RESUMO
The aim of this prospective observational longitudinal study was to explore and decipher the predictive value of prospective MRI biomarkers in the brain and lower limb muscles for 3-month lower limb motor recovery following stroke. In the brain, we measured the integrity of the corticospinal tract (fractional anisotropy/"FA"). In the muscles, we measured volume, fatty replacement (fat fraction analysis and proton spectroscopy) and oedema. Measurements were taken at two time points: (1) within 4 weeks of stroke (baseline measurement, clinical and imaging) and (2) 3 months following stroke (follow up measurement, clinical only). Clinical measurements consisted of assessments of functional ability and strength (Fugl-Meyer score, motor NIHSS, Functional Ambulation Category/"FAC", and muscle dynamometry). Twenty-three patients completed imaging and clinical assessments at baseline and follow-up; five patients had partial imaging assessment. The results provided some evidence that damage to the corticospinal tract would result in less motor recovery: recovery of the Fugl-Meyer score and dynamometric ankle plantarflexion, ankle dorsiflexion, and knee extension correlated positively and significantly with fractional anisotropy (0.406-0.457; p = 0.034-p = 0.016). However, fractional anisotropy demonstrated a negative correlation with recovery of the Functional Ambulation Category (-0.359, p = 0.046). For the muscle imaging, significant inverse correlation was observed between vastus lateralis fat fraction vs. NIHSS recovery (-0.401, p = 0.04), and a strong positive correlation was observed between ratio of intra- to extra-myocellular lipid concentrations and the recovery of knee flexion (0.709, p = 0.007). This study supports previous literature indicating a positive correlation between the integrity of the corticospinal tract and motor recovery post-stroke, expanding the limited available literature describing this relationship specifically for the lower limb. However, recovery of functional ambulation behaved differently to other clinical recovery markers by demonstrating an inverse relationship with corticospinal tract integrity. The study also introduces some muscle imaging biomarkers as potentially valuable in the prediction of 3-month lower limb motor recovery following stroke.
RESUMO
We evaluated the impact of the centralisation of three acute stroke units into a single hyperacute stroke unit within a large urban and rural NHS trust in North East England in June 2015. We performed retrospective interrupted time series analyses of 4,305 stroke patients admitted between 1 April 2013 and 31 December 2017 utilising data recorded for the Sentinel Stroke National Audit Programme. Centralisation was -associated with reductions in total length of inpatient stay (-4.9 days [95% CI: -8.1 to -1.7]). Time from admission to thrombolysis shortened by 26.0 minutes (95% CI: -40.0 to -12.1), and time from admission to brain imaging for thrombolysed patients improved by 16.2 minutes (95% CI: -22.0 to -10.4). Time from stroke onset to hospital admission, mortality and dependency (as measured by median modified Rankin Scale) were unaffected by centralisation. This study provides further evidence to support the centralisation of acute stroke services in England.
