De novo AVM formation following venous sinus thrombosis and prior AVM resection in adults: report of 2 cases

Pearls & Oy-sters: Arteriovenous Malformation With Sinus Thrombosis and Thalamic Hemorrhage: Unusual Cause of Parkinsonism and Dementia

Deep cerebral venous thrombosis is an uncommon condition, which usually produces headache, altered consciousness, and ocular movement abnormality. Parkinsonism occasionally occurs when there is basal ganglia involvement.We report a case of a 78-year-old male who presented with a rapidly progressive parkinsonism with poor response to dopaminergic therapy. The patient had bilateral and symmetrical hypokinesia, rigidity, and marked gait impairment with festination. Brain MRI showed bilateral thalamic hyperintensity on T2-weighted and FLAIR sequences, with right thalamic and intraventricular hemorrhage due to straight sinus thrombosis. Angiography revealed an arteriovenous malformation in the quadrigeminal cistern with afferent supply from the posterior cerebral arteries, as well as partial thrombosis of the vein of Galen and half of the straight sinus. No predisposing factor for thrombosis was found. Given the location and size of the malformation, and the substantial amount of thalamic and intraventricular hemorrhage, conservative management was decided, with slow but progressive gait improvement.The presence of deep cerebral venous thrombosis should be suspected in cases of rapidly progressive parkinsonism with cognitive decline. As in this case, thrombosis may be secondary to a deep arteriovenous malformation, a very rare occurrence that may require specific therapy.

Paediatric Cerebral Arteriovenous Malformation: Outcomes from a Singapore Children's Hospital

OBJECTIVES

Paediatric brain arteriovenous malformation (bAVM) is a rare and distinct clinical entity. There is a growing body of literature that support the success of multimodality approaches for this difficult condition. The authors aim to firstly, describe our institutional experience with a consecutive series of patients and next, corroborate our results with current literature.

MATERIAL AND METHODS

This is a single institution, retrospective study conducted over a 20-year period. Patients less than 19 years old with bAVM were included. Variables of interest included patient demographics, clinical presentation, neuroimaging features, bAVM characteristics and treatment modality. Functional outcomes were measured with modified Rankin scale (mRS).

RESULTS

There were 58 paediatric bAVMs, presenting at a mean age of 8.7 ± 4.2 years, and followed up for a mean duration of 7.7 years. Thirty-six patients (62.1%) underwent microsurgical resection, 10 patients had stereotactic radiosurgery (17.2%) and 2 patients had endovascular treatment (3.4%). 50 patients (86.2%) had a favourable outcome at 1-year follow up. Microsurgical resection and SRS had similar obliteration rates (resection 83.3%; SRS 80.0%) and recurrence (resection 10.0%; SRS 12.5%). There were 6 cases of bAVM recurrence (12.8%). This subgroup was noted to be less than 7.5 years old at presentation (OR 15.0, 95% CI 1.56 - 144), and less likely to present with bAVM rupture (OR 0.11, 95% CI 0.01 - 0.96).

CONCLUSION

This study describes our experience in managing paediatric bAVM, whereby monomodal therapy can still be effective. Of note, we also demonstrate the role of extended surveillance to detect recurrence.

Cerebral Arteriovenous Malformation Recurrence After Complete Surgical Excision in an Adult: Case Report and Review of the Literature

Angiographically confirmed complete surgical excision of brain arteriovenous malformations (bAVMs) is conventionally considered curative. Recurrence in adults is rarely encountered; only 18 cases have been reported in the English literature over the past 30 years. The potential for recurrence and consequent need for routine long-term follow-up are important considerations in the management of these lesions. We report a case of a 23-year-old female with a recurrent bAVM discovered incidentally on routine imaging three years after complete surgical excision. We review the existing literature and discuss the options for surveillance and management.

De Novo Pial Arteriovenous Fistula Associated With Cerebral Infarction and Venous Hypertension: Report of 2 Cases Suggesting a “Second Hit Theory”

BACKGROUND AND IMPORTANCE

The etiology of de novo pial arteriovenous fistula (AVF) is unknown. We found 2 cases of de novo pial AVF, which appeared after cerebral infarction and which was associated with venous hypertension secondary to venous sinus thrombosis with a dural AVF (dAVF). Additional angiogenic stimuli (second hit) were considered as one of the mechanisms of de novo pial AVF.

CLINICAL PRESENTATION

A 63-yr-old male was admitted to our hospital due to an intraventricular hemorrhage. He had a history of cerebral infarction 2 yr before. Angiography demonstrated multiple dAVFs with bilateral occlusion of the distal transverse sinus associated with prominent retrograde cortical venous drainage. A pial AVF was found at the border of his previous cerebral infarction. Both lesions were successfully treated using endovascular technique.

