Wundt-Jastrow Area Illusion Test (MD -4.40, 95% CI -8.28 to -0.52); no statistical significance was observed for the same outcomes at 30 days' follow-up. In another trial (10 participants), study authors showed statistically significant reduction in omissions in the three cancellation tasks under transdermal nicotine treatment (mean number of omissions 2.93 ± 0.5) compared with both baseline (4.95 ± 0.8) and placebo (5.14 ± 0.9) (main effect of treatment condition: F (2.23) = 11.06; P value < 0.0001). One major adverse event occurred in the transdermal nicotine treatment group, and treatment was discontinued in the affected participant. None of the included trials reported data on several of the prespecified outcomes (falls, balance, depression or anxiety, poststroke fatigue, and quality of life).