Natural History, Clinical, and Surgical Management of Cavernous Malformations

Identifying potential (re)hemorrhage among sporadic cerebral cavernous malformations using machine learning

The (re)hemorrhage in patients with sporadic cerebral cavernous malformations (CCM) was the primary aim for CCM management. However, accurately identifying the potential (re)hemorrhage among sporadic CCM patients in advance remains a challenge. This study aims to develop machine learning models to detect potential (re)hemorrhage in sporadic CCM patients. This study was based on a dataset of 731 sporadic CCM patients in open data platform Dryad. Sporadic CCM patients were followed up 5 years from January 2003 to December 2018. Support vector machine (SVM), stacked generalization, and extreme gradient boosting (XGBoost) were used to construct models. The performance of models was evaluated by area under receiver operating characteristic curves (AUROC), area under the precision-recall curve (PR-AUC) and other metrics. A total of 517 patients with sporadic CCM were included (330 female [63.8%], mean [SD] age at diagnosis, 42.1 [15.5] years). 76 (re)hemorrhage (14.7%) occurred during follow-up. Among 3 machine learning models, XGBoost model yielded the highest mean (SD) AUROC (0.87 [0.06]) in cross-validation. The top 4 features of XGBoost model were ranked with SHAP (SHapley Additive exPlanations). All-Elements XGBoost model achieved an AUROCs of 0.84 and PR-AUC of 0.49 in testing set, with a sensitivity of 0.86 and a specificity of 0.76. Importantly, 4-Elements XGBoost model developed using top 4 features got a AUROCs of 0.83 and PR-AUC of 0.40, a sensitivity of 0.79, and a specificity of 0.72 in testing set. Two machine learning-based models achieved accurate performance in identifying potential (re)hemorrhages within 5 years in sporadic CCM patients. These models may provide insights for clinical decision-making.

Amplification of protease-activated receptors signaling in sporadic cerebral cavernous malformation endothelial cells

In the central nervous system, thrombin-mediated activation of protease-activated receptors (PARs) results in neuroinflammation and increased vascular permeability. These events have been linked to cancer and neurodegeneration. Endothelial cells (ECs) isolated from sporadic cerebral cavernous malformation (CCM) specimens showed dysregulation of genes involved in "thrombin-mediated PAR-1 activation" signaling. CCM is a vascular disease involving brain capillaries. In CCM, ECs show defective cell junctions. Oxidative stress and neuroinflammation play a key role in disease onset and progression. In order to confirm the possible role of thrombin pathway in sporadic CCM pathogenesis, we evaluated PARs expression in CCM-ECs. We found that sporadic CCM-ECs overexpress PAR1, PAR3 and PAR4, together with other coagulation factor encoding genes. Moreover, we investigated about expression of the three familial CCM genes (KRIT1, CCM2 and PDCD10) in human cerebral microvascular ECs, following thrombin exposure, as well as protein level. Thrombin exposure affects EC viability and results in dysregulation of CCM gene expression and, then, in decreased protein level. Our results confirm amplification of PAR pathway in CCM suggesting, for the first time, the possible role of PAR1-mediated thrombin signaling in sporadic CCM. Thrombin-mediated PARs over activation results in increased blood-brain barrier permeability due to loss of cell junction integrity and, in this context, also the three familial CCM genes may be involved.

Distant Recurrence of a Cerebral Cavernous Malformation in the Vicinity of a Developmental Venous Anomaly: Case Report of Local Oxy-Inflammatory Events

BACKGROUND

Cerebral cavernous malformations (CCMs) are a major type of cerebrovascular lesions of proven genetic origin that occur in either sporadic (sCCM) or familial (fCCM) forms, the latter being inherited as an autosomal dominant condition linked to loss-of-function mutations in three known CCM genes. In contrast to fCCMs, sCCMs are rarely linked to mutations in CCM genes and are instead commonly and peculiarly associated with developmental venous anomalies (DVAs), suggesting distinct origins and common pathogenic mechanisms.

