- ischemic damage to the subcortical white matter
- frequent complication of hypertension-related microvascular disease
- contributes to the risk of stroke and vascular dementia
- at greater risk of sICH and have a worse functional outcome after tPA treatment for acute ischemic stroke
- Side Note: other risk factors for sICH post-tPA: age, stroke severity, DM, cardiac disease, elevated pre-treatment mean BP
Why is leukoaraiosis associated with greater risk of sICH after tPA?
Leukoaraiosis is a radiological marker for chronic ischemic damage of cerebral microcirculation, which worsens effects of acute ischemia and tPA at the BBB.
Pre-existing damage of cerebral microcirculation (including the endothelium) increases risk of vessel rupture and subsequent hemorrhage. Stroke damages endothelium and astrocytes, weakening the BBB. With tPA, further damage to BBB occurs.
Leukoaraiosis is likely a marker of increased susceptibility to hemorrhagic treatment complications, rather than a condition indicating a specific risk of thrombolytic treatment.
How is leukoaraiosis assessed?
For assessment of leukoaraiosis, studies used MRI with high-resolution T2-weighted sequence.
Sseverity of leukoaraiosis is rated using a visual rating scale proposed by Fazekas and Schmidt, with scores ranging from 0 to 3. FLAIR sequence or high-resolution T2-weighted sequence for deep WM and periventricular WM was used to determine extent of leukoaraiosis.
Deep white matter lesions were scored as follows:
- 0, no lesion
- 1, punctuate foci
- 2, beginning confluent foci
- 3, confluent changes
Periventricular white matter lesions were scored as follows:
- 0, no changes
- 1, caps or a pencil-thin lining
- 2, smooth halo
- 3, irregular changes extending into deep white matter
See figure below for examples illustrating different degrees of leukoaraiosis in deep white matter (arrow) and periventricular areas (with identical scores for deep and periventricular changes).
Ariës, M. J. H. et al. “Tpa Treatment For Acute Ischaemic Stroke In Patients With Leukoaraiosis”.European Journal of Neurology 17.6 (2010): 866-870. Web.
Neumann-Haefelin, T. et al. “Leukoaraiosis Is A Risk Factor For Symptomatic Intracerebral Hemorrhage After Thrombolysis For Acute Stroke”. Stroke 37.10 (2006): 2463-2466. Web.
Sph.umich.edu,. “Genetic Architecture Of Leukoaraiosis – Research – Kardia Lab – Genetic Epidemiology – Epidemiology – Faculty Research Projects – Faculty & Research – UM SPH”. N.p., 2016. Web. 29 Jan. 2016.
Debette, S. and Markus, H. The clinical importance of white matter hyperintensities on brain magnetic resonance imaging: systematic review and meta-analysis. BMJ 2010; 341:c3666.