Long-term treatment outcome of venous-predominant arteriovenous malformation

Arterial Spin-Labeling MR Imaging for the Differential Diagnosis of Venous-Predominant AVMs and Developmental Venous Anomalies

BACKGROUND AND PURPOSE

Venous-predominant AVMs are almost identical in appearance to developmental venous anomalies on conventional MR imaging. Herein, we compared and analyzed arterial spin-labeling findings in patients with developmental venous anomalies or venous-predominant AVMs, using DSA as the criterion standard.

MATERIALS AND METHODS

We retrospectively collected patients with either DVAs or venous-predominant AVMs, each available on both DSA and arterial spin-labeling images. Arterial spin-labeling imaging was visually assessed for the presence of hyperintense signal. CBF measured at the most representative section was normalized to the contralateral gray matter. The temporal phase of developmental venous anomalies or venous-predominant AVMs was measured on DSA as a delay between the first appearance of the intracranial artery and the lesion. Correlation between the normalized CBF and the temporal phase was evaluated.

RESULTS

Analysis of 15 lesions (13 patients) resulted in categorization into 3 groups: typical venous-predominant AVMs (temporal phase, <2 seconds), intermediate group (temporal phase between 2.5 and 5 seconds), and classic developmental venous anomalies (temporal phase, >10 seconds). Arterial spin-labeling signal was markedly increased in the typical venous-predominant AVM group, while there was no discernible signal in the classic developmental venous anomaly group. In the intermediate group, however, 3 of 6 lesions showed mildly increased arterial spin-labeling signal. The normalized CBF on arterial spin-labeling and the temporal phase on DSA were moderately negatively correlated: r(13) = 0.66, P = .008.

CONCLUSIONS

Arterial spin-labeling may predict the presence and amount of arteriovenous shunting in venous-predominant AVMs, and using arterial spin-labeling enables confirmation of typical venous-predominant AVMs without DSA. However, lesions with an intermediate amount of shunting suggest a spectrum of vascular malformations ranging from purely vein-draining developmental venous anomalies to venous-predominant AVMs with overt arteriovenous shunting.

Isolated hemorrhagic arterialized DVAs: revisiting symptomatic DVAs

We aim to present here a small case series of symptomatic isolated hemorrhagic arterialized developmental venous anomalies (sDVAs) with a larger goal of revisiting the classification based on patho-mechanisms plus emphasizing angiographic features coupled with CT and MRI. Typically, DVA is an incidental and silent abnormality on neuroimaging. Understanding its morphology in terms of arterialization and relationship with other entities is crucial for management. One adult and two pediatric cases presented with acute or sub-acute hemorrhage in the cerebellum or thalamus. Morphologic characterization on cross-sectional imaging and catheter angiography confirmed the integrated diagnosis of "symptomatic isolated hemorrhagic arterialized DVAs with deeper or superficial venous drainage". Conservative management was adopted in all cases. We emphasize the following classification and approach for symptomatic DVAs: (1) congestive isolated arterialized sDVAs, (2) congestive isolated resistive sDVAs, (3) coexisting sDVAs (with AVM or cavernous malformation), (4) compressive sDVAs (compressive effects), and (5) idiopathic DVAs. Like our three cases, ganglionic and infratentorial DVAs have higher propensity of hemorrhage, compressive effects, and usually harbor deeper venous drainage. Typical "caput medusae" as dominant collector vein on cross-sectional imaging is crucial to complement and even confirm the diagnosis of DVA before catheter angiography in sDVAs. Capillary stain or early opacification of DVAs is a marker of arteriovenous shunting in arterialized sDVAs. Recognition of this entity is crucial as treatment is usually conservative.

