Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study.

BACKGROUND AND PURPOSE: Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes. MATERIALS AND METHODS: A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals. RESULTS: A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34). CONCLUSIONS: This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

The FRED for Cerebral Aneurysms of the Posterior Circulation: A Subgroup Analysis of the EuFRED Registry.

BACKGROUND AND PURPOSE: Flow diversion for the posterior circulation remains a promising treatment option for selected posterior circulation aneurysms. The Flow-Redirection Intraluminal Device (FRED) system has not been previously assessed in a large cohort of patients with posterior circulation aneurysms. The purpose of the present study was to assess safety and efficacy of FRED in this location. MATERIALS AND METHODS: Consecutive patients with posterior circulation aneurysms treated at 8 centers participating in the European FRED study (EuFRED) between April 2012 and January 2019 were retrospectively reviewed. Complication and radiographic and functional outcomes were evaluated. RESULTS: Eighty-four patients (median age, 54 years) with 84 posterior circulation aneurysms were treated with the FRED. A total of 25 aneurysms (29.8%) had previously ruptured, even though most aneurysms were diagnosed incidentally (45.2%). The intradural vertebral artery was the most common location (50%), and saccular, the most common morphology (40.5%). The median size was 7 mm. There were 8 (9.5%) symptomatic thromboembolic and no hemorrhagic complications. Thromboembolic complications occurred mostly (90.9%) in nonsaccular aneurysms. On last follow-up at a median of 24 months, 78.2% of aneurysms were completely occluded. Functional outcome at a median of 27 months was favorable in 94% of patients. All mortalities occurred in patients with acute subarachnoid hemorrhage and its sequelae. CONCLUSIONS: The largest cohort of posterior circulation aneurysms treated with the FRED to date demonstrated favorable safety and efficacy profiles of the device for this indication. Treatment in the setting of acute subarachnoid hemorrhage was strongly related to mortality, regardless of whether procedural complications occurred.

The diagnostic value of quantitative texture analysis of conventional MRI sequences using artificial neural networks in grading gliomas.

AIM: To explore the value of quantitative texture analysis of conventional magnetic resonance imaging (MRI) sequences using artificial neural networks (ANN) for the differentiation of high-grade gliomas (HGG) and low-grade gliomas (LGG). MATERIALS AND METHODS: A total of 181 patients, 97 with HGG (53.5%) and 84 with LGG (46.5%) with brain MRI having T2-weighted (W) fluid attenuation inversion recovery (FLAIR), and contrast-enhanced T1W images were enrolled in the present study. Histogram parameters and high-order texture features were extracted using manually placed regions of interest (ROIs) on T2W-FLAIR and contrast-enhanced T1W images covering the whole volume of the tumours. The reproducibility of the features was assessed by interobserver reliability analyses. The cohort was divided into training (n=121) and test partitions (n=60). The training set was used for attribute selection and model development, and the test set was used to evaluate the diagnostic performance of the pre-trained ANNs in discriminating HGG and LGG. RESULTS: In the test cohort, the ANN models using texture data of T2W-FLAIR and contrast-enhanced T1W images achieved an area under the receiver operating characteristic curve (AUC) of 0.87 and 0.86, respectively. The combined ANN model with selected texture features achieved the highest diagnostic accuracy equating 88.3% with an AUC of 0.92. CONCLUSIONS: Quantitative texture analysis of T2W-FLAIR and contrast-enhanced T1W enhanced by ANN can accurately discriminate HGG from LGG and might be of clinical value in tailoring the management strategies in patients with gliomas.

Intracranial Serpentine Aneurysms: Spontaneous Changes of Angiographic Filling Pattern.

