Optic radiations: a microsurgical anatomical study

Peltier, Johann; Travers, Nadine; Destrieux, Christophe; Velut, Stéphane

doi:10.3171/jns.2006.105.2.294

Cited by 84 publications

(78 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…27 The evidence derived from our fiber microdissection that a temporal loop exists is consistent with the observations of previous studies applying this technique. [2][3][4]6,10,22,24,[28][29][30]34,44,46,47 Contrary to the assertions in these previous studies, we could not distinguish in this temporal loop between the various projection fibers that emerge from the IC-SL and compose the temporal loop. We could demonstrate with certainty the compact layer of projection fibers in the temporal loop, but it was not possible to irrefutably identify individual components, such as the optic radiation, because we were unable to demonstrate fibers that originate exclusively in the lateral geniculate body and to trace such fibers or differentiate them in their further course in the temporal loop.…”

contrasting

confidence: 55%

“…This limitation of the fiber dissection technique may explain the inconsistent and controversial anatomical quantitative data on the location of the temporal loop, as reported in previous fiber dissection studies. 6,28,29,42,46 Fiber microdissection is inadequate to accurately delineate the temporal loop from the intricate network of adjoining fibers. Furthermore, because individual optic radiation fibers cannot be distinguished among the various projection fibers of the temporal loop, fiber microdissection is an unsuitable method to elucidate the precise location of the optic radiation fibers in the anterior temporal region.…”

Section: Fiber Microdissection Reveals Individual Variations In the Amentioning

confidence: 99%

“…Because of these limitations, we believe that what has been defined as the optic radiation in previous studies 2, 3,6,10,22,[28][29][30]34,44,46,47 of fiber dissection may in fact be an oversimplified interpretation of the projection fibers in the temporal and occipital regions and the SS. Although there is only sparse reference to these complex projection fibers, they are visible in these studies' illustrations of the temporal loop.…”

mentioning

confidence: 99%

“…2,3,4,6,10,22,[28][29][30]34,44,46,47 However, close analysis of their supporting illustrations fails to demonstrate unequivocally the course of individual fibers from their origin in the lateral geniculate body to their termination in the visual occipital cortex. To understand the anatomical concept of the temporal loop and engender a realistic appreciation of the anatomical information that can be inferred from fiber microdissection, we revisited the anatomy of the temporal loop.…”

mentioning

confidence: 99%

See 3 more Smart Citations

The anatomy of Meyer's loop revisited: changing the anatomical paradigm of the temporal loop based on evidence from fiber microdissection

Goga

Türe

2015

JNS

View full text Add to dashboard Cite

OBJECT The goal in this study was to explore and further refine comprehension of the anatomical features of the temporal loop, known as Meyer's loop. METHODS The lateral and inferior aspects of 20 previously frozen, formalin-fixed human brains were dissected under the operating microscope by using fiber microdissection. RESULTS A loop of the fibers in the anterior temporal region was clearly demonstrated in all dissections. This temporal loop, or Meyer's loop, is commonly known as the anterior portion of the optic radiation. Fiber microdissection in this study, however, revealed that various projection fibers that emerge from the sublentiform portion of the internal capsule (IC-SL), which are the temporopontine fibers, occipitopontine fibers, and the posterior thalamic peduncle (which includes the optic radiation), participate in this temporal loop and become a part of the sagittal stratum. No individual optic radiation fibers could be differentiated in the temporal loop. The dissections also disclosed that the anterior extension and angulation of the temporal loop vary significantly. CONCLUSIONS The fiber microdissection technique provides clear evidence that a loop in the anterior temporal region exists, but that this temporal loop is not formed exclusively by the optic radiation. Various projection fibers of the IC-SL, of which the optic radiation is only one of the several components, display this common course. The inherent limitations of the fiber dissection technique preclude accurate differentiation among individual fibers of the temporal loop, such as the optic radiation fibers.

show abstract

contrasting

confidence: 55%

Section: Fiber Microdissection Reveals Individual Variations In the Amentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The anatomy of Meyer's loop revisited: changing the anatomical paradigm of the temporal loop based on evidence from fiber microdissection

Goga

Türe

2015

JNS

View full text Add to dashboard Cite

show abstract

“…30 Visual field deficit results from division of optic radiations coursing along the tapetum in the lateral wall of the temporal horn of the lateral ventricle. 36 They project from the lateral geniculate nucleus anterolaterally along the temporal horn 27 and are commonly encountered during the intraventricular exposure of the hippocampus. The extent of division of the fibers along the tapetum predicts the extent of visual field loss.…”