Direct electrophysiological evidence that spreading depolarization-induced spreading depression is the pathophysiological correlate of the migraine aura and a review of the spreading depolarization continuum of acute neuronal mass injury

Spreading depolarization is observed as a large negative shift of the direct current potential, swelling of neuronal somas, and dendritic beading in the brain's gray matter and represents a state of a potentially reversible mass injury. Its hallmark is the abrupt, massive ion translocation between intraneuronal and extracellular compartment that causes water uptake (= cytotoxic edema) and massive glutamate release. Dependent on the tissue's energy status, spreading depolarization can co-occur with different depression or silencing patterns of spontaneous activity. In adequately supplied tissue, spreading depolarization induces spreading depression of activity. In severely ischemic tissue, nonspreading depression of activity precedes spreading depolarization. The depression pattern determines the neurological deficit which is either spreading such as in migraine aura or migraine stroke or nonspreading such as in transient ischemic attack or typical stroke. Although a clinical distinction between spreading and nonspreading focal neurological deficits is useful because they are associated with different probabilities of permanent damage, it is important to note that spreading depolarization, the neuronal injury potential, occurs in all of these conditions. Here, we first review the scientific basis of the continuum of spreading depolarizations. Second, we highlight the transition zone of the continuum from reversibility to irreversibility using clinical cases of aneurysmal subarachnoid hemorrhage and cerebral amyloid angiopathy. These illustrate how modern neuroimaging and neuromonitoring technologies increasingly bridge the gap between basic sciences and clinic. For example, we provide direct electrophysiological evidence for the first time that spreading depolarization-induced spreading depression is the pathophysiological correlate of the migraine aura.

Role of developmental venous anomalies in etiopathogenesis of demyelinating diseases

OBJECTIVE

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. T2W-hyperintense demyelinating lesions are detected in cranial magnetic resonance imaging (MRI). Developmental venous anomalies (DVAs) have frequently been detected in enhanced cranial MRI images, and are generally accepted as normal variants of venous development. The aim of the present study was to investigate whether there was an association between demyelinating diseases and venous anomalies.

METHODS

One hundred five patients who were diagnosed as having MS in accordance with the McDonald diagnostic criteria, and 105 patients who were diagnosed as having vascular headache who had no lesions similar to MS were included in the present retrospective study.

RESULTS

DVAs were detected in 31 of the study group and in 14 patients in the control group. A statistically significant higher rate of DVAs and abnormal signal increase in the neighboring tissue was detected in the study group (p = 0.004) (p = 0.006). The DVA was superficially localized in the RRMS, It was deeply located in RIS.

CONCLUSION

Recent studies have emphasized the association of the central vein and the lesion severity of MS with the detection of the central collecting vein in MS lesions. In our study, DVAs, which are generally regarded as innocent developmental anomalies, and neighboring signal increase were found significantly higher in the MS group compared with the control group. The role of DVAs in the etiology of demyelinating lesions must be clarified through comprehensive future studies that use more advanced techniques.

Clinical and Arterial Spin Labeling Brain MRI Features of Transitional Venous Anomalies

BACKGROUND AND PURPOSE

Transitional venous anomalies (TVAs) are rare cerebrovascular lesions that resemble developmental venous anomalies (DVAs), but demonstrate early arteriovenous shunting on digital subtraction angiography (DSA) without the parenchymal nidus of arteriovenous malformations (AVMs). We investigate whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) can distinguish brain TVAs from DVAs and guide their clinical management.

METHODS

We conducted a single-center retrospective review of patients with brain parenchymal DVA-like lesions with increased ASL signal on MRI. Clinical histories and follow-up information were obtained. Two readers assessed ASL signal location relative to the vascular lesion on MRI and, if available, the presence of arteriovenous shunting on DSA.

RESULTS

Thirty patients with DVA-like lesions with increased ASL signal were identified. Clinical symptoms prompted MRI evaluation in 83%. Symptoms did not localize to the venous anomaly in 90%. Ten percent presented with acute symptoms, only one of whom presented with hemorrhage. ASL signal in relation to the venous anomaly was identified in: 50% in the adjacent parenchyma, 33% in the lesion, 7% in a distal draining vein/sinus, and 10% in at least two of these sites. Follow-up DSA confirmed arteriovenous shunting in 71% of ASL-positive venous anomalies. Interrater agreement was very good (κ = .81-1.0, P < .001).

CONCLUSION

A DVA-like lesion with increased ASL signal likely represents a TVA with arteriovenous shunting. Our study indicates that these lesions are usually incidentally detected and have a lower risk of hemorrhage than AVMs. ASL-MRI may be a useful tool to identify TVAs and guide further management of patients with TVAs.