In addition to appropriate antithrombotic therapy, the identification and treatment of modifiable ischemic stroke risk factors can reduce the likelihood of recurrent stroke. Neurosurgeons should be knowledgeable of the specific risk factors and general recommendations for ischemic stroke, as they may play a significant role in the management options for patients with intracranial and extracranial atherosclerotic disease. The authors of this article review the indications for and selection of antithrombotics in patients with cerebral ischemia. In addition, the identification and secondary prevention of select risk factors are discussed.
Brian S. Katz and Kelly D. Flemming
Kelly D. Flemming, George K. Bovis and Fredric B. Meyer
The risk of hemorrhage from an intracerebral cavernous malformation has been estimated at 2%–4% per year. In patients with multiple cavernous malformations, typically there are 1 or 2 dominant lesions that result in symptoms. This report highlights an unusual case of recurrent hemorrhage from de novo cavernous malformations.
This 35-year-old man had a generalized seizure in 2007. Magnetic resonance imaging performed at the time showed multiple hemorrhagic lesions suggestive of cavernous malformations. Two years later, the patient had clinical symptoms referable to a midbrain hemorrhage. This lesion was not present on 2007 standard and gradient echo images. One year later, the patient had another clinical hemorrhage at the cervical medullary junction. This lesion was also not present on earlier imaging. Genetic testing was negative for the known familial types of cavernous malformation. A lesion was biopsied to ensure correct diagnosis, and the results were pathologically consistent with a cavernous malformation. The patient had a fourth clinical hemorrhage in 2011 from a separate lesion. All hemorrhage symptoms were mild, and he returned to normal functioning and work after each hemorrhage.
This case highlights several unusual features of the known natural history of intracerebral cavernous malformations. In this case, resection of the hemorrhagic lesion would not have altered future hemorrhage risk since each new hemorrhage was from a de novo lesion.
Kelly D. Flemming, Keith Josephs and Eelco F. M. Wijdicks
Waleed Brinjikji, Kelly D. Flemming and Giuseppe Lanzino
The authors report a case of a developmentally normal child with a congenital complex torcular dural arteriovenous fistula (DAVF) who later, in his teenage years, developed several vermian cavernomas within a large cerebellar developmental venous anomaly (DVA). The patient had initially presented with an abnormally large head circumference but no neurological deficits. He underwent several partial embolization procedures in an attempt to decrease the blood supply of the fistula over the course of 8 years. Nine years following initial presentation, he presented with a fourth ventricular hemorrhage, due to development of a new vermian cavernoma adjacent to a previously known vermian DVA and suffered subsequent mild left-sided hemiataxia from which he later recovered. CT angiographic images demonstrated that the vermian DVA drained into the left transverse sinus, which also drained the torcular arteriovenous fistula. A routine follow-up MRI examination 10 years following initial presentation demonstrated interval development of several large cavernomas in the cerebellum, all within the DVA. The patient had no new symptoms at that time and was neurologically intact. This case report highlights the de novo development of multiple cavernous malformations potentially secondary to DAVF-induced venous congestion in a preexisting DVA.
Thomas J. Sorenson, Waleed Brinjikji, Kelly D. Flemming and Giuseppe Lanzino
Incidental vascular lesions are being discovered at an increasing frequency due to widespread noninvasive brain imaging studies. One of these lesions has recently been termed a “pure arterial malformation” (PAM), which is defined as dilated, overlapping, and tortuous arteries forming a mass of arterial loops with a coil-like appearance in the absence of arteriovenous shunting. The pathogenesis of these lesions is not known, but a congenital etiology is suspected. The authors report the case of a 17-year-old female who was found to have a PAM of the posterior inferior cerebellar artery with adipose tissue interspersed within the arterial loops. The authors believe that this abnormal intracranial association between blood vessel and adipose tissue lends further support to the theory that PAMs are the result of a congenital malformation and are therefore safe to manage conservatively given their presumed benign natural history. Far from offering conclusive evidence, this unique case report adds to the growing body of PAM literature and strengthens an increasingly supported congenital theory of genesis.
Kelly D. Flemming, Michael J. Link, Teresa J. H. Christianson and Robert D. Brown Jr.
The goal of this study was to determine the risk of using antithrombotic agents in patients with established intracerebral cavernous malformations (ICMs).
From a previously described cohort of 292 patients with radiographically defined ICMs, 40 required an antithrombotic after the ICM was diagnosed. Patients underwent follow-up to determine the incidence of hemorrhage.
The mean age of these 40 patients was 62.4 years; there were 21 male and 19 female patients. Five (12.5%) of the 40 patients initially presented with hemorrhage and 4 (10%) had multiple ICMs. Of these patients, 32 were placed on an antiplatelet agent alone, 6 on an anticoagulant alone, and 2 were placed on both. In patients necessitating any antithrombotic agent, 1 patient developed a prospective hemorrhage over the 258 person-years of follow-up (prospective hemorrhage rate 0.41% per person-year).
Antithrombotics likely do not precipitate hemorrhage in patients with known ICMs. However, caution should be exercised in the use of antithrombotics in patients with ICMs at high risk for hemorrhage. The risks and benefits of antithrombotics in each situation should be carefully weighed against the natural history of ICM.
