Choroidal Artery Research Articles

Infundibular Widening of Angiographically Invisible Duplicate Anterior Choroidal Artery Mimicking Typical Anterior Choroidal Artery Aneurysm

A diagnosis of an intracranial aneurysm depends on the angiographic configuration and should be cautiously differentiated from aneurysm mimics. In cases of duplicate anterior choroidal arteries (AChAs), infundibular widening of the distal minor AChA can be an aneurysm mimic. If the minor AChA with a smaller diameter is obscured angiographically due to poor contrast filling, an associated infundibular widening beside the proximal large AChA can misinterpreted as a typical AChA aneurysm in angiograms. The authors report on two such cases of duplicate AChAs with infundibular widening presenting like a typical AChA aneurysm in angiograms. Surgical exploration revealed a perforating artery emitting from the dome of the saccular lesion, confirming infundibular widening of a duplicate AChA. No reparative procedure was applied to the infundibular widening in a 48-year-old man, while two vascular outpouchings from the infundibular widening were clipped preserving the duplicate AChA in a 55-year-old woman.

Microanatomical study of the posterior medial choroidal artery

Introduction/Objective. The aim of this study was a detailed examination of microanatomy of the medial posterior choroidal artery (MPChA). Methods. The microanatomical characteristics of the MPChA were studied in 30 formalin fixed brain hemispheres using 6.3?10 ? magnification of the stereoscopic microscope. The arteries were injected with the mixture of 10% India ink and gelatin. The second group of 10 hemispheres consisted of specimens injected with methyl methacrylate fluid into the cerebral arterial vessels, for the preparation of corrosion casts. Results. The MPChA was present in all 30 hemispheres, always as the single artery. The MPChA were divided into proximal and distal types of vessels. We distinguished two segments of the MPChA: a cisternal and plexal. Proximal MPChA was present in 53.3% of cases, with the caliber of 0.6?1 mm (mean 0.8 mm). ?he point of its origin from the posterior cerebral artery was always before the origin of the first temporal cortical branch. Distal MPChA existed in 46.7% of cases, with the diameter of 0.4?1 (mean 0.74 mm). The cisternal segment the most frequently gave of the origin of fine branches to the cerebral crus, medial geniculate body and thalamus. The plexal segment gave rise arteries to the thalamus, and choroid branches for the supply of the choroid plexus of the third ventricle. Anastomoses in the region of the MPChA were found in all of 20 examined brains, most often among the plexal branches. Conclusion. The results describing the microanatomical characteristics of the MPChA may have diagnostic and microsurgical significance.

Mobilization of the temporal pole as integrated step in microsurgical clipping of pure posteriorly directed posterior communicating artery aneurysm

A pure posteriorly posterior communicating artery (PCoA) aneurysm represents a surgical challenge. This is mainly when there is a need for good exposure of the aneurysmal neck, sac, PCoA, and anterior choroidal arteries. Ruptured pure posteriorly directed PCoA aneurysm imposes significantly extra challenge as the surgeon undergoes dissection through a tight brain. Even with measures commonly used to attain brain relaxation like the lumbar drain and cisternal fenestration. Here, we describe a technique for posterior temporal pole mobilization (TPM) as an integrated part of microsurgical clipping of ruptured pure posteriorly directed PCoA aneurysms. This technique is implicated in twenty-three successive cases of ruptured PCoA aneurysms in the neurosurgery teaching hospital in Baghdad, Iraq, with no reported complications.

