Microscopic measurement of the facial nerve root exit zone from central glial myelin to peripheral Schwann cell myelin

2003 ◽  
Vol 99 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Masato Tomii ◽  
Hisashi Onoue ◽  
Masaharu Yasue ◽  
Shogo Tokudome ◽  
Toshiaki Abe
Keyword(s):  
Facial Nerve ◽  
Transitional Zone ◽  
Exit Point ◽  
En Bloc ◽  
Content Type ◽  
Medial Side ◽  
Root Exit Zone ◽  
Facial Nerves ◽  
The Relationship ◽  
Fine Print

Object. The authors have attempted to define the exact borders of the root exit zone (RExZ) of the facial nerve, measure the distribution of myelin histologically, and examine the relationship between contact vessels and the RExZ. Methods. Seventy-five facial nerves were obtained from brainstems excised from 44 adult patients at autopsy. The arteries and veins associated with the facial nerve were counted and measured. The facial nerves, associated vasculature, and adjoining portions of the brainstem were then removed en bloc. These tissues were serially sectioned and stained, and a photomicrograph of each section was obtained. The distribution of myelin on each section was measured from the upper edge of the supraolivary fossette, and the relationship between contact vessels and the RExZ was examined. The lateral transitional zone of the facial nerve began 8 mm distal to the upper edge of the supraolivary fossette (root exit point [RExP]) and had a mean length of 1.9 mm. The root detachment point (RDP) of the facial nerve at the medial side was located very close to the beginning of the medial transitional zone. In more than 80% of the nerves that were examined, vascular structures compressed the central glial myelin of the nerve. Conclusions. The authors propose the use of the terms “RExP,” “RDP,” and “transitional zone,” instead of RExZ, which cannot be well defined. The RDP appears to be a good landmark for use during microvascular decompression.

En bloc petrosectomy using a Gigli saw for petroclival lesions

1995 ◽  
Vol 83 (3) ◽  
pp. 559-560 ◽  
Author(s):  
Tomio Sasaki ◽  
Makoto Taniguchi ◽  
Ichiro Suzuki ◽  
Takaaki Kirino
Keyword(s):  
Facial Nerve ◽  
Semicircular Canals ◽  
Petrous Bone ◽  
New Technique ◽  
En Bloc ◽  
Content Type ◽  
A New Technique ◽  
Transtentorial Approach ◽  
Fine Print

✓ The authors report a new technique for en bloc petrosectomy using a Gigli saw as an alternative to drilling the petrous bone in the combined supra- and infratentorial approach or the transpetrosal—transtentorial approach. It is simple and easy and avoids postoperative cosmetic deformity. This technique has been performed in 11 petroclival lesions without injuring the semicircular canals, the cochlea, or the facial nerve.

Hemifacial spasm

1982 ◽  
Vol 57 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Tsutomu Iwakuma ◽  
Akihisa Matsumoto ◽  
Nishio Nakamura
Keyword(s):  
Facial Nerve ◽  
Hemifacial Spasm ◽  
Microvascular Decompression ◽  
Nerve Root ◽  
Posterior Inferior Cerebellar Artery ◽  
Content Type ◽  
Stylomastoid Foramen ◽  
Root Exit Zone ◽  
Selective Neurectomy ◽  
Fine Print

✓ Patients with hemifacial spasm were treated by three different surgical procedures: 1) partial sectioning of the facial nerve just distal to the stylomastoid foramen; 2) selective neurectomy of facial nerve branches; and 3) microvascular decompression. A retromastoid craniectomy with microvascular decompression was most effective in relieving hemifacial spasm and synkinesis. In a postmorten examination on one patient, microscopic examination of the facial nerve, which was compressed by an arterial loop of the posterior inferior cerebellar artery at the cerebellopontine angle, revealed fascicular demyelination in the nerve root. On the basis of surgical treatment, electromyography, and neuropathological findings, the authors conclude that compression of the facial nerve root exit zone by vascular structures is the main cause of hemifacial spasm and synkinesis.

Etiology and definitive microsurgical treatment of hemifacial spasm

1977 ◽  
Vol 47 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Peter J. Jannetta ◽  
Munir Abbasy ◽  
Joseph C. Maroon ◽  
Francisco M. Ramos ◽  
Maurice S. Albin
Keyword(s):  
Facial Nerve ◽  
Hemifacial Spasm ◽  
Mechanical Compression ◽  
Postoperative Results ◽  
Content Type ◽  
Microsurgical Treatment ◽  
Root Exit Zone ◽  
Operative Findings ◽  
Fine Print

✓ The clinical and operative findings are reviewed in 47 patients with intractable hemifacial spasm. The syndrome was classical in its features in 45 patients and atypical in two. Mechanical compression distortion of the root exit zone of the facial nerve was noted in all 47 patients. In 46 the abnormality was vascular cross-compression, usually by an arterial loop. In one patient, a small cholesteatoma was discovered and removed. Morbidity and postoperative results are discussed.