BACKGROUND AND PURPOSE: Serpentine aneurysms are partially thrombosed aneurysms with an eccentrically located tortuous intra-aneurysmal vascular channel. The large size, distinctive neck anatomy, and supply of the brain parenchyma by the outflow tract pose technical challenges in treatment. The aim of this study was to discuss the endovascular treatment results and illustrate the dynamic nature of serpentine aneurysms. Spontaneous transformation of saccular and fusiform aneurysms into serpentine morphology, along with a case of serpentine-into-fusiform aneurysm transformation during follow-up, is presented. MATERIALS AND METHODS: A retrospective analysis from 3 institutions revealed 15 patients with serpentine aneurysms who underwent diagnostic evaluation and endovascular treatment. Nine of the 15 patients underwent endovascular occlusion of the parent vessel with detachable balloon or coils. Six of the 15 patients underwent aneurysm and parent artery occlusion with coiling. RESULTS: In 11 patients, improvement or resolution of symptoms was achieved by an endovascular approach without any treatment-related morbidity. Morbidity related to treatment in the immediate postoperative period was seen in 3 patients, with resolution of the deficits at long-term follow-up in 2 patients and persistence of a mild deficit in 1 patient. Endovascular treatment failed to achieve resolution of symptoms in a case with a basilar tip aneurysm treated by aneurysm coiling. CONCLUSIONS: Serpentine aneurysms are dynamic structures with spontaneous transformation possible from a saccular or fusiform shape into a serpentine configuration. An endovascular approach by parent vessel occlusion or intra-aneurysmal occlusion is a successful treatment technique for serpentine aneurysms.

European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system. MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated. RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13-86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1-36.6 mm), and the median neck size 4.5 mm (range, 1-30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%. CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.

Multicenter Experience with FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms in Small Arteries.

BACKGROUND AND PURPOSE: Flow diverters are emerging as an endovascular treatment alternative for proximally located intracranial aneurysms. However, treatment of aneurysms at and beyond the circle of Willis is not well-established. We assessed the clinical safety and efficacy of the Flow Re-Direction Endoluminal Device Jr (FRED Jr) dedicated to small-vessel diameters between 2.0 and 3.0 mm. MATERIALS AND METHODS: This was a multicenter observational clinical study of 42 patients with 47 aneurysms treated by a flow-direction technique with the FRED Jr. The primary end point for clinical safety was the absence of death, major or minor stroke, and TIA. The primary end point for treatment efficacy was complete and near-complete occlusion according to the O'Kelly-Marotta grading scale at follow-up after 1, 6, and 12 months. RESULTS: The FRED Jr deployment was technically successful in all cases. In 39/42 (93%) patients, the primary safety end point was reached; in the 3 remaining patients, 1 disabling ischemic stroke, 1 minor stroke with complete recovery at discharge, and 1 TIA were observed. Two asymptomatic, completely reversible side-branch occlusions occurred. Angiographic (DSA or flat panel CT) and clinical follow-up were available after 1 month in 41/47 (87%), 6 months in 27/47 (57%), and 12 months in 11/47 (23%) aneurysms. The primary efficacy end point was reached at 1 month in 27/41 (66%), at 6 months in 21/27 (78%), and at 12 months in 11/11 (100%) aneurysms. CONCLUSIONS: Deployment of the FRED Jr is safe and effective in the treatment of intracranial aneurysms located in small vessels.

Intrathecal gadolinium-enhanced MR cisternography in the evaluation of CSF leakage.

BACKGROUND AND PURPOSE: Radiologic identification of the location of the CSF leakage is important for proper surgical planning and increases the chance of dural repair. This article describes our experience in analyzing clinically suspected cranial CSF fistulas by using MR imaging combined with the intrathecal administration of a gadolinium-based contrast agent. MATERIALS AND METHODS: A total of 85 consecutive patients with suspected CSF fistulas who presented with persistent or intermittent rhinorrhea or otorrhea lasting for more than 1 month between 2003 and 2007 were included in this study. RESULTS: We observed objective CSF leakage in 64 of 85 patients (75%). The CSF leak was located in the ethmoidal region in 37 patients (58%), in the superior wall of the sphenoid sinus in 8 patients (13%), in the posterior wall of the frontal sinus in 10 patients (15%), in the superior wall of the mastoid air cells in 6 patients (9%), and from the skull base into the infratemporal fossa in 1 patient (2%). Two patients (3%) showed leakage into >1 paranasal sinus. CONCLUSIONS: MR cisternography after the intrathecal administration of gadopentate dimeglumine represents an effective and minimally invasive method for evaluating suspected CSF fistulas along the skull base. It provides multiplanar capabilities without risk of radiation exposure and is an excellent approach to depict the anatomy of CSF spaces and CSF fistulas.

A cerebellar demyelinating lesion following treatment of acne with isotretinoin.

