Supracerebellar Transtentorial Approach for Occipital Meningioma to Maximize Visual Preservation: Technical Note

2018 ◽  
Vol 17 (4) ◽  
pp. E177-E183 ◽  
Author(s):  
Danielle Golub ◽  
Neal D Mehan ◽  
Kevin Kwan ◽  
Sussan J Salas ◽  
Michael Schulder
Keyword(s):  
Visual Cortex ◽  
Visual Function ◽  
Vision Loss ◽  
Significant Risk ◽  
Occipital Lobe ◽  
Technical Note ◽  
Right Visual Field ◽  
Who Grade ◽  
Simpson Grade ◽  
Tentorial Meningioma

Abstract BACKGROUND AND IMPORTANCE Surgery for resection of tentorial meningiomas compressing primary visual cortex carries a significant risk of worsening vision. This concern is especially acute in patients with a preexisting visual deficit. Approaches that involve mechanical retraction of the occipital lobe further threaten visual function. The supracerebellar transtentorial (SCTT) approach, which does not carry a risk of occipital retraction injury, should be considered for patients with occipital tentorial meningiomas to maximize functional visual outcomes. CLINICAL PRESENTATION A 54-yr-old woman underwent 2 resections and radiation therapy for a right occipital oligodendroglioma as a teenager. She was left with a complete left homonymous hemianopsia. The patient now presented with progressive vision loss in her remaining right visual field. Imaging revealed a left occipital superiorly projecting tentorial meningioma. To preserve her remaining visual function the SCTT approach was chosen for resection. A Simpson grade 1 removal was achieved without disrupting the occipital lobe pia or requiring mechanical cerebellar retraction. A diagnosis of a WHO grade II meningioma (presumably radiation induced) was made. The patient's vision returned to premorbid baseline 1 wk after surgery. CONCLUSION The SCTT approach should be considered for the surgical management of patients with occipital tentorial meningiomas when visual preservation is at risk. This approach avoids transgression of visual cortex and minimizes the risk of venous infarction or contusions from retraction injury.

scholarly journals Role of Extradural Clinoidectomy and Optic Unroofing in Resection of an Anterior Clinoidal Meningioma with Encasement of the Internal Carotid Artery and Its Branches

2021 ◽  
Author(s):  
Sima Sayyahmelli ◽  
Zhaoliang Sun ◽  
Emel Avci ◽  
Mustafa K. Başkaya
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Skull Base ◽  
Vision Loss ◽  
Internal Carotid ◽  
Extent Of Resection ◽  
World Health ◽  
Who Grade ◽  
The Right ◽  
Supraclinoid Internal Carotid Artery

AbstractAnterior clinoidal meningiomas (ACMs) remain a major neurosurgical challenge. The skull base techniques, including extradural clinoidectomy and optic unroofing performed at the early stage of surgery, provide advantages for improving the extent of resection, and thereby enhancing overall outcome, and particularly visual function. Additionally, when the anterior clinoidal meningiomas encase neurovascular structures, particularly the supraclinoid internal carotid artery and its branches, this further increases morbidity and decreases the extent of resection. Although it might be possible to remove the tumor from the artery wall despite complete encasement or narrowing, the decision of whether the tumor can be safely separated from the arterial wall ultimately must be made intraoperatively.The patient is a 75-year-old woman with right-sided progressive vision loss. In the neurological examination, she only had light perception in the right eye without any visual acuity or peripheral loss in the left eye. MRI showed a homogeneously enhancing right-sided anterior clinoidal mass with encasing and narrowing of the supraclinoid internal carotid artery (ICA). Computed tomography (CT) angiography showed a mild narrowing of the right supraclinoid ICA with associated a 360-degree encasement. The decision was made to proceed using a pterional approach with extradural anterior clinoidectomy and optic unroofing. The surgery and postoperative course were uneventful. MRI confirmed gross total resection (Figs. 1 and 2). The histopathology was a meningothelial meningioma, World Health Organization (WHO) grade I. The patient continues to do well without any recurrence and has shown improved vision at 15-month follow-up.This video demonstrates important steps of the microsurgical skull base techniques for resection of these challenging tumors.The link to the video can be found at https://youtu.be/vt3o1c2o8Z0

scholarly journals Visual Cortex Transcranial Direct Current Stimulation for Proliferative Diabetic Retinopathy Patients: A Double-Blinded Randomized Exploratory Trial