Surgical anatomy for direct hypoglossal—facial nerve side-to-end “anastomosis”

1999 ◽  
Vol 91 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Katsuyuki Asaoka ◽  
Yutaka Sawamura ◽  
Masabumi Nagashima ◽  
Takanori Fukushima
Keyword(s):  
Facial Nerve ◽  
Hypoglossal Nerve ◽  
Surgical Anatomy ◽  
Microsurgical Anatomy ◽  
Content Type ◽  
Pes Anserinus ◽  
Nearest Point ◽  
Facial Nerves ◽  
Nerve Anastomosis ◽  
Fine Print

Object. In this study the authors investigated the histomorphometric background and microsurgical anatomy associated with surgically created direct hypoglossal—facial nerve side-to-end communication or nerve “anastomosis.”Methods. Histomorphometric analyses of the facial and hypoglossal nerves were performed using 24 cadaveric specimens and three surgically obtained specimens of severed facial nerve. Both the hypoglossal nerve at the level of the atlas and the facial nerve just distal to the external genu were monofascicular. The number of myelinated axons in the facial nerve (7228 ± 950) was 73.2% of those in the normal hypoglossal nerve (9778 ± 1516). Myelinated fibers in injured facial nerves were remarkably decreased in number. The cross-sectioned area of the normal facial nerve (0.948 mm2) accounted for 61.5% of the area of the hypoglossal nerve (1.541 mm2), whereas that of the injured facial nerve (0.66 mm2) was less than 50% of the area of the hypoglossal nerve. Surgical dissection and morphometric measurements were performed using 18 sides of 11 adult cadaver heads. The length of the facial nerve from the pes anserinus to the external genu ranged from 22 to 42 mm (mean 30.5 ± 4.4 mm). The distance from the pes anserinus to the nearest point on the hypoglossal nerve ranged from 14 to 22 mm (mean 17.3 ± 2.5 mm). The former was always longer than the latter; the excess ranged from 6 to 20 mm (mean 13.1 ± 3.4 mm). Surgical anatomy and procedures used to accomplish the nerve connection are described.Conclusions. The size of a half-cut end of the hypoglossal nerve matches a cut end of the injured facial nerve very well. By using the technique described, a length of facial nerve sufficient to achieve a tensionless communication can consistently be obtained.

Repair of facial nerve after removal of cerebellopontine angle tumors: a comparative study

1993 ◽  
Vol 78 (5) ◽  
pp. 720-725 ◽  
Author(s):  
T. T. King ◽  
O. C. Sparrow ◽  
J. M. Arias ◽  
A. F. O'Connor
Keyword(s):  
Facial Nerve ◽  
Nerve Repair ◽  
Previous Treatment ◽  
Kappa Statistic ◽  
Complete Agreement ◽  
Grading System ◽  
Content Type ◽  
Nerve Tumor ◽  
Facial Nerves ◽  
Fine Print

✓ The results of repair of 18 facial nerves were examined by means of a modified House-Brackmann grading system. Six were repaired by end-to-end anastomosis and 12 by nerve graft. The reliability of the simplified House-Brackmann grading system was also assessed, using the kappa statistic to analyze the agreement between pairs of observers who examined the function of 40 nerves in 37 patients. Facial nerves studied had been either preserved, repaired or grafted, or divided and treated by faciohypoglossal nerve anastomosis. One nerve was not treated. The grading system proved to be somewhat unreliable, with complete agreement between observers in only 25% of cases. Facial nerve repair produced a fair return of function in just under two-thirds of the cases. The ability of an examiner ignorant of the patient's history to assess from the end result how the nerve had been managed was also estimated. Observers showed little ability to decide correctly on the previous treatment of the nerve when the patient showed moderate dysfunction postoperatively. The implications of these findings for grading systems and for management of the facial nerve in acoustic nerve tumor surgery are discussed.