Acute intracranial internal carotid artery occlusion: Extension and location of the thrombus as an influencing factor in Computed Tomography angiography findings

PurposeAcute intracranial internal carotid artery (ICA) occlusion can mimic an extracranial affectation on Computed Tomography angiography (CTA). This fact could be explained by the extension of the thrombus in the ICA concerning its arterial branches. This study aims to determine how this factor may influence imaging findings. MethodsA retrospective study was conducted from a single-center database of patients undergoing mechanical thrombectomy due to ICA occlusion between October 2017 and March 2022 (n = 77). Patients with acute intracranial ICA occlusion were included (n = 29) and divided into two groups, according to ICA opacification on CTA: the discernible extracranial ICA or group D, and the pseudo-occlusion or group P. Patency of posterior communicating, anterior choroidal, and ophthalmic arteries on digital subtraction angiography were collected to determine thrombus extension. Sensitivity and specificity were calculated for CTA. ResultsSignificant differences were found in DSA between group P (n = 17) and group D (n = 12) in the frequency of patency of major artery branches: the presence of posterior communicating (PCOM) and anterior choroidal arteries (AChA) was observed in 2 patients in group P vs. 10 in group D (p < 0.001); whereas the patency of the ophthalmic artery (OA) was visualized in 10 patients in group P vs. 12 in group D, p = 0.023). For the diagnosis of isolated intracranial ICA occlusion, CTA had a sensitivity of 43.5% and a specificity of 97.2%. ConclusionsThe location and extent of the thrombus in the intracranial ICA concerning major artery branches may influence CTA findings.

Duplicated fetal posterior cerebral artery in a patient with a ruptured fetal posterior cerebral artery aneurysm: a cerebrovascular variant.

The most common neurovascular variant is the fetal posterior cerebral artery (FPCA), in which the P1 branch is absent or hypoplastic, and the majority of P2 supply is derived from the anterior circulation. While there are reports of hyperplastic anterior choroidal arteries (AChA) with supply to the temporo-occipital and calcarine regions, no reports of a duplicated FPCA exist. This case report describes a patient with a ruptured right FPCA aneurysm. Digital subtraction angiogram (DSA) revealed an artery with origin distal to the FPCA associated with the aneurysm. This was not consistent with a typical AChA. The FPCA associated with the aneurysm had the typical origin, course, and supply of a FPCA. The distal FPCA had a similar course of a typical FPCA with significant supply to the typical PCA territory. The patient underwent successful clipping of the aneurysm, and the duplicated FPCA was identified during the craniotomy. The features of this duplicate FPCA, which has not been previously described, are discussed in comparison to another variant, the hyperplastic, anomalous AChA. The artery described in this report does not fit the typical criteria of this AChA variant. Therefore, the authors outline this variant as a duplicated FPCA. Recognition of variant cerebrovascular anatomy is vital to neurosurgeons and interventional neuroradiology specialists. FPCA aneurysms require special management considerations and are often more challenging to treat. This report discusses a duplicated FPCA. To our knowledge, this is the first description of this variant. A duplicated FPCA carries important management considerations in the management of neurovascular pathology.

Comparison of Lens Extraction Versus Laser Iridotomy on Anterior Segment, Choroid, and Intraocular Pressure in Primary Angle Closure Using Machine Learning.

Treatment strategy of primary angle closure (PAC) is not clear due to the large number of clinical and anatomic-topographic parameters in PAC, influencing the treatment algorithm. Using the machine learning method DD-SIMCA, we justify the expediency of early lens extraction (LE) in PAC. To compare the anatomic and functional efficacy of LE and laser peripheral iridotomy (LPI) in patients with PAC using Machine Learning. This prospective study included 120 patients aged 41-80 years: 60 eyes with PAC, 30 with PAC suspects, and 30 with healthy eyes (control). Thirty PAC eyes with intraocular pressure (IOP) up to 30 mm Hg were treated using LE with intraocular lens implantation and 30 eyes with LPI. All subjects underwent Swept Source optical coherence tomography. We analyzed 35 parameters of each eye including the lens vault, the choroidal thickness, the anterior chamber angle, and iris specifications such as iris curvature. Considering the correlations between them, the machine learning method DD-SIMCA 1-class classification was applied: the proximity of each sample to the target class (control) was characterized by the total distance to it. After LE, IOP was significantly lower than after LPI ( P =0). Every third eye with PAC after LE reached the target class: specificity according to DD-SIMCA equals 0.67. This was not observed for the eyes after LPI: specificity equals 1.0. After LE, all parameters of the anterior chamber angle did not differ from the control (all P >0.05). After LPI, there was an increase in anterior chamber depth ( P =0) and a decrease in lens vault ( P =0), but results comparable to the control were achieved only for iris curvature ( P =1.000). The efficacy of LE in PAC is higher than LPI due to the better postoperative anterior chamber topography and lower IOP. This study lends further clinical and anatomic support to the emerging notion of LE as an effective treatment for PAC.

