Search

Cerebral aneurysms and arachnoid cysts are relatively common cerebral malformations and the use of recent modalities has increased their detection rates. However, cerebral aneurysms associated with arachnoid cysts are unusual. We describe two cases of ruptured cerebral aneurysms associated with arachnoid cysts. According to previous reports, clinical presentation may sometimes be unusual, as cysts can prevent subarachnoid hemorrhage. Moreover, in some cases, CT may reveal typical arachnoid cysts without subarachnoid hemorrhage, without intracystic hematoma, or with subdural hematoma alone. These clinical presentations and radiologic findings can lead to delayed diagnosis of subarachnoid hemorrhage. Therefore, we should consider the coexistence of arachnoid cyst in case of a warning sign of aneurysm rupture.

A 17-year-old female in a lethargic state with mild dysarthria was transferred to our hospital after experiencing a generalized tonic seizure immediately after giving birth. Head CT showed a cortical subarachnoid hemorrhage(cSAH)in the left frontoparietal convexity. Three-dimensional rotational angiography(3D-RA)revealed multifocal narrowing of the cortical branches of the left middle cerebral artery(MCA)and severe stenosis of the left M1 segment with plexiform collateral networks, suggesting the presence of reversible vasoconstriction syndrome(RCVS)and aplastic or twig-like MCA(Ap/T-MCA). When 3D-RA was repeated on day 17, the narrowing of the cortical artery had resolved, and a new constriction of more proximal blood vessels was observed. The arterial spasm disappeared within 3 months, confirming the diagnosis of RCVS and Ap/T-MCA. Although non-aneurysmal SAH due to Ap/T-MCA is extremely rare, RCVS often complicates cSAH in the frontal/parietal region. It is suggested that RCVS triggers cSAH in the presence of incidental Ap/T-MCA. Ap/T-MCA is thought to be caused by developmental abnormalities during the embryonic period, but only 11 cases in children or adolescents have been reported. This suggests that there are a considerable number of asymptomatic young patients whose condition has not been detected. The majority of patients with Ap/T-MCA are from East Asia, suggesting that racial and genetic background differences are a factor. As this anomaly is more likely to present as a stroke in adulthood, long-term follow-up is recommended if it is found at a young age. There is no evidence that revascularization is effective in preventing stroke. Further studies are needed on how to manage this condition appropriately.

We report a rare case of reversible cerebral vasoconstriction syndrome(RCVS)with cortical subarachnoid hemorrhage(cSAH)associated with a fresh cortical infarction beneath the sulcus with thick cSAH. A 34-year-old woman presented with history of thunderclap headache. She was transferred to our hospital for further examination of a cSAH in the left frontal lobe. Results of the cerebrospinal fluid examination were unremarkable, but three-dimensional rotational angiography revealed multiple instances of narrowing of the cortical branches of the anterior and middle cerebral arteries, suggesting the diagnosis of RCVS. Diffusion weighted imaging(DWI)demonstrated a small cortical area with high-signal intensity around the sulcus , where a thick cSAH clot was observed. This cortical lesion appeared as low-signal intensity on the apparent diffusion coefficient maps, and the follow-up T2-weighted images(obtained 3 months after onset)demonstrated a residual lesion that was smaller than the initial DWI abnormality with high-signal intensity;thus indicating the presence of a coincident fresh cortical infarction. The position of the infarct next to the thickest portion of cSAH suggested that it was the bleeding source of the cSAH. Ten days after onset, the cerebral blood flow and volume in the cortex around the cSAH increased as compared to the same area on the contralateral side. These findings suggested that at least one of the bleeding mechanisms of the cSAH was related to the hemorrhagic infarction or subpial hemorrhage resulting from the "ischemia-reperfusion injury" due to the acute disturbance of the pial vessel microcirculation with subsequent rapid resolution of the blood flow during the early phases of RCVS. These dynamics could not be demonstrated with contemporary angiographic imaging.

Distal anterior cerebral artery(DACA)aneurysms have a low incidence. Particularly, DACA mirror aneurysms are extremely rare, although DACA multiple aneurysms are not rare. Generally, it is said that tiny aneurysms have a low risk of rupture. However, we sometimes encounter cases of ruptured tiny aneurysm. We describe a rare case of a mirror image of DACA ruptured tiny aneurysm. A tiny aneurysm can rupture if the aneurysmal wall is fragile. Detection of the aneurysm may often be difficult with a single modality, even if the modality is digital subtraction angiography. Moreover, the distribution of subarachnoid hemorrhage may not be typical. It might be important to capture a slight change of aneurysm in follow-up imaging to detect a ruptured aneurysm over multiple iterations of imaging.

