Dynamic nature of cavernous malformations: a prospective magnetic resonance imaging study with volumetric analysis

2000 ◽  
Vol 93 (6) ◽  
pp. 981-986 ◽  
Author(s):  
Richard E. Clatterbuck ◽  
John L. Moriarity ◽  
Ilhan Elmaci ◽  
Roland R. Lee ◽  
Steven N. Breiter ◽  
...  

Object. Although cavernous malformations (CMs) are not detected in angiographic studies, they have a characteristic appearance on magnetic resonance (MR) images. A number of reports published in the last decade have focused on the behavior of these lesions within the clinical environment. However, little has been published about the evolution of CMs over time, as observed in imaging studies. To understand imaging-documented changes in CMs over time, we analyzed MR images of 114 cavernous malformations in 68 patients who were followed prospectively.Methods. For each CM the location, volume, and MR imaging signal characteristics were recorded. Volume data were available for 107 lesions from initial images. The mean volume of these 107 CMs was 2779 mm3. The lesions ranged in size from 0.5 to 46,533 mm3 (46.5 cm3). Volume data from a second set of images were available for 76 CMs (mean interval from first imaging session 26 months), and from a third set of images for 24 lesions (mean interval from second imaging session 18 months). Over the first follow-up interval, the mean volume change was −991 mm3 (a decrease of approximately 1 cm3) and over the second interval the mean volume change was −642 mm3. Although these mean volume changes appear modest, volume changes in single lesions during follow-up intervals were more dramatic, with decreases as large as 45,629 mm3 (45.6 cm3) and increases as large as 6,074 mm3 (6 cm3). Serial examinations of the MR imaging signal characteristics of these CMs demonstrate a trend for maturation of blood products from a subacute, to a mixed, and finally to a chronic appearance. Three lesions appeared de novo during the follow-up period.Conclusions. On the basis of their analysis, the authors conclude that CMs exhibit a range of dynamic behaviors including enlargement, regression, and de novo formation, as well as progression through a series of characteristic MR imaging appearances.

1994 ◽  
Vol 80 (3) ◽  
pp. 422-432 ◽  
Author(s):  
Joseph M. Zabramski ◽  
Thomas M. Wascher ◽  
Robert F. Spetzler ◽  
Blake Johnson ◽  
John Golfinos ◽  
...  

✓ Cavernous malformations are congenital abnormalities of the cerebral vessels that affect 0.5% to 0.7% of the population. They occur in two forms: a sporadic form characterized by isolated lesions, and a familial form characterized by multiple lesions with an autosomal dominant mode of inheritance. The management of patients with cavernous malformations, particularly those with the familial form of the disease, remains a challenge because little is known regarding the natural history. The authors report the results of an ongoing study in which six families afflicted by familial cavernous malformations have been prospectively followed with serial interviews, physical examinations, and magnetic resonance (MR) imaging at 6- to 12-month intervals. A total of 59 members of these six families were screened for protocol enrollment; 31 (53%) had MR evidence of familial cavernous malformations. Nineteen (61%) of these 31 patients were symptomatic, with seizures in 12 (39%), recurrent headaches in 16 (52%), focal sensory/motor deficits in three (10%), and visual field deficits in two (6%). Twenty-one of these 31 patients underwent at least two serial clinical and MR imaging examinations. A total of 128 individual cavernous malformations (mean 6.5 ± 3.8 lesions/patient) were identified and followed radiographically. During a mean follow-up period of 2.2 years (range 1 to 5.5 years), serial MR images demonstrated 17 new lesions in six (29%) of the 21 patients; 13 lesions (10%) showed changes in signal characteristics, and five lesions (3.9%) changed significantly in size. The incidence of symptomatic hemorrhage was 1.1% per lesion per year. The results of this study demonstrate that the familial form of cavernous malformations is a dynamic disease; serial MR images revealed changes in the number, size, and imaging characteristics of lesions consistent with acute or resolving hemorrhage. It is believed that the de novo development of new lesions in this disease has not been previously reported. These findings suggest that patients with familial cavernous malformations require careful follow-up monitoring, and that significant changes in neurological symptoms warrant repeat MR imaging. Surgery should be considered only for lesions that produce repetitive or progressive symptoms. Prophylactic resection of asymptomatic lesions does not appear to be indicated.


2004 ◽  
Vol 100 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Vaijayantee Kulkarni ◽  
Vedantam Rajshekhar ◽  
Lakshminarayan Raghuram

Object. The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging. Methods. Preoperative and short-term follow-up (mean duration 17.5 months, range 10–48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classifed as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes. Conclusions. On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.


