Dorello's canal: a microanatomical study

1991 ◽  
Vol 75 (2) ◽  
pp. 294-298 ◽  
Author(s):  
Felix Umansky ◽  
Josef Elidan ◽  
Alberto Valarezo
Keyword(s):  
Cranial Nerve ◽  
Venous Blood ◽  
Abducens Nerve ◽  
Microsurgical Anatomy ◽  
Sixth Cranial Nerve ◽  
Content Type ◽  
Dorello’S Canal ◽  
Pathological Conditions ◽  
Anatomical Relationship ◽  
Fine Print

✓ The microsurgical anatomy of Dorello's canal has been studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. The bow-shaped canal through which courses the abducens nerve before reaching the cavernous sinus is located inside a venous confluence which occupies the space between the dural leaves of the petroclival area. The petrosphenoidal ligament (Gruber's ligament), which forms the posteromedial wall of the canal, appears as a fibrous trabecula surrounded by venous blood. Canal measurements were performed and its anatomical relationship with the sixth cranial nerve is described. Angulations of variable degrees were observed in the course of the nerve inside and outside the canal. The influence of this relatively tortuous course of the abducens nerve upon its vulnerability in some pathological conditions is discussed.

The abducens nerve

1974 ◽  
Vol 41 (5) ◽  
pp. 561-566 ◽  
Author(s):  
Hilel Nathan ◽  
Georges Ouaknine ◽  
Isaac Z. Kosary
Keyword(s):  
Cavernous Sinus ◽  
Subarachnoid Space ◽  
Cranial Nerve ◽  
Rectus Muscle ◽  
Abducens Nerve ◽  
The Other ◽  
Sixth Cranial Nerve ◽  
Content Type ◽  
Lateral Rectus Muscle ◽  
Fine Print

✓ The authors describe the origins and course of the sixth cranial nerve in 62 cadaver or autopsy cases and describe three patterns. In Pattern 1 the nerve originates and runs all its way as a single trunk. In Pattern 2 it originates as a single trunk, but splits into two branches in the subarachnoid space, while in Pattern 3 it originates as two separate trunks. In both Patterns 2 and 3 the trunks perforate the dura mater independently and enter the cavernous sinus by passing one above and the other below the petrosphenoidal ligament. In the sinus the two trunks fuse into a single trunk which then continues to the lateral rectus muscle. The practical neurological importance of these variations is discussed.

Intracranial sympathetic pathways associated with the sixth cranial nerve

1974 ◽  
Vol 40 (2) ◽  
pp. 236-243 ◽  
Author(s):  
J. A. Johnston ◽  
Dwight Parkinson
Keyword(s):  
Cavernous Sinus ◽  
Cranial Nerve ◽  
Abducens Nerve ◽  
Sixth Cranial Nerve ◽  
Content Type ◽  
Photographic Documentation ◽  
Parasellar Region ◽  
Fine Print

✓ During a continuing study of the anatomy of the parasellar region, a macroscopically identifiable nerve has been observed to leave the foramen lacerum and join the abducens nerve within the cavernous sinus. A description and photographic documentation of this sympathetic branch to the fifth cranial nerve by way of the sixth cranial nerve are presented.

The suboccipital cavernous sinus

1997 ◽  
Vol 86 (2) ◽  
pp. 252-262 ◽  
Author(s):  
Kenan I. Arnautović ◽  
Ossama Al-Mefty ◽  
T. Glenn Pait ◽  
Ali F. Krisht ◽  
Muhammad M. Husain
Keyword(s):  
Cavernous Sinus ◽  
Internal Carotid ◽  
Microsurgical Anatomy ◽  
Transverse Foramen ◽  
Cross Sectional ◽  
Anatomical Structures ◽  
Content Type ◽  
Arterial Walls ◽  
Pathological Conditions ◽  
Fine Print

