Frequency and natural history of fatigue after stroke: a systematic review of longitudinal studies

Fatigue is a common and distressing symptom after stroke. Stroke survivors and health professionals need to know whether fatigue is likely to improve, or get worse over time; and whether there is a temporal association with depression or anxiety, which might provide a target for treatment,

To systematically review all longitudinal observational studies which have assessed fatigue on at least two separate time points after stroke onset to determine its frequency, natural history and temporal relationship with anxiety and/or depression.

We systematically searched MEDLINE, EMBASE, CINAHL and PsychInfo using the keywords "fatigue" and "stroke" and their associated terms or synonyms. Data were extracted regarding time points after stroke where fatigue was assessed, frequency of fatigue at each time point and any reported associations with anxiety and/or depression.

101 full texts were retrieved after scrutinising the titles and abstracts. Nine fulfilled our inclusion criteria. Fatigue was assessed at a variety of time points after stroke (from admission -to 36 months). The frequency of fatigue ranged from 35%-92% at the first time point. Frequency of fatigue declined across time points in seven of the studies (n=764) and increased in two studies (n=195). Three papers found significant associations between fatigue and mood at the same time point. The single study investigating temporal associations between fatigue and mood disorders reported that depression predicted subsequent fatigue.

Fatigue is present soon after stroke onset and remains common in the longer term. There is little evidence regarding the temporal relationship between fatigue and mood: this is an area where further research is needed.