Supratentorial cavernous malformations

Giant Intracranial Cavernous Malformations: A Review on Magnetic Resonance Imaging Characteristics

Background  Intracranial cavernous malformations (CMs), commonly known as cavernomas or cavernous angiomas, are low-flow, well-circumscribed vascular lesions composed of sinusoidal spaces lined by a single layer of endothelium and separated by a collagenous matrix without elastin, smooth muscle, or other vascular wall elements. A diameter greater than 3 cm for a CM is unlikely. These lesions may have atypical appearances on magnetic resonance imaging (MRI). MRI with advanced techniques such as a susceptibility-weighted image or T2-gradient echo, a diffusion-weighted image and corresponding apparent diffusion coefficient map, and diffusion tensor tractography have revolutionized the diagnostic approach to these lesions. Materials and Method  The present study reviews the etiopathogenesis, clinical manifestations, MRI strategy, and MRI appearances of the CMs, with a few examples of the giant CMs from our archive. Results  Intracranial giant CMs may have unexpected locations, sizes, numbers, and varied imaging appearances due to repeated hemorrhages, unusual enhancement patterns, intense perifocal edema, and unusual associations, making the differential diagnosis difficult. Conclusion  Familiarity with the MRI appearances of the giant intracranial CMs and the differential diagnosis improves diagnostic accuracy and patient management.

Single-nucleus DNA sequencing reveals hidden somatic loss-of-heterozygosity in Cerebral Cavernous Malformations

Cerebral Cavernous Malformations (CCMs) are vascular malformations of the central nervous system which can lead to moderate to severe neurological phenotypes in patients. A majority of CCM lesions are driven by a cancer-like three-hit mutational mechanism, including a somatic, activating mutation in the oncogene PIK3CA, as well as biallelic loss-of-function mutations in a CCM gene. However, standard sequencing approaches often fail to yield a full complement of pathogenic mutations in many CCMs. We suggest this reality reflects the limited sensitivity to identify low-frequency variants and the presence of mutations undetectable with bulk short-read sequencing. Here we report a single-nucleus DNA-sequencing approach that leverages the underlying biology of CCMs to identify lesions with somatic loss-of-heterozygosity, a class of such hidden mutations. We identify an alternative genetic mechanism for CCM pathogenesis and establish a method that can be repurposed to investigate the genetic underpinning of other disorders with multiple somatic mutations.

Early Detection of Underlying Cavernomas in Patients with Spontaneous Acute Intracerebral Hematomas

BACKGROUND AND PURPOSE

Early identification of the etiology of spontaneous acute intracerebral hemorrhage is essential for appropriate management. This study aimed to develop an imaging model to identify cavernoma-related hematomas.

MATERIALS AND METHODS

Patients 1-55 years of age with acute (≤7 days) spontaneous intracerebral hemorrhage were included. Two neuroradiologists reviewed CT and MR imaging data and assessed the characteristics of hematomas, including their shape (spherical/ovoid or not), their regular or irregular margins, and associated abnormalities including extralesional hemorrhage and peripheral rim enhancement. Imaging findings were correlated with etiology. The study population was randomly split to provide a training sample (50%) and a validation sample (50%). From the training sample, univariate and multivariate logistic regression was performed to identify factors predictive of cavernomas, and a decision tree was built. Its performance was assessed using the validation sample.

RESULTS

Four hundred seventy-eight patients were included, of whom 85 had hemorrhagic cavernomas. In multivariate analysis, cavernoma-related hematomas were associated with spherical/ovoid shape (P < .001), regular margins (P = .009), absence of extralesional hemorrhage (P = .01), and absence of peripheral rim enhancement (P = .002). These criteria were included in the decision tree model. The validation sample (n = 239) had the following performance: diagnostic accuracy of 96.1% (95% CI, 92.2%-98.4%), sensitivity of 97.95% (95% CI, 95.8%-98.9%), specificity of 89.5% (95% CI, 75.2%-97.0%), positive predictive value of 97.7% (95% CI, 94.3%-99.1%), and negative predictive value of 94.4% (95% CI, 81.0%-98.5%).

