Spinal Cord Cavernous Malformations Research Articles

A Rare Instance of Spinal Cord Cavernous Malformation With Adjacent Intramedullary Microhemorrhage.

The natural history of spinal cord cavernous malformation (SCM) may be characterized by recurrent episodes of hemorrhage resulting in a range of neurologic deficits, most of which are microhemorrhage and subsequent gliosis that can lead to progressive myelopathy. Macrohemorrhage with acute onset of symptoms is extremely rare and leads to irreversible neurologic deficits. In this article, we present an unusual case of ruptured cavernous malformation (CM) in the cervical spinal cord with large extralesional hemorrhage. The patient underwent an operation of posterior longitudinal myelotomy and had a good neurologic recovery. A histologic examination revealed the typical features of cavernous angioma.

Intramedullary Spinal Cord Cavernous Malformation Presenting After Strenuous Weightlifting (P9-5.018)

Intramedullary Spinal Cord Cavernous Malformation Presenting After Strenuous Weightlifting (P9-5.018)

Surgical timing and long-term outcomes in patients with severe haemorrhagic spinal cord cavernous malformations

BackgroundSurgical resection of the lesions remains the main treatment method for most symptomatic spinal cord cavernous malformations (SCCMs) to eliminate the occupation and associated subsequent lifelong haemorrhagic risk. However, the...

Surgical Outcomes of Symptomatic Intramedullary Spinal Cord Cavernous Malformations: Analysis of Consecutive Cases in a Single Center.

Intramedullary spinal cavernous malformations (ISCMs) are rare vascular lesions of the spinal cord with unclear natural history and controversy over treatment. This study aimed to report a series of symptomatic ISCMs underwent microsurgical management to illustrate the natural history, clinical presentation, and surgical outcomes and to evaluate factors associated with hemorrhage events and neurological prognosis. This single-center retrospective study included 29 consecutive patients with whose demographic, symptomology, imaging, neurological, and surgical data were collected. The risk for hemorrhage events and factors affecting surgical outcomes were retrospectively analyzed. There were 12 female (41.4%) and 17 male patients (58.6%), with an average age of 45.2 years (range, 17-69 years). The mean size of the lesion was 9.7 mm (range, 3-20 mm). Most patients had a bowel or/and bladder dysfunction symptom (n = 11, 37.9%), followed by sensory deficits (n = 5, 17.2%), gait disturbance (n = 5, 17.2%), pain (n = 4, 13.8%), and weakness (n = 4, 13.8%), most (n = 15, 51.7%) with a chronic onset. All patients received total resection without rehemorrhages after surgical resection in follow-up. Sixty-five point five percent patients (n = 19) improved, 13.8% (n = 4) remained stable, 20.7% (n = 6) got worsen. The overall annual hemorrhage risk was 2.1% per patient-year. A total of 27 hemorrhages occurred in the 18 patients, of which rehemorrhage rate increased to 50.0% (n = 9) with a previous history of hemorrhage. Patients with smaller lesion sizes were more likely to have hemorrhage or rehemorrhage events (p = 0.008). Recurrent hemorrhage of the lesions was a risk factor for neurological outcomes (p = 0.016). The risk of rehemorrhage was significantly increased in symptomatic ISCM patients with a previous history of hemorrhage. Rehemorrhage was a risk factor for neurological outcomes. Patients can benefit from microsurgical treatment to avoid rehemorrhage and further neurological deterioration.

Commentary on "Surgical Outcomes of Symptomatic Intramedullary Spinal Cord Cavernous Malformations: Analysis of Consecutive Cases in a Single Center".

Commentary on "Surgical Outcomes of Symptomatic Intramedullary Spinal Cord Cavernous Malformations: Analysis of Consecutive Cases in a Single Center".

Acceptance of Early Surgery for Treatment of Spinal Cord Cavernous Malformation in Contemporary Japan.

