The determinants of neurological phenotypes during acute hypertensive crises – a preliminary study

Background and Purpose: Acute blood pressure elevations lead to wide spectrum of neurologic manifestations, ranging from no overt neurologic symptoms to catastrophic events like ICH. Little is known regarding the determinants of this clinical variability. We determined clinical and imaging features of hypertensive crisis patients with normal neurological examination, ICH and posterior reversible encephalopathy syndrome (PRES).

Methods: Cranial MRI was performed in patients with hypertensive urgency or emergency but normal neurological examination. Their clinical characteristics, and imaging features regarding cerebral small vessel disease were compared to ICH and PRES patients.

Results: Hypertensive ICH patients (n = 58) were older, less likely to have hyperlipidemia, less commonly used calcium channel blockers, and had higher burden of chronic cSVD features in comparison to hypertensive crisis patients with normal neurological findings (n = 51). Multivariate analyses revealed cSVD burden score (p = 0.003) to be related with ICH, while higher admission blood pressure levels (p < 0.001), hyperlipidemia (p = 0.006) and calcium channel blocker usage (p = 0.005) were more common in patients with normal neurological examination. The PRES (n = 9) group was comprised of younger patients with recent history of hypertension and low burden of cSVD.

Conclusions: Hypertensive surge is associated with ICH when cSVD burden is high, probably caused by microvascular dysfunction secondary to long-standing hypertension, while the episode causes no structural damage if this burden is less. Although our observations are exploratory, short term but severe hypertension manifests with PRES possibly due to the absence of adaptive changes.