Cognitive rehabilitation for memory deficits after stroke

Review question

We reviewed the evidence for the effectiveness of cognitive rehabilitation for memory problems in people with stroke.

Background

People often struggle with memory problems following stroke and this can lead to difficulties in everyday life. The degree and kind of memory problems, mood changes, and performance of everyday activities can vary widely depending on many factors, including the location of the stroke in the brain, severity, age, and the previous health of the person experiencing a stroke.

Memory rehabilitation, a part of cognitive rehabilitation, is a therapeutic activity that may play a role in the recovery of memory functions, or in enabling the individual to adapt to the problems. Memory rehabilitation is a standard part of rehabilitation in many settings. However, it is uncertain whether memory rehabilitation can improve people's memory problems, or whether it has an effect on mood, performance in everyday activities, or quality of life.

Study characteristics

The evidence is current to May 2016. In this review, we included 13 studies with 514 participants. Seven trials were conducted with community participants, four with in-patients, and two with mixed community and in-patient samples. Participants received various types of memory retraining techniques, including training using computer programs and training in the use of memory aids, such as diaries or calendars. In three studies treatment was provided in groups and in 10 studies treatment was provided individually. Treatment lasted between two weeks and 10 weeks. In these studies, those who received the treatment were compared with a control group. The control group included those who did not receive cognitive rehabilitation or received another form of treatment. The control groups varied. Some studies had a control group wherein people received their usual care, whereas in others individuals in the control groups were placed on a waiting list to receive cognitive rehabilitation.

Key results

We found that people who received cognitive rehabilitation reported fewer memory problems in daily life immediately after treatment compared with the control groups. This represents a small to moderate effect of the intervention in comparison to the control group. However, there was no evidence that the benefits persisted in the long term. We found no evidence that cognitive rehabilitation improved people's independence in activities of daily living, mood, or quality of life. There was no information about any harm caused to participants from taking part in cognitive rehabilitation.

Quality of the evidence

The quality of the evidence ranged from very low (effect on outcomes that relate to everyday activities) to moderate (effect on self-reported memory problems, memory tests, and mood measures). There were a number of flaws in these studies, such as having very few people in them, and these could have affected our findings.

Authors' conclusions: 

Participants who received cognitive rehabilitation for memory problems following a stroke reported benefits from the intervention on subjective measures of memory in the short term (i.e. the first assessment point after the intervention, which was a minimum of four weeks). This effect was not, however, observed in the longer term (i.e. the second assessment point after the intervention, which was a minimum of three months). There was, therefore, limited evidence to support or refute the effectiveness of memory rehabilitation. The evidence was limited due to the poor quality of reporting in many studies, lack of consistency in the choice of outcome measures, and small sample sizes. There is a need for more robust, well-designed, adequately powered, and better-reported trials of memory rehabilitation using common standardised outcome measures.

Read the full abstract...
Background: 

Memory problems are a common cognitive complaint following stroke and can potentially affect ability to complete functional activities. Cognitive rehabilitation programmes either attempt to retrain lost or poor memory functions, or teach patients strategies to cope with them.

Some studies have reported positive results of cognitive rehabilitation for memory problems, but the results obtained from previous systematic reviews have been less positive and they have reported inconclusive evidence. This is an update of a Cochrane review first published in 2000 and most recently updated in 2007.

Objectives: 

To determine whether participants who have received cognitive rehabilitation for memory problems following a stroke have better outcomes than those given no treatment or a placebo control.

The outcomes of interest were subjective and objective assessments of memory function, functional ability, mood, and quality of life. We considered the immediate and long-term outcomes of memory rehabilitation.

Search strategy: 

We used a comprehensive electronic search strategy to identify controlled studies indexed in the Cochrane Stroke Group Trials Register (last searched 19 May 2016) and in the Cochrane Central Register of Controlled Trials (CENTRAL2016, Issue 5), MEDLINE (2005 to 7 March 2016), EMBASE 2005 to 7 March 2016), CINAHL (2005 to 5 February 2016), AMED (2005 to 7 March 2016), PsycINFO (2005 to 7 March 2016), and nine other databases and registries. Start dates for the electronic databases coincided with the last search for the previous review. We handsearched reference lists of primary studies meeting the inclusion criteria and review articles to identify further eligible studies.

Selection criteria: 

We selected randomised controlled trials in which cognitive rehabilitation for memory problems was compared to a control condition. We included studies where more than 75% of the participants had experienced a stroke, or if separate data were available from those with stroke in mixed aetiology studies. Two review authors independently selected trials for inclusion, which was then confirmed through group discussion.

Data collection and analysis: 

We assessed study risk of bias and extracted data. We contacted the investigators of primary studies for further information where required. We conducted data analysis and synthesis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. We performed a 'best evidence' synthesis based on the risk of bias of the primary studies included. Where there were sufficient numbers of similar outcomes, we calculated and reported standardised mean differences (SMD) using meta-analysis.

Main results: 

We included 13 trials involving 514 participants. There was a significant effect of treatment on subjective reports of memory in the short term (standard mean difference (SMD) 0.36, 95% confidence interval (CI) 0.08 to 0.64, P = 0.01, moderate quality of evidence), but not the long term (SMD 0.31, 95% CI -0.02 to 0.64, P = 0.06, low quality of evidence). The SMD for the subjective reports of memory had small to moderate effect sizes.

The results do not show any significant effect of memory rehabilitation on performance in objective memory tests, mood, functional abilities, or quality of life.

No information was available on adverse events.

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