UNASSIGNED: Cranial nerve palsy (CNP) in patients with intracranial aneurysms (IAs) can impose significant burdens on a patient\'s quality of life. The literature has a paucity of reviews addressing patterns of overall reported cranial nerve (CN) involvement and outcomes in patients with IA.
UNASSIGNED: The literature systematically reviewed CNP at presentation in the setting of IA using PubMed, Web-of-Science, and Scopus according to the PRISMA guidelines.
UNASSIGNED: Fifty-two studies reported a total of 513 patients with IA and 630 CNPs observed at presentation: oculomotor (58.25%), abducent (15.87%), optic (12.06%), trochlear (8.7%), and trigeminal (1.9%). Most common aneurysms are located in a posterior communicating artery (46%) and cavernous internal carotid artery (29.2%). Trends of CNP based on the rupture status of IAs showed that 80% were associated with unruptured IAs and 20% with ruptured IAs. Post-treatment of IA, 55% of patients had complete resolution of CNP, with most (89%; n = 134) resolving within the first 6 months. Stratified by CNP type: Complete resolution rate is 100% in CN VII-IX, 60% in CN VI, 59% in CN IV, 54% in CN III, 45% in CN V, and 43% in CN II.
UNASSIGNED: In patients with cranial nerve palsies attributed to IAs, the location and rupture status of the aneurysm could determine the type and severity of the nerve palsy. Most patients experienced favorable outcomes in terms of their resolution and long-term function of the CNP after treatment of the IA.

OBJECTIVE: To describe a case of replaced posterior cerebral artery (PCA) in which all branches of the PCA arose from the anterior choroidal artery (AChA) with an early branching temporal artery.
METHODS: An 83-year-old man with cerebral infarctions underwent cranial magnetic resonance (MR) imaging and MR angiography using a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.
RESULTS: A large anomalous artery arose from the supraclinoid segment of the right internal carotid artery (ICA) and supplied all branches of the right PCA, mimicking fetal-type PCA. The temporal branch arose from the proximal segment of this artery. In MR angiographic source images, a tiny artery arose from the right ICA proximal to the origin of the anomalous artery, indicating a hypoplastic right posterior communicating artery (PCoA). Thus, we concluded that the anomalous artery was a replaced PCA; all branches of the PCA arose from the AChA.
CONCLUSIONS: We present a case involving a replaced PCA with an early branching temporal artery, as seen on MR angiography. Careful observation of MR angiographic source images is useful for identifying small arteries. To our knowledge, this is the first report of this combined variation in the relevant English-language literature.

BACKGROUND: The fetal-type posterior cerebral artery (PCA) is defined as a variant anatomy in which the posterior communicating artery (PCOM) is larger than the hypoplastic or aplastic P1 segment of the PCA. The authors present the novel case of a patient with a duplicated right PCA in parallel with fetal-type and conventional PCAs supplying adjacent components of the PCA cerebral territory.
METHODS: A 59-year-old woman presented with a modified Fisher Scale score 4 subarachnoid hemorrhage. A right irregular PCOM aneurysm that measured 9.5 mm × 4.5 mm × 4.5 mm arose from the base of a variant branch supplying a portion of the PCA, rather than a conventional PCOM, and was found on digital subtraction angiography. Following endovascular coil embolization, the patient was discharged home.
CONCLUSIONS: The fetal-type variant has implications for thromboembolic events. If an embolism occludes the anterior circulation in a patient with a fetal-type PCA, it may result in an infarct in the PCA territory. Awareness of cerebral arterial anatomy, including an atypical collateral supply, informs a treating team\'s latitude in tolerance of which sites must be preserved and which can be safely sacrificed. https://thejns.org/doi/10.3171/CASE23735.

UNASSIGNED: Ruptured cerebral artery aneurysms (RCAA) are devastating diseases with high morbidity and mortality rates if not promptly managed. In Nigeria, access to timely neurosurgical services remains a challenge and aneurysm coiling is still not possible in virtually all centres in Nigeria. The aim of this study is to report on our 9 years\' experience with clipping of cerebral aneurysm and on the attendant clinical outcomes.
UNASSIGNED: A retrospective analysis of all consecutive operated RCAA between March 2012 and June 2021 was conducted. Patients\' demographic parameters, World Federation of Neurosurgical Societies (WFNS) grade, Hunt and Hess (HH) grade, aneurysm location, timing of surgery and outcome were analysed. Outcome was measured using Glasgow Outcome Scale (GOS) score.
UNASSIGNED: A total 29 were included in the study. The most common age group affected was between 50-59 years. RCAA were mainly in the region of the middle cerebral artery and posterior communicating artery (PComA) territories. All the patients presented after 24 hours of the ictus. Two (6.9%) patients had multiple aneurysms. Early clipping (<72hours after presentation) was possible in 8 (27.6%) patients. At least one episode of a rebleed occurred in 19 (65.5%) patients prior to surgery. Mortality rate was 17.2%. None of the patients with PComA aneurysm died. The patients\' pre-operative WFNS and HH grades were significantly associated with GOS.
UNASSIGNED: Modifiable factors like under diagnoses, delayed referral, cultural belief and financial challenges may account for the low number of patients presenting for neurosurgical care. The possibility of a sizeable number of patients dying due to these factors is a strong possibility for the low number of patients presenting for neurosurgical care.