We report the case of a demyelinating lesion located in the left cerebellar region that developed 3 months after the onset of oral isotretinoin treatment. In April 2001, 1 year before admission, the patient underwent cranial magnetic resonance imaging (MRI) because of endocrinological problems. This was found to be completely normal. In January 2002, oral isotretinoin treatment was started to treat severe acne. Three months after the onset of therapy, the patient reported lack of appetite, faintness and tinnitus. Her second cranial MRI scan showed a cerebellar lesion, and oral isotretinoin treatment was stopped (April 2002). One month after the cessation of oral isotretinoin treatment, the lesion became less prominent on the MRI scan, and after 3 months, it had disappeared. Although it is difficult to determine the causal association between the demyelinating cerebellar lesion and isotretinoin treatment, we would like to alert physicians to this possibility, because of the common usage of this drug in daily practice.

Gadolinium-enhanced MR cisternography to evaluate dural leaks in intracranial hypotension syndrome.

BACKGROUND AND PURPOSE: We evaluated the use of MR cisternography after intrathecal administration of gadopentetate dimeglumine to detect the presence and localization of CSF leaks in 19 patients diagnosed with spontaneous intracranial hypotension syndrome according to the criteria of International Headache Society. MATERIALS AND METHODS: Lumbar puncture with an injection of 0.5 mL of gadopentetate dimeglumine into the subarachnoid space in the lumbar area was performed. MR images of the cervical, thoracic, and lumbar regions in axial, coronal, and sagittal planes with fat-saturated T1-weighted images were acquired. RESULTS: We observed objective CSF leakage in 17 (89%) of 19 patients. In 14 of these 17 patients, the site of dural tear was demonstrated accurately. In 3 of these 17 patients, the contrast leakage was diffuse, and site of the leak could not be located accurately. No leakage was observed in 2 patients. No complications were detected in any of the patients during the first 24 hours after the procedure or during the 6- to 12-month follow-up. CONCLUSION: The current results demonstrate the relative safety, accuracy, and feasibility of intrathecal gadolinium-enhanced MR cisternography to evaluate dural leaks.

Persistent hypoglossal artery associated with a ruptured ipsilateral posterior inferior cerebellar artery aneurysm. A case report.

A rare case of persistent hypoglossal artery in conjuction with a ruptured aneurysm at the left proximal posterior inferior cerebellar artery (PICA) is presented. A ruptured PICA aneurysm was successfully treated by endovascular occlusion of the aneurym with coiling.

Reversible reduction of apparent diffusion coefficient values in bilateral internal capsules in transient hypoglycemia-induced hemiparesis.

A woman aged 68 years who experienced recurrent right hemiparesis caused by hypoglycemia was admitted to our hospital. When she was experiencing a low level of glucose, diffusion-weighted MR imaging showed the presence of hyperintensity lesions in the bilateral internal capsule. Diffusion-weighted MR imaging has been infrequently performed in patients with hypoglycemia. We report the reversible hyperintensity lesions on diffusion-weighted MR imaging in a hypoglycemic period in a patient with reversible hemiparesis. A reduction of apparent diffusion coefficient in a hypoglycemic period was clearly shown.

Progressive white-matter disease with primary cerebellar involvement: a separate entity?

Abstract. Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity.

Behçet's disease: diagnostic and prognostic aspects of neurological involvement.

This study was conducted to describe clinical and prognostic aspects of neurological involvement in Behçet's disease (BD). Patients referred for neurological evaluation fulfilled the criteria of the International Study Group for Behçet's Disease. We analyzed disability and survival by the Kaplan-Meier method, using Kurtzke's Extended Disability Status Scale (modified for BD) and the prognostic effect of demographic and clinical factors by Cox regression analysis. We studied 164 patients; of the 107 diagnostic neuroimaging studies: 72.1% showed parenchymal involvement, 11.7% venous sinus thrombosis (VST) and the others were normal. CSF studies were performed in 47 patients; all with inflammatory CSF findings (n = 18) had parenchymal involvement. An isolated increase in pressure was compatible with either VST or normal imaging. The final diagnoses were VST (12.2%), neuro-Behçet syndrome (NBS) (75.6%), isolated optic neuritis (0.6%), psycho-Behçet syndrome (0.6%), and indefinite (11%). VST and NBS were never diagnosed together. Ten years from onset of BD 45.1% (all NBS) reached a disability level of EDSS 6 or higher, and 95.7 +/- 2.1% of the patients were still alive. Having accompanying cerebellar symptoms at onset or a progressive course is unfavorable. Onset with headache or a diagnosis of VST is favorable. Two major neurological diagnoses in BD are NBS and VST. These are distinct in clinical, radiological, and prognostic aspects, hence suggesting a difference in pathogenesis.

