Intracranial dolichoectasia in patients with symptomatic intracranial atherosclerotic disease: Results from the MYRIAD study

Abstract

Background and Purpose It is unknown whether intracranial atherosclerotic disease (ICAD), in addition to causing stenosis, also associates with abnormal arterial enlargement, a condition known as intracranial dolichoectasia (IDE). Across symptomatic ICAD patients, we aim to determine IDE prevalence and IDE impact on cerebral hemodynamics and recurrent cerebral ischemia. Methods We analyzed 98 participants (mean age 63.8 ± 11.9 years, 56.1% men) of the prospective observational study MYRIAD. Participants were enrolled within 21 days of an ischemic stroke or transient ischemic attack caused by moderate‐to‐severe ICAD. Semi‐automatic vessel segmentation was used to determine diameters, length, and tortuosity‐index of proximal intracranial arteries. Either ectasia (increased diameter) or dolichosis (increased length or TI) defined IDE. We assessed IDE association with new infarcts during 12‐month follow‐up, and IDE correlation with cerebral hemodynamics determined by quantitative MR‐angiography (QMRA), MR‐perfusion weighted‐imaging, and transcranial Doppler breath‐holding index. Results IDE was present in 35.7% of patients and 10.2% of symptomatic arteries. Basilar stenosis was associated with higher IDE prevalence (27.8% vs. 8.8%, p = 0.04), whereas other symptomatic arteries showed no association with IDE. Symptomatic arteries with IDE had lower hypoperfusion prevalence on MR‐PWI (11.1% vs. 28.4%, p = 0.03). Increased diameter (r = 0.33, p<0.01) and tortuosity‐index (r = 0.29, p = 0.01) showed positive correlation with QMRA flow rate. IDE was not associated with new infarcts during follow‐up. Conclusions IDE was common among symptomatic ICAD patients. IDE was not associated with stroke recurrence. Instead, increased diameter and tortuosity correlated with improved blood flow across the stenotic artery, suggesting that IDE may originate as an adaptive mechanism in ICAD.

Association of brain arterial diameters with demographic and anatomical factors in a multi-national pooled analysis of cohort studies

“…35 Also, age-related buildup of fatty plaques within arteries (i.e., atherosclerosis) can cause arterial narrowing and stenosis, which can result in compensatory larger diameters in unaffected arterial segments that provide collateral flow. 36 Our study also confirms that men have larger brain arterial diameters compared to women irrespective of body size. On average, ICA and BA diameters in men were 0.2 mm larger, whereas MCA diameters were 0.1 mm larger.…”

Persistent Posterior Fossa Hypoperfusion in the Setting of Vertebrobasilar Dolichoectasia

“…Hemodynamic factors, such as circle of Willis variations, vessel hypoplasia, and intracranial arterial disease, can result in blood flow diversion and subsequent dolichoectasia. 1,4 Metabolic disorders, particularly Fabry and Pompe disease, which are lysosomal storage disorders that affect smooth muscle cells, have shown association with IADE. The mechanism of ischemic stroke can involve mural thrombus causing artery-to-artery embolization or occlusion of penetrating arteries.…”