The human placenta as a model for training and research in mechanical thrombectomy: Clarifications and use of the chorionic plate veins.

Indications for mechanical thrombectomy in acute ischemic stroke are increasing, resulting in the continuous development of new devices and techniques. Therefore, there is a need for a realistic testing and training environment that offers the opportunity to practice different procedures and test the latest devices. Some authors have described the use of the human placenta as a model for neurointerventional surgery, with striking similarities to real-life conditions. This model has many advantages, including its relatively low cost and minimal infrastructure requirements, with fewer ethical concerns compared to animal models. So far, some preparation and set-up details were missing, and only arteries from the chorionic plate were used. This article provides the necessary clarifications and a mapping of the chorionic plate veins, so that the use of this model, which is particularly well suited for mechanical thrombectomy, can be as easy and wide as possible. A video explaining how to prepare the model is provided.

Is there a timing for sensitivity to acute cerebral ischemia in migraine patients?

BACKGROUND: Migraine may be a factor of increased cerebral sensitivity to ischemia. Previous studies were conducted within 6 to 72 after stroke onset. We aimed to determine if an accelerated infarct growth exists in migraine patients within the first 4.5 h. METHOD: A retrospective case-control study was conducted where all patients admitted for acute stroke started <4.5 h before and who underwent perfusion CT were assessed. The hypoperfusion and necrosis volumes on initial CT perfusion were analyzed, as well as the final infarct volume on MRI performed within 72 h after admission. A no-mismatch pattern was defined as a ratio necrosis/hypoperfusion volume > 83%. RESULTS: 24 patients with personal history of migraine were identified, 8 of them with aura. The control cohort included 51 patients. No difference was found between groups in terms of demographics, initial severity or outcome or presumed cause of stroke. Mean time to CT scan was 125 min in migraine patients and 127 min in the control group. A no-mismatch pattern was equally found in migraine patients and controls, even after adjustment for age, sex and presence of proximal occlusion (p = .22). The final infarct volume was also similar in both groups. CONCLUSIONS: Migraine patients did not display more no-mismatch pattern than controls within the 4.5 h of stroke onset. This deviates from previous studies and may be due to our earlier time from stroke onset to CT scan. A history of migraine may lead to malignant progression of ischemia but occurring only after several hours.

White matter tracts lesions and decline of verbal fluency after deep brain stimulation in Parkinson's disease.

Decline of verbal fluency (VF) performance is one of the most systematically reported neuropsychological adverse effects after subthalamic nucleus deep brain stimulation (STN-DBS). It has been suggested that this worsening of VF may be related to a microlesion due to the electrode trajectories. We describe the disruption of surrounding white matter tracts following electrode implantation in Parkinson's disease (PD) patients with STN-DBS and assess whether damage of fiber pathways is associated with VF impairment after surgery. We retrospectively analyzed 48 PD patients undergoing bilateral STN DBS. The lesion mask along the electrode trajectory transformed into the MNI 152 coordinate system, was compared with white matter tract atlas in Tractotron software, which provides a probability and proportion of fibers disconnection. Combining tract- and atlas-based analysis reveals that the trajectory of the electrodes intersected successively with the frontal aslant tract, anterior segment of arcuate tract, the long segment of arcuate tract, the inferior longitudinal fasciculus, the superior longitudinal fasciculus, the anterior thalamic radiation, and the fronto striatal tract. We found no association between the proportion fiber disconnection and the severity of VF impairment 6 months after surgery. Our findings demonstrated that microstructural injury associated with electrode trajectories involved white matter bundles implicated in VF networks.

Slc20a2, Encoding the Phosphate Transporter PiT2, Is an Important Genetic Determinant of Bone Quality and Strength.

Osteoporosis is characterized by low bone mineral density (BMD) and fragility fracture and affects over 200 million people worldwide. Bone quality describes the material properties that contribute to strength independently of BMD, and its quantitative analysis is a major priority in osteoporosis research. Tissue mineralization is a fundamental process requiring calcium and phosphate transporters. Here we identify impaired bone quality and strength in Slc20a2-/- mice lacking the phosphate transporter SLC20A2. Juveniles had abnormal endochondral and intramembranous ossification, decreased mineral accrual, and short stature. Adults exhibited only small reductions in bone mass and mineralization but a profound impairment of bone strength. Bone quality was severely impaired in Slc20a2-/- mice: yield load (-2.3 SD), maximum load (-1.7 SD), and stiffness (-2.7 SD) were all below values predicted from their bone mineral content as determined in a cohort of 320 wild-type controls. These studies identify Slc20a2 as a physiological regulator of tissue mineralization and highlight its critical role in the determination of bone quality and strength. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Imaging spectrum of Bing-Neel syndrome: how can a radiologist recognise this rare neurological complication of Waldenström's macroglobulinemia?

