Internal carotid artery vasospasm syndrome: demonstration by neuroimaging

Recurring cervical internal carotid artery vasospasm elicited by head rotation: illustrative case

BACKGROUND

Idiopathic extracranial internal carotid artery vasospasm (IEICAV) is a rare cerebrovascular disorder causing transient or permanent cerebral ischemia. The pathophysiology underlying this disorder is not well understood. Although various medical treatments have been tried, complete remission of vasospasm is difficult to achieve. The first case of bilateral IEICAV induced by head rotation, which was successfully treated by carotid artery stenting (CAS), was presented.

OBSERVATIONS

A 40-year-old woman with bilateral IEICAV had been conservatively treated for 13 years. However, transient ischemic attacks (TIAs) were not suppressed. She eventually presented with a large brain infarction in the left hemisphere and was referred to our department. Digital subtraction angiography clearly demonstrated the triggering of internal carotid artery (ICA) vasospasm by head rotation. After CAS treatment, the TIAs disappeared completely.

LESSONS

Clinicians should recognize that ordinary mechanical stimulation to the ICA by head rotation can induce vasospasm, and CAS should be performed for refractory IEICAV at the appropriate time to avoid cerebral infarction causing severe neurological deficits.

[Evaluation of cerebral hemodynamics using arterial spin labeling perfusion MR imaging in a patient with cervical internal carotid artery vasospasm]

57-year-old woman with sequelae of cerebral infarction was admitted to our hospital because her left-sided hemiparesis was worsened. The right internal carotid artery (ICA) was not visualized by carotid duplex sonography and brain MRA. Arterial spin labeling (ASL) perfusion MR images showed reduced signals in the bilateral ICA territories at post labeling delay 1,525 ms. Her neurological symptoms improved on the day after hospitalization. On day 3, the bilateral ICAs were well visualized on MRA, while cerebral perfusion in the ICA territories appeared to be normalized on ASL. We diagnosed cervical ICA vasospasm, based on the findings of cervical MRA and cerebral angiography. Three months later, the recurrence of ICA vasospasm occurred. ASL was useful for the serial non-invasive evaluation of cerebral hemodynamics from the onset to improvement in a patient with ICA vasospasm.

Treatment challenges in idiopathic extracranial ICA vasospasm case report and review of the literature

Idiopathic extracranial internal carotid artery (ICA) vasospasm is a rare pathological phenomenon that may lead to stroke in young patients. We report a case of an 18 year-old female with recurrent extracranial ICA vasospasm since age thirteen. We summarize published data related to this condition including all twenty-three reported cases of extracranial ICA vasospasm. We describe the various proposed pathophysiological mechanisms underlying this disorder. Various treatment modalities have been attempted but there is no known long-term effective treatment.

ACOX3 Dysfunction as a Potential Cause of Recurrent Spontaneous Vasospasm of Internal Carotid Artery

Recurrent spontaneous vasospasm of the extracranial internal carotid artery (RSV-eICA) is a rarely recognized cause of ischemic stroke in young adults. However, its pathophysiology remains largely unknown. Through whole-exome sequencing of the ACOX3 gene of two dizygotic Korean twin brothers affected by RSV-eICA, we identified two compound heterozygous missense variants c.235 T > G (p.F79 V) and c.665G > A (p.G222E). In silico analysis indicated that both variants were classified as pathogenic. In vitro ACOX3 enzyme assay indicated practically no enzyme activity in both F79 V and G222E mutants. To determine the effect of the mutants on vasospasm, we used a collagen contraction assay on human aortic smooth muscle cells (HASMC). Carbachol, a cholinergic agonist, induces contraction of HASMC. Knockdown of ACOX3 in HASMC, using siRNA, significantly repressed HASMC contraction triggered by carbachol. The carbachol-induced HASMC contraction was restored by transfection with plasmids encoding siRNA-resistant wild-type ACOX3, but not by transfection with ACOX3 G222E or by co-transfection with ACOX3 F79 V and ACOX3 G222E, indicating that the two ACOX3 mutants suppress carbachol-induced HASMC contraction. We propose that an ACOX3 dysfunction elicits a prolonged loss of the basal aortic myogenic tone. As a result, smooth muscles of the ICA's intermediate segment, in which the sympathetic innervation is especially rich, becomes hypersensitive to sympathomimetic stimuli (e.g., heavy exercise) leading to a recurrent vasospasm. Therefore, ACOX3 dysfunction would be a causal mechanism of RSV-eICA. For the first time, we report the possible involvement of ACOX3 in maintaining the basal myogenic tone of human arterial smooth muscle.

