Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Gattringer, T.
Acute lacunar stroke: risk factors, biomarkers and prognosis
Doktoratsstudium der Medizinischen Wissenschaft; Humanmedizin; [ Dissertation ] ; 2015. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Berghold Andrea
- Enzinger Christian
- Fazekas Franz
- Altmetrics:
- Abstract:
- Introduction: Lacunar stroke (LS) is responsible for at least an estimated quarter of all ischemic strokes. The morphological correlate of LS is a recent small subcortical infarct (RSSI), which is reliably detected only by brain magnetic resonance imaging (MRI). The causes, pathophysiological mechanisms, treatment strategies and prognosis of LS are incompletely understood and prospective long-term studies are lacking. Therefore, we implemented such a longitudinal study to investigate various clinical, laboratory, neuropsychological, neuroimaging and prognostic aspects of LS in a multidisciplinary manner. In a parallel step, we evaluated the newly suggested imaging criteria for RSSI using a retrospectively identified in-hospital stroke cohort regarding their application in clinical practice. Methods: In May 2012, we started to invite all in-hospital stroke patients < 76 years with MRI defined RSSI to participate in the longitudinal 15-months lacunar stroke study. Patients receive a comprehensive clinical vascular/stroke workup, assessment of blood biomarkers, neuropsychological testing and retinal vessel analysis, including two follow-up visits at three and 15-months together with extensive MRI investigations of the brain. For the second project, we retrospectively identified all acute stroke patients from 2008 to 2013 in whom MRI showed a RSSI with an axial diameter = 20 mm. We calculated the largest axial and longitudinal diameter and RSSI lesion volume. Morphometric differences of RSSI regarding location and demographic variables and the impact of various definitions for lesion selection were assessed. Results: Up to May 2015, 72 patients (mean age: 59.5¿11.5 years, 72% men) with RSSI were included in the prospective study. Further 135 patients with RSSI were identified but did not fulfill the inclusion criteria (n=99) or disagreed to participate (n=36). Most prevalent vascular risk factors were hypertension (80.5%), hyperlipidemia (n=75%) and smoking (n=41.7%). The follow-up rates at three and 15-months are nearly 100%. Patient’s adherence to secondary stroke prevention is high and only 3 patients suffered from a recurrent vascular event. For detailed analyses concerning blood biomarkers, neuropsychological function and neuroimaging characteristics, we have planned to continue patient recruitment up to at least a total number of 100 study participants for considerations of statistical power. Regarding the second retrospective project, we were able to identify 344 patients (median age: 72; range: 25-92 years, 65% men) with RSSI. Most RSSI were located in the basal ganglia (n=111), followed by pons (n=92), thalamus (n=77) and centrum semiovale (n=64). All morphometric variables were strongly correlated and comparable on analyzed MRI sequences (DWI and FLAIR). RSSI in the basal ganglia were significantly (p<0.05) larger both in the axial and longitudinal direction compared with other regions. Dichotomization of RSSI according to axial (= / >15 mm) or longitudinal (= / >20 mm) diameters resulted in different regional frequencies and distributions. Age, sex and time from stroke onset to MRI did not influence morphological parameters or RSSI distribution. Discussion: Interim analysis of the basic results of the prospective lacunar stroke study shows that such a comprehensive, multidisciplinary project is feasible in clinical practice and also adds to long-term patient care. This is supported by a high patient compliance and a low rate of subsequent vascular complications. Our integrated retrospective study confirms that the new imaging criteria for RSSI are applicable in clinical routine. Definitions of the maximal axial and longitudinal diameters have a significant impact on the frequency and distribution of RSSI, which has to be considered when comparing studies and for future study design.