Early neurological deterioration in acute lacunar ischaemic stroke: systematic review of incidence, mechanisms, and prospects for treatment.

Early neurological deterioration occurs in over 20% of patients with acute lacunar ischaemic stroke and might provide a novel target for clinical trials. A definition of an NIHSS ≥2 decrease is most used and provides the best between-study homogeneity. END is consistently associated with poor functional outcome. Further research is needed to better identify patients at risk of END, to understand the underlying mechanisms and to carry out new trials to test potential interventions.