CONCLUSIONS

An imaging model including ovoid/spherical shape, regular margins, absence of extralesional hemorrhage, and absence of peripheral rim enhancement accurately identifies cavernoma-related acute spontaneous cerebral hematomas in young patients.

Reliability of Functional and Diffusion MR Imaging Near Cerebral Cavernous Malformations

BACKGROUND AND PURPOSE

Surgical resection of cerebral cavernous malformations close to eloquent regions frequently uses fMRI and DTI for surgical planning to best preserve neurologic function. This study investigates the reliability of fMRI and DTI near cerebral cavernous malformations.

MATERIALS AND METHODS

Consecutive patients with cerebral cavernous malformations undergoing presurgical fMRI and DTI mapping were identified. Each cerebral cavernous malformation was hand-contoured; 2 sequential 4-mm expansion shells (S1 and S2) were created, generating 2 ROIs and 2 contralateral controls. Fractional anisotropy and regional homogeneity measurements were then extracted from each ROI and compared with the contralateral controls. Reliability, accuracy, and precision were compared as appropriate.

RESULTS

Fifty-four patients were identified and included. Errors of fractional anisotropy were significantly lower than those of regional homogeneity in S1 and S2 (P < .001), suggesting that fractional anisotropy is more reliable than regional homogeneity near cerebral cavernous malformations. Proximity to cerebral cavernous malformations worsened the reliability of regional homogeneity (S1 versus S2, P < .001), but not fractional anisotropy (P = .24). While fractional anisotropy was not significantly biased in any ROI (P > .05), regional homogeneity was biased toward lower signals in S1 and S2 (P < .05), an effect that was attenuated with distance from cerebral cavernous malformations (P < .05). Fractional anisotropy measurements were also more precise than regional homogeneity in S1 and S2 (P < .001 for both).

CONCLUSIONS

Our findings suggest that hemosiderin-rich lesions such as cerebral cavernous malformations may lead to artifactual depression of fMRI signals and that clinicians and surgeons should interpret fMRI studies near cerebral cavernous malformations with caution. While fMRI is considerably affected by cerebral cavernous malformation-related artifacts, DTI appears to be relatively unaffected and remains a reliable imaging technique near cerebral cavernous malformations.

Radiosurgery effects and adverse effects in symptomatic eloquent brain-located Cavernomas

In this study, the dose schedule efficacy, safety and late adverse effects of stereotactic radiosurgery (SRS) were evaluated for patients with symptomatic cavernomas who were not eligible for surgery and treated with SRS. Between January 2013 and December 2018, 53 patients with cavernomas were treated using SRS with the CyberKnife® system. Patients' diseases were deeply located or were in subcortical functional brain regions. In addition to bleeding, 23 (43.4%) patients had epilepsy, 12 (22.6%) had neurologic symptoms and 16 patients (30.2%) had severe headaches. The median volume was 741 (range, 421-1351) mm3, and the median dose was 15 (range, 14-16) Gy in one fraction. After treatment, six (50%) of 12 patients with neurologic deficits still had deficits. Rebleeding after treatment developed in only two (3.8%) patients. The drug was completely stopped in 14 (60.9%) out of 23 patients who received epilepsy treatment, and the dose of levetiracetam decreased from 2000 mg to 1000 mg in four (17.3%) of nine patients. Radiologically, complete response (CR) was observed in 13 (24.5%) patients, and partial responses (PR) were observed in 32 (60.2%) patients. Clinical response of CR was observed in 30 (56.6%) patients, PR was observed in 16 (30.2%), stable disease (SD) was observed in three (5.7%) and four (7.5%) patients progressed. In conclusion, SRS applied in the appropriate dose schedule may be an effective and reliable method in terms of symptom control and prevention of rebleeding, especially in patients with inoperable cavernomas.

Refractory psychiatric symptoms and seizure associated with Dandy-Walker syndrome: A case report and literature review

BACKGROUNDS

Dandy-Walker syndrome (DWS) is a group of brain malformations which occasionally accompanied by psychotic symptoms. The co-occurrence of DWS and epilepsy in children is quite rare.