Spinal cord cavernous malformation (CM) is an intramedullary vascular lesion that may present with progressive symptoms. Surgery is recommended for symptomatic patients, but optimal timing of surgery is debatable. Some advocate waiting until plateau of neurological recovery and others support emergency surgery. There is no statistic on how commonly these strategies are utilized. We aimed to find contemporary practice pattern among neurosurgical spine centers in Japan. A database of intramedullary spinal cord tumors assembled by Neurospinal Society of Japan was surveyed and 160 patients with spinal cord CM were identified. Neurological function, disease duration, and number of days between presentation to hospitals and surgery were analyzed. Duration of disease before presentation to hospitals ranged from 0 to 336 months (median, 4 months). Number of days between patients' presentation and surgery ranged from 0 to 6,011 days (median, 32 days). Time from symptom onset to surgery ranged from 0 to 336.9 months (median, 6.6 months). Patients with severe preoperative neurological dysfunction had shorter duration of disease, fewer days between presentation and surgery, and shorter time between symptom onset and surgery. Patients with paraplegia or quadriplegia were more likely to improve when operated on within 3 months from onset. Timing of surgery for spinal cord CM in Japanese neurosurgical spine centers generally was early, with 50% of patients undergoing surgery within 32 days after presentation. Further study is needed to clarify optimal timing of surgery.

The Reality of Benefit in Surgical Removal for Spinal Cord Cavernous Malformation: Commentary on "Acceptance of Early Surgery for Treatment of Spinal Cord Cavernous Malformation in Contemporary Japan".

The Reality of Benefit in Surgical Removal for Spinal Cord Cavernous Malformation: Commentary on "Acceptance of Early Surgery for Treatment of Spinal Cord Cavernous Malformation in Contemporary Japan".

Radiation-induced cavernous malformations in the spine: patient series.

Radiation-induced spinal cord cavernous malformations (RISCCMs) are a rare subset of central nervous system lesions and are more clinically aggressive than congenital cavernous malformations (CMs). The authors assessed the characteristics and outcomes of patients with RISCCM at a single institution and systematically reviewed the pertinent literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among the 146 spinal CMs at the authors' institution, 3 RISCCMs were found. Symptom duration ranged from 0.1 to 8.5 months (mean [standard deviation], 3.2 [4.6] months), and latency ranged from 16 to 29 years (22.4 [9.6] years). All 3 RISCCMs were surgically treated with complete resection; 2 patients had stable outcomes, and 1 improved postoperatively. A review of 1240 articles revealed 20 patients with RISCCMs. Six of these patients were treated with resection, 13 were treated conservatively, and in 1 case, the treatment type was not stated. Five of the 6 patients treated surgically reported improvement postoperatively or at follow-up; 1 was stable, and none reported worsened outcomes. RISCCMs are rare sequelae following radiation that inadvertently affect the spinal cord. Altogether, the frequency of stable and improved outcomes on follow-up suggests that resection could prevent further patient decline caused by symptoms of RISCCM. Therefore, surgical management should be considered primary therapy in patients presenting with RISCCMs.

Patient Reported Outcomes by Location in Patients with Cavernous Malformation (P6-5.012)

<h3>Objective:</h3> To describe differences in patient reported outcomes between patients with cavernous malformations (CM) of different locations. <h3>Background:</h3> Little is known about patient reported outcomes in patients with CM. <h3>Design/Methods:</h3> A database of adults with CM has been maintained since January 1, 2015. Annual surveys are sent to patients for five years after diagnosis, followed by biennial surveys indefinitely. PROMIS-29 profiles, which assess seven health domains by self-report, have been collected since 2018. T-scores standardize raw scores to the general population with a mean of 50 and standard deviation (SD) of 10. We assessed the T-scores and proportion of abnormal scores in each domain by CM location at the time of last follow up (LFU). <h3>Results:</h3> Of the 382 patients enrolled as of June 1, 2022, 267 had available PROMIS-29 data. The cohort was 61.8% female with an average age at the time of LFU of 54.0. Median time from diagnosis to LFU was 5.3 years (range, 1.0 to 38.1). 18.7% were familial and 81.3% sporadic. 40.1% were cortical, 19.5% subcortical, 25.1% brainstem, 6.4% cerebellum, and 7.9% spinal cord, with 1.1% in other locations. 43.9% of patients were abnormal in at least one of seven domains (&gt;1 SD). The most commonly affected domains were pain (18.4%), anxiety (18.1%), physical function (16.5%), and fatigue (15.8%). Patients with brainstem or spinal cord CM reported significantly worse physical functional than their counterparts with CM in other locations (p&lt;0.0001). Patients with brainstem or spinal cord CM had a median T-score of 48.0 (range, 22.9 to 56.9) compared to a median of 56.9 for CM in other locations (range, 29.1 to 56.9). Other domains did not differ significantly by location. <h3>Conclusions:</h3> Patients with brainstem or spinal cord CM report decreased physical functionality relative to patients with other CM locations but do not score significantly different in other PROMIS domains. <b>Disclosure:</b> Dr. Griffin has nothing to disclose. Dr. Lanzino has nothing to disclose. Dr. Flemming has nothing to disclose.

