Convexity Subarachnoid Hemorrhage Due to Cardioembolic Stroke in a Woman with Thyrotoxicosis: Α Case Report

Convexity subarachnoid hemorrhage revealed contralateral internal carotid artery dissection due to Eagle syndrome: a case report

BACKGROUND

Atraumatic localized convexity subarachnoid hemorrhage (cSAH) is an uncommon form of nonaneurysmal subarachnoid hemorrhage characterized by bleeding limited to the cerebral convexities. Ipsilateral cSAH can result from a variety of causes, such as internal carotid artery stenosis, obstruction, and dissection, although concomitant contralateral cSAH is exceptionally rare. In this case, the initial findings of cSAH led us to discovering contralateral internal carotid artery dissection (ICAD) and an elongated styloid process (ESP). ESP is recognized as a risk factor for ICAD, which is a hallmark of Eagle syndrome. This sequence of findings led to the diagnosis of Eagle syndrome, illustrating a complex and intriguing interplay between cerebrovascular conditions and anatomical variations.

CASE PRESENTATION

A 47-year-old Japanese woman experienced acute onset of headache radiating to her neck, reaching its zenith approximately two hours after onset. Given the intractable nature of the headache and its persistence for three days, she presented to the emergency department. Neurological examination revealed no abnormalities, and the coagulation screening parameters were within normal ranges. Brain computed tomography (CT) revealed right parietal cSAH, while CT angiography (CTA) revealed ICAD and an ESP measuring 30.1 mm on the left side, positioned only 1.4 mm from the dissected artery. The unusual occurrence of contralateral cSAH prompted extensive and repeated imaging reviews that excluded reversible cerebral vasoconstriction syndrome (RCVS), leading to a diagnosis of left ICAD secondary to Eagle syndrome. The patient underwent conservative management, and the dissected ICA spontaneously resolved. The patient has remained recurrence-free for two and a half years.

CONCLUSIONS

Managing cSAH requires diligent investigation for ICAD, extending beyond its identification to explore underlying causes. Recognizing Eagle syndrome, though rare, as a potential etiology of ICAD necessitates the importance of evaluating ESPs. The method for preventing recurrent cervical artery dissection due to Eagle syndrome is controversial; however, conservative management is a viable option.

Epidemiology and treatment of atraumatic subarachnoid hemorrhage over 10 years in a population-based registry

INTRODUCTION

Incidence of atraumatic subarachnoid hemorrhage (SAH) is decreasing over time and its treatment is changing. We reported epidemiologic data on aneurysmal (a-) and non-aneurysmal (na-) SAH over 10 years.

PATIENTS AND METHODS

Our prospective population-based registry included patients with first-ever SAH occurring from January 2011 to December 2020. Clinical and neuroimaging records were screened to evaluate the presence and location of intracranial aneurysms, to identify naSAH subtypes and to retrieve information on surgical treatments. Incidence rates were standardized to the 2011 Italian and European population. We also estimated 30-day and 1-year case-fatality rates after SAH. Multivariate hazard ratios for 30-days and 1-year fatality were estimated with Cox regression analysis.

RESULTS

194 patients (60.8% women; mean age 62.5 ± 16.0 years) were included (76.8% aSAH and 23.2% naSAH). The crude incidence rates per 100,000 person-years of SAH, aSAH, and naSAH were 6.5 (95% CI 5.6-7.5), 5.0 (95% CI 4.2-5.9), and 1.5 (95% CI 1.1-2.0), respectively, and remained stable over time. Compared to aSAH, naSAH patients had higher age (68.8 ± 19.7 yearsvs 60.6 ± 14.2 years; p = 0.012), lower cigarette smoking (17.9%vs 36.4%; p < 0.001) and higher atrial fibrillation (15.7% vs 2.8%; p = 0.005). SAH case-fatality rates within 30-days and 1-year were 28.4% (95% CI 21.4-36.9) and 37.1% (95% CI 29.0-46.7), respectively. The relative proportion of surgically treated patients did not change over time.

CONCLUSION

We found a low and stable incidence of SAH over the 2011-2020 period. naSAH remained rare and deserves further investigation in larger prospective cohorts.

Acute ischemic stroke with contralateral convexal subarachnoid hemorrhage: two cases report

Background

Convexal subarachnoid hemorrhage (cSAH) is characterized by isolated bleeding in one or a few adjacent sulci and has diverse etiologies and symptoms. Acute ischemic stroke co-occurring with cSAH has been infrequently reported. Nearly all cases of cSAH have been described to occur on the side with acute ischemic stroke, and it is unusual for cSAH to occur on the opposite side of the infarct territory.

Case presentation

Our report presents two cases of acute ischemic stroke associated with contralateral cSAH. The first patient had left atherosclerotic internal carotid artery (ICA) occlusion with developing right parietal cSAH. The other patient developed left parietal cSAH in the setting of right ICA occlusion caused by cardiogenic embolism with acute right cerebral hemisphere infarction. Both patients remained clinically stable with good prognosis after antithrombotic treatment.

Conclusions

Our report suggest that cSAH may simultaneously occur on the opposite side of an infarction. Although there is no consensus on the etiology and treatment of this rare phenomenon, cSAH did not lead to a poor outcome in our patients.

Convexal subarachnoid hemorrhage and acute ischemic stroke: a border zone matter?

BACKGROUND

Convexal subarachnoid hemorrhage (c-SAH) is an infrequent condition with variable causes. c-SAH concomitant to acute ischemic stroke (AIS) is even less frequent, and the relationship between the two conditions remains unclear.

METHODS

Between January 2016 and January 2018, we treated four patients who were referred to our stroke unit with ischemic stroke and concomitant nontraumatic c-SAH. The patients underwent an extensive diagnostic workup, including digital subtraction angiography (DSA).

RESULTS

All four patients developed acute focal neurological symptoms with restricted MRI diffusion in congruent areas. In three of the patients, infarcts were in a border zone between the main cerebral arteries and c-SAH was nearby. The fourth patient showed a small cortical infarct, and c-SAH was in a border zone territory of the contralateral hemisphere. An embolic source was discovered or strongly suspected in all cases. One patient was treated with intravenous thrombolysis, but this treatment was not related to c-SAH. None of the four patients showed microbleeds or further cortical siderosis, thus excluding cerebral amyloid angiopathy. In addition, DSA did not show signs of vasculitis, reversible cerebral vasoconstriction syndrome, or intracranial arterial dissection.

CONCLUSIONS

We proposed the embolism or hemodynamic changes of the border zone arterioles as a unifying pathogenetic hypothesis of coexisting c-SAH and AIS.