OBJECTIVES: Bing-Neel syndrome (BNS) is a rare neurological complication of Waldenström's macroglobulinemia. The aim of this study is to describe the spectrum of radiological manifestations of this syndrome and their prevalence in order to facilitate its early diagnosis. METHODS: Twenty-four patients with BNS were diagnosed between 1994 and 2016 in eight centres in France. We retrospectively examined the medical records of these patients as well as the corresponding literature, focusing on imaging studies. Recorded data were statistically analysed and radiological findings described. RESULTS: The mean age of our patients was 62.4 years (35-80 years). The vast majority of patients were men, with a male to female ratio of 9:1. Findings included parenchymal or meningeal involvement or both. The most common finding was leptomeningeal infiltration, either intracranial or spinal, with a prevalence reaching 70.8%. Dural involvement was present in 37.5% of patients. In 41.7% (10/24) of patients, there was parenchymal involvement with a higher prevalence of brain comparing to medullar involvement (33.3% and 23.1% respectively). High T2 signal of the parenchyma was identified in 41.7% of patients and high signal in diffusion was evident in 25% of them. Intraorbital or periorbital involvement was also detected in four cases. A proposition regarding the appropriate imaging protocol completed our study. CONCLUSION: BNS's diagnosis remains challenging. Central nervous system MRI findings in the setting of known or suspected Waldenström's macroglobulinemia appear to be highly suggestive of BNS and appropriate imaging protocols should be implemented for their depiction. KEY POINTS: • Diagnosis of Bing-Neel syndrome (BNS) remains challenging and recent expert recommendations include MRI in the diagnostic criteria for the syndrome. • The most common radiological manifestations of BNS are leptomeningeal/dural infiltration or parenchymal involvement of brain or spinal cord, but many atypical forms may exist with various presentations. • Appropriate imaging protocol for BNS should include enhanced MRI studies of both brain and spine.

Glioblastoma as differential diagnosis of autoimmune encephalitis.

OBJECTIVE: To identify the clinical and radiological features that should raise suspicion for the autoimmune encephalitis (AE)-like presentation of glioblastoma. METHODS: This is an observational, retrospective case series of patients referred to the French National Reference Center on Paraneoplastic Neurological Diseases for suspected AE (possible, probable or definite, using the 2016 criteria) who later received a final diagnosis of glioblastoma according to 2016 WHO criteria. An extensive literature search was also conducted for similar existing cases. RESULTS: Between 2014 and 2016, 306 patients were referred to our center for suspected AE. Six of these patients (2%) later developed pathologically confirmed glioblastoma. Thirteen patients (9 male) were included for analysis (6 from the present series and 7 from the literature); median age was 63. Initially, a diagnosis of AE was clinically suspected based on: working memory deficits (77%), seizures (62%) (including status epilepticus in 23%), and psychiatric symptoms (46%). Initial brain MRI was not in favor of a typical glioblastoma pattern and showed bilateral (54%) or unilateral selective limbic involvement. Five patients exhibited initial slight contrast enhancement. A clear inflammatory CSF was present in five patients and three from the literature showed autoantibody positivity (NMDAR, VGKC, GluRepsilon2). Median delay between suspicions of AE to GBM diagnosis was 3 months (range 1.5-24) and one patient from the literature was diagnosed post-mortem. CONCLUSIONS: An alternative diagnosis of glioblastoma should be considered in patients presenting initially as AE, especially in patients who do not fulfill the criteria for definite AE and in those with a poor clinical evolution despite initial improvement.

Predictive Factors of Headache Resolution After Chiari Type 1 Malformation Surgery.