A second case involved a 47-yr-old female who was admitted to our hospital due to venous infarction also associated with sinus thrombosis. De novo pial AVF at the border of the venous infarction and dAVF at the transverse sigmoid junction were demonstrated on angiography 6 mo later.

CONCLUSION

We speculate that venous hypertension associated with additional angiogenic stimuli (second hit) due to brain ischemia and/or brain injury related to infarction caused de novo pial AVF in these 2 cases.

'De Novo' Brain AVMs-Hypotheses for Development and a Systematic Review of Reported Cases

Background and Objectives: Brain arteriovenous malformations AVMs have been consistently regarded as congenital malformations of the cerebral vasculature. However, recent case reports describing "de novo AVMs" have sparked a growing debate on the nature of these lesions. Materials and Methods: We have performed a systematic review of the literature concerning de novo AVMs utilizing the PubMed and Google Academic databases. Termes used in the search were "AVM," "arteriovenous," "de novo," and "acquired," in all possible combinations. Results: 53 articles including a total of 58 patients harboring allegedly acquired AVMs were identified by researching the literature. Of these, 32 were male (55.17%), and 25 were female (43.10%). Mean age at de novo AVM diagnosis was 27.833 years (standard deviation (SD) of 21.215 years and a 95% confidence interval (CI) of 22.3 to 33.3). Most de novo AVMs were managed via microsurgical resection (20 out of 58, 34.48%), followed by radiosurgery and conservative treatment for 11 patients (18.97%) each, endovascular embolization combined with resection for five patients (8.62%), and embolization alone for three (5.17%), the remaining eight cases (13.79%) having an unspecified therapy. Conclusions: Increasing evidence suggests that some of the AVMs discovered develop some time after birth. We are still a long way from finally elucidating their true nature, though there is reason to believe that they can also appear after birth. Thus, we reason that the de novo AVMs are the result of a 'second hit' of a variable type, such as a previous intracranial hemorrhage or vascular pathology. The congenital or acquired characteristic of AVMs may have a tremendous impact on prognosis, risk of hemorrhage, and short and long-term management.

Cerebral Arteriovenous Malformations as Acquired Lesions: Case Reports and Review of the Literature

Cerebral arteriovenous malformations (AVMs) are generally attributed to congenital lesions that arise from aberrant vasculogenesis between the fourth and eighth weeks of embryonic life. However, this dogma has been challenged by several recent observations, one of which is de novo formation of AVMs. Forty cases of de novo AVMs were published between 2000 and 2019, all of which involved a history of intracranial insult, such as vascular abnormalities or nonvascular conditions, prior to AVM diagnosis. We hereby present two unique operative cases of ruptured de novo AVMs in older adult patients. Case 1 is novel in the sense that the patient did not experience any kind of environmental trigger ("second hit") such as a previous intracranial insult, while Case 2 serves as the second report of a de novo AVM patient with a medical history of Bell's palsy. Although the exact mechanisms of AVM formation remain to be elucidated, it is likely to be a multifactorial process related to environmental and hemodynamic factors.

Spontaneous appearance of de novo intracranial arteriovenous malformation in hepatic cirrhosis

BACKGROUND

Intracranial arteriovenous malformations (AVMs) are rare lesions that can be congenital or acquired in early childhood, with fatal outcome in approximately 30% of cases. De novo formation during adulthood without established predisposing vascular pathology or previous brain insult is even less frequent.

CASE DESCRIPTION

We present a case of de novo brain AVM in an alcoholic Child-B cirrhosis setting. Thirty previously reported cases presented de novo AVM in patients of all ages that had another previous brain pathology or insult, such as AVM resection. Seventeen of those cases occurred in adult patients, with only 2 showing no significant predisposing factor. The present pathophysiological review covers and completes Mullan's hemodynamic "two-hit" model, associating probable thrombotic predisposition to AVM with brain insult triggering a later stage based on angiogenic stimuli.

CONCLUSIONS

This case report and literature review renews previously discussed hemodynamic theories and contributes to a fuller understanding of the pathogenesis and progression of AVM. We postulate a causal link between hepatopathy and de novo AVM, which should be strengthened and interpreted based on recent genetic data and future prospective studies.

