Anatomical study of the trigeminal and facial cranial nerves with the aid of 3.0-tesla magnetic resonance imaging

2008 ◽  
Vol 108 (3) ◽  
pp. 483-490 ◽  
Author(s):  
Yukinari Kakizawa ◽  
Tatsuya Seguchi ◽  
Kunihiko Kodama ◽  
Toshihiro Ogiwara ◽  
Tetsuo Sasaki ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Facial Nerve ◽  
Trigeminal Nerve ◽  
Cranial Nerves ◽  
Older Individuals ◽  
Normal Anatomy ◽  
Contact Points ◽  
Facial Nerves ◽  
The Mean ◽  
Trigeminal Nerves

Object Neuroimages often reveal that the trigeminal or facial nerve comes in contact with vessels but does not produce symptoms of trigeminal neuralgia (TN) or hemifacial spasm (HFS). The authors conducted this study to determine how often the trigeminal and facial nerves came in contact with vessels in individuals not suffering from TN or HFS. They also investigated the correlation between aging and the anatomical measurements of the trigeminal and facial nerves. Methods Between November 2005 and August 2006, 220 nerves in 110 individuals (60 women and 50 men; mean age 55.1 years, range 19–85 years) who had undergone brain magnetic resonance (MR) imaging for other reasons were studied. The lengths, angles, ratio, and contact points were measured in each individual. A correlation between each parameter and age was statistically analyzed. Results The mean (± standard deviation) length of the trigeminal nerve was 9.66 ± 1.71 mm, the mean distance between the bilateral trigeminal nerves was 31.97 ± 1.82 mm, and the mean angle between the trigeminal nerve and the midline was 9.71 ± 5.83°. The trigeminal nerve was significantly longer in older patients. Of 220 trigeminal nerves, 108 (49.0%; 51 women and 57 men) came in contact with vasculature. There was 1 contact point in 99 nerves (45%) and 2 contact points in 9 nerves (4.1%). Contact without deviation of the nerve was seen in 91 individuals (43 women and 48 men), and mild deviation was noted in 17 individuals (8 women and 9 men). There was no moderate or severe deviation in any individual in this series. The mean length of the facial nerve was 29.78 ± 2.31 mm, the mean distance between the bilateral facial nerves was 28.65 ± 2.22 mm, the angle between the nerve and midline was 69.68 ± 5.84°, and the vertical ratio at the porus acusticus was 0.467 ± 0.169. Of all facial nerves, 173 (78.6%; 101 in women and 72 in men) came in contact with some vasculature. Contact without deviation was seen on 64 sides (in 37 women and 27 men), mild deviation on 98 sides (in 57 women and 41 men), and moderate deviation on 11 sides (in 7 women and 4 men). There was no severe deviation of the facial nerve in this series. The proximal length of the facial nerve, interval, angle, and ratio against the age were significantly shorter or smaller in the older individuals. Conclusions The findings in asymptomatic individuals in this study will help in deciding which findings observed on MR images may cause symptoms. In addition, the authors describe the variations of normal anatomy in older individuals. Knowledge of the normal anatomy helps to hone the diagnostic practices for microvascular decompression, which may increase the feasible results on such surgery.

scholarly journals Bilateral facial nerve involvement in a patient with Tolosa–Hunt syndrome

2020 ◽  
Vol 33 (5) ◽  
pp. 424-427
Author(s):  
Ajay A Madhavan ◽  
David R DeLone ◽  
Jared T Verdoorn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Facial Nerve ◽  
Nerve Palsy ◽  
Facial Nerve Palsy ◽  
Cranial Nerves ◽  
Corticosteroid Treatment ◽  
Resonance Imaging ◽  
Hunt Syndrome ◽  
Facial Nerves

Tolosa–Hunt syndrome is characterized by unilateral retro-orbital headaches and cranial nerve palsies, usually involving cranial nerves III–VI. It is rare for other cranial nerves to be involved, although this has previously been reported. We report a 19-year-old woman presenting with typical features of Tolosa–Hunt syndrome but ultimately developing bilateral facial nerve palsies and enhancement of both facial nerves on magnetic resonance imaging. The patient presented with unilateral retro-orbital headaches and palsies of cranial nerves III–VI. She was diagnosed with Tolosa–Hunt syndrome but was non-compliant with her corticosteroid treatment due to side effects. She returned with progressive left followed by right facial nerve palsy. Her corresponding follow-up magnetic resonance imaging scans showed sequential enhancement of the left and right facial nerves. She ultimately had clinical improvement with IV methylprednisolone. To our knowledge, Tolosa–Hunt syndrome associated with bilateral facial nerve palsy and corroborative facial nerve enhancement on magnetic resonance imaging has not previously been described. Moreover, our patient’s clinical course is instructive, as it demonstrates that this atypical presentation of Tolosa–Hunt syndrome can indeed respond to corticosteroid treatment and should not be mistaken for other entities such as Bell’s palsy.