Development of an in vitro model to estimate mass transfer from the anterior cavity

Knowledge of drug mass transfer from the anterior chamber via the iris-lens barrier has important implications for the development of front of the eye medicines that can also deliver drugs to the vitreous cavity. Here, the design and evaluation of a novel in vitro model that estimates anterior clearance (CL) kinetics is described. To mimic some aspects of the human eye to aid with pharmaceutical modelling, the model incorporated a simulation of aqueous inflow from the ciliary inlet at the physiological flow rate, two CL elimination pathways [anterior hyaloid pathway and retina choroid sclera (RCS) pathway], human cavity dimensions and use of simulated vitreous fluid (SVF). An eye movement platform that incorporated 3 different eye movements (smooth pursuit, microsaccadic and saccadic) was tested against the control (no movement) to observe any difference in anterior kinetics profile and drug convection to the posterior cavity. Both timolol and brimonidine injected in the intracameral space were evaluated in the new in vitro prototype. An initial release study with one selected eye movement (smooth pursuit) with timolol (6.8 ± 0.4 µg, 30 μL) and brimonidine (15.3 ± 1.5 µg, 30 μL) showed half-life values of 105.3 and 97.8 min respectively in the anterior cavity (AC) space. Another study evaluated the effect of all eye movements against control with both drugs with higher doses of timolol (146.0 ± 39.1 μg, 25 μL) and brimonidine (134.5 ± 39.5 μg, 25 μL). The amounts of timolol in the back of the eye (RCS membrane and outflow) were 0.07 ± 0.05%, 1.36 ± 0.88%, 1.55 ± 1.03% and 0.98 ± 0.06% by 8 h with smooth pursuit, microsaccadic, saccadic and no movement respectively; whereas brimonidine amounts were 0.70 ± 0.21%, 0.94 ± 0.40%, 1.48 ± 1.02%, and 0.76 ± 0.33% respectively. A small amount of both drugs was seen in other compartments in the model (lens part, iris part, hyaloid membrane part and silicone cornea). These results indicate that this model can be used to determine transfer of small molecules via the iris-lens barrier to help optimise front of the eye formulations to treat tissues further back in the eye.

Clinical significance of “periventricular collateral enhancement sign” in symptomatic moyamoya disease: A vessel wall imaging study

BackgroundPeriventricular collaterals are associated with high risk of hemorrhagic stroke in adult moyamoya disease (MMD). However, the clinical significance of the periventricular collateral enhancement sign (PCES), which indicates wall enhancement of periventricular collaterals on contrast-enhanced vessel wall imaging (VWI), has yet to be determined. MethodsThirty-seven patients with MMD with acute neurological symptoms were consecutively recruited. Periventricular collaterals including lenticulostriatal artery, thalamic artery, and choroidal artery collaterals were evaluated on digital subtraction angiography, and then PCES was detected on pre- and postcontrast VWI. First, the association between PCES and hemorrhagic presentation was evaluated using multivariate analyses. Second, two raters investigated the culprit vessels responsible for bleeding in hemorrhagic MMD using the Cohen kappa statistic. ResultsFifteen sites of PCES on postcontrast VWI were observed in 15 patients. Multivariate analysis revealed that hemorrhagic presentation was the only independent factor for PCES (OR = 37.3, 95%CI = 3.9–113, p =.002). In patients with hemorrhagic presentation (n = 20), the identification rate of the ruptured vessel was 80% by rater 1, with excellent agreement. (inter-rater, κ = 0.86, 95%CI = 0.59–1.00; intra-rater, κ = 0.83, 95%CI = 0.50–1.00). Choroidal (50%) and thalamic artery collaterals (15%) were the most common and the second most common types of culprit vessels. Inter-rater and intra-rater reliabilities for the classification of culprit vessels were also excellent (intra-rater, κ = 0.86, 95%CI = 0.67–1.00; inter-rater, κ = 0.93, 95%CI = 0.79–1). ConclusionAcute hemorrhagic stroke in MMD is independently associated with PCES on postcontrast VWI. PCES can help to detect the culprit vessels that are responsible for hemorrhage in patients with MMD.