2021 ◽  
Vol 11 (2) ◽  
pp. 270
Author(s):  
Angelito Braulio F. de Venecia ◽  
Shane M. Fresnoza
Keyword(s):  
Diabetic Retinopathy ◽  
Visual Cortex ◽  
Proliferative Diabetic Retinopathy ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Vision Loss ◽  
Sham Stimulation ◽  
Direct Current Stimulation ◽  
Residual Vision ◽  
Cathodal Tdcs

Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes. PDR-related retinal hemorrhages often lead to severe vision loss. The main goals of management are to prevent visual impairment progression and improve residual vision. We explored the potential of transcranial direct current stimulation (tDCS) to enhance residual vision. tDCS applied to the primary visual cortex (V1) may improve visual input processing from PDR patients’ retinas. Eleven PDR patients received cathodal tDCS stimulation of V1 (1 mA for 10 min), and another eleven patients received sham stimulation (1 mA for 30 s). Visual acuity (logarithm of the minimum angle of resolution (LogMAR) scores) and number acuity (reaction times (RTs) and accuracy rates (ARs)) were measured before and immediately after stimulation. The LogMAR scores and the RTs of patients who received cathodal tDCS decreased significantly after stimulation. Cathodal tDCS has no significant effect on ARs. There were no significant changes in the LogMAR scores, RTs, and ARs of PDR patients who received sham stimulation. The results are compatible with our proposal that neuronal noise aggravates impaired visual function in PDR. The therapeutic effect indicates the potential of tDCS as a safe and effective vision rehabilitation tool for PDR patients.

scholarly journals Neurosurgical experience of managing optic pathway gliomas

2021 ◽  
Author(s):  
Ciaran Scott Hill ◽  
Mehdi Khan ◽  
Kim Phipps ◽  
Katherine Green ◽  
Darren Hargrave ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Surgical Resection ◽  
Visual Function ◽  
Optic Pathway ◽  
Who Grade ◽  
Radiographic Findings ◽  
Surgical Interventions ◽  
Hypothalamic Dysfunction ◽  
Cerebrospinal Fluid Diversion ◽  
Optic Pathway Gliomas

Abstract Background Optic pathway gliomas (OPGs), also known as visual pathway gliomas, are debilitating tumors that account for 3–5% of all pediatric brain tumors. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of these tumors results in visual loss and blindness, endocrine and hypothalamic dysfunction, hydrocephalus, and premature death. Their involvement of the visual pathways and proximity to other eloquent brain structures typically precludes complete resection or optimal radiation dosing without incurring significant neurological injury. There are various surgical interventions that can be performed in relation to these lesions including biopsy, cerebrospinal fluid diversion, and partial or radical resection, but their role is a source of debate. This study catalogues our surgical experience and patient outcomes in order to support decision-making in this challenging pathology. Methods A retrospective review of all cases of OPGs treated in a single center from July 1990 to July 2020. Data was collected on patient demographics, radiographic findings, pathology, and management including surgical interventions. Outcome data included survival, visual function, endocrine, and hypothalamic dysfunction. Results One hundred twenty-one patients with OPG were identified, and 50 of these patients underwent a total of 104 surgical procedures. These included biopsy (31), subtotal or gross total resection (20 operations in 17 patients), cyst drainage (17), Ommaya reservoir insertion (9), or cerebrospinal fluid diversion (27). During the study period, there was 6% overall mortality, 18% hypothalamic dysfunction, 20% endocrine dysfunction, and 42% had some cognitive dysfunction. At diagnosis 75% of patients had good or moderate visual function in at least one eye, and overall, this improved to 83% at the end of the study period. In comparison the worst eye had good or moderate visual function in 56%, and this reduced to 53%. Baseline and final visual function were poorer in patients who had a surgical resection, but improvements in vision were still found—particularly in the best eye. Discussion/conclusion OPG are debilitating childhood tumor that have lifelong consequences in terms of visual function and endocrinopathies/hypothalamic dysfunction; this can result in substantial patient morbidity. Decisions regarding management and the role of surgery in this condition are challenging and include cerebrospinal fluid diversion, biopsy, and in highly select cases cystic decompression or surgical resection. In this paper, we review our own experience, outcomes, and surgical philosophy.

