WSO - July 2023 - 686

686
International Journal of Stroke 18(6)
Table 3. Results of multivariable regression model for favorable functional outcome (modified Rankin Scale 0-2) at discharge.
Adjusted odds ratio 95% Confidence interval
Neurologic deterioration
NIHSS score on admission (per point increase)
Female
Age
Dual antiplatelet with loading dose (single antiplatelet as reference)
Thrombolysis
Length of hospitalization
Delay time from onset to hospitalization (h)
Glucose on admission (mmol/L)
SBP dropping ⩾ 20 mm Hg
PremRS
NIHSS: National Institutes of Health Stroke Scale; SBP: systolic blood pressure.
induced-hypertension therapy may improve motor function.9
However, these studies had their limitations: some studies
did not report the blood pressure value,12 or the admission
blood pressure between the groups was relatively low and
similar, and the sample size was small,9 and one study
excluded END patients occurred beyond 24 h after admission
that could underestimate the influence of high SBP on
END.3 In our large cohort study, we found that higher
SBP(⩾160 mm Hg) is significantly associated with END,
which agrees with some other previous studies.7,10,13 The
explanation may be that acute hypertension could induce
penetrating artery lipohyalinosis, which is the characteristic
vascular pathology of lacunar stroke,6 and clinical symptoms
of brain infarction often developed during periods of an
increase in blood pressure,14 hypertension also could lead to
cerebral arterial spasm,15 which may result in lacunar stroke
and END. Concerns may be raised that hypertension may be
a response to END to improve cerebral perfusion; however,
hypertension may also reduce cerebral blood perfusion and,
finally, lead to END. One study using 133Xe inhalation for
cerebral perfusion assessment found reductions in cerebral
blood perfusion in hypertensive patients,16 another SPECTbased
study in healthy older men reported reduced CBF with
increasing blood pressure.17 And interestingly, lowering
hypertension could increase blood flow velocity in the middle
cerebral artery,18 and intensive blood pressure lowering
raised cerebral blood flow in older patients with hypertension.19
However, caution must be taken that, we did not analyze
the perfusion data and could not directly confirm if
reduced perfusion may be relevant to END, and the mechanism
of how acute hypertension affected the extent of infarction
and functional outcome is still uncertain.
International Journal of Stroke, 18(6)
Since higher admission SBP increased the risk of END,
BP lowering may prevent the occurrence of END. The most
concern has been raised that BP lowering may exacerbate
cerebral hypoperfusion,20 which could underlie END.4
However, the result was not replicated by another study,21
and one RCT further demonstrated that even intensive BP
lowering did not reduce cerebral perfusion in severe small
vessel disease,22 and blood pressure lowering did not exacerbate
the functional outcome of lacunar stroke.23 Similarly,
we did not find BP-lowering-induced END in our study.
Furthermore, since most END occurred within 3 days after
admission, we explored the effect of SBP dropping
(⩾20 mm Hg) within 3 days on END, and found that SBP
dropping (⩾20 mm Hg) was significantly inversely associated
with END.
Prior studies revealed that infarction location in ventral
pons predicted END3,24; however, another MRI-based study
did not find a significant influence of pons infarction on
END occurrence.12 Similarly, we also find no significant
association between ventral pons lacunar stroke and END.
Interestingly, we found thalamic lacunar stroke was
inversely associated with END, and this phenomenon was
also seen in the above MRI-based study, which found that
thalamic lacunar strokes had the lowest risk for END occurrence.12
One explanation may be that thalamus is a sensory
organ, so even if the infarction progressed, it cannot be
reflected by motor dysfunction. However, the mechanism
underlying this observation is unclear and the association
needs further investigation.
Unlike a previous study which suggested that dual antiplatelet
protected lacunar stroke patients from END occurrence,3
we did not find a significant influence of dual
12.374
1.488
1.296
1.017
0.815
0.395
0.989
0.997
0.994
1.058
1.119
6.881-22.254
1.359-1.629
0.451-1.320
0.995-1.040
0.478-1.389
0.120-1.298
0.955-1.026
0.993-1.001
0.936-1.055
0.623-2.011
0.623-2.011
p-value
<0.001
<0.001
0.344
0.126
0.451
0.126
0.565
0.194
0.833
0.844
0.707
WSO - July 2023

Table of Contents for the Digital Edition of WSO - July 2023
