Progression of Large Vessel Disease in Patients With Giant Cell Arteritis-Associated Ischemic Stroke: The Role of Vascular Imaging: A Case Series

Giant-cell arteritis related strokes: scoping review of mechanisms and rethinking treatment strategy?

Stroke is a rare and severe complication of giant cell arteritis (GCA). Although early diagnosis and treatment initiation are essential, the mechanism of stroke is often related to vasculitis complicated by arterial stenosis and occlusion. Its recurrence is often attributed to early steroid resistance or late GCA relapse, so immunosuppressive treatment is often reinforced. However, many questions concerning the mechanisms of stroke remain elusive, and no review to date has examined the whole data set concerning GCA-related stroke. We therefore undertook this scoping review. GCA-related stroke does not necessarily display general signs and inflammatory parameters are sometimes normal, so clinicians should observe caution. Ischemic lesions often show patterns predating watershed areas and are associated with stenosis or thrombosis of the respective arteries, which are often bilateral. Lesions predominate in the siphon in the internal carotid arteries, whereas all the vertebral arteries may be involved with a predominance in the V3-V4 segments. Ultrasonography of the cervical arteries may reveal edema of the intima (halo sign), which is highly sensitive and specific of GCA, and precedes stenosis. The brain arteries are spared although very proximal arteritis may rarely occur, if the patient has microstructural anatomical variants. Temporal artery biopsy reveals the combination of mechanisms leading to slit-like stenosis, which involves granulomatous inflammation and intimal hyperplasia. The lumen is sometimes occluded by thrombi (<15%), suggesting that embolic lesions may also occur, although imaging studies have not provided strong evidence for this. Moreover, persistence of intimal hyperplasia might explain persisting arterial stenosis, which may account for delayed stroke occurring in watershed areas. Other possible mechanisms of stroke are also discussed. Overall, GCA-related stroke mainly involves hemodynamic mechanisms. Besides early diagnosis and treatment initiation, future studies could seek to establish specific preventive or curative treatments using angioplasty or targeting intimal proliferation.

Giant cell arteritis presenting as a stroke in the internal carotid artery territory: a case-based review

Giant cell arteritis (GCA) is a large-vessel vasculitis, typically affecting the aorta and its branches. The involvement of vertebral and internal carotid arteries occurs in a limited number of cases, and stroke as a presenting symptom of GCA is extremely unusual: this subset of the disease has a poor prognosis and rarely responds to immunosuppression.

We report the case of a 70-year-old woman, who presented to the Emergency Department for ischemic stroke, which appeared to be the first and only symptom of GCA. The prompt administration of steroids and tocilizumab (TCZ) led to clinical and radiological resolution, with no residual disability at 6-month follow-up.

Our case-based review, highlighting the rarity of a large vessel vasculitis presenting only with a cerebrovascular accident, provides new evidence for the efficacy of TCZ even in more unusual varieties of GCA: in these cases, TCZ should be immediately prescribed, in order to prevent mortality and severe long-term morbidity.

Cervical duplex ultrasound for the diagnosis of giant cell arteritis with vertebral artery involvement

Giant cell arteritis (GCA) is a systemic inflammatory arteriopathy of medium and large-sized arteries, predominantly affecting branches of the external carotid artery. Ischemic stroke has been reported in 2.8-7% of patients diagnosed with GCA. The majority of ischemic strokes may involve the posterior circulation as a result of vertebral and/or, less frequently, of basilar artery vasculitis. Prompt diagnosis is crucial since high-dose corticosteroid treatment is highly effective in preventing the occurrence or recurrence of ischemic complications, including posterior circulation ischemic stroke in cases with vertebrobasilar involvement. Cervical duplex sonography (CDS) of the temporal arteries is a powerful diagnostic tool with high sensitivity and specificity for the diagnosis of GCA. In cases with clinical suspicion or a temporal artery ultrasonographic confirmation of GCA, a detailed evaluation of the cervical, axillary, and intracranial arteries with CDS and transcranial-duplex-sonography, respectively, should be part of the ultrasound examination protocol. Specifically, signs of extracranial vertebral artery wall inflammation ("halo" sign) and focal luminar stenoses may be accurately depicted by ultrasounds in high-risk patients or individuals with ischemic stroke attributed to GCA. In this review, we present three cases of GCA and posterior circulation ischemic complications that were initially evaluated with comprehensive neurosonology protocol and were promptly diagnosed with GCA based on the characteristic "halo" sign in the temporal and vertebral arteries. In addition, we discuss the relevant literature concerning the utility of CDS for the early diagnosis of GCA, focusing on the subtype with extracranial arterial involvement, particularly that of the vertebral arteries.