A case of anterior choroidal artery injury after resection of a pilocytic astrocytoma in the amygdale—a case report

The anterior choroidal artery (AChA) arises from the last segment of internal carotid artery (ACI), the communicating C7 segment and comprises the terminal branch of ACI. Anatomical its origin located supraclionoidal after the ophthalmic C6 segment of ACI and after the rise of posterior communicating artery. The AChA gains greater importance because of its small size and its region of blood supply. With its perforating branches supplies important intracranial structures such as the optic tract, the posterior limb of the internal capsule, the lateral geniculate body, the medial temporal lobe and the medial area of the pallidum. The anterior choroidal artery is a fine artery and consists of two parts, a cisternal and a plexal one. There are only few studies published, which describe the exact anatomy and the impact of its damage. On the present report, we discuss a case of an iatrogenic injury of the anterior choroidal artery and its hazardous consequences.

Distribution of IntraThalamic Injury According to Nuclei and Vascular Territories in Children With Term Hypoxic-Ischemic Injury

BackgroundTerm hypoxic-ischemic injury (HII) on magnetic resonance imaging (MRI) is described as the basal ganglia thalamus [BGT], watershed [WS], or combined [BGT/WS] groups. We aimed to determine differences between HII groups in intrathalamic distribution. MethodsDelayed MRIs of children with HII and thalamic injury were reviewed. Custom tools were placed over T2-weighted and/or fluid-attenuated inversion recovery axial images to determine distribution of intrathalamic injury: (1) six subjective (whole/near-whole, central, anterior, posterior, lateral, medial); (2) four nuclear (anterior [AN], ventrolateral [VLN], medial [MN], and pulvinar [PN]); and (3) three arterial (thalamoperforating arteries [TPA], thalamogeniculate arteries [TGA], and posterior choroidal arteries [PCA]) locations. We compared the frequency of injury of the aforementioned intrathalamic locations between HII groups. ResultsThe 128 children (mean age at MRI 7.35 ± 3.6 years) comprised 41% (n = 53) BGT, 26% (n = 33) WS, and 33% (n = 42) BGT/WS. The VLN was the most frequent injured nuclear region (66%, n = 85), and the TGA (93%, n = 128) was the most frequent arterial region involved. VLN injury occurred more frequently in the BGT group (P < 0.001), PN in the WS group (P < 0.001), and AN (P < 0.001), MN (P < 0.001), PN (P = 0.001), and all nuclei together (P < 0.001) in the BGT/WS group. The combination of all vascular territories was significantly associated with BGT/WS (P < 0.001). ConclusionsThere are significant differences in intrathalamic nuclear and arterial injuries between the different types of HII.

Bypass surgery for ruptured dissecting aneurysms of the proximal posterior cerebral artery: illustrative case.