✓ The authors studied the microsurgical anatomy of the suboccipital region, concentrating on the third segment (V3) of the vertebral artery (VA), which extends from the transverse foramen of the axis to the dural penetration of the VA, paying particular attention to its loops, branches, supporting fibrous rings, adjacent nerves, and surrounding venous structures. Ten cadaver heads (20 sides) were fixed in formalin, their blood vessels were perfused with colored silicone rubber, and they were dissected under magnification. The authors subdivided the V3 into two parts, the horizontal (V3h) and the vertical (V3v), and studied the anatomical structures topographically, from the superficial to the deep tissues. In two additional specimens, serial histological sections were acquired through the V3 and its encircling elements to elucidate their cross-sectional anatomy. Measurements of surgically and clinically important features were obtained with the aid of an operating microscope. This study reveals an astonishing anatomical resemblance between the suboccipital complex and the cavernous sinus, as follows: venous cushioning; anatomical properties of the V3 and those of the petrous—cavernous internal carotid artery (ICA), namely their loops, branches, supporting fibrous rings, and periarterial autonomic neural plexus; adjacent nerves; and skull base locations. Likewise, a review of the literature showed a related embryological development and functional and pathological features, as well as similar transitional patterns in the arterial walls of the V3 and the petrous-cavernous ICA. Hence, due to its similarity to the cavernous sinus, this suboccipital complex is here named the “suboccipital cavernous sinus.” Its role in physiological and pathological conditions as they pertain to various clinical and surgical implications is also discussed.

Fibroblastic tumor of the abducens nerve

1985 ◽  
Vol 62 (2) ◽  
pp. 296-299 ◽  
Author(s):  
Daniel G. Nehls ◽  
Volker K. H. Sonntag ◽  
Alan R. Murphy ◽  
Peter C. Johnson ◽  
John D. Waggener
Keyword(s):  
Electron Microscopy ◽  
Case Report ◽  
Cranial Nerves ◽  
Abducens Nerve ◽  
Sixth Cranial Nerve ◽  
Content Type ◽  
The Third ◽  
Nerve Sheath ◽  
Pathological Material ◽  
Fine Print

✓ Tumors of the cranial nerves are uncommon, and are usually schwannomas or neurofibromas. The authors describe a case of a fibroblastic tumor involving the sixth cranial nerve. Based upon electron microscopy and immunohistochemistry, the tumor was not of nerve-sheath origin, but was comprised of fibroblasts. Clinical, radiographic, and pathological material are presented, and the literature is discussed. This represents the third case report of a tumor of the abducens nerve, and the first report of a fibroma of a cranial or peripheral nerve.

Stereotactic radiotherapy for the treatment of acoustic neuromas

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 362-372 ◽  
Author(s):  
Michael T. Selch ◽  
Alessandro Pedroso ◽  
Steve P. Lee ◽  
Timothy D. Solberg ◽  
Nzhde Agazaryan ◽  
...  
Keyword(s):  
Stereotactic Radiotherapy ◽  
Tumor Size ◽  
Cranial Nerve ◽  
Target Volume ◽  
Tumor Control ◽  
Content Type ◽  
Seventh Cranial Nerve ◽  
Acoustic Neuromas ◽  
Fine Print

Object. The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas. Methods. Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1%) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two. Conclusions. Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.

Contralateral motor rootlets and ipsilateral nerve transfers in brachial plexus reconstruction

2004 ◽  
Vol 101 (5) ◽  
pp. 770-778 ◽  
Author(s):  
Jayme Augusto Bertelli ◽  
Marcos Flávio Ghizoni
Keyword(s):  
Brachial Plexus ◽  
Ulnar Nerve ◽  
Phrenic Nerve ◽  
Cranial Nerve ◽  
External Rotation ◽  
Elbow Flexion ◽  
Content Type ◽  
Nerve Transfers ◽  
Contralateral Motor ◽  
Fine Print