Variations at the junction of embryonic internal carotid and vertebrobasilar systems are rare and associated with a high incidence of stroke. During cadaver dissection, we demonstrated for the first time a case of hypoplastic right vertebral artery associated with partial duplication of the distal part of the right P1 segment of a partial fetal posterior cerebral artery (FPCA) and bilateral duplication of superior cerebellar arteries (SCAs), of which, the upper right SCA originated from PCA. We hypothesize that the poor development of the right half of the vertebrobasilar system caused the persistence of FPCA with anomalous origin of the right upper SCA as well as partial duplication of P1 segment of PCA as a remnant of the weak anastomosis between the embryonic right PCA and the basilar system. Such complex variations provide a huge challenge in their diagnosis and in choosing the suitable treatment modality for the stroke.

OBJECTIVE: To report an unusual case of combined Lie\'s types A and D of internal carotid artery (ICA) agenesis, diagnosed by magnetic resonance angiography (MRA).
METHODS: A 60-year-old woman with dizziness underwent cranial magnetic resonance imaging (MRI) and MRA of the intracranial region for the evaluation of brain and vascular lesions. The magnetic resonance machine was a 3.0-T scanner.
RESULTS: MRI showed no abnormalities, except for multiple small white matter lesions. MRA showed that the left ICA was absent, except for the supraclinoid segment, and an anastomotic vessel was present between the paraclinoid segments of the bilateral ICAs, indicating Lie\'s type D ICA agenesis. The left posterior communicating artery (PCoA) was also present. Thus, there were also features of type A ICA agenesis. The anastomotic vessels between the bilateral ICAs and ipsilateral PCoA were relatively small in caliber.
CONCLUSIONS: Lie\'s type D ICA agenesis usually does not communicate with the anterior and posterior circulations. We encountered a case of combined type D and type A ICA agenesis. To our knowledge, no similar case has been reported in the English literature. This is the second case of type D ICA agenesis with patent ipsilateral PCoA. We speculate that in case of type A ICA agenesis, when the development of the PCoA is insufficient to support collateral blood flow, an anastomotic vessel between bilateral ICAs may develop.

OBJECTIVE: To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.
METHODS: Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP.
RESULTS: Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP.
CONCLUSIONS: Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

BACKGROUND: Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever.
METHODS: We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations.
RESULTS: We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping.
CONCLUSIONS: In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Since subarachnoid hemorrhage (SAH) due to the re-rupture of cerebral aneurysms severely worsens the prognosis, an accurate initial diagnosis is essential. Computed tomography (CT) and magnetic resonance imaging (MRI) usually detect aneurysmal subarachnoid hemorrhage (aSAH). However, in rare cases, its identification on CT- and MRI scans is difficult, and a cerebrospinal fluid (CSF) examination is required. We present preoperative imaging and intraoperative findings in patients whose aSAH detection necessitated a CSF examination. Of 225 aSAH patients who underwent preoperative imaging studies at our institution between April 2010 and August 2019, 3 females (1.3%, mean age 57.3 years) harbored undetectable aSAH due to the rupture of an internal carotid artery-posterior communicating artery (ICA-PcomA) aneurysm. The aneurysmal orientation was inferolateral. Intraoperatively, the anterior petroclinoid ligament hampered the detection of the aneurysms that firmly adhered to the surrounding arachnoid membrane. Sustained arterial pulsation and successive minor hemorrhage can lead to the gradual adhesion of an ICA-PcomA aneurysm to the surrounding arachnoid membrane and explain their atypical rupture undetectable on imaging studies and the development of acute subdural hematoma without SAH.

A 46-year-old female came to neurosurgery outpatient department with sudden onset of drooping of RE upper eyelid and restriction of movements in adduction, depression and elevation in right eye. Patient was a known case of diabetes mellitus whose blood sugar levels were deranged. On examination, patient was diagnosed pituitary macroadenoma. Patient was treated for her uncontrolled diabetes mellitus following which she had underwent transsphenoidal pituitary macroadenoma removal. On treatment, patient\'s ptosis had subsided and restriction of movement has resolved.