scholarly journals Conduction velocity of the rabbit facial nerve: a noninvasive functional evaluation

2003 ◽  
Vol 17 (2) ◽  
pp. 126-131 ◽  
Author(s):  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Cosme Gay Escoda ◽  
Ricardo José de Holanda Vasconcellos ◽  
Riedel Frota Sá Nogueira Neves
Keyword(s):  
Facial Nerve ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Action Potentials ◽  
Functional Evaluation ◽  
Surface Electrodes ◽  
Nerve Grafts ◽  
Synthetic Materials ◽  
Facial Nerves ◽  
The Mean

The aim of this study was to evaluate standardized conduction velocity data for uninjured facial nerve and facial nerve repaired with autologous graft nerves and synthetic materials. An evaluation was made measuring the preoperative differences in the facial nerve conduction velocities on either side, and ascertaining the existence of a positive correlation between facial nerve conduction velocity and the number of axons regenerated postoperatively. In 17 rabbits, bilateral facial nerve motor action potentials were recorded pre- and postoperatively. The stimulation surface electrodes were placed on the auricular pavilion (facial nerve trunk) and the recording surface electrodes were placed on the quadratus labii inferior muscle. The facial nerves were isolated, transected and separated 10 mm apart. The gap between the two nerve ends was repaired with autologous nerve grafts and PTFE-e (polytetrafluoroethylene) or collagen tubes. The mean of maximal conduction velocity of the facial nerve was 41.10 m/s. After 15 days no nerve conduction was evoked in the evaluated group. For the period of 2 and 4 months the mean conduction velocity was approximately 50% of the normal value in the subgroups assessed. A significant correlation was observed between the conduction velocity and the number of regenerated axons. Noninvasive functional evaluation with surface electrodes can be useful for stimulating and recording muscle action potentials and for assessing the functional state of the facial nerve.

Cranial Reflexes and Related Techniques

2009 ◽  
pp. 529-542 ◽  
Author(s):  
Benn E. Smith
Keyword(s):  
Cranial Nerves ◽  
Blink Reflex ◽  
Sensory Function ◽  
Electrophysiologic Study ◽  
Sensory Pathways ◽  
Facial Nerves ◽  
Upper Cervical ◽  
Central Inhibition ◽  
Demyelinating Peripheral Neuropathy ◽  
Trigeminal Nerves

Although a certain level of expertise is necessary, electrophysiologic study of cranial reflexes is not technically demanding, time-consuming, or associated with substantial patient discomfort. The information obtained may document objective abnormality and assist with localization. The blink reflexes are useful for studying the function of the trigeminal and facial nerves and their central connections in the brain stem. When NCS in the limbs suggest a demyelinating peripheral neuropathy, the blink reflex can provide information about involvement of proximal nerve segments. Patterns of involvement of the facial and trigeminal nerves are often helpful in suggesting the type of neuropathy under investigation. The jaw jerk is useful in assessing the mandibular division of the trigeminal nerve, and it can aid in evaluating patients with suspected sensory ganglionopathies. The MIR is sometimes helpful in evaluating patients with demyelinating neuropathies and in assessing central inhibition. The great auricular sensory NCS is a useful method to assess proximal somatic sensory function in the upper cervical dermatomes. The CHEPS technology provides a method to study somatic small fiber sensory pathways from the trigeminal dermatomes to the sensory cortex. Although not discussed in this chapter, needle electrode examination of muscles innervated by the trigeminal and facial cranial nerves are usually performed in combination with cranial nerve reflex studies.

scholarly journals Dissection and Exposure of the Whole Course of Deep Nerves in Human Head Specimens after Decalcification

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Longping Liu ◽  
Robin Arnold ◽  
Marcus Robinson
Keyword(s):  
Facial Nerve ◽  
Human Head ◽  
Chorda Tympani ◽  
Tympanic Cavity ◽  
Chorda Tympani Nerve ◽  
Stylomastoid Foramen ◽  
Greater Petrosal Nerve ◽  
Facial Nerves ◽  
Pterygoid Canal ◽  
The Mean

The whole course of the chorda tympani nerve, nerve of pterygoid canal, and facial nerves and their relationships with surrounding structures are complex. After reviewing the literature, it was found that details of the whole course of these deep nerves are rarely reported and specimens displaying these nerves are rarely seen in the dissecting room, anatomical museum, or atlases. Dissections were performed on 16 decalcified human head specimens, exposing the chorda tympani and the nerve connection between the geniculate and pterygopalatine ganglia. Measurements of nerve lengths, branching distances, and ganglia size were taken. The chorda tympani is a very fine nerve (0.44 mm in diameter within the tympanic cavity) and approximately 54 mm in length. The mean length of the facial nerve from opening of internal acoustic meatus to stylomastoid foramen was 52.5 mm. The mean length of the greater petrosal nerve was 26.1 mm and nerve of the pterygoid canal was 15.1 mm.

