Spontaneous Intracranial Hemorrhages in a Community of Asian Americans: Case Series and Literature Review

Abstract

Background and objectives Several Asian populations abroad are reported to have a higher prevalence of spontaneous intracranial hemorrhages (sICH) and a greater proportion of all stroke types attributed to ICH compared to non-Asians. However, the causes are unknown, and few studies have examined the issue among Asian Americans. This report aims to highlight some less common, but not rare, clinical features that could bear on several pathophysiological factors, by presenting a selected case series of 13 Asian American patients admitted to a Boston-based healthcare system and hospital. Methods The selected cases were classified into six categories based on presumed sICH mechanisms including vasculopathy, hypertensive crises, moyamoya disease/syndrome, venous sinus thrombosis, brainstem hemorrhages, and arterial malformation/aneurysm. We also examined 5 years of medical records at our institution, a single healthcare system among several in a large urban area having its main hospital embedded in an Asian community, to arrive at stroke-type proportions, comparing our Asian to non-Asian population. ICH cases excluded trauma, coagulopathy, and hemorrhagic transformation. ICH patient counts were compared to acute ischemic stroke and subarachnoid hemorrhage across various ethnicities. Results Pathophysiology-biomarker correlations within each ICH stroke category were reviewed, some possibly having specificity for Asian populations. We found some evidence to support an increased proportion of sICH among all stroke types in our Asian American patients, relative to other ethnic groups. A higher apparent estimate of sICH incidence in Asian Americans vs. Caucasians was also uncovered. However, these did not reach statistical significance and so no conclusion on risk could be made from this preliminary study. Conclusions We review the extensive literature on epidemiology and genetic markers and affirm that an awareness of the potential increased risk of sICH in this expanding population is clinically prudent. An expanded epidemiologic study to refine ICH risk estimates in Asian Americans is planned.

Keywords: asian americans; case-series; incidence and prevalence; s: biomarkers; spontaneous intracranial hemorrhage.

Figure 1. Multicompartment (ICH, IVH, SAH) intracranial hemorrhage examples in an Asian American population.

(1A) Case 5: Axial non-contrast head CT (a) shows acute right thalamic parenchymal hemorrhage with pan-ventricle and tentorial subarachnoid extension. Axial MRI FLAIR (b) DWI (c) and gradient echo T2(*) (d) show acute right thalamic parenchymal hemorrhage. CT angiography of RICA (e) demonstrating severe stenosis of RICA (yellow arrow) with the pronounced appearance of lenticulostriate vessels (white arrow). (1B) Case 12: Axial non-contrast head CT (a) shows high left frontoparietal ICH with associated small volume subarachnoid hemorrhage (SAH) (yellow arrow) and right frontoparietal subdural hematoma (SDH)(black arrow). Axial non-contrast CT (b) shows more caudal large left parietal ICH with IVH.  CT angiography shows high parietal (c) and lower down (d) AVM measuring 2.6 cm in the largest dimension (yellow arrow). CT angiography (e) delayed phase shows venous drainage pattern (black arrow). AVM - arteriovenous malformation), FLAIR - fluid-attenuated inversion recovery, DWI - diffusion-weighted imaging, RICA - right internal carotid artery, ICH - intracerebral hemorrhage, IVH - intraventricular hemorrhage, SAH - subarachnoid hemorrhage.