Published online before print October 23, 2003, doi: 10.1161/01.STR.0000094763.71864.89
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(Stroke. 2003;34:2669.)
© 2003 American Heart Association, Inc.
Original Contributions |
Editorial Comment—Age-Dependent Brain AVM Characteristics: What is the Evidence?
Department of Neurosurgery, University of Messina, Messina, Italy
Cerebral arteriovenous malformations (AVMs) came to clinical attention more than a century ago,1 and since that time, they have been recognized as lesions that can cause serious neurological deficits or death. Although AVMs can present mostly with hemorrhage or seizure, the advent of contemporary brain imaging techniques has allowed an increasing number of AVMs to be detected before rupture. Over the last decade, there has been a growing interest in knowing more about the incidence, frequency, and clinical course of these vascular lesions; thus, both retrospective and prospective-based studies offering new insights have accumulated.
Population-based studies have reported that half of the adults with a first presentation of brain AVM have intracranial hemorrhage.2 Other important presenting symptoms include seizures, headaches, progressive neurological deficit, pulsatile tinnitus, and other unrelated symptoms that lead to a fortuitous diagnosis.3 Finally, an AVM can be suggested by a distinctive combination of these features.
An understanding of the different modes of presentation and their relative frequencies is important to raise the clinical suspicion of an AVM, so that clinical management is undertaken appropriately. The study by Stapf and colleagues4 provides seminal findings in this issue by reporting preliminary results of the Columbia AVM Data Bank, an ongoing prospective study.5,6 By collecting demographic, clinical, and morphological data on 542 consecutive patients with brain AVM, the authors assessed the effect of age at the time of the diagnostic event on clinical and morphological characteristics of brain AVM.
To define precise criteria of analysis, patients were stratified into 7 different age classes (<10, 10 to 19, 20 to 29, 30 to 39, 40 to 49, 50 to 59, and 
60 years). As far as the clinical characteristics are concerned, the authors found that hemorrhage was the presenting symptom in 46% of the cases. Interestingly, the highest bleeding frequencies were found among patients in the lowest and highest age groups. Increasing age correlated well with hemorrhage, focal neurological deficits, infratentorial AVM location, and concurrent arterial aneurysm. On the other hand, an inverse correlation was found with seizure, AVM size, and lobar, deep, and borderzone location. No significant differences were detected across different age groups for sex, headache, asymptomatic presentation, or venous drainage pattern.
These data are unique in that they provide an excellent characterization of AVMs with respect to patient age at the time of initial presentation. Important differences among patients mainly between 2 different classes of age, younger and older, are suggested. From the data reported, intracranial hemorrhage is the clinically most relevant mode of AVM presentation, especially in patients presenting after 60 years of age. This is in agreement with the data reported by Karlsson et al7 that increasing age confers an increased risk of AVM rupture. Furthermore, in this class of patients, no case with AVM-related seizures and deeply located AVM was detected.
A few points, however, are worthy of note. By age stratification, older patient were found to have the smallest mean AVM diameter in the analyzed cohort study. This finding, as the authors state, differs with the widely accepted notion of AVM representing a congenital malformation that grows over time. However, a spontaneous AVM regression could be a hazardous explanation for such an observation because, to date, strong evidence does not exist. In this regard, spontaneous AVM regression is considered to be a rare occurrence. In a series of 700 cerebral AVMs treated for 20 years,8 just 6 cases of angiographically documented lesions that disappeared on follow-up angiograms were identified, and 24 similar cases from the preexisting literature were reviewed. The common threads of such cases were modest size, a limited number of arterial feeders, isolated venous drainage, and a history of hemorrhage.
Finally, on the basis of their data, the authors provide an estimate of the probability of hemorrhage as a presenting symptom, because, in this study, the older AVM patients have the maximum risk of bleeding compared with the other age classes. Unfortunately, this type of study cannot completely address this issue. Because this study is merely observational and does not provide a longitudinal risk analysis, it may underestimate the overall frequency of incident AVM hemorrhage and associated risk factors. Hence, although Stapf and collaborators4 provide a reasonable argument linking age with AVM variables, they appropriately caution that referral bias to specialized treatment centers may significantly influence the analysis of the local patient cohort. Despite this inherent limitation of epidemiologically based observations, the authors’ findings provide a compelling argument against the assumption of uniform AVM characteristics across different age of presentation.
In summary, the findings reported by Stapf and collaborators, especially the notion that a 
dynamic
risk exposure at different ages may caution against stable annual risk predictions in AVM patient, even if deserving further population-based AVM data, add an important contribution to our existing knowledge that could be helpful in our decision-making process when treating patients with cerebral AVM.
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References |
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- Steinheil SO. Ueber einen fall von varix aneurysmaticus im bereich der gehirngefaesse. Würzburg F Fromme. 1895: 1–56.
- Stapf C, Mast H, Sciacca RR, Berenstein A, Nelson PK, Gobin YP, Pile-Spellman J, Mohr JP. The New York Islands AVM Study: design, study progress, and initial results. Stroke. 2003; 34: e29–e33.
[Abstract/Free Full Text] - Brown RD Jr, Wiebers DO, Forbes G, O’Fallon WM, Piepgras DG, Marsh WR, Maciunas RJ. The natural history of unruptured intracranial arteriovenous malformations. J Neurosurg. 1988; 68: 352–357.[Medline] [Order article via Infotrieve]
- Stapf C, Khaw AV, Sciacca RR, Hofmeister C, Schumacher HC, Pile-Spellman J, Mast H, Mohr JP, Hartmann A. Effect of age on clinical and morphological characteristics in patients with brain arteriovenous malformation. Stroke. 2003; 34: 2664–2670.
[Abstract/Free Full Text] - Mast H, Young WL, Koennecke HC, Sciacca RR, Osipov A, Pile-Spellman J, Hacein-Bey L, Duong H, Stein BM, Mohr JP. Risk of spontaneous haemorrhage after diagnosis of cerebral arteriovenous malformation. Lancet. 1997; 350: 1065–1068.[CrossRef][Medline] [Order article via Infotrieve]
- Hartmann A, Mast H, Mohr JP, Koennecke HC, Osipov A, Pile-Spellman J, Duong DH, Young WL. Morbidity of intracranial hemorrhage in patients with cerebral arteriovenous malformation. Stroke. 1998; 29: 931–934.
[Abstract/Free Full Text] - Karlsson B, Lindquist C, Johansson A, Steiner L. Annual risk for the first hemorrhage from untreated cerebral arteriovenous malformations. Minim Invasive Neurosurg. 1997; 40: 40–46.[Medline] [Order article via Infotrieve]
- Abdulrauf SI, Malik GM, Awad IA. Spontaneous angiographic obliteration of cerebral arteriovenous malformations. Neurosurgery. 1999; 44: 280–287;discussion 287–288.
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