[Type I neurofibromatosis and megadolichobasilar artery]

Anatomical distribution of cerebral microbleeds and intracerebral hemorrhage in vertebrobasilar dolichoectasia

OBJECTIVES

Vertebrobasilar dolichoectasia (VBD) is a dilatative arteriopathy associated with intracerebral hemorrhage. In the present study, we sought to evaluate the frequency and anatomical distribution of cerebral microbleeds (cMBs) and intracerebral hemorrhage (ICH) in VBD.

METHODS

From a MRI database 94 VBD patients were identified and analyzed with special emphasis on cMBs and ICH on T2*-weighted gradient echo images (GRE) in relation to the established diagnostic MRI criteria of VBD (diameter, height, and lateral position). cMBs/ICH location was categorized into anterior/posterior circulation. Clinical information like demographic details, clinical symptoms, and comorbidities were abstracted from the case records. An extensive modelling approach using generalized linear mixed-effects models was used.

RESULTS

Overall, 79 (84.0%) patients (mean age 72.1±10.0 years, 74.7% male) with a standard stroke MRI protocol including T2*-weighted images were included in the analysis. cMBs were observed in 38/79 (48.1%) patients, ranging from 1 to 84 cMBs per patient. In the posterior circulation cMBs were observed more frequently (34/38 (89.5%)) in comparison to the anterior circulation (24/38 (63.2%)). cMBs were observed in the thalamus in 20/38 (52.6%), hippocampus in 1/38 (2.6%), occipital lobe in 18/38 (47.4%), pons in 6/38 (15.8%), medulla oblongata in 2/38 (5.2%), and cerebellum in 14/38 (36.8%) patients. ICH was observed in only 6/79 (7.6%) patients. There were significantly more cMBs in the posterior- (NCMBs-PC = 1.717, 95%CI: 1.336-2.208, p = 0.0315) than in the anterior circulation. Logistic regression model showed a significant positive effect of clinical symptoms such as ischemic, TIA and hemorrhagic stroke on the presence of cMBs (OR = 3.34, 95%CI [2.0-5.57], p = 0.0184; ndf = 78, AIC = 107.51). General linear model showed that clinical symptoms have a highly significant effect on the number of cMBs (N = 2.78, 95%CI [2.51-3.07], p<2*10-16; ndf = 78, AIC = 1218).

CONCLUSION

cMBs and ICH may be observed in the anterior and posterior circulation in VBD but they occur more frequently in the posterior circulation. Most common anatomical locations of cMBs in VBD were the thalamus, occipital lobe and cerebellum. This posterior dominance of cMBs and ICH in VBD might reflect a specific underlying vascular pathology.

Dilative Arteriopathy and Leucencephalopathy as Manifestations of a Neurometabolic Disease

Background:

Dilative arteriopathy plus leucencephalopathy as a manifestation of a mitochondrial disorder (MID) is rare.

Case report:

In a 70yo Caucasian female, height 160cm, weight 62kg, with mild right-sided hemiparesis due to subacute ischemic stroke in the posterior leg of the left internal capsule, a megadolichobasilar artery and marked leucencephalopathy and gliosis of the pons were detected. In addition, microbleeds in a peripheral distribution at the cortical/subcortical border were noted. After the exclusion of various differentials, which could have explained her abnormalities, a MID was suspected.

Conclusions:

Dilative arteriopathy of the intra-cerebral arteries, in association with recurrent stroke and supra- and infratentorial leucencephalopathy, but the absence of neurofibromatosis or increased low-density lipoprotein values, is most likely attributable to a non-syndromic MID.

A comparison of CT/CT angiography and MRI/MR angiography for imaging of vertebrobasilar dolichoectasia

PURPOSE

Vertebrobasilar dolichoectasia (VBD) is a rare dilatative arteriopathy predominantly affecting the basilar artery (BA) and vertebral arteries. Until today, the value of computed tomography (CT)/CT angiography (CTA) compared with magnetic resonance imaging (MRI)/time-of-flight MR angiography (TOF-MRA) has not been studied systematically.

METHODS

We (1) compare CTA and TOF-MRA according to the established criteria (diameter at the mid-pons level, height, and lateral position), (2) explore the value of further CTA- and TOF-MRA-derived measures (maximum transverse diameter and length), as well as (3) explore the value of further non-contrast-enhanced MRI sequences such as T1, fluid-attenuated inversion recovery, and T2* for a detailed characterization of VBD in a series of 18 patients.

RESULTS

Comparison of CTA and TOF-MRA revealed very good consistency of the measured diameter (Pearson's r = 0.994, p = 0.01) and the noted height of the BA (Kendall's tau = 1.0, p = 0.001). The same held true for the maximum transverse diameter (Pearson's r = 0.988, p = 0.01) and length of the BA (Pearson's r = 0.986, p = 0.01). In contrast to this, there was a lower agreement concerning the lateral position (Kendall's tau = 0.866, p = 0.01). In comparison with the diameter at the mid-pons level, the maximum transverse diameter was significantly larger (p = 0.002). Luminal thrombus was detected equally well by CTA and TOF-MRA. CT was useful to detect small circumscribed calcifications, whereas MRI was advantageous to demonstrate perifocal brainstem edema.

CONCLUSIONS

We could demonstrate a substantial comparability of CT/CTA and MRI/TOF-MRA in the diagnosis of VBD. The maximum transverse diameter and length may be useful when an endovascular treatment is considered. Taking into account the different informative value of both techniques, it may be worth to perform both imaging procedures.