Rotational compression of the vertebral artery at the point of dural penetration. Case report.

Vertebrobasilar insufficiency (VBI) due to vertebral artery (VA) compression occurs in a significant number of patients. Rotational compression of the VA usually occurs below C-2, where the artery is pinched during head rotation, leading to thrombus formation and subsequent cerebellar infarction. Although this problem has been reported to occur at the atlantooccipital levels, a review of the literature revealed no published cases of VA compression at the point of dural penetration, which is located above the atlantooccipital membrane. The authors report the case of a 30-year-old woman who presented with signs and symptoms of VBI. Dynamic angiography demonstrated left-sided VA compression at the site at which dural penetration had occurred, proximal to the posterior inferior cerebellar artery. Surgical decompression of the left VA at the point of dural penetration relieved the symptoms, and postoperative dynamic angiography demonstrated complete resolution of the positional compression of the left VA. Because of these findings, an additional possible location for rotational compression of the VA is described, namely, the point of dural penetration. The authors suggest a method of surgically treating rotational VA compression at this site.

Spontaneously regressing infundibular cyst: a case report.

A 74-year-old man reported headaches and blurring of vision for 1 month. MRI showed a nonenhancing infundibular cyst. Neurologic findings, blood and cerebrospinal fluid examinations, and chest and abdominal CT were all normal. MRI 4 months later showed no change. The patient was without any medication other than simple analgesics. One year later, the stalk had returned to its normal size and configuration on MRI.

Spontaneous regression of a cyst of the cavum septi pellucidi.

A 20-year-old woman with secondary amenorrhoea and an empty sella turcica was found to have a cyst of the cavum septi pellucidi (CSP) on MRI. The cyst had regressed spontaneously on follow-up MRI.

Endovascular coil embolization of residual or recurrent aneurysms after surgical clipping.

PURPOSE: Treatment of residual or recurrent aneurysms after surgical clipping is a challenge and most surgeons prefer to avoid a second surgical attempt. We present treatment of 4 residual or recurrent aneurysms after surgical clipping with electrolytically detachable coils. MATERIAL AND METHODS: In 3 of 4 patients, recurrent aneurysms were diagnosed with angiography 2 months, 5 years and 14 years after surgery, although the domes of the aneurysms were opened following clipping during the surgery. In the 4th patient, an early postoperative angiogram revealed filling of a residual aneurysm secondary to the incomplete neck clipping. Guglielmi detachable coils were used to occlude the residual or recurrent aneurysm. RESULTS: The endovascular approach was successful in all patients and the control angiograms showed complete obliteration of the aneurysms with no recanalization. CONCLUSION: The endovascular approach is a good treatment option for patients in whom complete obliteration of the aneurysm cannot be achieved by surgical clipping. Opening of the aneurysm sac after clipping does not necessarily preclude aneurysm regrowth from a neck remnant proximal to the clip.

Neuroimaging findings of four patients with Sandhoff disease.

Sandhoff disease is a severe form of GM2 gangliosidosis that is caused by the deficiency of both hexosaminidase A and B. Startle reaction, hypotonia, psychomotor retardation, and blindness are the main clinical features. Presented are computed tomography and magnetic resonance imaging findings of four patients with Sandhoff disease diagnosed by enzymatic analyses. Bilateral homogeneous thalamic hyperdensity was evident on computed tomography. Magnetic resonance imaging scans revealed mild cortical atrophy, a thin corpus callosum, and abnormal signal intensities in the caudate nucleus, globus pallidum, putamen, cerebellum, and brainstem. No correlation was evident between the severity of the central nervous system imaging findings and the clinical pictures. In this article the neuroimaging findings of four patients with Sandhoff disease are discussed.