Somatic variants of MAP3K3 are sufficient to cause cerebral and spinal cord cavernous malformations.

Cerebral cavernous malformations (CCMs) and spinal cord cavernous malformations (SCCMs) are common vascular abnormalities of the CNS that can lead to seizure, haemorrhage and other neurological deficits. Approximately 85% of patients present with sporadic (versus congenital) CCMs. Somatic mutations in MAP3K3 and PIK3CA were recently reported in patients with sporadic CCM, yet it remains unknown whether MAP3K3 mutation is sufficient to induce CCMs. Here we analysed whole-exome sequencing data for patients with CCM and found that ∼40% of them have a single, specific MAP3K3 mutation [c.1323C>G (p.Ile441Met)] but not any other known mutations in CCM-related genes. We developed a mouse model of CCM with MAP3K3I441M uniquely expressed in the endothelium of the CNS. We detected pathological phenotypes similar to those found in patients with MAP3K3I441M. The combination of in vivo imaging and genetic labelling revealed that CCMs were initiated with endothelial expansion followed by disruption of the blood-brain barrier. Experiments with our MAP3K3I441M mouse model demonstrated that CCM can be alleviated by treatment with rapamycin, the mTOR inhibitor. CCM pathogenesis has usually been attributed to acquisition of two or three distinct genetic mutations involving the genes CCM1/2/3 and/or PIK3CA. However, our results demonstrate that a single genetic hit is sufficient to cause CCMs.

Residual and Recurrent Spinal Cord Cavernous Malformations: Outcomes and Techniques to Optimize Resection and a Systematic Review of the Literature.

Intramedullary spinal cord cavernous malformations (SCCMs) account for only 5% of overall cavernous malformations (CMs). The occurrence of recurrent or residual SCCMs has not been well discussed, nor have the technical nuances of resection. To assess the characteristics of residual SCCMs and surgical outcomes and describe the techniques to avoid leaving lesion remnants during primary resection. Demographic, radiologic, intraoperative findings and surgical outcomes data for a cohort of surgically managed intramedullary SCCMs were obtained from an institutional database and retrospectively analyzed. A systematic literature review was performed using PRISMA guidelines. Of 146 SCCM resections identified, 17 were for residual lesions (12%). Patients with residuals included 13 men and 4 women, with a mean age of 43 years (range 16-70). All patients with residual SCCMs had symptomatic presentations: sensory deficits, paraparesis, spasticity, and pain. Residuals occurred between 3 and 264 months after initial resection. Approaches for 136 cases included posterior midline myelotomy (28.7%, n = 39), pial surface entry (37.5%, n = 51), dorsal root entry zone (27.9%, n = 38), and lateral entry (5.9%, n = 8). Follow-up outcomes were similar for patients with primary and residual lesions, with the majority having no change in modified Rankin Scale score (63% [59/93] vs 75% [9/12], respectively, P = .98). SCCMs may cause significant symptoms. During primary resection, care should be taken to avoid leaving residual lesion remnants, which can lead to future hemorrhagic events and neurological morbidity. However, satisfactory results are achievable even with secondary or tertiary resections.

Intramedullary spinal cord cavernous malformations—association between intraoperative neurophysiological monitoring changes and neurological outcome