S. Arthur Moore, Robert D. Brown Jr., Teresa J. H. Christianson and Kelly D. Flemming
The aim of this study was to determine the prospective hemorrhage rate in a group of retrospectively identified patients in whom symptoms had an unclear relationship to an intracerebral cavernous malformation (ICM) or the malformation itself was an incidental finding.
Patients with incidentally discovered ICMs diagnosed between 1989 and 1999 were identified from a previously published cohort. Those with ICMs having an unclear relationship with existing symptoms were also eligible for analysis. Updated clinical and radiographic data pertaining to symptomatic intracerebral hemorrhage related to the ICM or new seizures were obtained through medical chart review and mail survey. In select patients, phone calls were made and death certificates were obtained when possible. The prospective hemorrhage rate was calculated as the number of prospective hemorrhages divided by the number of patient-years of follow-up.
There were 1311 patient-years of follow-up among the 107 patients (49.5% male; mean age at diagnosis 52 years) eligible for this study. Forty-four patients died in the follow-up period, and the cause of death could be determined in 34 (77%). Two patients had a prospective hemorrhage, which was definitively related to the ICM in only one. Thus, the definitive prospective bleed rate was 0.08% per patient-year. No new seizures developed in any of the patients during the follow-up period.
The risk of prospective hemorrhage in patients presenting asymptomatically with ICM is very low. This information can be useful in managing such patients and may be most applicable to those with a single ICM.
Jeremy K. Cutsforth-Gregory, Giuseppe Lanzino, Michael J. Link, Robert D. Brown Jr. and Kelly D. Flemming
The objective of this study was to characterize the clinical features of radiation-induced cavernous malformations (RICMs).
The authors retrospectively reviewed the clinical and radiological characteristics of patients with RICMs. The features of these RICMs were then compared with features of nonradiation cavernous malformations (CMs) in 270 patients.
Thirty-two patients with RICMs were identified (56.2% men), with a median age of 31.1 years at RICM diagnosis. The median latency from radiation treatment to RICM diagnosis was 12.0 years (interquartile range 5.0–19.6 years). RICMs were always within the previous radiation port. RICMs were symptomatic at diagnosis in 46.9%, and were associated with symptomatic intracranial hemorrhage at any time in 43.8%. Older age at the time of radiation treatment and higher radiation dose were associated with shorter latency. RICMs tended to be diagnosed at a younger age than nonradiation CMs (median 31.1 vs 42.4 years, respectively; p = 0.054) but were significantly less likely to be symptomatic at the time of diagnosis (46.9% vs 65.8%, respectively; p = 0.036). RICMs were more likely to be multiple CMs than nonradiation CMs (p = 0.0002). Prospectively, the risk of symptomatic hemorrhage was 4.2% for RICMs and 2.3% for nonradiation CMs per person-year (p = 0.556). In the absence of symptoms at presentation, the risk of hemorrhage for RICMs was higher than for nonradiation CMs (4.2% vs 0.35%, respectively; p = 0.118).
In this patient population, RICMs occurred within the radiation port approximately 12 years after radiation treatment. Compared with nonradiation CMs, RICMs were more likely to occur as multiple CMs, to present at a younger age, and were at least as likely to cause symptomatic hemorrhage.
Waleed Brinjikji, Harry J. Cloft, Kelly D. Flemming, Simone Comelli and Giuseppe Lanzino
Over the last half century, there have been isolated case reports of purely arterial malformations. In this study, the authors report a consecutive series of patients with pure arterial malformations, emphasizing the clinical and radiological features of these lesions.
Pure arterial malformations were defined as dilated, overlapping, and tortuous arteries with a coil-like appearance and/or a mass of arterial loops without any associated venous component. Demographic characteristics of the patients, cardiovascular risk factors, presentation, radiological characteristics, and follow-up data were collected. Primary outcomes were new neurological symptoms including disability, stroke, and hemorrhage.
Twelve patients meeting the criteria were identified. Ten patients were female (83.3%) and 2 were male (16.6%). Their mean age at diagnosis was 26.2 ± 11.6 years. The most common imaging indication was headache (7 patients [58.3%]). In 3 cases the pure arterial malformation involved the anterior cerebral arteries (25.0%); in 4 cases the posterior communicating artery/posterior cerebral artery (33.3%); in 2 cases the middle cerebral artery (16.6%); and in 1 case each, the superior cerebellar artery, basilar artery/anterior inferior cerebellar artery, and posterior inferior cerebellar artery. The mean maximum diameter of the malformations was 7.2 ± 5.0 mm (range 3–16 mm). Four lesions had focal aneurysms associated with the pure arterial malformation, and 5 were partially calcified. In no cases was there associated intracranial hemorrhage or infarction. One patient underwent treatment for the pure arterial malformation. All 12 patients had follow-up (mean 29 months, median 19 months), and there were no cases of disability, stroke, or hemorrhage.
Pure arterial malformations are rare lesions that are often detected incidentally and probably have a benign natural history. These lesions can affect any of the intracranial arteries and are likely best managed conservatively.