BACKGROUND: Headache is the main and often isolated symptom of patients with Chiari type 1 malformation (CM1). Classically described as occipital and exacerbated by cough, headaches may be poorly characterized, making it difficult to establish CM1 as the underlying cause. Current guidelines for surgical posterior fossa decompression are undefined. The challenge is to distinguish headaches related to CM1 from headaches coincidentally coexisting with CM1. We aimed to determine predictive factors of headache resolution after surgery and applied to our cohort the Chiari Severity Index, a recently developed predictive prognostic score. METHODS: This retrospective study enrolled 49 patients with CM1 and preoperative headache. Standardized telephone interviews regarding headaches before and after surgery were conducted by the same neurologist; magnetic resonance imaging morphometric analyses were performed by an independent neuroradiologist. Headache resolution was defined as ≥50% reduction in frequency of headache days. RESULTS: Preoperative factors of headache resolution after multivariate analysis were attack duration <5 minutes (P = 0.001), triggering by Valsalva maneuvers (P = 0.003), severe intensity of attack (P = 0.05), occipital location (P = 0.05), and greater number of headache days per month (P = 0.04). These characteristics are part of International Headache Society diagnostic criteria for headache attributed to CM1. No radiologic predictive factor was demonstrated. Postoperative improvement was inversely correlated with Chiari Severity Index. CONCLUSIONS: This study confirms the relevance of International Headache Society criteria to identify headaches related to CM1. We propose their systematic use in a preoperative questionnaire.

Comparison of electromagnetic neuronavigation system and free-hand method for ventricular catheter placement in internal shunt.

OBJECTIVE: Optimal ventricular catheter positioning is able to reduce the risk of catheter dysfunction, and subsequently the risk of multiple revision surgery. The objective of our study was to compare the proportion of optimal ventricular catheter placements in a cohort of patients operated for ventriculoperitoneal (VP) shunt between a free-hand group and a neuronavigated group. PATIENTS AND METHODS: Twenty patients with hydrocephalus requiring VP shunt were prospectively included in this study. Patients were divided into two groups; the ventricular catheter was positioned using free-hand method (n=10) or magnetic navigation system (n=10). For the two groups, clinical baseline characteristics, etiology of hydrocephaly and initial ventricular size were assessed. The main judgment criterion was the proportion of optimal catheter placements defined by the presence of all catheter holes in the ventricle, evaluated on post-operative CT scan. RESULTS: There was no initial difference between the two groups in terms of hydrocephalus etiology or initial ventricular size. The number of optimal catheter placements was 6/10 in the neuronavigated group versus 1/10 in the free-hand group (p<0.05). There were no complications during post-operative period in either cohort. CONCLUSION: In patients suffering from hydrocephaly, the use of an electromagnetic neuronavigation system for ventricular catheter placement significantly improved the proportion of optimal catheter placements. Long-term follow-up is necessary to evaluate the number of revision surgeries and the cost in each group.

Leucoencephalopathy following abuse of sniffed heroin.

A 29-year-old man was admitted for acute cognitive impairment. Three weeks earlier, he had been admitted for coma due to sniffed heroin abuse responsive to naloxone infusion. At admission, the patient presented with apraxia, severe memory impairment and anosognosia. Brain MRI revealed symmetric hyperintensities of supratentorial white matter, sparing brainstem and cerebellum, on FLAIR and B1000 sequences. Four months later, repeated neuropsychological assessment revealed dramatic improvement of global cognitive functions. Toxic leucoencephalopathy excluding the cerebellum and brainstem is a rare complication of heroin abuse, and seems to concern especially patients that use heroin by sniff or injection. In these patients, cognitive troubles are predominant, prognosis seems better and infratentorial brain structures can be spared. In conclusion, our observation emphasizes that heroin-induced encephalopathy can have a favourable outcome and that imaging and clinical patterns can indicate the mode of drug administration.

Early verbal fluency decline after STN implantation: is it a cognitive microlesion effect?

BACKGROUNDS: Worsening of verbal fluency is reported after subthalamic nucleus deep brain stimulation in Parkinson's disease. It is postulated that these changes could reflect microlesion consecutive to the surgical procedure itself. METHODS: We evaluated verbal fluency, in 26 patients (mean age, 57.9±8.5 years; mean disease duration, 11.4±3.5 years) both before surgery (baseline) and, after surgery respectively the third day (T3), the tenth day (T10) just after STN implantation before turning on the stimulation and at six months (T180). RESULTS: Number of total words and switches was significantly reduced at T3 and T10, while average cluster size was unchanged. Repeated post-operative neuropsychological testing demonstrated reliable improvement from T3 to T180 on verbal fluency. CONCLUSION: This study provides evidence of transient verbal fluency decline consecutive to a microlesion effect. Further studies needed to determine a putative relationship between early and long-term verbal fluency impairment.

