Ruptured mycotic aneurysm of the distal middle cerebral artery manifesting as subacute subdural hematoma

Mycotic aneurysm presenting as subdural empyema: illustrative case

BACKGROUND

Mycotic aneurysms (MAs) are rare intracranial pathologies. They are associated with spontaneous rupture, which is often the first presenting sign. Subarachnoid hemorrhage and intraparenchymal hemorrhage are the most common sequelae of ruptured MAs, with subdural hematoma being an atypical presentation. The presentation of an MA as a subdural empyema has not yet been reported in the literature.

OBSERVATIONS

The authors discussed a 68-year-old man who presented with subdural empyema and received surgery for evacuation. He was found to have a ruptured mycotic aneurysm intraoperatively.

LESSONS

This case demonstrated a rare and atypical presentation of an MA.

Ruptured giant aneurysm of a cortical middle cerebral artery: A case report

Background

Aneurysms of the cortical branches of the middle cerebral artery (MCA) are rare. They usually are secondary to traumatic or infectious etiologies and are rarely idiopathic. The specific characteristics of idiopathic aneurysms in such location are not well defined in the literature. The authors report a rare case of a ruptured giant idiopathic cortical MCA aneurysm with review of the available literature on this clinical entity.

Case Description

A 24-year-old female presented with headache, disturbed level of consciousness, and right-sided weakness. Imaging studies showed a left frontoparietal intracerebral hematoma and a giant saccular aneurysm in the posterior parietal cortical branch of the MCA. The patient had no history of head trauma or active infection; therefore, the aneurysm was considered idiopathic. A microsurgical clipping of the aneurysm with evacuation of the hematoma was performed. There were no surgical complications, and the patient achieved a good outcome modified Rankin Scale of 1 with no neurological deficits.

Conclusion

Idiopathic aneurysms of the cortical branches of the MCA are rare, and usually present with intraparenchymal hemorrhage due to rupture. There is no clear consensus regarding the optimal management strategy. This case shows that timely management can lead to good outcomes.

Onyx Embolization of Distal Middle Cerebral Artery Aneurysm in a Patient with Nontraumatic Subdural Hematoma

Distal cortical middle cerebral artery (MCA) aneurysm is a rare entity. Despite the challenging procedure, the role of endovascular treatment is emerging due to its safety and efficacy in obliterating the microaneurysm. We report a 25-year-old male, who presented with a history of dizziness and headache for almost 2 weeks. Computed tomography scan showed a right front parietal subdural hematoma (SDH). We could not identify any underlying defining etiology of SDH neither head injury nor coagulopathy disorder. Therefore, diagnostic cerebral angiogram was performed, which showed a microaneurysm in the distal right MCA cortical branch. Hence, complete obliteration of this microaneurysm was performed using Onyx for endovascular embolization. Therefore, this case report demonstrates the efficacy of this modality in the treatment of microaneurysms with SDH.

The Surgical Treatment of a Large Cortical Atherosclerotic Middle Cerebral Artery Aneurysm Presenting With Parietal Lobe Infarction

Distal MCA aneurysms are rarely seen in daily neurosurgical practice and they are, more commonly associated with infectious processes. Here, the authors present a 65-year-old, patient who had an atherosclerotic M4 segment located aneurysm. It was confirmed, that the aneurysm was not related with any infectious process. The patient had, presented clinically by a parietal infarction and she had been successfully operated. The neuronavigation system for this particular case aided us for a precise localization of the aneurysm and gave a chance for a smaller craniotomy.

Usefulness of Intraoperative Imaging in a Patient with a Ruptured Aneurysm of the M4 Segment of the Middle Cerebral Artery

BACKGROUND

Treating cerebral aneurysms in the M4 segment of the middle cerebral artery (MCA) is challenging because they are small and are buried in the brain parenchyma.