BackgroundMicrosurgical resection of spinal cord cavernous malformations can be assisted by intraoperative neurophysiological monitoring (IONM). While the clinical outcome after surgical resection has been discussed in several case series, the association of intraoperative IONM changes and detailed neurological outcome, however, has not been analyzed so far.MethodsSeventeen patients with spinal cavernomas underwent surgery between 02/2004 and 06/2020. Detailed neurological and clinical outcome as well as IONM data including motor-evoked potential (MEP) and somatosensory-evoked potential (SSEP) monitoring were retrospectively analyzed. Intraoperative IONM changes were compared to outcome at 3-month and 1-year follow-up in order to identify surrogate parameters for an impending neurological deficit.ResultsCompared to the preoperative state, McCormick score at 1-year follow-up remained unchanged in 12 and improved in five patients, none worsened, while detailed neurological examination revealed a new or worsened sensorimotor deficit in 4 patients. The permanent 80% amplitude reduction of MEP and 50% amplitude reduction of SSEP showed the best diagnostic accuracy with a sensitivity of 100% and 67% respectively and a specificity of 73% and 93% respectively. The relative risk for a new neurological deficit at 1-year follow-up, when reversible IONM-deterioration was registered compared to irreversible IONM deterioration, was 0.56 (0.23–1.37) for MEP deterioration and 0.4 (0.18–0.89) for SSEP deterioration.ConclusionsReversible IONM changes were associated with a better neurological outcome at follow-up compared to irreversible IONM deterioration during SCCM surgery. Our study favors the permanent 80% amplitude reduction criterion for MEP and 50% amplitude reduction criterion for SSEP for further prospective evaluation of IONM significance and the effectiveness of corrective maneuvers during SCCM surgeries.

How I do it: resection of spinal cord cavernous malformation.

Spinal cord cavernous malformations (CMs) account for 5 to 12% of all spinal vascular malformations. Surgical removal is indicated in symptomatic patients, especially if the CM comes close to the dorsal or lateral surface of the spinal cord. Spinal cord CMs pose critical challenges for the potential of severe disabling complications. We described the step-by-step surgical principles of spinal cord CM microsurgical resection. The main surgical steps are also illustrated in an accompanying operative video. Pre-surgical planning of the basic steps and good contingency management skills are paramount for an effective and safe spinal cord CM excision.

Natural course of untreated spinal cord cavernous malformations: a follow-up study within the initial 5 years after diagnosis.

Cavernous spinal cord malformations (SCMs) are believed to have a high rate of bleeding. The risk of intramedullary hemorrhage (IMH) or recurrent IMH and the neurological impact of bleeding events are important for clinical decision-making and could impact current treatment strategies. The authors screened their institutional database for patients with cavernous SCM treated between 2003 and 2020. Patients with complete MRI data sets and clinical baseline characteristics were included. Surgically treated patients were censored after cavernous SCM removal. Neurological functional status was obtained using the modified McCormick (MMcC) scale at diagnosis, first IMH, and second IMH. Kaplan-Meier and Cox regression analyses were performed to determine the cumulative 5-year risk for hemorrhage or rehemorrhage. Seventy-one patients with cavernous SCM were analyzed. Cox regression analysis identified previous IMH (hazard ratio 7.86, 95% confidence interval 1.01-61.47, p = 0.049) as an independent predictor for rehemorrhage during the 5-year follow-up. The cumulative 5-year risk of bleeding or rebleeding was 41.3% for cavernous SCM. The MMcC score significantly deteriorated in 75% of patients after recurrent hemorrhage (p = 0.012). During untreated 5-year follow-up, a considerably increased risk for hemorrhage or rehemorrhage was found in cavernous malformations of the spinal cord compared to cerebral cavernous malformations. Neurological function significantly deteriorates after the second bleeding. The probability of recurrent IMH increased significantly after initial presentation with hemorrhage.

Spinal involvement in pediatric familial cavernous malformation syndrome.

The aim of the study was to assess the prevalence and characteristics of spinal cord cavernous malformations (SCCM) and intraosseous spinal vascular malformations (ISVM) in a pediatric familial cerebral cavernous malformation (FCCM) cohort and evaluate clinico-radiological differences between children with (SCCM +) and without (SCCM-) SCCM. All patients with a pediatric diagnosis of FCCM evaluated at three tertiary pediatric hospitals between January 2010 and August 2021 with [Formula: see text] 1 whole spine MR available were included. Brain and spine MR studies were retrospectively evaluated, and clinical and genetic data collected. Comparisons between SCCM + and SCCM- groups were performed using student-t/Mann-Whitney or Fisher exact tests, as appropriate. Thirty-one children (55% boys) were included. Baseline spine MR was performed (mean age = 9.7years) following clinical manifestations in one subject (3%) and as a screening strategy in the remainder. Six SCCM were detected in five patients (16%), in the cervico-medullary junction (n = 1), cervical (n = 3), and high thoracic (n = 2) regions, with one appearing during follow-up. A tendency towards an older age at first spine MR (P = 0.14) and [Formula: see text] 1 posterior fossa lesion (P = 0.13) was observed in SCCM + patients, lacking statistical significance. No subject demonstrated ISVM. Although rarely symptomatic, SCCM can be detected in up to 16% of pediatricFCCM patients using diverse spine MR protocols and may appear de novo. ISVM were instead absent in our cohort. Given the relative commonality of asymptomatic SCCM, serial screening spine MR should be considered in FCCM starting in childhood.