A radiopathological classification of dural tail sign of meningiomas

2012 ◽  
Vol 117 (4) ◽  
pp. 645-653 ◽  
Author(s):  
Song-tao Qi ◽  
Yi Liu ◽  
Jun Pan ◽  
Silky Chotai ◽  
Lu-xiong Fang
Keyword(s):  
Tumor Cells ◽  
Histopathological Examination ◽  
Who Grade ◽  
Simpson Grade ◽  
Mri Studies ◽  
Dural Tail Sign ◽  
Significant Difference ◽  
Different Types ◽  
Dural Tail

Object The completeness of meningioma resection depends on the resection of dura mater invaded by the tumor. The pathological changes of the dura around the tumor can be interpreted by evaluating the dural tail sign (DTS) on MRI studies. The goal of this study was to clarify the pathological characteristics of the DTSs, propose a classification based on the histopathological and radiological correlation, and identify the invasive range of tumor cells in different types of DTS. Methods The authors retrospectively reviewed 179 patients with convexity meningiomas who underwent Simpson Grade I resection. All patients underwent an enhanced MRI examination preoperatively. The convexity meningiomas were dichotomized into various subtypes in accordance with the 2007 WHO classification of tumors of the CNS, and the DTS was identified based on the Goldsher criteria. The range of resection of the involved dura was 3 cm from the base of the tumor, which corresponded with the length of DTS on MRI studies. Histopathological examination of dura at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm from the base of the tumor was conducted, and the findings were correlated with the preoperative MRI appearance of the DTS. Results A total of 154 (86%) of 179 convexity meningiomas were classified into WHO Grade I subtype, including transitional (44 [28.6%] of 154), meningothelial (36 [23.4%] of 154), fibrous (23 [14.9%] of 154), psammomatous (22 [14.3%] of 154), secretory (10 [6.5%] of 154), and angiomatous (19 [12.3%] of 154). The other 25 (14%) were non–Grade I (WHO) tumors, including atypical (12 [48%] of 25), anaplastic (5 [20%] of 25), and papillary (8 [32%] of 25). The DTS was classified into 5 types: smooth (16 [8.9%] of 179), nodular (36 [20.1%] of 179), mixed (57 [31.8%] of 179), symmetrical multipolar (15 [8.4%] of 179), and asymmetrical multipolar (55 [30.7%] of 179). There was a significant difference in distribution of DTS type between Grade I and non–Grade I tumors (p = 0.004), whereas the difference was not significant among Grade I tumors (0.841) or among non–Grade I tumors (p = 0.818). All smooth-type DTSs were encountered in Grade I tumors, and the mixed DTS (52 [33.8%] of 154) was the most common type in these tumors. Nodular-type DTS was more commonly seen in non–Grade I tumors (12 [48%] of 25). Tumor invasion was found in 88.3% (158 of 179) of convexity meningiomas, of which the range of invasion in 82.3% (130 of 158) was within 2 cm and that in 94.9% (150 of 158) was within 2.5 cm. The incidence of invasion and the range invaded by tumor cells varied in different types of DTS, and differences were statistically significant (p < 0.001). Conclusions Nodular-type DTS on MRI studies might be associated with non–Grade I tumors. The range of dural resection for convexity meningiomas should be 2.5 cm from the tumor base, and if this extent of resection is not feasible, the type of DTS should be considered. However, for skull base meningiomas, in which mostly Simpson Grade II resection is achieved, the use of this classification should be further validated. The classification of DTS enables the surgeon to predict preoperatively and then to achieve the optimal range of dural resection that might significantly reduce the recurrence rate of meningiomas.

