Sleep correlates of motor recovery in chronic stroke: a pilot study using sleep diaries and actigraphy

Introduction: Sleep facilitates neuroplasticity (Tononi & Cirelli, 2006), an important process for post-stroke recovery, particularly when re-learning motor skills. Associations between poor sleep and poorer recovery during the acute phase have been reported (Good et al. 1996; Gottselig et al. 2002). In addition, increased subjective sleep needs have been associated with poorer outcome during the chronic phase (Hermann, et al. 2008). However motor recovery, which is of particular relevance for sleep dependent neuroplasticity, has not been addressed. We aimed to investigate sleep behaviour in the context of motor recovery within a homogenous stroke patient sample during the chronic phase. Method: Twelve patients with chronic upper limb hemiparesis (412 months) completed sleep diaries (SD) and wore an actiwatch (Cambridge Neurotechnology Ltd.) for two weeks. The SD included twice daily Karolinska Sleepiness Scale (KSS) and Daily Fatigue Scale (D-FIS) measures. Residual motor ability was assessed through a series of neurobehavioural motor tests. Results: Increasing daytime nap length (SD and actigraphy) significantly correlated, or by near significant trend with better motor ability on all neurobehavioural tests. Age was not associated with napping behaviour or residual motor ability. Chronicity, psychological adjustment, health, or nocturnal sleep did not correlate with napping behaviour (SD and actigraphy) or motor ability. Furthermore, increased subjective fatigue was associated with increased napping behaviour. Discussion and Conclusion: Patients who habitually napped had better residual movement ability at least one year after stroke. It may be that the benefits of napping facilitate performance as well as consolidating motor learning. This has been shown in healthy persons (Backhaus & Junghanns, 2006; Nishida & Walker, 2007) which may translate into motor skill re-learning during stroke recovery. Although the data is suggestive, previous rehabilitation and medical care will contribute to residual motor ability in addition to the reported napping behaviour, therefore further clarification is required