CASE DESCRIPTION

We reported a 14-year-old male who presented with a 8-month history of inconsistent upper limb tremor and accidental seizure. The MRI showed the typical alterations of DWS: cystic dilatation of the fourth ventricle, vermian hypoplasia, enlarged posterior fossa. He received the ventriculoperitoneal shunting (VPS) placement for hydrocephalus and had a symptom-free period for 8 days. Then he experienced a recurrence of involuntary upper limb tremor and behavior disturbance after decreasing the pressure of cerebrospinal fluid (CSF) from 150 to 130 mm Hg. After being treated with Olanzapine 10 mg/d, Clonazepam 3 mg/qn and Valproate acid (VPA) 500 mg/bid for nearly a month, his mental status and psychotic symptoms fluctuated. A search of Pub Med showed little report of hydrocephalus and DWS comorbidity with seizure and psychosis. Here we presented the whole process of a rare disease from the very beginning with all his symptoms, examinations and treatments.

CONCLUSION

VPS placement surgery at an earlier stage may be an effective way to avoid inevitable brain damage so as to improve the clinical outcomes for patients with DWS. Continued treatment with regard to DWS condition may include shunt placement, but it mainly focus on developmental concerns, with occupational and physical therapy along with ongoing supportive psychotherapy to improve the coping skills and quality of life.

Efficacy and safety of the endoscopic "wet-field" technique for removal of supratentorial cavernous malformations

OBJECTIVE

Cerebral cavernous malformations (CMs) presenting with focal neurological symptoms or mass effects require surgical removal. In recent years, cylindrical retractors have been widely utilized for the removal of deep-seated lesions during both microscopic and endoscopic surgery. In the present study, we evaluated the efficacy and safety of endoscopic transcylinder removal of CMs using a novel wet-field technique.

METHODS

We included 13 patients with supratentorial CMs who had undergone endoscopic transcylinder surgery between April 2013 and March 2022. One patient experienced recurrence of the CM and underwent a second endoscopic transcylinder surgery. Therefore, we retrospectively evaluated 14 procedures. The surgical field was continuously irrigated with artificial cerebrospinal fluid to maintain expansion and visualization of the tumor bed. We termed this method as the "wet-field technique." Patient characteristics, symptoms, and pre- and postoperative magnetic resonance imaging results were obtained from medical records.

RESULTS

The average maximum CM diameter was 35.3 mm (range: 10-65 mm). Cylinder diameters were 6 mm in eight procedures, 10 mm in four procedures, and 17 mm in one procedure. Wet-field technique was applied in all cases. The endoscope provided a bright field of view even under water. Continuous water irrigation made it easier to observe the entire tumor bed which naturally expanded by water pressure. Gross total resection was achieved in 13 procedures, while subtotal resection was achieved in one procedure. No surgical complications were observed.

CONCLUSIONS

The endoscopic transcylinder removal using wet-field technique is safe and effective for the removal of symptomatic intracranial supratentorial CMs.

Academics versus the Internet: Evaluating the readability of patient education materials for cerebrovascular conditions from major academic centers

Background:

Health literacy profoundly impacts patient outcomes as patients with decreased health literacy are less likely to understand their illness and adhere to treatment regimens. Patient education materials supplement in-person patient education, especially in cerebrovascular diseases that may require a multidisciplinary care team. This study aims to assess the readability of online patient education materials related to cerebrovascular diseases and to contrast the readability of those materials produced by academic institutions with those of non-academic sources.

Methods:

The readability of online patient education materials was analyzed using Flesch-Kincaid Grade Level (FKGL) and Flesch Reading Ease (FRE) assessments. Readability of academic-based online patient education materials was compared to nonacademic online patient education materials. Online patient education materials from 20 academic institutions and five sources from the web were included in the analysis.

Results:

Overall median FKGL for neurovascular-related patient online education documents was 11.9 (95% CI: 10.8–13.1), reflecting that they are written at a 12th grade level, while the median FRE was 40.6 (95% CI: 34.1–47.1), indicating a rating as “difficult” to read. When comparing academic-based online patient education materials to other internet sources, there was no significant difference in FRE and FKGL scores (P = 0.63 and P = 0.26 for FKGL and FRE, respectively).