Man, Monkey, and Blindsight

1998 ◽  
Vol 4 (4) ◽  
pp. 227-230 ◽  
Author(s):  
Tirin Moore ◽  
Hillary R. Rodman ◽  
Charles G. Gross
Keyword(s):  
Visual Cortex ◽  
Visual System ◽  
Primary Visual Cortex ◽  
Visual Function ◽  
Forced Choice ◽  
Neural Mechanisms ◽  
Residual Vision ◽  
Choice Testing

The visual function that survives damage to the primary visual cortex (V1) in humans is often unaccompanied by awareness. This type of residual vision, called “blindsight,” has raised considerable interest because it implies a separation of conscious from unconscious vision mechanisms. The monkey visual system has proven to be a useful model in elucidating the possible neural mechanisms of residual vision and blindsight in humans. Clear similarities, however, between the phenomenology of human and monkey residual vision have only recently become evident. This article summarizes parallels between residual vision in monkeys and humans with damage to V1. These parallels Include the tendency of the remaining vision to require forced-choice testing and the fact that more robust residual vision remains when V1 damage is sustained early in life. NEUROSCIENTIST 4:227–230

scholarly journals Combined supra/infratentorial approach to tentorial meningiomas

2005 ◽  
Vol 63 (1) ◽  
pp. 50-54 ◽  
Author(s):  
Igor de Castro ◽  
Daniel de Holanda Christoph ◽  
José Alberto Landeiro
Keyword(s):  
Surgical Treatment ◽  
Surgical Technique ◽  
Occipital Lobe ◽  
Transverse Sinus ◽  
Surgical Removal ◽  
Tentorial Meningioma ◽  
Operative Evaluation ◽  
Unique Approach ◽  
Microsurgical Techniques ◽  
Brain Retraction

In spite of significant advancements in imaging technology, monitoring, and microsurgical techniques, complete and safe removal of tentorial meningiomas remains a challenge for most neurosurgeons. Classifications of tentorial meningiomas are revised. The combined supra/infratentorial approach to resects tentorial meningioma is discussed. This approach provides a wider exposure of the supra/infratentorial region with less brain retraction. With this approach the occipital lobe and the cerebellum are exposed along the tentorium. Two illustrative cases are presented. The patients were studied with computerized tomography, magnetic resonance and angiography. The anatomy of the transverse sinus and the confluence of the sinus could be appreciated with these studies. The operative technique is described stepwise. Emphasis is placed on pre-operative evaluation and surgical technique, leading to a total surgical removal of the lesion with margins of safety. The goal of surgical treatment of tentorial meningiomas is their complete and safe removal. With this unique approach we sought to confirm that it offers a safe means of resection not only the neoplasm but also the infiltrated dura.

Interocular torsional disparity and visual cortical development in the cat

1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ocular Dominance ◽  
Visual Fields ◽  
Receptive Fields ◽  
Right Visual Field ◽  
Orientation Columns ◽  
Areas 17 And 18 ◽  
The Right ◽  
Visual Cortical

1. The present experiments were designed to assess the effects of relatively large optically induced interocular torsional disparities on the developing kitten visual cortex. Kittens were reared with restricted visual experience. Three groups viewed a normal visual environment through goggles fitted with small prisms that introduced torsional disparities between the left and right eyes' visual fields, equal but opposite in the two eyes. Kittens in the +32 degrees goggle rearing condition experienced a 16 degrees counterclockwise rotation of the left visual field and a 16 degrees clockwise rotation of the right visual field; in the -32 degrees goggle condition the rotations were clockwise in the left eye and counterclockwise in the right. In the control (0 degree) goggle condition, the prisms did not rotate the visual fields. Three additional groups viewed high-contrast square-wave gratings through Polaroid filters arranged to provide a constant 32 degrees of interocular orientation disparity. 2. Recordings were made from neurons in visual cortex around the border of areas 17 and 18 in all kittens. Development of cortical ocular dominance columns was severely disrupted in all the experimental (rotated) rearing conditions. Most cells were classified in the extreme ocular dominance categories 1, 2, 6, and 7. Development of the system of orientation columns was also affected: among the relatively few cells with oriented receptive fields in both eyes, the distributions of interocular disparities in preferred stimulus orientation were centered near 0 degree but showed significantly larger variances than in the control condition.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Transient and localized optogenetic activation of somatostatin-interneurons in mouse visual cortex abolishes long-term cortical plasticity due to vision loss

2018 ◽  
Vol 223 (5) ◽  
pp. 2073-2095 ◽  
Author(s):  
Isabelle Scheyltjens ◽  
Samme Vreysen ◽  
Chris Van den Haute ◽  
Victor Sabanov ◽  
Detlef Balschun ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Vision Loss ◽  
Cortical Plasticity ◽  
Mouse Visual Cortex
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