Inflammatory pseudotumor of the cerebellum in a patient with Crohn's disease.

BACKGROUND: Inflammatory pseudotumors are ubiquitous lesions characterized by a polymorphous inflammatory infiltrate containing plasma cells and lymphocytes. In the central nervous system, this pathological condition is rare and the association with Crohn's disease has never been described. CASE DESCRIPTION: A 31-year-old woman with a history of Crohn's disease was referred to our department for progressive headaches and nausea. Neurological examination was normal. Magnetic resonance imaging showed an irregular heterogeneous enhanced mass infiltrating the left cerebellar hemisphere. Total resection was performed and pathological examination led to the conclusion of an inflammatory pseudotumor. CONCLUSION: To our knowledge, this case is the first describing an intra-cerebral inflammatory pseudotumor associated with an inflammatory bowel disease. The diagnosis of an extradigestive location of Crohn's disease was excluded by pathological examination. Although the precise cause of this association remains unknown, it could be hypothesized that the intra-cranial lesion could be the result of the immunosuppressive therapy given for Crohn's disease, or, more likely, could be a part of a systemic dysimmune process.

Perfusion MR imaging and MR spectroscopy of gemistocytic astrocytoma.

This report is of a case of gemistocytic astrocytoma investigated by perfusion-weighted magnetic resonance (MR) imaging associated with proton MR spectroscopy. The conventional MR imaging presentation of gemistocytic astrocytoma is similar to that of HGG, metastasis or lymphoma. Nevertheless, a precise diagnosis is crucial as the prognosis and therapy of these diseases are different. Quantitative MR imaging sequences, which provide metabolic and vascular information, could be useful in the prevention of misdiagnosis.

Pain due to osteoarthritis may impair the early outcome of deep brain stimulation in Parkinson's disease.

OBJECTIVE: To analyse postoperative pain due to osteoarthritis in patients with Parkinson's disease submitted to bilateral subthalamic nucleus stimulation. METHODS: Fifty-three parkinsonian patients (mean age, 59.9 ± 8.3 years; mean disease duration, 11.5 ± 4.2 years) referred for subthalamic nucleus stimulation were enrolled. Patients were prospectively asked to refer and describe any pain due to osteoarthritis they experienced at any time during the preoperative period and within the 6 postoperative months. Pre-existing pain due to osteoarthritis, therapeutic changes, parkinsonian motor disability and weight gain were assessed as explanatory factors for occurrence pain due to osteoarthritis after surgery. RESULTS: After surgery, thirty patients (57%) complained of pain due to osteoarthritis whereas all demonstrated great functional improvement. Twenty (67%) among the 30 experienced similar pain sensation before surgery. Symptoms occurred rapidly, between 4 and 26 postoperative weeks. Multiple stepwise regression analysis showed that pre-existing pain due to osteoarthritis, 6-month postoperative UPDRS III motor score and axial sub-score improvements in the off-drug/on-stimulation condition were accurate independent predictors of pain due to osteoarthritis after surgery (F(8,41)=2.20, p<0.047). CONCLUSION: Our results highlight the high prevalence of pain due to osteoarthritis arising shortly after subthalamic implantation. An accurate pain and osteo-articular assessment should be performed preoperatively in parkinsonian candidates for subthalamic nucleus stimulation in order to limit occurrence of complications in the early postoperative period.

Alleviation of off-period dystonia in Parkinson disease by a microlesion following subthalamic implantation.