A 55-year-old man presented with difficulty breathing, chest pain, and disturbance of consciousness, and was transferred to our hospital. Initial whole body CT revealed a diffuse subarachnoid hemorrhage(SAH)with severe pulmonary edema that was considered neurogenic in origin. He received controlled ventilation under sedation and conservative care for the SAH. One day after the onset of the SAH, his left pupil suddenly became dilated to 6mm, with no reaction to light. Head CT showed no new bleeding. Subsequent CT angiogram revealed a right internal carotid-posterior communicating artery aneurysm(IC-PC AN)with a posterior-lateral projection; however, no vessel abnormality was observed in the left anterior or posterior circulations. The aneurysm was successfully treated with coil embolization. We reviewed reported cases of isolated oculomotor nerve palsy(ONP), without direct compression by ruptured aneurysms, and found that only 11 cases exist, including our case. Interestingly, six of them were associated with anterior communicating artery aneurysms. A mass effect, chemical stimulation, and a jet stream of blood were proposed as the mechanisms of this rare type of ONP, in addition to the specific neurovascular relationships between the oculomotor nerve and the posterior cerebral/posterior communicating/superior cerebellar arteries, with abnormal nerve contact or compression. Though rare, ruptured IC-PC ANs could cause contralateral ONP; other types of ruptured aneurysms may also lead to indirect effects on nervous structures without direct compression. This type of rare presentation of ruptured aneurysms should be considered, especially in cases of multiple aneurysms, such as IC-PC ANs.

Objective: Surgical treatment for recurrent lesions of embolized aneurysms is difficult and challenging for many neurosurgeons because intra-aneurysmal coil masses are sometimes scarred to the wall of the aneurysm or adherent to adjacent vital structures. To assess the efficacy and safety of surgical treatment without coil removal for recurrent aneurysms after previous coil embolization, we retrospectively studied clinical results, angiographic results, and complications in patients treated with additional microsurgical clipping., Methods: From April 2003 to April 2013, 7 patients with recurrent previous embolized aneurysms underwent microsurgical treatment., Results: This series included 1 man and 6 women receiving endovascular coiling as the first-line treatment. One patient's aneurysm was unruptured, whereas the other 6 were ruptured. The aneurysm locations were posterior communicating (n = 3), anterior communicating (n = 2), ophthalmic (n = 1), and posterior inferior cerebellar (n = 1). The initial sizes ranged from 3-11.5 mm in diameter (mean, 6.6 mm), and the aspect ratios were 1.2 to 3.4 (mean, 1.9). In these aneurysms, the initial coiling result was complete occlusion in 5 patients, and neck remnants in 2 patients. The mechanism underlying aneurysm recurrence was coil compaction in 3 aneurysms, aneurysm regrowth in 3 aneurysms, and fundal migration in 1 aneurysm. The median recurrence latency was 28.8 months (range, 0.7-115 months). Microsurgical clippings without coil removal were used in 6 patients; a parent artery occlusion under bypass protection was done in 1 case with a posterior inferior cerebellar aneurysm. Fenestrated clips in combination with another type of clip were successfully used for 4 of 6 patients who were treated with direct neck clipping. No postoperative morbidity was observed, and postoperative imaging studies revealed complete occlusion of the aneurysms in all cases. There were no recurrences of aneurysms during the follow-up period (mean, 44.7 months; range, 0.5-118 months)., Conclusions: The microsurgical clipping without coil removal for recurrent lesions of embolized aneurysms is effective and safe when it is technically feasible. The tandem clipping in combination with a fenestrated clip is a crucial method for direct neck clipping without coil removal for previously coiled recurrent aneurysms. For unclippable lesions, a parent artery occlusion under bypass protection should be taken into consideration., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We report a rare case of a vertebral arteriovenous fistula presenting with subarachnoid hemorrhage (SAH). A 60-year-old man was admitted to our hospital with a sudden onset of headache and neck pain. A neurological examination showed no abnormalities. Computed tomography scans revealed SAH in the pontine cistern and cistern magna. Although the first cerebral angiogram failed to depict the cause of bleeding, the second angiogram on day 15 demonstrated an arteriovenous fistula in the left vertebral artery at C4-5, which was draining into the internal vertebral venous plexus and forming a venous pouch. The fistula was successfully obliterated by transarterial embolization using detachable platinum coils. In patients with SAH with predominance in the posterior fossa, attention should also be paid to spinal vascular lesions. Three-dimensional digital angiography and digital subtraction angiography allow a reliable visualization of such lesions.