The treatment of cerebral AVMs should include all hemorrhagic AVMs and unruptured AVMs with high-risk angiographic features such as associated aneurysms, deep location, only deep venous drainage, and single venous drainage [22].

Microsurgical resection of the entire nidus of the AVM by omitting the primary source of bleeding is the mainstay treatment. Endovascular treatment is a reasonable therapeutic choice when the lesion is deep and inaccessible; it can also be used as an adjuvant therapy to microsurgery or radiosurgery [11]. Radiosurgery is a favorable alternative for managing small AVMs with a nidus lesser than 2-3cm and for patients who are medically unsuitable for surgery [8,25].

Two hypotheses exist regarding the impact of the resection or omission of one AVM on the remaining ones. According to one hypothesis, by omitting one AVM, the blood flow may undergo alteration or even increase toward the remaining AVMs, contributing to an increased chance of bleeding. As a result, these authors recommend prompt elimination of the remaining AVMs [6,18,20]. Several others argue that after removing one AVM, the blood flow to other AVMs may decrease, potentially resulting in thrombosis and even the disappearance of other AVMs [26,31]. So, it is reasonable that all related AVMs to the hemorrhagic one also be treated following the hemorrhagic one [13,20,26].

According to ABURA (a randomized trial of unruptured brain arteriovenous malformations) guidelines, conservative management with follow-up imaging is proved to be the safest intervention for unruptured AVMs [16]. However, selected cases of unruptured AVMs, with low-grade Spetzler-Martin grading and situated in non-eloquent areas, may be considered for intervention after meticulous evaluation [3]. In patients with HHT and multiple AVMs, AVMs are primarily present in younger patients, located in non-eloquent, cortical regions and with smaller than 3 cm size [3,30]; conservative management is often recommended due to their reduced risk of bleeding [21,24].

There are rare reports of patients with multiple AVMs that present with irrelevant symptoms, and their AVMs are found incidentally.

A seven-year-old girl experienced recurrent episodes of fever without any apparent signs or symptoms indicative of generalized vascular disorders. An angiography evaluation revealed the presence of six distinct AVMs, of which one was located superficially in the temporal lobe and was relatively larger than the others. Surgical intervention was performed on it, while the remaining five underwent stereotaxic irradiation. However, the authors did not provide details regarding the outcomes or follow-up procedures performed [7].

A 48-year-old male patient presenting with mild occipitalgia was referred to the neurosurgical department for further evaluation. A brain CT scan revealed two small enhanced lesions in the right occipital and left parietal regions. Angiography subsequently confirmed the presence of two AVMs, one supplied by temporo-occipital and calcarine arteries and the other by parenchymal arteries; both were draining to the superior sagittal sinus. Despite the diagnosis, the patient refused treatment, and after two years of diligent follow-up, he remained free of hemorrhage and bleeding [29].

In a case series by Robert et al., they report three patients with multiple cerebral AVMs that present with irrelevant symptoms to their AVMs and are managed conservatively [22]. One patient was a 37-year-old man present with vertigo whose angiography revealed two cortical AVMs, one in the frontal and the other one in the occipital region, that was concomitant with intranidal aneurysm (SMG 3). The intranidal aneurysm coiled but two AVMs due to no history of bleeding and low risk of bleeding according to angiography approached conservatively during 26 months follow up was asymptomatic. The other patient was a 20-year-old man with HHT who had a headache on one side of his head. After an angiography, doctors found two AVMs in his brain. One was in the superior area, and the other was in the mesencephalic area. The supra-AVM was treated with endovascular treatment, while the mesencephalic AVM received conservative treatment due to the high risk of treatment and asymptomatic nature. After 35 months of follow-up, the patient was still asymptomatic. The last patient was a 63-year-old man referred with vertigo and a history of HIV. That angiography revealed two separate AVMs, one in the central region and one in the cerebellum (SMG 1). Both were asymptomatic, at low risk of bleeding and underwent conservative management. During one-year follow-up, they remain asymptomatic.

In our case, we had scheduled endovascular therapy for the third AVM due to stenosis in its draining vein and close follow-up observation of the remaining AVMs due to their sensitive locations, asymptomatic presentation, and the absence of high-risk imaging features. However, the patient declined treatment and angiography; after one year, the patient did not exhibit any neurological signs or symptoms. Our findings also support the concept of ABURA, suggesting that conservative management is reasonable for asymptomatic multiple AVMs located in eloquent regions where treatment carries a risk of complications. It is important to note that, in our case, only one of the three AVMs exhibited the high-risk imaging trait for hemorrhage. In instances where multiple AVMs present with a high-risk feature of hemorrhage, the decision-making process, as previously explained, would be different.