Section: 4350mentioning

confidence: 99%

Transorbital endoscopic amygdalohippocampectomy: a feasibility investigation

Chen¹,

Bohman²,

Loevner

et al. 2014

JNS

View full text Add to dashboard Cite

S urgical resection of the hippocampus is the standard of care for medically intractable temporal lobe epilepsy 46 and significantly improves seizure control and quality of life.14,42 The 2 most common surgical approaches are anterior temporal lobectomy and selective amygdalohippocampectomy, both of which are performed through a standard temporal craniotomy. Despite the marked success of these approaches, craniotomy for the treatment of temporal lobe epilepsy is not without risk. Complications range from cosmetic disfigurement to permanent neurological and cognitive disability (Table 1). Though uncommon, these complications significantly diminish quality of life for affected patients. Alternative strategies that minimize these risks while still achieving an adequate hippocampectomy, the principle goal of surgery, could further improve patient outcomes.Minimally invasive approaches have the potential to access the hippocampus with minimal disruption of the lateral temporal cortex and white matter pathways. For instance, stereotactic radiofrequency ablation permits hippocampal lesioning with 16-38 ablations through a single occipital bur hole. 29,35 Likewise, endoscopic approaches may provide access to the hippocampus and permit resection under direct visualization. The present cadaveric study examines the feasibility of a transorbital approach to the mesial temporal lobe using endoscopic visualization and image guidance. Unlike the occipital approach, the transorbital route affords the surgeon a short working distance and early access to the anterior portion of the hippocampus. We present the quantitative metrics of transorbital endoscopic amygdalohippocampectomy (TEA) predicted by predissection neuroimaging in relation to the measurements taken during the dissections. These measurements are compared with scans from 10 patients with epilepsy for clinical validation of the angles of exposure. Object. Resection of the hippocampus is the standard of care for medically intractable epilepsy in patients with mesial temporal sclerosis. Although temporal craniotomy in this setting is highly successful, the procedure carries certain immutable risks and may be associated with cognitive deficits related to cortical and white matter disruption. Alternative surgical approaches may reduce some of these risks by preserving the lateral temporal lobe. This study examined the feasibility of transorbital endoscopic amygdalohippocampectomy (TEA) as an alternative to open craniotomy in cadaveric specimens.Methods. TEA dissections were performed in 4 hemispheres from 2 injected cadaveric specimens fixed in alcohol. Quantitative predictions of the limits of exposure based on predissection imaging were compared with intradissection measurements. The extent of resection and angles of exposure during the dissection and on postdissection imaging were recorded. These measurements were validated with MRI studies from 10 epilepsy patients undergoing standard surgical evaluations.Results. The transorbital approach permitted direct access to t...

show abstract

What's your name again? A review of the superior longitudinal and arcuate fasciculus evolving nomenclature

2021

View full text Add to dashboard Cite

Studies of the superior longitudinal fasciculus (SLF) have multiplied in recent decades owing to methodological advances, but the absence of a convention for nomenclature remains a source of confusion. Here, we have reviewed existing nomenclatures in the context of the research studies that generated them and we have identified their agreements and disagreements. A literature search was conducted using PubMed/MEDLINE, Web‐of‐Science, Embase, and a review of seminal publications, without restrictions regarding publication date. Our search revealed that diffusion imaging, autoradiography, and fiber dissection have been the main methods contributing to tract designation. The first two have been particularly influential in systematizing the horizontal elements distant from the lateral sulcus. Twelve approaches to naming were identified, eight of them differing considerably from each other. The terms SLF and arcuate fasciculus (AF) were often used as synonyms until the second half of the 20th century. During the last 15 years, this has ceased to be the case in a growing number of publications. The term AF has been used to refer to the assembly of three different segments, or exclusively to long frontotemporal fibers. Similarly, the term SLF has been employed to denote the whole superior longitudinal associative system, or only the horizontal frontoparietal parts. As only partial correspondence can be identified among the available nomenclatures, and in the absence of an official designation of all anatomical structures that can be encountered in clinical practice, a high level of vigilance regarding the effectiveness of every oral or written act of communication is mandatory.

show abstract

Optic radiations: a microsurgical anatomical study

Abstract: Various practical surgical approaches are discussed. The knowledge gained by studying this particular anatomy will help prevent injury to the optic radiations during neurosurgery.

Cited by 84 publications

References 46 publications

The anatomy of Meyer's loop revisited: changing the anatomical paradigm of the temporal loop based on evidence from fiber microdissection

The anatomy of Meyer's loop revisited: changing the anatomical paradigm of the temporal loop based on evidence from fiber microdissection

Transorbital endoscopic amygdalohippocampectomy: a feasibility investigation

What's your name again? A review of the superior longitudinal and arcuate fasciculus evolving nomenclature

Contact Info

Product

Resources

About