Object. The goal of this study was to evaluate outcomes in patients with brachial plexus avulsion injuries who underwent contralateral motor rootlet and ipsilateral nerve transfers to reconstruct shoulder abduction/external rotation and elbow flexion. Methods. Within 6 months after the injury, 24 patients with a mean age of 21 years underwent surgery in which the contralateral C-7 motor rootlet was transferred to the suprascapular nerve by using sural nerve grafts. The biceps motor branch or the musculocutaneous nerve was repaired either by an ulnar nerve fascicular transfer or by transfer of the 11th cranial nerve or the phrenic nerve. The mean recovery in abduction was 90° and 92° in external rotation. In cases of total palsy, only two patients recovered external rotation and in those cases mean external rotation was 70°. Elbow flexion was achieved in all cases. In cases of ulnar nerve transfer, the muscle scores were M5 in one patient, M4 in six patients, and M3+ in five patients. Elbow flexion repair involving the use of the 11th cranial nerve resulted in a score of M3+ in five patients and M4 in two patients. After surgery involving the phrenic nerve, two patients received a score of M3+ and two a score of M4. Results were clearly better in patients with partial lesions and in those who were shorter than 170 cm (p < 0.01). The length of the graft used in motor rootlet transfers affected only the recovery of external rotation. There was no permanent injury at the donor sites. Conclusions. Motor rootlet transfer represents a reliable and potent neurotizer that allows the reconstruction of abduction and external rotation in partial injuries.

Targeting the cranial nerve: microradiosurgery for trigeminal neuralgia with CISS and 3D-Flash MR imaging sequences

2005 ◽  
Vol 102 ◽  
pp. 107-110 ◽  
Author(s):  
Vasilios A. Zerris ◽  
Georg C. Noren ◽  
William A. Shucart ◽  
Jeff Rogg ◽  
Gerhard M. Friehs
Keyword(s):  
Mr Imaging ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Trigeminal Nerve ◽  
Cranial Nerve ◽  
Fusion Imaging ◽  
Vascular Compression ◽  
Content Type ◽  
History Of ◽  
Fine Print

Object.The authors undertook a study to identify magnetic resonance (MR) imaging techniques that can be used reliably during gamma knife surgery (GKS) to identify the trigeminal nerve, surrounding vasculature, and areas of compression.Methods.Preoperative visualization of the trigeminal nerve and surrounding vasculature as well as targeting the area of vascular compression may increase the effectiveness of GKS for trigeminal neuralgia. During the past years our gamma knife centers have researched different MR imaging sequences with regard to their ability to visualize cranial nerves and vascular structures. Constructive interference in steady-state (CISS) fusion imaging with three-dimensional gradient echo sequences (3D-Flash) was found to be of greatest value in the authors' 25 most recent patients.In 24 (96%) out of the 25 patients, the fifth cranial nerve, surrounding vessels, and areas of compression could be reliably identified using CISS/3D-Flash. The MR images were acceptable despite patients' history of microvascular decompression, radiofrequency (RF) ablation, or concomitant disease. In one of 25 patients with a history of multiple RF lesions, the visualization was inadequate due to severe trigeminal nerve atrophy.Conclusions.The CISS/3D-Flash fusion imaging has become the preferred imaging method at the authors' institutions during GKS for trigeminal neuralgia. It affords the best visualization of the trigeminal nerve, surrounding vasculature, and the precise location of vascular compression.

Neurilemmoma of the fourth cranial nerve

1979 ◽  
Vol 50 (4) ◽  
pp. 519-521 ◽  
Author(s):  
James E. Boggan ◽  
Mark L. Rosenblum ◽  
Charles B. Wilson
Keyword(s):  
Cranial Nerve ◽  
Trochlear Nerve ◽  
Content Type ◽  
Nerve Sheath ◽  
Trigeminal Nerves ◽  
Fourth Cranial Nerve ◽  
Fine Print

✓ A tumor of the trochlear nerve sheath with an unusual but diagnostic presentation is described. The rarity of reported cases may reflect failure to differentiate tumors originating from the trochlear and trigeminal nerves.