OBJECT: A collision/implantation or microlesion effect is commonly described after subthalamic nucleus (STN) implantation for high-frequency stimulation, and this is presumed to reflect disruption of cells and/or fibers. Off-period dystonia, a frequent cause of disability in patients with advanced Parkinson disease, can lead to the need for surgical treatment. The authors assessed the early effect of this microlesion on off-period dystonia. METHODS: The authors assessed 30 consecutive patients with the advanced levodopa-responsive form of Parkinson disease. The patients' symptoms were Hoehn and Yahr Scale score > or = 3, the mean duration of their disease was 11.4 +/- 3.5 years, and they had undergone bilateral implantation of electrodes within the STN for high-frequency stimulation between February 2004 and December 2006. The microlesion effect was defined by the clinical improvement (Unified Parkinson's Disease Rating Scale [UPDRS] Part III score, UPDRS Part IV, item 35) assessed the morning of the 3rd day following STN implantation, after at least a 12-hour withdrawal of dopaminergic treatment and before the programmable pulse generator was switched on (off-drug/off-stimulation mode). RESULTS: Compared with baseline (off state), the microlesion effect improved the motor score (UPDRS Part III) by 27%. Subscores for tremor, rigidity, and bradykinesia respectively improved by 42, 37, and 25%. Nineteen patients (63%) suffered from off-period dystonia before surgery. Twelve (41%) reported complete relief of their symptoms in the immediate postoperative period and remained free of painful off-period dystonia throughout the 6-month follow-up period. CONCLUSIONS: The author postulated that off-period dystonia alleviation may reflect both a microsubthalamotomy and micropallidotomy effect. They hypothesize, moreover, that the microlesion could play a role in the 6-month postoperative outcome.

Usefulness of multislice computerized tomographic angiography in the postoperative evaluation of patients with clipped aneurysms.

BACKGROUND: The aim of our study was to evaluate the diagnostic efficacy of multislice computed tomographic angiography (MSCTA) regarding exclusion quality after aneurysm clipping. METHODS: Sixty patients (74 aneurysms) underwent microsurgical exclusion using titanium clips. The presence of aneurysm remnants on MSCTA was compared by a neuroradiologist to 2D digital subtraction angiography (DSA), which was considered as a reference examination. The contribution of 3D DSA was assessed in a subpopulation of 29 patients (35 aneurysms). RESULTS: With 2D DSA, six aneurysm remnants (8%) were diagnosed, and only five (7%) by MSCTA. The specificity and sensitivity were 98.5 and 83%, respectively. MSCTA failed to demonstrate one large remnant (>2 mm) because of clip artifacts (six clips). With 3D DSA six supplementary remnants were diagnosed. Two were large remnants blinded by vessel overlaps and clip artifacts. Four were small "dog-eared" remnants (< or =2 mm). No additional treatment was required for small remnants. CONCLUSION: In the postoperative period, MSCTA was considered a useful tool to evaluate the large remnants as well as a non-invasive ulterior examination for suspected bifurcation. Nevertheless, 3D DSA is still required for an accurate evaluation of aneurysms treated by more than three clips.

Deep brain stimulation of the subthalamic nucleus in Parkinson's disease: usefulness of intraoperative radiological guidance. The Stereoplan.

BACKGROUND: In our stereotactic procedure, intraoperative radiological documentation of electrode localization is performed using the Stereoplan. The aim of the study was to evaluate its accuracy. PATIENTS AND METHODS: Data of 20 consecutive patients, treated for Parkinson's disease by implantation of deep brain stimulators into the subthalamic nucleus, were collected prospectively. During surgery, Stereoplan coordinates of the tip of the central macroelectrodes were compared with intended coordinates along the central trajectory at 4 levels: (1) 10 mm above the anatomical target, (2) in the target, (3) in the substantia nigra pars reticulata, and (4) at the depth of contact 1. Before the frame's removal, Stereoplan coordinates of the contacts of the definitive electrode were compared with postoperative MRI coordinates. The mean of the differences was calculated in the x-, y-, and z-axis. Clinical results at 6 months were recorded. RESULTS: The mean of the differences between Stereoplan coordinates and intended coordinates for the macroelectrodes was lower than 1 mm. A submillimeter difference was also found for the definitive contacts. At 6 months, the Unified Parkinson's Disease Rating Scale III score improved by 70.6% compared with the baseline score. Dyskinesia and motor fluctuations decreased by 85.7 and 87%, respectively (p < 0.0001). CONCLUSION: Stereoplan could be considered an accurate intraoperative radiological system which assures the correct position of the electrode in the anatomical target.

Foot, face and hand representation in the human supplementary motor area.