CASE DESCRIPTION

A right-handed Asian woman in her 80s was referred to our hospital with a chief complaint of altered level of consciousness. On admission, her consciousness level on the Glasgow Coma Scale was 7 (E1V1M5), and a computed tomography (CT) scan showed subarachnoid hemorrhage with intracerebral hematoma in the left temporal lobe. Subsequent 3-dimensional CT angiography showed an aneurysm in the M4 segment of the left MCA. The aneurysm of the patient was clipped safely and effectively because of the navigation system in combination with intraoperative angiography. The navigation system was especially useful for estimating the proximal part of the parent artery at the brain surface, whereas intraoperative angiography was especially useful for confirming that the proximal portion of the parent artery identified by the navigation system was correct.

CONCLUSIONS

We emphasize the importance of choosing the modality of intraoperative imaging according to each characteristic when treating M4 segment aneurysms.

Cortical aneurysms of the middle cerebral artery: A review of the literature

Background:

Middle cerebral artery (MCA) aneurysms constitute from 18–40% of all intracranial aneurysms. They are mainly found in the proximal and bifurcation tracts and only in the 1.1-1.7% of cases they are located in the distal segment. The authors report a case of a ruptured saccular cortical MCA aneurysm with unknown etiology.

Case Description:

A 53-year-old female was admitted with a sudden severe headache, nausea, vomiting, and a slight left hemiparesis. The computed tomography (CT) scan showed subarachnoid hemorrhage (SAH) in the left sylvian fissure and intracerebral hemorrhage (ICH) in the left posterior parietal area. The CT angiography (CTA) reconstructed with 3D imaging showed a small saccular aneurysm in the M4 segment in proximity of the angular area. A left parieto-temporal craniotomy was performed, the aneurysm was clipped and the ICH evacuated. The motor deficit was progressively recovered. At 3-month follow-up examination, the patient was asymptomatic and feeling well.

Conclusions:

In our opinion, surgery is the best choice for the treatment of ruptured M4 aneurysms with ICH, because it allows to evacuate the hematoma and to exclude the aneurysm from the intracranial circulation. In addition, we suggest both the use of the neuronavigation technique and of the indocyanine green videoangiography (ICGV) for the aneurismal surgery.

Clinical management of infectious cerebral vasculitides

A wide range of infections (virus, bacteria, parasite and fungi) may cause cerebral vasculitides. Headache, seizures, encephalopathy and stroke are common forms of presentation. Infection and inflammation of intracranial vessels may cause pathological vascular remodelling, vascular occlusion and ischemia. Vasculitis in chronic meningitis may cause ischemic infarctions, and is associated with poor outcome. Appropriate neuroimaging (CT-angiography, MR-angiography, conventional 4-vessel angiography) and laboratory testing (specific antibodies in blood and CSF, CSF culture and microscopy) and even brain biopsy are needed to quickly establish the aetiology. Enhancement of contrast, wall thickening and lumen narrowing are radiological signs pointing to an infectious vasculitis origin. Although corticosteroids and prophylactic antiplatelet therapy have been used in infectious cerebral vasculitis, there are no randomized clinical trials that have evaluated their efficacy and safety. Stable mycotic aneurysms can be treated with specific antimicrobial therapy. Endovascular therapy and intracranial surgery are reserved for ruptured aneurysms or enlarging unruptured aneurysms.

Delayed Hypersensitive Process in Subacute Subdural Hematoma

The authors report 2 patients with subacute subdural hematoma (sASDH). An inflammatory process is known to be involved in the development of traumatic subdural effusion (TSE) evolving into chronic subdural hemorrhage (CSDH), but a similar event has not been previously described in acute subdural hematoma (ASDH) evolving into sASDH. In our cases, dexamethasone (DXM) and other conservative treatments were administered to our first patient with dramatic clinical outcome, and a postoperative pathologic examination of the neomembrane of the sASDH in the second patient was done, which showed marked inflammatory process with T-lymphocytes and neutrophils infiltration. The good response to DXM in the first patient and the definite laboratory result of the second patient and their radiologic presentations, as well as a review of relevant literature, suggest that a T-lymphocyte-mediated, delayed hypersensitive reaction triggered by undissolved blood clot may be the driving force of ASDH developing into sASDH, which starts after the seventh day, and peaked by the end of the second week of the clinical course.