BACKGROUNDPosterior cerebral artery (PCA) dissecting aneurysms commonly occur in the proximal PCA and are considered rare. The treatment of proximal PCA dissecting aneurysms is challenging because of the existence of perforators supplying the vital neural structures. Recently, endovascular intervention has been used; however, concerns for ischemic or hemorrhagic complications exist.OBSERVATIONSA 54-year-old woman presented with subarachnoid hemorrhage due to dissecting aneurysm rupture at the P1-P2 junction of the PCA. The thalamoperforating artery (TPA) and medial posterior choroidal artery (MPchA) originated from the proximal end and the distal end of the aneurysm, respectively. Additionally, the posterior communicating artery (PcomA) connected with the dissected segment. To preserve these perforators, we performed surgical trapping combined with superficial temporal artery (STA) PCA anastomosis. Clips were applied for trapping the proximal and distal end of the aneurysm, with preservation of the TPA and MPchA origin. PcomA was left open for blood flow preservation to the perforators directly arising from the aneurysm. The postoperative course was uneventful, and the patient was discharged.LESSONSSurgical trapping using STA-PCA bypass could be a treatment of choice for proximal PCA dissecting aneurysms, considering its potential for cure and prevention of ischemic complications.

Changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic moyamoya disease.

Periventricular anastomosis in moyamoya disease (MMD) is an unusual angiographic finding that arises from perforating arteries such as the lenticulostriate artery (LSA), thalamic artery (THA), and anterior choroidal artery (AChA). This anastomosis is associated with increased hemorrhagic risk in MMD and can be corrected by direct revascularization surgery. The present supplementary analysis on a prospective cohort aimed to elucidate changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Twenty-two patients with misery perfusion in the symptomatic cerebral hemisphere who underwent indirect revascularization surgery alone also underwent six-vessel cerebral angiography via arterial catheterization before and at 6months after surgery. Before surgery, two patients (9%) had positive periventricular anastomosis from the LSA and another (5%) from the AChA; all three of these periventricular anastomoses regressed after surgery, but these changes were not statistically significant (p = 0.0833). The degree of formation of collateral vessels from the LSA significantly decreased after surgery (p = 0.0143), but the degree of collateral vessels from the THA or AChA did not differ between pre- and postoperative conditions. Eight patients with postoperative regression of the collateral vessels from any perforating artery exhibited postoperative rich collateral flow from indirect revascularization. Periventricular anastomosis tended to regress after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Collateral vessels formed from the LSA likely regressed after indirect revascularization surgery alone for such patients, but those vessels from the THA or AChA seldom changed.

Treatment results of anterior choroidal artery aneurysms treated mostly with coil embolization: A single-center experience.

Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute. The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute. In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6-174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed. The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.

Three-Dimensional Angioarchitecture of Rete Middle Cerebral Artery Anomalies and the Clinical Significance.

Rete middle cerebral artery (MCA) anomaly is characterized by aweb-like network of arteries involving the first MCA segment (M1) and anormal downstream MCA. The detailed composition of this anomaly and the hemodynamic impacts on cerebral perfusion are rarely addressed. The purpose of this study was to elucidate the anatomical and hemodynamic perspectives of the rete MCA anomaly. From August 2020 to December 2021, 4rete MCA anomalies were identified at Shuang Ho hospital. Clinical information, perfusion magnetic resonance (MR) imaging, and angiographic images were collected. Detailed angioarchitecture, including types of arterial feeders and extent of rete involvement, were analyzed based on three-dimensional volume-rendering reconstruction images obtained from the catheter-based angiographies. Despite their variable clinical presentations (two hemorrhage, one ischemia, and one asymptomatic), all cases shared common angiographic findings as follows: (1)the internal carotid artery did not connect directly to the rete, (2)the anterior choroidal artery (AChA) was the artery constantly supplying the rete and (3)there was awatershed zone shift toward MCA territory. The perfusion MR cerebral blood flow map was symmetric in all studied cases. The AChA is an artery constantly supplying the rete, which suggests that the angioarchitectural features associated with this anomaly may be the result of both congenital and acquired compensatory processes. Cerebral perfusion remains preserved at the lesion side, despite angiographic evidence of watershed zone shift. These findings will be important for making better clinical judgments about this condition.

