Childhood basilar artery occlusion: a report of 5 cases and review of the literature

The Anatomic Study of Intracranial Structures Related to Clival Screw Placement

BACKGROUND

A clival plate and screw fitted to the craniovertebral junction (CVJ) were developed in our previous studies. However, the anatomy of intracranial structures related to clival screw placement has not been studied.

OBJECTIVE

To measure the intracranial anatomic parameters delineating the basilar plexus and vertebrobasilar artery (VBA) course and to determine the relationship between brainstem and clivus for safer screw placement.

METHODS

Morphometric analysis of the VBA was conducted on 95 patients (48 men, 47 women) by CT angiography (CTA) and of the basilar plexus and brainstem on 80 patients (44 men, 36 women) by magnetic resonance imaging (MRI) The narrowest distance between the VBA and the intracranial clivus and the distance between the VBA and the median line of the skull were measured on the axial plane at different parts. The relative positions of point I (intersection of vertebral artery and basilar artery) and the pharyngeal tubercle were analyzed. The distance between the clivus and the brainstem was measured at different levels.

RESULTS

As the VBA ascended the distances to the intracranial clivus and the midline decreased. In 83.3% cases, point I was above the pharyngeal tubercle, and in only 9.5% cases was it located on the vertical line drawn from pharyngeal tubercle. The smallest safe space between the intracranial clivus and the brainstem was 7.46 mm at the lower part.

CONCLUSION

Appropriate screw size at the lower clivus and the pharyngeal tubercle may help avoiding inadvertent injury to the brainstem and the VBA. Preoperative CTA and MRI of the CVJ are suggested to guide the surgeon in this regard.

Childhood acute basilar artery thrombosis successfully treated with mechanical thrombectomy using stent retrievers: case report and review of the literature

INTRODUCTION

Acute basilar artery occlusion (ABAO) is an infrequent but potentially fatal cause of strokes in both adults and children, and it is usually due to vertebral artery dissection (VAD). VAD has been found to be usually a consequence of traumatic vertebral artery injury. ABAO usually presents with symptoms of acute ischemic stroke (AIS) of the posterior circulation or transient ischemic attack (TIA). It may lead to death or long-term disability if not promptly recanalized. Basilar artery recanalization in children can be achieved safely and with excellent clinical outcome using endovascular thrombectomy with the new generation self-expanding and retrievable stents.

CLINICAL PRESENTATION

We report the case of a 23-month old baby that came to the emergency room of our hospital for progressive impairment of consciousness associated with widespread stiffness and plaintive cry, appeared after accidental fall from stroller. An emergency brain CT scan was obtained showing multiple infarction lesions in the brainstem and left cerebellum suggestive of acute stroke in posterior circulation territories. An MR scan with angiography and diffusion-weighted sequences confirmed the multiple infarction lesions and demonstrated poor representation of the flow signal at the V3 segment of the left vertebral artery and absent representation of the flow signal at the distal segment of the basilar artery suggestive of acute thrombotic occlusion. The patient was immediately referred to interventional neuroradiology unit, and digital subtraction angiography showed complete basilar artery occlusion and left vertebral artery dissection at extracranial V2-V3 segment. The patient underwent intra-arterial thrombectomy using stent retrievers and occlusion of the V2-V3 segment of the left vertebral artery. The patient survived and long-term outcome was excellent.

CONCLUSIONS

To our knowledge, only nine cases of ABAO in children treated with intra-arterial thrombectomy have been previously reported in the literature. In only three cases, the Solitaire stent was applied. Our case is the first case of basilar artery occlusion treated with Solitaire stent, in a child under 24 months. The reports that are available so far indicate that basilar artery recanalization in children can be achieved safely and with excellent clinical outcome using endovascular thrombectomy with the new generation self-expanding and retrievable stents.

Indications for the performance of neuroimaging in children

Pediatric neurology relies on ultrasound, computed tomography (CT), and magnetic resonance (MR) imaging. CT prevails in acute neurologic presentations, including traumatic brain injury (TBI), nontraumatic coma, stroke, and status epilepticus, because of easy availability, with images of diagnostic quality, e.g., to exclude hemorrhage, usually completed quickly enough to avoid sedation. Concerns over the risks of ionizing radiation mean re-imaging and higher-dose procedures, e.g., arteriography and venography, require justification. T1/T2-weighted imaging (T1/T2-WI) MR with additional sequences (arteriography, venography, T2*, spectroscopy, diffusion tensor, perfusion, diffusion- (DWI) and susceptibility-weighted imaging (SWI)) often clarifies the diagnosis, which may alter management in acute settings, as well as chronic conditions, e.g., epilepsy. Clinical acumen remains essential to avoid imaging, e.g., in genetic epilepsies or migrainous headaches responding to treatment, or to target sequences to specific diagnosis, e.g., T1/T2-WI for shunt dysfunction (with SWI for TBI); DWI, arteriography including neck vessels, and venography for acute hemiplegia or coma; coronal temporal cuts for partial epilepsy; or muscle imaging for motor delay. The risk of general anesthesia is low; "head-only" scanners may allow rapid MRI without sedation. Timely and accurate reporting, with discrepancy discussion between expert neuroradiologists, is important for management of the child and the family's expectations.