Mitomycin C in preventing spinal epidural fibrosis in a laminectomy model in rats

2004 ◽  
Vol 100 (1) ◽  
pp. 52-55 ◽  
Author(s):  
Jin-Yul Lee ◽  
Werner Stenzel ◽  
Heinrich Ebel ◽  
Christoph Wedekind ◽  
Ralf-Ingo Ernestus ◽  
...  
Keyword(s):  
Mitomycin C ◽  
Spinal Column ◽  
Failed Back Surgery Syndrome ◽  
Epidural Fibrosis ◽  
En Bloc ◽  
Content Type ◽  
Failed Back Surgery ◽  
Back Surgery ◽  
Spinal Epidural ◽  
Fine Print

Object. Extensive epidural fibrosis after lumbar surgery may be the underlying cause in most cases of failed—back surgery syndrome. Various materials have been used to prevent epidural fibrosis, but only moderate success has been shown. Mitomycin C, an alkylosing antibiotic substance isolated from Streptomyces caespitosus, potentially supresses fibroblast proliferation after surgery. In this study, the authors investigated the effect of mitomycin C by local application on spinal epidural fibrosis in a rat laminectomy model. Methods. Five Wistar rats underwent laminectomy at cervical, thoracic, and lumbar levels. Based on data obtained from ophthalmological studies, mitomycin C was applied to the laminectomy sites in various concentrations (0.01, 0.05, and 0.1 mg/ml). One laminectomy site in each rat was left untreated and thus served as a control. Evoked potentials were measured pre- and postoperatively, and all rats underwent clinical evaluation. Mobility status and evidence of neurological deficit were recorded. Twelve weeks later, the rats were killed, and the spinal column, including surrounding muscle tissue, was removed en bloc, decalcified, and fixed in formaldehyde. Epidural fibrosis was evaluated histologically. In all mitomycin C—treated laminectomy sites, epidural scarring was significantly reduced compared with control sites. Remarkably, dural adhesions were absent in laminectomy defects treated with mitomycin C concentrations of 0.05 and 0.1 mg/ml. Moderate to marked epidural fibrosis with adhesion to the dura mater was noted at sites receiving 0.01 mg/ml of mitomycin C. All control sites showed dense epidural fibrosis with marked dura adherence. Conclusions. In this experimental model, mitomycin C applied locally at a concentration of 0.1 mg/ml effectively reduced epidural fibrosis, completely avoided dural adherence, and induced no side effects.

Monostotic fibrous dysplasia of the thoracic spine: clinopathological description and follow up

2004 ◽  
Vol 100 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Mehmet Arazi ◽  
Onder Guney ◽  
Mustafa Ozdemir ◽  
Omer Uluoglu ◽  
Nuket Uzum
Keyword(s):  
Fibrous Dysplasia ◽  
Thoracic Spine ◽  
Histopathological Examination ◽  
En Bloc Resection ◽  
Spinal Tumors ◽  
En Bloc ◽  
Content Type ◽  
Thoracic Spinal ◽  
Fine Print

✓ The authors report the case of a 53-year-old woman with monostotic fibrous dysplasia of the thoracic spine. The patient presented with a 1-month history of pain in the thoracic spinal region. En bloc resection of the lesion was successfully performed via a transthoracic approach, and a histopathological examination confirmed the diagnosis of fibrous dysplasia. At 24-month follow-up examination, pain and vertebral instability were absent. The findings in this case illustrate that, although very rare, monostotic fibrous dysplasia of the thoracic spine should be considered in the differential diagnosis of spinal tumors. Although a consensus for management of this disease has not been achieved, the authors recommend radical removal of all involved bone as well as internal fixation or bone graft—assisted fusion to achieve long-term stabilization.

En bloc laminoplasty without dissection of paraspinal muscles

2005 ◽  
Vol 3 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Noboru Hosono ◽  
Hironobu Sakaura ◽  
Yoshihiro Mukai ◽  
Takahiro Ishii ◽  
Hideki Yoshikawa
Keyword(s):  
Ct Scanning ◽  
Cord Compression ◽  
Neck Muscle ◽  
Open Door ◽  
En Bloc ◽  
Cross Sectional ◽  
Content Type ◽  
Spinous Processes ◽  
Significant Difference ◽  
Fine Print