A novel method to determine the natural course of unruptured brain arteriovenous malformations without the need for follow-up information

OBJECTIVEThere is a strong clinical need to accurately determine the average annual hemorrhage risk in unruptured brain arteriovenous malformations (AVMs). This need motivated the present initiative to use data from a uniquely large patient population and design a novel methodology to achieve a risk determination with unprecedented accuracy. The authors also aimed to determine the impact of sex, pregnancy, AVM volume, and location on the risk for AVM rupture.METHODSThe present study does not consider any specific management of the AVMs, but only uses the age distribution for the first hemorrhage, the shape of which becomes universal for a sufficiently large set of patients. For this purpose, the authors collected observations, including age at first hemorrhage and AVM size and location, in 3425 patients. The average annual risk for hemorrhage could then be determined from the simple relation that the number of patients with their first hemorrhage at a specific age equals the risk for hemorrhage times the number of patients at risk at that age. For a subset of the patients, the information regarding occurrence of AVM hemorrhage after treatment of the first hemorrhage was used for further analysis of the influence on risk from AVM location and pregnancy.RESULTSThe age distribution for the first AVM hemorrhage was used to determine the average annual risk for hemorrhage in unruptured AVMs at adult ages (25-60 years). It was concluded to be 3.1% ± 0.2% and unrelated to AVM volume but influenced by its location, with the highest risk for centrally located AVMs. The hemorrhage risk was found to be significantly higher for females in their fertile years.CONCLUSIONSThe present methodology allowed the authors to determine the average annual risk for the first AVM hemorrhage at 3.1% ± 0.2% without the need for individual patient follow-up. This methodology has potential also for other similar types of investigations. The conclusion that centrally located AVMs carry a higher risk was confirmed by follow-up information. Follow-up information was also used to conclude that pregnancy causes a substantially greater AVM hemorrhage risk. The age distribution for AVM hemorrhage is incompatible with AVMs present at birth having the same hemorrhage risk as AVMs in adults. Plausibly, they instead develop in the early years of life, possibly with a lower hemorrhage risk during that time period.

Review of de novo cerebral arteriovenous malformation: haemorrhage risk, treatment approaches and outcomes

Objective A small number of patients has been reported to develop a completely new or de novo arteriovenous malformation (AVM) after brain surgery, haemorrhage, head trauma or ischaemic stroke. The natural history of these lesions is unknown. In this review, both ruptured and unruptured de novo AVMs and their treatments were reviewed. Methods Published literature in the PubMed database citing 'de novo cerebral arteriovenous malformation' was reviewed. Additional studies were identified through reference searches in each reviewed article. A review was performed using all published cases, the treatment approaches and outcomes. Results A total of 38 patients, including 37 de novo AVMs reported from 1988 to 17 November 2017 and our one patient, was collected. The age at AVM diagnosis was 5-73 years (mean ± SD, 27.6 ± 20.5 years). The duration time, from negative examination to AVM diagnosis, was 2 months to 25 years (mean ± SD, 6.6 ± 4.9 years). The presentation of de novo AVM was headaches in three (7.9%) patients, bleedings in 12 (31.6%), incidental in 14 (36.8%) and seizure in nine (23.7%). The estimated risk of haemorrhage was 4.8% per year. Seventeen (44.7%) patients were treated with surgical resection, 10 (26.3%) were conservatively observed, nine (23.7%) were treated with radiosurgery and two (5.3%) were endovascularly embolised. The morbidity and mortality were reported as 5.3% and 7.9%, respectively. Conclusion Post-natal de novo AVMs have been reported. Their annual haemorrhage risk is 4.8%. Most of them are treated by surgical resection and are associated with morbidity and mortality.

Anatomical Variations of Brain Venous Sinuses in Patients with Arteriovenous Malformations: Incidental Finding or Causative Factor?

OBJECTIVE

Acquired anomalies of the dural venous sinuses (DVS) have been correlated extensively with the development of dural arteriovenous fistulas (DAVFs). Despite the known similarities of DAVFs' pathogenesis with that of arteriovenous malformations (AVMs), the relationship of venous sinuses anomalies with AVMs scarcely has been studied. We aimed to investigate whether patients with AVM show a greater prevalence of congenital DVS anomalies. We hypothesized that these congenital anomalies trigger AVM development during early childhood just as acquired DVS anomalies trigger DAVFs formation during adulthood.

METHODS

Angiographic anomalies of the brain venous sinuses were studied in a cohort of 45 consecutive patients with AVM and compared with the angiographic; venous sinus anomalies of a control group formed by a second consecutive; series of 45 patients with subarachnoid hemorrhage.

RESULTS

Congenital anomalies of any DVS were more frequent in patients with AVM than in the control group (49.8% vs. 22.2%; P = 0.015). Congenital abnormalities of the superior sagittal sinus not only were more frequent in patients with AVM (27% vs. 6.7%; P = 0.021) but seemed also related to the AVM location: in 5 of the 6 AVM cases with unilateral superior sagittal sinus aplasia, the AVM was ipsilateral to the venous anomaly.

CONCLUSIONS

Patients with AVM have a greater likelihood of congenital anomalies of any DVS. These anomalies seem to be related also to the AVM location. These findings suggest that congenital anomalies of DVS may be related to the development of AVMs.