The ability to localize the limb representation in the supplementary motor area (SMA) would be useful in planning surgical ablation of medial frontal lobe tumours. We investigated the relationship between the anatomy of the SMA and the functional representation of fingers, toes, and lips using fMRI in healthy volunteers. There was a significant difference between the location of the different body parts in the SMA, with a rostro-caudal location of the face, hand and foot areas. Limb representation was located in an area spanning < 1 cm rostral and 1 cm caudal to the paracentral sulcus. These results support the somatotopic organization of the human SMA and suggest that the paracentral sulcus represents a landmark for body representation.

Treatment of anterior communicating artery aneurysms: complementary aspects of microsurgical and endovascular procedures.

OBJECT: Endovascular and surgical treatment must be clearly defined in the management of anterior communicating artery (ACoA) aneurysms. In this study the authors report their recent experience in using a combined surgical and endovascular team approach for ACoA aneurysms, and compare these results with those obtained during an earlier period in which surgical treatment was used alone. Morbidity and mortality rates, causes of unfavorable outcomes, and morphological results were also assessed. METHODS: The prospective study included 223 patients who were divided into three groups: Group A (83 microsurgically treated patients, 1990-1995); Group B (103 microsurgically treated patients, 1996-2000); and Group C (37 patients treated with Guglielmi Detachable Coil [GDC] embolization, 1996-2000). Depending on the direction in which the aneurysm fundus projected, the authors attempted to apply microsurgical treatment to Type 1 aneurysms (located in front of the axis formed by the pericallosal arteries). They proposed the most adapted procedure for Type 2 aneurysms (located behind the axis of the pericallosal arteries) after discussion with the neurovascular team, depending on the physiological status of the patient, the treatment risk, and the size of the aneurysm neck. In accordance with the classification of Hunt and Hess, the authors designated those patients with unruptured aneurysms (Grade 0) and some patients with ruptured aneurysms (Grades I-III) as having good preoperative grades. Patients with Grade IV or V hemorrhages were designated as having poor preoperative grades. By performing routine angiography and computerized tomography scanning, the causes of unfavorable outcome (Glasgow Outcome Scale [GOS] score < 5) and the morphological results (complete or incomplete occlusion) were analyzed. Overall, the clinical outcome was excellent (GOS Score 5) in 65% of patients, good (GOS Score 4) in 9.4%, fair (GOS Score 3) in 11.6%, poor (GOS Score 2) in 3.6%, and fatal in 10.3% (GOS Score 1). Among 166 patients in good preoperative grades, an excellent outcome was observed in 134 patients (80.7%). The combined permanent morbidity and mortality rate accounted for up to 19.3% of patients. The rates of permanent morbidity and death that were related to the initial subarachnoid hemorrhage were 6.2 and 1.5% for Group A, 6.6 and 1.3% for Group B, and 4 and 4% for Group C, respectively. The rates of permanent morbidity and death that were related to the procedure were 15.4 and 1.5% for Group A, 3.9 and 0% for Group B, and 8 and 8% for Group C, respectively. When microsurgical periods were compared, the rate of permanent morbidity or death related to microsurgical complications decreased significantly (Group A, 11 patients [16.9%] and Group B, three patients [3.9%]); Fisher exact test, p = 0.011) from the period of 1990 to 1995 to the period of 1996 to 2000. The combined rate of morbidity and mortality that was related to the endovascular procedure (16%) explained the nonsignificance of the different rates of procedural complications for the two periods, despite the significant decrease in the number of microsurgical complications. Among 57 patients in poor preoperative grade, an excellent outcome was observed in 11 patients (19.3%); however, permanent morbidity (GOS Scores 2-4) or death (GOS Score 1) occurred in 46 patients (80.7%). With regard to the correlation between vessel occlusion (the primary microsurgical complication) and the morphological characteristics of aneurysms, only the direction in which the fundus projected appeared significant as a risk factor for the microsurgically treated groups (Fisher exact test: Group A, p = 0.03; Group B, p = 0.002). The difference between endovascular and microsurgical procedures in the achievement of complete occlusion was considered significant (chi2 = 6.13, p = 0.01). CONCLUSIONS: The direction in which the fundus projects was chosen as the morphological criterion between endovascular and surgical methods. The authors propose that microsurgical clip application should be the preferred option in the treatment of ACoA aneurysms with anteriorly directed fundi and that endovascular packing be selected for those lesions with posteriorly directed fundi, depending on morphological criteria.