CASE REPORT

A hemorrhagic sCCM in the right frontal lobe of the brain was surgically excised from a symptomatic 3 year old patient, preserving intact and pervious the associated DVA. MRI follow-up examination performed periodically up to 15 years after neurosurgery intervention demonstrated complete removal of the CCM lesion and no residual or relapse signs. However, 18 years after surgery, the patient experienced acute episodes of paresthesia due to a distant recurrence of a new hemorrhagic CCM lesion located within the same area as the previous one. A new surgical intervention was, therefore, necessary, which was again limited to the CCM without affecting the pre-existing DVA. Subsequent follow-up examination by contrast-enhanced MRI evidenced a persistent pattern of signal-intensity abnormalities in the bed of the DVA, including hyperintense gliotic areas, suggesting chronic inflammatory conditions.

CONCLUSIONS

This case report highlights the possibility of long-term distant recurrence of hemorrhagic sCCMs associated with a DVA, suggesting that such recurrence is secondary to focal sterile inflammatory conditions generated by the DVA.

A systematic review on the outcome of intramedullary spinal cord cavernous malformations

PURPOSE

This study aimed to investigate the neurological outcome, trends and sequelae following surgical or conservative treatment of intramedullary spinal cord cavernous malformations (ISCCMs).

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The primary outcome measure was the change in the neurological status after surgery or conservative management. A logistic regression analysis investigating prognostic factors related to outcome was also performed.

RESULTS

Twenty-one studies with 1091 patients in total were included, of which 1005 (92.1%) underwent surgical resection and 86 (7.9%) were treated conservatively. Gross total resection was achieved in 95.7% of the patients and partial resection in 4.3%. Most lesions (60.2%) were located in the thoracic spine and presented with motor (60.4%) and sensory deficits (59.7%). In the long term, surgical treatment resulted in an improved neurological status in 36.9% of the patients, in 55.8% it remained stable, and in 7.3% it deteriorated compared to the preoperative state. In the conservative cohort, 21.7% improved, 69.6% remained stable, and 8.7% deteriorated. Solitary lesions, duration of preoperative symptoms less than 3 months as well as an improved post-operative neurological status were predictors of a favourable long-term outcome.

CONCLUSIONS

Whenever feasible, symptomatic patients with ISCCM are recommended to undergo surgery within 3 months from symptom onset. Absence of multiple lesions and, most importantly, post-operative symptom improvement foresee a favourable long-term outcome. Further research is warranted to discern the role of conservative treatment in symptomatic patients.

Next-Generation Sequencing Advances the Genetic Diagnosis of Cerebral Cavernous Malformation (CCM)

Cerebral Cavernous Malformation (CCM) is a cerebrovascular disease of genetic origin that predisposes to seizures, focal neurological deficits and fatal intracerebral hemorrhage. It may occur sporadically or in familial forms, segregating as an autosomal dominant condition with incomplete penetrance and highly variable expressivity. Its pathogenesis has been associated with loss-of-function mutations in three genes, namely KRIT1 (CCM1), CCM2 and PDCD10 (CCM3), which are implicated in defense mechanisms against oxidative stress and inflammation. Herein, we screened 21 Italian CCM cases using clinical exome sequencing and found six cases (~29%) with pathogenic variants in CCM genes, including a large 145−256 kb genomic deletion spanning the KRIT1 gene and flanking regions, and the KRIT1 c.1664C>T variant, which we demonstrated to activate a donor splice site in exon 16. The segregation of this cryptic splicing mutation was studied in a large Italian family (five affected and seven unaffected cases), and showed a largely heterogeneous clinical presentation, suggesting the implication of genetic modifiers. Moreover, by analyzing ad hoc gene panels, including a virtual panel of 23 cerebrovascular disease-related genes (Cerebro panel), we found two variants in NOTCH3 and PTEN genes, which could contribute to the abnormal oxidative stress and inflammatory responses to date implicated in CCM disease pathogenesis.

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.