[Magnetic resonance angiography and magnetic resonance tomography in dissection of the vertebral artery]

[Neurovascular complications in fractures of the extremities, part 1 : Vascular lesions]

Neurovascular injuries in fractures threaten at least the function of extremities. The timely interaction between diagnosis and treatment of vascular injuries helps to avoid a poor outcome or even fatal complications. An important parameter is to "think about it" for injuries under strain. An ankle-brachial index (ABI) of <0.9 is an indicator. Massive bleeding, manifest and long-lasting peripheral ischemia and a rapidly expanding hematoma necessitate an immediate surgical intervention. Endovascular techniques are recommended on the extremities of stable patients with circumscribed vascular lesions. The debate about the sequence of repair (vascular vs. osseous) has to be decided on an individual basis; however, when in doubt vascular repair should be given priority. Vessel reconstructions should be performed without tension and must be covered by vital soft tissues, the indications for fasciotomy should be liberally interpreted. The prognosis with respect to preservation of the extremity and long-term functional outcome substantially depends on the quality of treatment of accompanying injuries.

Neuroimaging of headaches associated with vascular disorders

Headaches from vascular causes need to be differentiated from primary headaches because a misdiagnosis may lead to dire consequences for the patient. Neuroimaging is critical in identifying patients with vascular headaches and identifying the nature of the pathologic disorder causing these headaches. In addition, the imaging findings guide the physician regarding the optimal treatment modality for these lesions. This review summarizes the nuances of differentiating patients with secondary headaches related to vascular disease and discusses pertinent neuroimaging studies.

Spontaneous resolution of nontraumatic bilateral intracranial vertebral artery dissections

A 49-year-old man presented with nontraumatic bilateral intracranial vertebral artery dissections without subarachnoid hemorrhage manifesting as Wallenberg's syndrome on the right. Magnetic resonance imaging revealed an infarct in the right dorsolateral aspect of the medulla oblongata. Antiplatelet therapy was administered. Vertebral angiography performed on the 9th hospital day (Day 9) revealed pearl and string sign in the right vertebral artery and narrowing of the left vertebral artery. Second angiography performed on Day 25 showed no change, but third angiography performed on Day 74 revealed spontaneous resolution of the bilateral vertebral artery dissections. Magnetic resonance angiography performed on Day 250 showed no evidence of dissection. However, magnetic resonance imaging revealed a small infarct in the splenium of the corpus callosum. Spontaneous resolution of stenotic dissections of the bilateral vertebral arteries is extremely unusual. Serial cerebral angiography and magnetic resonance angiography are very important for monitoring the time course of changes in patients with vertebral artery dissections.

Efficacy of MR Angiography in the Detection and Characterization of Occlusive Disease in the Vertebrobasilar System

PURPOSE

The purpose of this work was to determine the efficacy of MR angiography (MRA) in the detection and characterization of occlusive disease in the vertebrobasilar system.

METHOD

We retrospectively reviewed the posterior circulation registry of our institution to select 42 consecutive patients with posterior circulation ischemic symptoms who underwent both MRA and angiography. The extracranial vertebral arteries (ECVAs) were examined by two-dimensional time-of-flight MRA above the C6 level, and the intracranial vertebral arteries (ICVAs) and basilar arteries (BAs) were examined by three-dimensional time-of-flight MRA. Sixty-two ECVAs, 63 ICVAs, and 39 BAs were examined by the readers.

RESULTS

Occlusive disease was seen on angiography in 22 of the 42 patients. The sensitivity and specificity values for detection of lesions in 12 ECVA, 19 ICVA, and 12 BA abnormalities were as follows: ECVA, 92 and 96% for Reader A and 100 and 90% for Reader B; ICVA, 84 and 93% for Reader A and 74 and 82% for Reader B; and BA, 100 and 88% for Reader A and 100 and 78% for Reader B. For ICVA, the sensitivity of MRA was less than that of angiography because of lesions missed by the readers at the junctional area of the extra-and intracranial MRA. MRA accurately characterized 9 of the 12 (75%) ECVA, 10 of the 19 (43%) ICVA, and 11 of the 12 (92%) BA lesions.

CONCLUSION

MRA is an effective method for detection of occlusive lesions in the ECVAs and BAs. Clinically important lesions can be missed by MRA in the ICVA. MRA is more accurate in characterization of occlusive lesions in BAs than in ECVAs or ICVAs.

Extracranial vertebral artery dissection causing cervical root lesion

The authors report an unusual manifestation of extracranial vertebral artery dissection (VAD), presenting with a predominantly motor radicular manifestation. Cervical magnetic resonance imaging (MRI) revealed the intramural hematoma in the dissected vessel wall, compressing mainly the segmental motor root and, to a lesser degree, the sensory ganglion. In the digital subtraction angiography (DSA), a circumscribed narrowing of the incriminated vessel was demonstrated. Color-coded Duplex imaging (CDDI) revealed complete recanalization after a few days of anticoagulation treatment. Complete neurologic recovery was seen after 3 months. Considering the MRI data, the likely pathogenetic mechanism was compression of the nerve root by the intramural hematoma. The synopsis with similar cases in the literature points to the characteristic features, i.e., the association of neck pain with radicular motor deficit and the absence of degenerative disk disease. The respective syndrome should raise the suspicion of vertebral artery dissection, especially in young individuals.