Object. Although conducting cervical laminoplasty in patients with multisegmental cord compression provides good neurological results, it is not without shortcomings, including C-5 palsy, axial neck pain, and undesirable radiologically detectable changes. Postoperative kyphosis and segmental instability can cause neurological problems and are believed mainly to result from neck muscle disruption. The authors developed a new laminoplasty technique, with the aim of preserving optimal muscle function. Methods. The present technique is a modification of unilateral open-door laminoplasty. By using an ultrasonic osteotome in small gaps of muscle bellies, a gutter is made without disrupting muscles, spinous processes, or their connections on the hinged side. Ceramic spacers are then positioned between elevated laminae and lateral masses at C-3, C-5, and C-7 on the opened side, which is exposed in a conventional manner. This new procedure was used to treat 37 consecutive patients with compression myelopathy. Postoperative computerized tomography (CT) scanning revealed a significant difference in a cross-sectional area of muscles between the hinged and opened side. The mean follow-up period was 40.2 months (range 24–54 months). Changes in alignment were observed in only one patient, and vertebral slippage developed in two. Performed at regular intervals, CT scanning demonstrated that the elevated laminae remained in situ throughout the study period. Conclusions. In using the present unilateral open-door laminoplasty technique, deep extensor muscles are left intact along with their junctions to spinous processes on the hinged side. Radiologically documented changes were minimal because the preserved muscles functioned normally immediately after the operation.

Antitumor effects of antiprogesterones on human meningioma cells in vitro and in vivo

1994 ◽  
Vol 80 (3) ◽  
pp. 527-534 ◽  
Author(s):  
Yasuhiro Matsuda ◽  
Keiichi Kawamoto ◽  
Katsuzo Kiya ◽  
Kaoru Kurisu ◽  
Kazuhiko Sugiyama ◽  
...  
Keyword(s):  
Marked Reduction ◽  
Tumor Volume ◽  
Collagen Gel ◽  
Antitumor Effects ◽  
Histological Changes ◽  
Content Type ◽  
The Relationship ◽  
Fine Print

✓ The presence of the progesterone receptor (PR) in meningioma tissue has been confirmed by previous investigations. Studies have shown that the antiprogesterone drug, mifepristone, is a potent agent that inhibits the growth of cultured meningioma cells and reduces the size of meningiomas in experimental animal models and humans. However, these studies have not fully examined the relationship between the antitumor effects of an antiprogesterone agent and the expression of the PR. The present study examined the antitumor effects of mifepristone and a new potent antiprogesterone agent, onapristone; a correlation between the antitumor effects of these antiprogesterones and the presence of PR's in meningiomas in vitro and in vivo was also investigated. Meningioma tissue surgically removed from 13 patients was used in this study. In the in vitro arm of the study, mifepristone and onapristone exhibited cytostatic and cytocidal effects against cultured meningioma cells, regardless of the presence or absence of PR's; however, three PR-negative meningiomas showed no response to any dose of mifepristone and/or onapristone. In the in vivo arm, meningioma cells, embedded in a collagen gel, were implanted into the renal capsules of nude mice. Antiprogesterone treatment resulted in a marked reduction of the tumor volume regardless of the presence or absence of PR's. No histological changes in the meningioma cells suggestive of necrosis or apoptosis were detected in any of the mice treated with antiprogesterones. These findings suggest that mifepristone and onapristone have an antitumor effect against meningioma cells via the PR's and/or another receptor, such as the glucocorticoid receptor.

Preservation of olfaction in anterior craniofacial approaches

1993 ◽  
Vol 79 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Robert F. Spetzler ◽  
James M. Herman ◽  
Stephen Beals ◽  
Edward Joganic ◽  
John Milligan
Keyword(s):  
Cribriform Plate ◽  
Csf Leak ◽  
En Bloc ◽  
Reconstructive Procedures ◽  
Content Type ◽  
The Mean ◽  
Ethmoid Sinuses ◽  
Fine Print ◽  
Csf Leaks

✓ Through the combined efforts of neurosurgeons, head and neck surgeons, and craniofacial surgeons, the standard transbasal approach to the frontal fossa has been modified to include removal of the orbital roofs, nasion, and ethmoid sinuses. This approach has been combined further with facial disassembly procedures to provide extensive midline exposure to the midface and clival region. Extended frontal approaches, however, necessitate removal of the crista galli and sectioning of the olfactory rootlets with the associated risk of anosmia, cerebrospinal fluid (CSF) leak, and the need for complex reconstruction of the frontal floor. To avoid these problems, the authors have modified the technique of handling the cribriform plate to preserve the olfactory unit. Circumferential osteotomy cuts are made around the cribriform plate to allow an en bloc removal with its attachment to both the dura and underlying mucosa. Opening of the dura is avoided and the cribriform bone is used to reconstruct the floor. Four patients underwent this approach, for treatment of an angiofibroma in three and a fibrosarcoma in one. The mean follow-up period was 7 months. No patients developed a CSF leak, and within 8 weeks olfaction had returned in all patients. There was no other associated morbidity. These data suggest that this modification of the transbasilar approach can alleviate extensive reconstructive procedures and CSF leaks while preserving olfaction.

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