Endovascular Treatment of Vein of Galen Malformation in Kenya, East Africa

Vein of Galen aneurysmal malformations (VGAM) are arteriovenous fistulas between the choroidal or quadrigeminal arteries and the embryonic precursor of the vein of Galen – the median prosencephalic vein. VGAM represents 30% of arteriovenous malformations in the paediatric age group. They are associated with a high morbidity and 90% mortality if untreated but respond well to intervention with mortality reduced to below 40%. There are few documented cases of VGAM worldwide and scarce data about these lesions in sub-Saharan Africa with challenges in diagnosis and management. We present two cases of infants diagnosed with VGAM and treated with endovascular embolisation. We examine the clinical and radiological data at presentation, intervention and follow-up at one year. We report on some of the technical neurointerventional details. Both patients had satisfactory radiological results and the interventions resulted notable clinical improvements from baseline. Physicians should maintain a high index of suspicion treating infants and toddlers presenting with macrocephaly, neurocognitive decline and cardiopulmonary symptoms. Upon diagnosis endovascular interventions are feasible and available.

Predictors of Ischemic Complication in Anterior Choroidal Artery Aneurysm Repair

Treatment of anterior choroidal artery (AchoA) aneurysms is challenging because of the risk of artery injury. The objective of the study was to evaluate the incidence and predictors of AchoA infarction in patients who underwent surgical or endovascular procedure. We included 123 patients with AchoA aneurysms treated by surgical clipping (n=62; 50.4%) or endovascular coiling, including flow diverter placement (n=61; 49.6%). The clinical and radiological data were retrospectively analyzed. AchoA infarction was defined as the presence of a hyperintense signal on diffusion-weighted imaging in the area of AchoA, including the posterior limb of the internal capsule. AchoA infarction was detected in 8 cases (6.5%), with similar incidence in both groups (6.5% [4/62] vs. 6.6% [4/61]). It occurred in ruptured aneurysms more frequently than in unruptured aneurysms (14.3% [6/42] vs. 2.5% [2/81], P=0.019). In the surgical group, all 4 affected patients had a non-proximal type AchoA, whereas in the non-infarction group, 9 patients (15.5%) had a non-proximal type AchoA (P=0.001). In the endovascular group, the incidence was higher in patients with ruptured aneurysms (17.3% [4/23] vs. 0% [0/38], P=0.017) and lower in patients with pre-admission antiplatelet therapy (0% [0/39] vs. 18.8% [4/22], P=0.014). Repair of an AchoA aneurysm is associated with the risk of incurring post-procedural AchoA infarction. Surgical clipping and endovascular coiling have similar complication rates, but risk factors specific to each intervention exist. Careful surgical planning to avoid these risk factors in each therapeutic modality may improve patient outcomes.

Variations in the branching patterns of the anterior choroidal artery: an angiographic study with special reference to temporal lobe epilepsy surgery.

The preservation of the anterior choroidal artery (AChA) is essential for avoiding neurological sequelae after mesial temporal lobe epilepsy (mTLE) surgery. The purpose of this study is to reveal the anatomical variation in which the perforating branches arise from the plexal segment of the AChA by using a modern neuroimaging modality. This study analyzed 3D rotational angiography (3DRA) images from 56 subjects. The AChA and perforating branches were visualized using slab MIP. We analyzed branching patterns, courses of the perforating arteries arising from the plexal segment of the AChA, and the anastomosis of the AChA with other cerebral arteries. The slab MIP applied to 3DRA visualized one or more perforating branches from the AChA in 92.9% of cases. The presence of perforating branches arising from the AChA plexal segment was 17.3%. Most of the branching points of plexal perforators were likely located in the operative field during hippocampal resection. The course of the AChA plexal perforators included the posterior limb of the internal capsule. Anastomosis with other cerebral arteries was visualized in 25% of the AChA with plexal perforators. 3DRA slab MIP was useful for visualizing the perforating branches of the AChA. Our results showed the possibility that surgical manipulation of the choroid plexus may cause infarction in the AChA territory. We suggest that the existence of the AChA plexal perforators should be recognized to further enhance the safety of hippocampal resection for mTLE.