2003 ◽  
Vol 98 (2) ◽  
pp. 337-341 ◽  
Author(s):  
Kelly D. Foote ◽  
William A. Friedman ◽  
Thomas L. Ellis ◽  
Frank J. Bova ◽  
John M. Buatti ◽  
...  

Object. The goal of this study was to evaluate the outcomes of patients who underwent repeated radiosurgery to treat a residual intracranial arteriovenous malformation (AVM) after an initial radiosurgical treatment failure. Methods. The authors reviewed the cases of 52 patients who underwent repeated radiosurgery for residual AVM at the University of Florida between December 1991 and June 1998. In each case, residual arteriovenous shunting persisted longer than 36 months after the initial treatment; the mean interval between the first and second treatment was 41 months. Each AVM nidus was measured at the time of the original treatment and again at the time of retreatment, and the dosimetric parameters of the two treatments were compared. After retreatment, patients were followed up and their outcomes were evaluated according to a standard posttreatment protocol for radiosurgery for AVMs. The mean original lesion volume was 13.8 cm3 and the mean volume at retreatment was 4.7 cm3, for an average volume reduction of 66% after the initial treatment failure. Only two AVMs (3.8%) failed to demonstrate size reduction after the primary treatment. The median doses on initial and repeated treatment were 12.5 and 15 Gy, respectively. Five patients were lost to follow up and five refused neuroimaging follow up. One patient died of a hemorrhage shortly after retreatment. Of the remaining 41 patients, 24 had evidence of cure, 15 on angiographic studies and nine on magnetic resonance (MR) images. Seventeen had evidence of treatment failure, 10 on angiographic studies and seven on MR images. By angiographic criteria alone, the cure rate after retreatment was 60%, whereas according to angiographic and MR imaging results, the cure rate was 59%. Conclusions. Although initial radiosurgical treatment failed to obliterate the AVM in these 52 patients, it did produce a substantial therapeutic effect (volume reduction). This size reduction commonly allowed higher doses to be delivered during radiosurgical retreatment. The results show rates of angiographically confirmed cure comparable to primary treatment and a low incidence of complications, indicating that salvage radiosurgical retreatment is a safe and effective therapy in cases of failed AVM radiosurgery.


1996 ◽  
Vol 85 (6) ◽  
pp. 1044-1049 ◽  
Author(s):  
Bruce E. Pollock ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Atul K. Patel ◽  
David J. Bissonette ◽  
...  

✓ To determine the accuracy of magnetic resonance (MR) imaging in comparison to cerebral angiography after radiosurgery for an arteriovenous malformation (AVM), the authors reviewed the records of patients who underwent radiosurgery at the University of Pittsburgh Medical Center before 1992. All patients in the analysis had AVMs in which the flow-void signal was visible on preradiosurgical MR imaging. One hundred sixty-four postradiosurgical angiograms were obtained in 140 patients at a median of 2 months after postradiosurgical MR imaging (median 24 months after radiosurgery). Magnetic resonance imaging correctly predicted patency in 64 of 80 patients in whom patent AVMs were seen on follow-up angiography (sensitivity 80%) and angiographic obliteration in 84 of 84 patients (specificity 100%). Overall, 84 of 100 AVMs in which evidence of obliteration was seen on MR images displayed angiographic obliteration (negative predictive value, 84%). Ten of the 16 patients with false-negative MR images underwent follow-up angiography: in seven the lesions progressed to complete angiographic obliteration without further treatment. Exclusion of these seven patients from the false-negative MR imaging group increases the predictive value of a negative postradiosurgical MR image from 84% to 91%. No AVM hemorrhage was observed in clinical follow up of 135 patients after evidence of obliteration on MR imaging (median follow-up interval 35 months; range 2–96 months; total follow up 382 patient-years). Magnetic resonance imaging proved to be an accurate, noninvasive method for evaluating the patency of AVMs that were identifiable on MR imaging after stereotactic radiosurgery. This imaging modality is less expensive, more acceptable to patients, and does not have the potential for neurological complications that may be associated with cerebral angiography. The risk associated with follow-up cerebral angiography may no longer justify its role in the assessment of radiosurgical results in the treatment of AVMs.