Conclusion:

This study demonstrates that online patient education materials pertaining to cerebrovascular diseases from major academic centers and other nonacademic internet sites are difficult to understand and written at levels significantly higher than that recommended by national agencies. Both academic and nonacademic sources reflect this finding equally. Further study and implementation are warranted to investigate how improvements can be made.

Cavernous malformations

Cavernous malformations are relatively common intracerebral malformations of which we only became properly aware after the introduction of MRI. They may be sporadic or familial. Familial CMs may be multiple and new lesions appear over time requiring intermittent MR control. Many sporadic CMs have no symptoms. The commonest location is in the supratentorial cerebral parenchyma presenting with epilepsy. The best treatment is microsurgery. A small proportion are in the brainstem and may rebleed and even be lethal. Treatment includes microsurgery and radiosurgery. Microsurgery cures the patient but has substantial problems with complications, deterioration and partial removal. Radiosurgery has taken time to demonstrate that it can over 2 years substantially reduce the risk of rebleeds without the risks of microsurgery. Both methods have a part to play in the treatment.

Cavernous malformation hemorrhage due to trans-mural pressure alterations after cerebrospinal fluid diversion: a case report

BACKGROUND

Cavernous malformations are rare cerebral pseudo-vascular lesions with annualized bleeding rates of 0.5-3% in most studies. Of the various explored risk factors for bleeding to date, only prior hemorrhage has shown significant correlation.

CASE PRESENTATION

In this case, we describe a 65-year old man with a peri-ventricular atrial cavernous malformation that hemorrhaged after CSF diversion via ventriculoperitoneal shunting. Serial imaging showed that bleeding continued until the shunt was revised with a programmable valve set at maximum resistance with the addition of a gravitational unit, thereby lowering the trans-mural pressure differential across the cavernous malformation.

CONCLUSIONS

Given that other vascular lesions are subject to hemorrhage from alterations in trans-mural pressure dynamics, we hypothesize that cavernous malformations are similarly affected by trans-mural pressure gradients as they are composed of primitive vascular elements. This hypothesis is corroborated by the temporal correlation of interventions, imaging, and exam findings in the present case, and suggests a potentially important risk factor for hemorrhage in CM patients that affects prognostication and management.

Symptomatic Hemorrhage From Cerebral Cavernous Malformations: Evidence from a Cohort Study

OBJECTIVE

Patients with a cerebral cavernous malformation (CCM) can have intracranial hemorrhages ranging from insignificant and chronic microbleeds to life-threatening hemorrhage. Management decisions and patient counseling are based on a heterogeneous body of evidence. We sought to improve the literature by providing our results based on the standardized definitions and aimed to delineate differences in the symptomatic burden for CCMs, based on their anatomic location and presence of developmental venous anomalies. This evidence will aid in clinical decision making and patient counseling.

METHODS

A retrospective cohort analysis between 1990 and 2018 was performed, including patients with a diagnosis of a CCM. The primary outcome was acute symptomatic hemorrhages.

RESULTS

We identified 438 patients harboring 632 CCMs. Mean age at diagnosis was 50 years (standard deviation ±17 years). Median follow-up was 26 months (interquartile range, 7-72 hours). Multiple lesions were encountered in 64 patients (15%). An initial symptomatic presentation was observed in 64% of the patients. There were 438 supratentorial lesions (69%) and 194 infratentorial lesions (31%). A symptomatic hemorrhage was observed in 25% of the supratentorial lesions and 29% of the infratentorial lesions (P < 0.001). A linear mixed-effects regression model showed a significant difference in developing a symptomatic hemorrhage at diagnosis or follow-up between CCMs with an infratentorial location and those with a supratentorial location (odds ratio, 1.81; 95% confidence interval, 1.17-2.81; P = 0.008).

CONCLUSIONS

Infratentorial cavernous malformations are more likely to present with symptomatic hemorrhages at diagnosis or during follow-up when accounting for size differences between lesions.