Monitoring the Patient with Retinal Angiopathy Associated with Hereditary Transthyretin Amyloidosis: Current Perspectives.

Retinal angiopathy associated with hereditary transthyretin amyloidosis (ATTRv), if untreated, may lead to irreversible vision loss. Our purpose was to systematically review the clinical and imaging features of retinal angiopathy associated with ATTRv and assemble a monitoring approach for these patients. All types of original research studies reporting clinical and imaging findings on retinal angiopathy associated with ATTRv were included. The most common clinical findings were tortuous retinal vessels, microaneurysms, retinal hemorrhages, sheathing of retinal vessels, whitish amyloid deposits along retinal arteries, obliteration of retinal vessels, vitreous hemorrhage, retinal and iris neovascularization. The most relevant imaging findings were hyperautofluorescence of perivessel amyloid deposits; delayed arterial filling, vascular leakage, and retinal ischemia on fluorescein angiography; late hypercyanescence along the choroidal arteries on indocyanine green angiography; perivascular hyperreflective material, needle-shaped deposits on the retinal surface and macular edema on optical coherence tomography (OCT) and attenuated retinal vascular network on OCT-angiography. ATTRv patients should be strictly followed to detect and treat retinal angiopathy, avoiding complications. Both panretinal photocoagulation and intravitreal anti-vascular endothelial growth factor have been used to treat retinal angiopathy in ATTRv. In an individual that presents with retinal angiopathy of unknown etiology, ATTRv should be considered as in the differential diagnosis, even out of the initial core countries. The prognostic value of subclinical findings, namely in OCT-A, is not yet established.

Vein of Galen aneurysmal malformation

The vein of Galen aneurysmal malformation (VGAM) is arare aneurysmatic cerebrovascular malformation in newborns and children. The VGAM results from an arteriovenous fistula between the persistent vein of Markowski (embryonic precursor of the vein of Galen) and deep choroidal arteries. The VGAM is the most common noncardiac cause of high-output cardiac failure in newborns. It may also cause hemorrhage, seizures, and liquor malabsorption resulting in hydrocephalus. Preferred treatment of VGAM is transarterial embolization (TAE) to reduce the arteriovenous shunt volume and allow normal brain development.

Histological reinterpretation of paraphysis cerebri in Ambystoma mexicanum

Intraventricular and extraventricular choroid plexuses are neuroepithelial folds which arise from the roof of the diencephalon. We describe the circumventricular structure of the diencephalon roof (paraphysis cerebri) during the various development stages of Ambystoma mexicanum. The parasagittal sections of the larvae epithalamus exhibit the presence, in addition to the epiphysis, of two dorsal primordia in nearby areas, which appear to be extraventricular saccular evaginations of different origin that give rise to two structures we define as the anterior extraventricular choroid plexus (AEP) and posterior extraventricular choroid plexus (PEP). During larvae development, the primordia arise perpendicular to each other, grow and show luminal folds and invaginations. Later, the two extraventricular evaginations, which are separate units, become interrelated. As the PEP grows, it covers the AEP dorsally, but it is difficult to define the borders of these organs. AEP is formed by alveolar-acinar epithelial aggregates with evidence of secretion-like content. PEP structure is like a choroid plexus, but its position is extraventricular and dorsal to the AEP. The PEP is always between the AEP and the meninges and can be small or large in size. This means that in A. mexicanum, the paraphysis cerebri is made up of two adjacent organs, which arise almost simultaneously from two different primordia (the AEP and the PEP) and as the posterior one grows, it overlaps the anterior one and masks itself. In conclusion, we suggest that AEP and PEP are homologous to paraphysis cerebri and the dorsal sac, respectively.