2002 ◽  
Vol 97 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Langston T. Holly ◽  
Ulrich Batzdorf

Object. The authors review their experience in the diagnosis and management of 32 patients with slitlike syrinx cavities. Methods. There were 18 men and 14 women with a mean age of 40 years. Presenting symptoms that prompted magnetic resonance (MR) imaging evaluation were mechanical spinal pain (13 patients), radicular pain (seven patients), paresthesia (six patients), numbness (five patients), and muscle spasm (one patient). In 12 patients neurological examination demonstrated normal status, and in the remainder only minimal sensory or motor abnormalities were found. The mean diameter of the syrinx cavity was 2 mm (range 1–5 mm), and on average it covered three vertebral levels. The cavities were limited to the cervical region in 16 patients, the thoracic in 12, and both regions in four patients. The mean follow-up time for changes in clinical condition and repeated MR imaging features were 38 and 32 months, respectively. Thirty-one patients were treated nonoperatively, and one was treated surgically. During the follow-up period clinical improvement was documented in six patients, worsened status in seven, and no change was demonstrated in the clinical status of 19 patients. None of the syrinx cavities changed in size. In 16 patients medical workup revealed alternative diagnoses that were determined to be the true causes of each patient's symptoms. Conclusions. Slitlike cavities likely do not represent true syringomyelia but rather remnants of the central canal detected in a small percentage of adults. Review of the authors' experience indicates that these cavities are asymptomatic and are unlikely to change in size. They can be considered an incidental finding, and in many of these patients another condition explaining the patient's symptoms may be found.


2003 ◽  
Vol 98 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Prithvi Narayan ◽  
Daniel L. Barrow

✓ There is a growing body of evidence in the literature suggesting that cavernous malformations of the central nervous system may develop after neuraxis irradiation. The authors discuss the case of a 17-year-old man who presented with progressive back pain and myelopathy 13 years after undergoing craniospinal irradiation for a posterior fossa medulloblastoma. Spinal magnetic resonance (MR) imaging, performed at the time of his initial presentation with a medulloblastoma, demonstrated no evidence of a malformation. Imaging studies and evaluation of cerebrospinal fluid revealed no evidence of recurrence or dissemination. Spinal MR imaging demonstrated an extensive lesion in the thoracic spine with an associated syrinx suggestive of a cavernous malformation. A thoracic laminectomy was performed and the malformation was successfully resected. Pathological examination confirmed the diagnosis. The patient did well after surgery and was ambulating without assistance 6 weeks later. To the best of the authors' knowledge, this is the second reported case in the literature and the first in the young adult age group suggesting the de novo development of cavernous malformations in the spinal cord after radiotherapy. An increased awareness of these lesions and close follow-up examination are recommended in this setting.


2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 120-127 ◽  
Author(s):  
Chihiro Ohye ◽  
Tohru Shibazaki ◽  
Junji Ishihara ◽  
Jie Zhang

Object. The effects of gamma thalamotomy for parkinsonian and other kinds of tremor were evaluated. Methods. Thirty-six thalamotomies were performed in 31 patients by using a 4-mm collimator. The maximum dose was 150 Gy in the initial six cases, which was reduced to 130 Gy thereafter. The longest follow-up period was 6 years. The target was determined on T2-weighted and proton magnetic resonance (MR) images. The point chosen was in the lateral-most part of the thalamic ventralis intermedius nucleus. This is in keeping with open thalamotomy as practiced at the authors' institution. In 15 cases, gamma thalamotomy was the first surgical procedure. In other cases, previous therapeutic or vascular lesions were visible to facilitate targeting. Two types of tissue reaction were onserved on MR imaging: a simple oval shape and a complex irregular shape. Neither of these changes affected the clinical course. In the majority of cases, the tremor subsided after a latent interval of approximately 1 year after irradiation. The earliest response was demonstrated at 3 months. In five cases the tremor remained. In four of these cases, a second radiation session was administered. One of these four patients as well as another patient with an unsatisfactory result underwent open thalamotomy with microrecording. In both cases, depth recording adjacent to the necrotic area revealed normal neuronal activity, including the rhythmic discharge of tremor. Minor coagulation was performed and resulted in immediate and complete arrest of the remaining tremor. Conclusions. Gamma thalamotomy for Parkinson's disease seems to be an alternative useful method in selected cases.


2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 68-73 ◽  
Author(s):  
Pierre-Hugues Roche ◽  
Jean Régis ◽  
Henry Dufour ◽  
Henri-Dominique Fournier ◽  
Christine Delsanti ◽  
...  

