Developmental venous anomalies and brainstem cavernous malformations: a proposed physiological mechanism for haemorrhage

Cerebral Cavernous Malformation Bleeding Following Cerebrospinal Fluid Diversion Surgery: A Case Report and Literature Review

Cavernous malformations (CM) are rare intracerebral vascular lesions occurring in the brain, or less commonly in the spine, with an annual bleeding risk of up to 1.1%. These lesions can be occult or present to signs and symptoms based on location or, more frequently, are a result of hemorrhagic events. The most challenging aspect of managing these cases is weighing the risks and benefits of surgical treatment and intervening before the onset of a devastating hemorrhagic event. Here, we present the second case of CM haemorrhage following the cerebrospinal fluid (CSF) diversion procedure with a literature review of theories explaining this phenomenon. We present a 37-year-old female who has a known case of brainstem cavernoma and underwent left sub-temporal resection with stable residual since 2011, then was managed conservatively due to patient preference till she had a deterioration in December 2021 manifested as confusion, diplopia, dysarthria, and significant left sided weakness leaving her wheelchair bound. CT showed supratentorial hydrocephalus with extensive periventricular transependymal edema and no clear haemorrhage. A ventriculoperitoneal (VP) shunt was inserted, with no intraoperative complications. A few hours post-VP shunt insertion, she experienced a worsening in her mental status, hemiparesis, and dysarthria. Subsequent imaging found evidence of acute haemorrhage in the location of the previously noted residual. She was managed by supportive care. Causative factors of CM haemorrhage are poorly understood, and current data only suggest that prior haemorrhage and CM location could increase bleeding risk. Only one case of CM bleeding post-shunt insertion was reported; however, studies on other types of intracranial vascular lesions suggest that alterations in transmural pressure (including cerebrospinal fluid diversion procedures) can increase the risk of haemorrhage by changing the hemodynamic flow in these abnormally formed and weak vascular structures.

Symptomatic Developmental Venous Anomaly: State-of-the-Art Review on Genetics, Pathophysiology, and Imaging Approach to Diagnosis

Developmental venous anomalies (DVAs) are the most common slow-flow venous malformation in the brain. Most DVAs are benign. Uncommonly, DVAs can become symptomatic, leading to a variety of different pathologies. DVAs can vary significantly in size, location, and angioarchitecture, and imaging evaluation of symptomatic developmental venous anomalies requires a systematic approach. In this review, we aimed to provide neuroradiologists with a succinct overview of the genetics and categorization of symptomatic DVAs based on the pathogenesis, which forms the foundation for a tailored neuroimaging approach to assist in diagnosis and management.

Familial CCM Genes Might Not Be Main Drivers for Pathogenesis of Sporadic CCMs-Genetic Similarity between Cancers and Vascular Malformations

Cerebral cavernous malformations (CCMs) are abnormally dilated intracranial capillaries that form cerebrovascular lesions with a high risk of hemorrhagic stroke. Recently, several somatic "activating" gain-of-function (GOF) point mutations in PIK3CA (phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit p110α) were discovered as a dominant mutation in the lesions of sporadic forms of cerebral cavernous malformation (sCCM), raising the possibility that CCMs, like other types of vascular malformations, fall in the PIK3CA-related overgrowth spectrum (PROS). However, this possibility has been challenged with different interpretations. In this review, we will continue our efforts to expound the phenomenon of the coexistence of gain-of-function (GOF) point mutations in the PIK3CA gene and loss-of-function (LOF) mutations in CCM genes in the CCM lesions of sCCM and try to delineate the relationship between mutagenic events with CCM lesions in a temporospatial manner. Since GOF PIK3CA point mutations have been well studied in reproductive cancers, especially breast cancer as a driver oncogene, we will perform a comparative meta-analysis for GOF PIK3CA point mutations in an attempt to demonstrate the genetic similarities shared by both cancers and vascular anomalies.

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.

Hemifacial spasm caused by the brainstem developmental venous anomaly: A case report and review of the literature

Background:

Hemifacial spasm (HFS) is usually caused by vascular compression of the root exit zone (REZ) of the facial nerve. Dual compression of the REZ by veins and arteries is also associated with HFS, but venous origin alone is rarely reported. We present a rare case of HFS caused by the brainstem developmental venous anomaly (DVA) treated with microvascular decompression (MVD).

Case Description:

A 30-year-old women presented with the left-sided HFS since the age of 18 years. The brainstem DVA was diagnosed by magnetic resonance imaging (MRI) and followed by two attempts of MVD at some other clinics without any improvement. At our hospital, MVD was performed through a left retromastoid craniotomy. Intraoperatively, after detaching the strong adhesions between the cerebellar hemisphere, petrosal dura and lower cranial nerves, and removing the Teflon sponge inserted during the previous operations, the compressing large vein was found, separated from facial nerve REZ and MVD was completed. The postoperative computed tomography angiography and MRI showed the thrombosis of the main trunk of DVA and decompression of the facial nerve REZ. Complete cessation of HFS with hearing preservation was observed with only slight weakness of mimic muscles which disappeared within 3 months after surgery.

Conclusion:

HFS associated with brainstem DVA is a very rare condition. MVD of the facial nerve REZ with transposition of the large draining vein should be considered as an effective treatment option.

Brain cavernous hemangioma mimicking radiation-induced necrosis in a patient with non-small cell lung cancer

In patients with non‐small cell lung cancer (NSCLC), stereotactic radiotherapy (SRT) is one of the standard therapies for those suffering with intracranial metastatic NSCLC. Radiation‐induced necrosis (RIN) sometimes occurs as the result of the delayed effects of SRT. The magnetic resonance imaging (MRI) of RIN typically shows hypointense and hyperintense lesions on T1‐ and T2‐weighted images, respectively. We herein report a patient with a growing brain cystic lesion mimicking RIN adjacent to a post‐radiation brain metastasis from NSCLC harboring anaplastic lymphoma kinase rearrangement. The patient underwent surgical resection of the brain tumor because of the symptoms. The pathological diagnosis was cavernous hemangioma, and the pathological findings were an encapsulated nodular mass composed of dilated, cavernous vascular spaces with no residual tumor or recurrence. Clinicians should be aware of the possibility for the development of a brain cavernous hemangioma following SRT in NSCLC patients.