Missing relationship of moyamoya and persistent primitive artery in Europeans. Another distinctive feature or artifact?

Clinical Importance of the Persistent Primitive Trigeminal Artery in Vascular Lesions and Its Role in Endovascular Treatment

The persistent primitive trigeminal artery (PPTA) extends from the internal carotid artery to the basilar artery between the origins of the anterior inferior cerebellar artery and superior cerebellar artery. PPTAs have complex anatomical characteristics. Salas and Saltzman classifications are most often used in PPTAs. The PPTA can play many roles in vascular lesions, including intracranial aneurysms, brain arteriovenous malformations, trigeminal artery-cavernous fistulas, Moyamoya disease, and large vessel occlusion. For these lesions, surgical treatment is difficult due to the deep location and complex anatomy of the PPTA, but endovascular treatment (EVT) has emerged as a good alternative. Currently, a complete review of the clinical importance of the PPTA in terms of its role in the development and EVT of vascular lesions is lacking. Therefore, we conducted a PubMed search, performed a review of the relevant extracted literature and cataloged our experience with PPTAs. By review, we found that a thorough understanding of the anatomical and angiographic features of this PPTA is of utmost importance when making therapeutic decisions for any of these pathological conditions.

Idiopathic Moyamoya Disease Presenting as Isolated Hemichorea

The study aimed to describe a case of a 7-year-old Caucasian girl who developed isolated chorea in her right upper and lower extremities progressively increasing over 2 years. This study is a case report and conducted at tertiary care center. A 7-year-old Caucasian girl who gradually developed worsening choreiform movements in her right upper and lower extremities over the course of 2 years until medical attention was sought. Literature review of children presenting with chorea as the only manifestation in moyamoya disease. A 7-year-old right-handed Caucasian girl presented with progressively worsening choreiform movements in her right upper and lower extremities affecting her fine motor skills and gait impairment There was no weakness, hyperreflexia, or spasticity on her neurological exam. Neuroimaging studies showed “ivy sign,” asymmetric prominence of vessels within the subarachnoid spaces overlying the left cerebral hemisphere with corresponding serpiginous T2 fluid-attenuated inversion recovery abnormality, but no parenchymal volume loss or diffusion restriction. Magnetic resonance angiography showed focal moderate-to-severe stenosis at the junction of the paraophthalmic and supraclinoid segments of the left internal carotid artery, with poststenotic dilatation. Angiography demonstrated focal stenosis involving the ophthalmic segment of the left internal carotid artery with 50% stenosis. There was compensation through a medium sized left posterior communicating artery as well as posterior cerebral artery to middle cerebral artery and anterior cerebral artery collateralization. Brain single-photon emission computerized tomography scan showed no evidence of perfusion defects in the cerebral hemispheres, basal ganglia, or thalami. She underwent successful revascularization procedure (left pial synangiosis) with resolution of her choreiform movements and normalization of her gait. Our case demonstrates that moyamoya disease should be suspected when evaluating a child with hemichorea and describes resolution of symptoms after revascularization surgery. Neuroimaging and vascular studies should be obtained in children with unilateral movement disorder.

Prevalence and Clinical Implications of the Primitive Trigeminal Artery and its Variants: A Meta-Analysis

BACKGROUND

The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features.

METHODS

Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis.

RESULTS

A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3-0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA.

CONCLUSIONS

PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.

Incidence, Locations, and Longitudinal Course of Cerebral Microbleeds in European Moyamoya

BACKGROUND AND PURPOSE

Cerebral microbleeds (cMBs) have previously been linked with especially high incidence in Asian patients with moyamoya together with high tendency to bleed. This, presumably, is characteristic of patients with moyamoya. Herein, we, therefore, investigate retrospectively the frequency, location, and longitudinal course of cMBs in a large German cohort.

METHODS

We included all patients with moyamoya who underwent standard magnetic resonance imaging, including T2*-weighted images, in our department between 1998 and 2015. Two independent readers evaluated magnetic resonance imaging scans to determine the occurrence of cMBs according to the Brain Observer Microbleed Scale. Demographics, initial symptoms leading to hospitalization, and associated diseases were obtained by chart review.

RESULTS

Overall, there was a total of 242 T2* studies of 101 included moyamoya patients available with a strong female predominance (69.3%). Eight patients (7.9%) were ≤18 years of age. We detected 25 cMBs within 13 patients (12.9%). One patient <18 of age was presented with a cMB; 2 of 3 patients with an intracranial hemorrhage as initial event demonstrated cMB(s). In 72 of 101 cases, there were 1719 person months of follow-up, with 3 adult patients showing 3 de novo cMBs in the course. The majority of cMBs (64.0%) were located at the cortex/gray-white junction.

CONCLUSIONS

Although the frequency of cMBs herein is much higher than the expected age-specific incidence, it is still much lower compared with previous reports on cMBs in moyamoya patients of Asian descent. These results might reflect another ethnic-specific difference in patients diagnosed with moyamoya.