Object. The authors sought to assess the functional tolerance and tumor control rate of cavernous sinus meningiomas treated by gamma knife radiosurgery (GKS). Methods. Between July 1992 and October 1998, 92 patients harboring benign cavernous sinus meningiomas underwent GKS. The present study is concerned with the first 80 consecutive patients (63 women and 17 men). Gamma knife radiosurgery was performed as an alternative to surgical removal in 50 cases and as an adjuvant to microsurgery in 30 cases. The mean patient age was 49 years (range 6–71 years). The mean tumor volume was 5.8 cm3 (range 0.9–18.6 cm3). On magnetic resonance (MR) imaging the tumor was confined in 66 cases and extensive in 14 cases. The mean prescription dose was 28 Gy (range 12–50 Gy), delivered with an average of eight isocenters (range two–18). The median peripheral isodose was 50% (range 30–70%). Patients were evaluated at 6 months, and at 1, 2, 3, 5, and 7 years after GKS. The median follow-up period was 30.5 months (range 12–79 months). Tumor stabilization after GKS was noted in 51 patients, tumor shrinkage in 25 patients, and enlargement in four patients requiring surgical removal in two cases. The 5-year actuarial progression-free survival was 92.8%. No new oculomotor deficit was observed. Among the 54 patients with oculomotor nerve deficits, 15 improved, eight recovered, and one worsened. Among the 13 patients with trigeminal neuralgia, one worsened (contemporary of tumor growing), five remained unchanged, four improved, and three recovered. In a patient with a remnant surrounding the optic nerve and preoperative low vision (3/10) the decision was to treat the lesion and deliberately sacrifice the residual visual acuity. Only one transient unexpected optic neuropathy has been observed. One case of delayed intracavernous carotid artery occlusion occurred 3 months after GKS, without permanent deficit. Another patient presented with partial complex seizures 18 months after GKS. All cases of tumor growth and neurological deficits observed after GKS occurred before the use of GammaPlan. Since the initiation of systematic use of stereotactic MR imaging and computer-assisted modern dose planning, no more side effects or cases of tumor growth have occurred. Conclusions. Gamma knife radiosurgery was found to be an effective low morbidity—related tool for the treatment of cavernous sinus meningioma. In a significant number of patients, oculomotor functional restoration was observed. The treatment appears to be an alternative to surgical removal of confined enclosed cavernous sinus meningioma and should be proposed as an adjuvant to surgery in case of extensive meningiomas.


2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  

Object. The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation. Methods. A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3 (range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months. A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor. Conclusions. Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.


1996 ◽  
Vol 84 (6) ◽  
pp. 962-971 ◽  
Author(s):  
Tohru Mizutani

✓ A long-term follow-up study (minimum duration 2 years) was made of 13 patients with tortuous dilated basilar arteries. Of these, five patients had symptoms related to the presence of such arteries. Symptoms present at a very early stage included vertebrobasilar insufficiency in two patients, brainstem infarction in two patients, and left hemifacial spasm in one patient. Initial magnetic resonance (MR) imaging in serial slices of basilar arteries obtained from the five symptomatic patients showed an intimal flap or a subadventitial hematoma, both of which are characteristic of a dissecting aneurysm. In contrast, the basilar arteries in the eight asymptomatic patients did not show particular findings and they remained clinically and radiologically silent during the follow-up period. All of the lesions in the five symptomatic patients gradually grew to fantastic sizes, with progressive deterioration of the related clinical symptoms. Dilation of the basilar artery was consistent with hemorrhage into the “pseudolumen” within the laminated thrombus, which was confirmed by MR imaging studies. Of the five symptomatic patients studied, two died of fatal subarachnoid hemorrhage (SAH) and two of brainstem compression; the fifth patient remains alive without neurological deficits. In the three patients who underwent autopsy, a definite macroscopic double lumen was observed in both the proximal and distal ends of the aneurysms within the layer of the thickening intima. Microscopically, multiple mural dissections, fragmentation of internal elastic lamina (IEL), and degeneration of media were diffusely observed in the remarkably extended wall of the aneurysms. The substantial mechanism of pathogenesis and enlargement in the symptomatic, highly tortuous dilated artery might initially be macroscopic dissection within a thickening intima and subsequent repetitive hemorrhaging within a laminated thrombus in the pseudolumen combined with microscopic multiple mural dissections on the basis of a weakened IEL. The authors note and caution that symptomatic, tortuous dilated basilar arteries cannot be overlooked because they include a group of malignant arteries that may grow rapidly, resulting in a fatal course.


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