407 Residual and Recurrent Spinal Cord Cavernous Malformations: Outcomes and Technical Notes for Optimal Resection

INTRODUCTION: Intramedullary spinal cord cavernous malformations (SCCMs) account for a small proportion (5%) of CMs overall and of spinal vascular malformations. However, they are well reported in the literature, with over 700 cases as of 2020. To date, the occurrence of recurrent or residual SCCMs has not been assessed or discussed, nor have the technical nuances of resection related to this issue. METHODS: An institutional database of vascular malformations was queried for all surgically managed cases of intramedullary cavernous malformations. Demographic, radiologic, intraoperative findings, and surgical outcomes data were obtained and retrospectively analyzed. A systematic review was performed using three databases (PubMed, Ovid MEDLINE, and Scopus) to analyze all cases of spinal cavernous malformations in the literature, to augment a prior review. RESULTS: 146 cases of SCCM surgeries were identified in the database, including 17 recurrent lesions. Recurrences occurred at various time points, from as few as 3 to 264 months following initial resection. At the postoperative exam, 10 patients had better outcome scores than preoperative scores, 1 of which was status post resection of a recurrent lesion. A total of 21 patients had worse outcome scores, 4 of which were status post resection of recurrent lesion. CONCLUSION: Intramedullary spinal cord cavernous malformations are rare findings but may cause significant symptoms. Resection of these lesions is technically challenging, akin to the resection of brainstem cavernous malformations. Care should be taken to avoid leaving residual lesion, as this can leave the patient vulnerable to future hemorrhagic events and neurological morbidity. Satisfactory results are still achievable even with secondary or tertiary resections.

Natural History of Spinal Cord Cavernous Malformations: A Multicenter Cohort Study.

The natural history of spinal cord cavernous malformations (SCCMs) remains relatively unclear. To investigate the natural history for hemorrhagic risks and neurological outcomes, as well as relevant predicting factors, of SCCMs. All patients between 2002 and 2019 with diagnosis of SCCMs were identified retrospectively. An observational study of patients with conservative management was performed to reveal the natural history of SCCMs. We identified 305 patients in the full cohort, including 126 patients who were conservatively treated for at least 6 months (median observational period, 24.0 months). Forty-five hemorrhage events occurred during 527 person-years of follow-up, yielding an annual hemorrhage rate of 8.5% per person-year. The 1-, 2-, and 5-year cumulative risks of hemorrhage were 13.9%, 26.1%, and 35.1%, respectively. Prior hemorrhage (hazard ratio [HR] = 12.948, P = .012) and pediatric patients (HR = 2.841, P = .031) were independent predictors of hemorrhage in the long-term follow-up. Familial form (adjusted odds ratio [OR] = 30.695, P = .010) and subsequent hemorrhage events (adjusted OR = 16.333, P = .000) were independent risk factors for worsening of neurological function, and baseline neurological status (adjusted OR = 78.984, P = .000) and presence of subsequent hemorrhage (adjusted OR = 9.611, P = .001) were significantly associated with neurological outcomes. The natural history of SCCMs varies. Baseline characteristics, such as pediatric patients, familial form, and baseline neurological status, as well as prior and subsequent hemorrhagic events, significantly affect the natural history of the SCCMs, which prompts a differentiated treatment strategy.

Long-term surgical outcomes and prognostic factors of adult symptomatic spinal cord cavernous malformations