Microvascular decompression of cranial nerves: lessons learned after 4400 operations

1999 ◽  
Vol 90 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Mark R. McLaughlin ◽  
Peter J. Jannetta ◽  
Brent L. Clyde ◽  
Brian R. Subach ◽  
Christopher H. Comey ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Trigeminal Neuralgia ◽  
Hemifacial Spasm ◽  
Microvascular Decompression ◽  
Cranial Nerve ◽  
Glossopharyngeal Neuralgia ◽  
Complication Rates ◽  
Content Type ◽  
Csf Leakage ◽  
Fine Print

Object. Microvascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and other cranial nerve rhizopathies. The senior author (P.J.J.) began performing this procedure in 1969 and has performed more than 4400 operations. The purpose of this article is to review some of the nuances of the technical aspects of this procedure.Methods. A review of 4415 operations shows that numerous modifications to the technique of microvascular decompression have occurred during the last 29 years. Of the 2420 operations performed for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia before 1990, cerebellar injury occurred in 21 cases (0.87%), hearing loss in 48 (1.98%), and cerebrospinal fluid (CSF) leakage in 59 cases (2.44%). Of the 1995 operations performed since 1990, cerebellar injuries declined to nine cases (0.45%), hearing loss to 16 (0.8%), and CSF leakage to 37 (1.85% p < 0.01, test for equality of distributions). The authors describe slight variations made to maximize surgical exposure and minimize potential complications in each of the six principal steps of this operation. These modifications have led to decreasing complication rates in recent years.Conclusions. Using the techniques described in this report, microvascular decompression is an extremely safe and effective treatment for many cranial nerve rhizopathies.

Transcerebellomedullary fissure approach with special reference to the methods of dissecting the fissure

2001 ◽  
Vol 94 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Toshio Matsushima ◽  
Tooru Inoue ◽  
Takanori Inamura ◽  
Yoshihiro Natori ◽  
Kiyonobu Ikezaki ◽  
...  
Keyword(s):  
Fourth Ventricle ◽  
Posterior Margin ◽  
Lateral Wall ◽  
Microsurgical Anatomy ◽  
Optimal Method ◽  
Content Type ◽  
Lateral Recess ◽  
Tela Choroidea ◽  
Opening Method ◽  
Fine Print

Object. The purpose of the present study was to refine the transcerebellomedullary fissure approach to the fourth ventricle and to clarify the optimal method of dissecting the fissure to obtain an appropriate operative view without splitting the inferior vermis. Methods. The authors studied the microsurgical anatomy by using formalin-fixed specimens to determine the most appropriate method of dissecting the cerebellomedullary fissure. While dissecting the spaces around the tonsils and making incisions in the ventricle roof, the procedures used to expose each ventricle wall were studied. Based on their findings, the authors adopted the best approach for use in 19 cases of fourth ventricle tumor. The fissure was further separated into two slit spaces on each side: namely the uvulotonsillar and medullotonsillar spaces. The floor of the fissure was composed of the tela choroidea, inferior medullary velum, and lateral recess, which form the ventricle roof. In this approach, the authors first dissected the spaces around the tonsils and then incised the taenia with or without the posterior margin of the lateral recess. These precise dissections allowed for easy retraction of the tonsil(s) and uvula and provided a sufficient view of the ventricle wall such that the deep aqueductal region and the lateral region around the lateral recess could be seen without splitting the vermis. The dissecting method could be divided into three different types, including extensive (aqueduct), lateral wall, and lateral recess, depending on the location of the ventricle wall and the extent of surgical exposure required. Conclusions. When the fissure is appropriately and completely opened, the approach provides a sufficient operative view without splitting the vermis. Two key principles of this opening method are sufficient dissection of the spaces around the tonsil(s) and an incision of the appropriate portions of the ventricle roof. The taenia(e) with or without the posterior margin of the lateral recess(es) should be incised.

Sign in / Sign up

Export Citation Format

Share Document