Successful Corticosteroid Treatment of Refractory Spontaneous Vasoconstriction of Extracranial Internal Carotid and Coronary Arteries

Introduction:

Spontaneous vasoconstriction of the extracranial internal carotid artery (SVEICA) is a rare cause of cerebral infarction. Most patients with SVEICA suffer recurrent attacks of vasoconstriction. The standard treatment for this condition has not been established and its long-term prognosis is unclear.

Case Report:

A 25-year-old man with a history of refractory vasospasm angina presented with transient alternating hemiplegia in both the right and left side. Serial carotid ultrasonography examinations showed severe transient stenosis or occlusion of cervical internal carotid arteries on 1 or both sides, with and without neurological symptoms. This condition resolved completely within 1 day to 1 week. The patient did not present any other risk factors for atherosclerosis and was diagnosed with SVEICA. The treatment with calcium antagonists and nitrates did not prevent the attacks. Administration of a corticosteroid substantially reduced the vasospasm attacks.

Conclusions:

SVEICA is intractable and difficult to diagnose. It has been reported that SVEICA sometimes complicates coronary artery disease, as observed in this case. The present case demonstrated the effectiveness of corticosteroid treatment against this disease. Serial ultrasonography examinations helped us to diagnose and follow-up the vasospasm attacks.

Recurrent Strokes due to Transient Vasospasms of the Extracranial Internal Carotid Artery

Vasospasms of the intracranial arteries are a well-known complication of subarachnoid hemorrhage and are also frequently encountered in other disorders such as migraine, cerebral vasculitis or reversible cerebral vasoconstriction syndrome. In contrast, recurrent spontaneous vasospasms of the extracranial circulation appear to be extremely rare and have most often been associated with migraine. We present a patient with recurrent strokes due to spontaneous transient vasospastic occlusions of the internal carotid artery (ICA) without migraine over a time period of at least 13 years. Initially, the patient had presented with a bilateral ICA occlusion and a cerebral infarct on the right side. While the right ICA remained occluded, a reopening of the left ICA could be detected 3 days after this initial event. In subsequent years, both duplex sonography and magnetic resonance angiography revealed recurrent occlusions of the left ICA, which resolved spontaneously within days. This case and other rare previous reports indicate that recurrent non-migrainous vasospasms of the extracranial carotid artery likely reflect a distinct entity which can cause ischemic strokes.

[Idiopathic vasospastic angiopathy of the internal carotid arteries: A rarely recognized cause of ischemic stroke in young individuals]

INTRODUCTION

Idiopathic vasospastic angiopathy of the internal carotid arteries is a rare and largely unknown cause of ischemic stroke.

METHODS

We report the case of a 39-year-old man with migraine treated by beta-blockers, who had been suffering from progressive right visual impairment and headache for one week. He then experienced a seizure and left hemiparesis. Ophthalmological examination revealed right retinal ischemia and partial left homonymous hemianopia. MRI revealed a long stenosis of both carotid arteries and a recent ischemic stroke in the territory of the right middle cerebral artery. The diagnosis of vasospastic angiopathy of the internal carotid arteries was made based on a second MRI and colored duplex sonography which showed a decrease in the stenosis and no intraparietal hematoma confirming the vasospasm mechanism for stenosis. The clinical course was favorable with calcium channel blockers and aspirin. Use of vasoconstrictor treatments was contraindicated.

DISCUSSION/CONCLUSION

Idiopathic vasospastic angiopathy of the internal carotid arteries has been rarely documented. Association with migraine has been mentioned but remains unclear in the literature. This etiology for stroke is probably under-diagnosed due to lack of rapid and repeated examinations of the cervical arteries (angio-MR and colored duplex sonography) to confirm the vasospasm mechanism. Recurrences have been reported justifying a specific secondary preventive treatment to induce vasodilatation. Vasoconstrictor treatments should be contraindicated.