Cervical and thoracic or lumbar intramedullary spinal cavernous malformations (ISCMs) may behave differently. We conducted this retrospective study by using data from adult ISCMs to compare their natural histories and explore prognostic factors for improved clinical outcomes. Neurological functions were assessed by using the Modified McCormick Scale (MMCS) and Aminoff-Logue Disability Scale. A total of 111 study-eligible adult patients were included in this study. Patients with cervical ISCMs mostly demonstrated a shorter duration of symptoms (P = 0.026), an acute onset pattern with some recovery (P = 0.026), and a larger lesion size (P = 0.033) than their thoracic or lumbar counterparts. Thoracic or lumbar lesions had a higher proportion of motor symptoms (P = 0.001) and sphincter problems (P = 0.005), and they were usually associated with an aggressive clinical course (P = 0.001, OR = 9.491, 95% CI = 2.555–35.262) in multivariate analysis. There was no difference in age, sex distribution, hemorrhage risk between the cervical and thoracic-lumbar groups. A better preoperative neurological status (P = 0.034, OR = 2.768, 95% CI = 1.081–7.177) and improvement immediately after surgery (P < 0.001, OR = 8.756, 95% CI = 4.837–72.731) were identified as indicators for long-term improvement by multivariate analysis. Cervical lesions had a high proportion for long-term improvement, but it was not a predictor for improvement in multivariate analysis. ISCMs in the thoracic or lumbar location should be considered for surgical removal more aggressively than those in the cervical location. Surgical removal of symptomatic ISCMs can avoid further neurological deterioration and usually result in satisfactory long-term outcomes.

Spinal Neurovascular Malformations in Klippel-Trenaunay Syndrome: A Single Center Study.

A number of studies have demonstrated spinal anomalies associated with Klippel-Trenaunay syndrome (KTS). To date, there are no large consecutive series examining the prevalence and subtype distribution of spinal neurovascular malformations in patients with KTS. To report the spectrum and incidence of spinal neurovascular manifestations in the KTS population. This was a cross-sectional study. Consecutive patients with definite KTS as defined by International Society for the Study of Vascular Anomalies criteria who underwent spinal neuroimaging at our institution were included. All studies were evaluated by a staff neuroradiologist and a senior radiology resident for the presence of developmental venous anomalies, cavernous malformations (CMs), and arteriovenous shunts (AVS). A total of 116 patients with definite KTS who underwent spinal neuroimaging were included. A total of 23 neurovascular anomalies were found in 19 patients (16.4%), including 4 patients with multiple anomalies. These included 5 patients with spinal cord CMs (4.3%), 14 patients with a paraspinal or epidural venous malformation (12.1%), and 4 patients with an AVS (3.4%). Of the AVS, 3 were epidural arteriovenous fistulas, 1 of which likely formed de novo in an epidural venous malformation. One was a conus medullaris arteriovenous malformation. Our study cohort of 116 KTS patients demonstrated a wide spectrum of spinal neurovascular anomalies with a relatively high prevalence. Potential phenotypic descriptions of KTS should include the possibility for spinal neurovascular anomalies.

Influence of Pregnancy on Hemorrhage Risk in Women With Cerebral and Spinal Cavernous Malformations.

Pregnancy as a hemorrhage risk factor in women with cavernous malformations (CMs) is controversial. We describe prospective hemorrhage risk in women who become pregnant after an established CM diagnosis. Beginning in 2015, we recruited consecutive patients with radiologically confirmed CM of the brain or spinal cord to participate in a prospective registry. Participants underwent a baseline and annual medical record review, imaging review, and annual surveys to ascertain pregnancies, deliveries, and neurological complications. We collected prospective hemorrhage data on reproductive age women. We calculated prospective hemorrhage rates on childbearing age patients based on the number of hemorrhages occurring post-CM diagnosis during pregnancy and nonpregnancy, divided by the years of follow-up and censored at last follow-up, age 46, or surgery in sporadic-form CM. The hemorrhage rates were compared and the 95% CI presented with a P value of <0.05. Of 160 women, 90 presented with CM under the age of 46 (average age 31.6 years; 25.6% familial form; 46.7% with hemorrhage; 24.4% brain stem location). These 90 patients had 136 pregnancies before CM diagnosis; 36 pregnancies occurred at or after the diagnosis of CM. Four patients had a hemorrhage while pregnant or postpartum leading to the first CM diagnosis. During 402.6 years of follow-up while not pregnant, 42 hemorrhages occurred prospectively yielding a 10.4% per year (95% CI, 7.5-14.0) risk of hemorrhage while not pregnant. No hemorrhages occurred during 32 prospective pregnancies (26 live births including 1 twinset and 7 nonviable fetuses) after CM diagnosis during 26.9 years of pregnancy time yielding a rate of 0% per year (95% CI, 0-13.6). We found no statistical difference in the rates of hemorrhage during pregnant and nonpregnant time (P=0.09). No hemorrhage occurred during delivery. Our prospective data suggest that pregnancy does not increase the risk of hemorrhage in women with a known brain or spinal cord CM and that vaginal delivery is safe in appropriate candidates.