Hamartomas of the Internal Auditory Canal: Report of Two Cases

Neurosurgery ◽  
2003 ◽  
Vol 52 (4) ◽  
pp. 944-949 ◽  
Author(s):  
Gustavo A. Carvalho ◽  
Cordula Matthies ◽  
Enrique Osorio ◽  
Madjid Samii
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Facial Nerve ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Auditory Brainstem ◽  
Tumor Infiltration ◽  
Resonance Imaging ◽  
Imaging Studies ◽  
Tumor Removal

Abstract OBJECTIVE AND IMPORTANCE To highlight the clinical, radiological, and surgical findings and therapeutic options for this rare entity, which may mimic a purely intrameatal vestibular schwannoma, and to define the particular aspects of preoperative differential diagnosis and surgical management. CLINICAL PRESENTATION Two patients presented with clinical findings typical of vestibular schwannomas, i.e., tinnitus, hearing loss of 30 dB, and an intrameatal contrast-enhancing lesion on magnetic resonance imaging studies. TECHNIQUE The lesions were exposed via a suboccipital transmeatal approach, and tumor infiltration of the cochlear and/or facial cranial nerves was identified. In view of the unclear intraoperative histology, surgical management was based on criteria of cranial nerve function. In Patient 1, after nerve decompression by subtotal tumor removal, preserved auditory brainstem responses and facial nerve electromyography indicated functional nerve preservation and facilitated the decision for partial resection. In Patient 2, minimal tumor dissection resulted in complete loss of auditory brainstem response without reversibility. Therefore, a radical tumor removal was performed that sacrificed the cochlear but preserved the facial nerve. CONCLUSION Symptoms and signs of internal auditory canal hamartomas are congruent with other typical pathological lesions of the internal auditory canal and cerebellopontine angle. Accurate preoperative diagnosis by radiological means is not possible, but careful evaluation of the different signal intensities on magnetic resonance imaging studies may indicate this rare pathological condition. Intraoperative surgical findings of tumor infiltration of the faciocochlear cranial nerve complex may support simple observation. In view of the nonneoplastic characteristic of these lesions, a more conservative approach is justified. The decision should be based on the functional status of the cranial nerves, for which reliable electrophysiological monitoring is indispensable.

Significance of the tentorial alignment in approaching the trigeminal nerve and the ventral petrous region through the suboccipital retrosigmoid technique

2007 ◽  
Vol 107 (5) ◽  
pp. 932-936 ◽  
Author(s):  
Burak Sade ◽  
Joung H. Lee
Keyword(s):  
Trigeminal Nerve ◽  
Pearson Correlation ◽  
Cranial Nerves ◽  
Inverse Correlation ◽  
Magnetic Resonance Images ◽  
Retrosigmoid Approach ◽  
Mean Values ◽  
Pearson Correlation Test ◽  
Operative Planning ◽  
The Mean

Object In this study, the authors aimed to identify the factors that would predict the operative distance between the trigeminal nerve (fifth cranial nerve) and the acousticofacial nerve complex (seventh–eighth cranial nerves) preoperatively when approaching the cerebellopontine angle (CPA) through the suboccipital retrosigmoid approach. Methods In 40 consecutive patients who underwent microvascular decompression of the trigeminal nerve via a sub-occipital retrosigmoid approach for trigeminal neuralgia, the following three parameters were assessed on preoperative magnetic resonance images: 1) the angle between the tentorium and the line drawn from the hard palate (tentorial angle); 2) the angle between the lines drawn along the petrous bones ventral to the internal auditory canals (petrous angle); and 3) the angle between the tentorium and the line connecting the opisthion to the inion (occipital angle). The distance between the trigeminal nerve and the acousticofacial nerve complex (referred to as “distance”) was measured intraoperatively. Statistical analysis was performed using the Pearson correlation test. Results The mean values were 50.9 ± 11.5° for the tentorial angle, 102.5 ± 13.1° for the petrous angle, 83.4 ± 9.7° for the occipital angle, and 3.1 ± 1.5 mm for distance. There was a strong inverse correlation between the tentorial angle and distance (r = −0.228, p = 0.08). The mean distance was 3.5 ± 1.9 mm for a tentorial angle less than 51° and 2.7 ± 1.1 mm for a tentorial angle of at least 51°. No correlation existed between either the petrous or occipital angles and distance. Conclusions The distance between the trigeminal nerve and acousticofacial nerve complex decreases in the presence of a steep tentorial angle. This limits the operating field between these cranial nerves when reaching the petroclival or the superior CPA regions through the retrosigmoid approach. Awareness of such anatomical features at the time of pre-operative planning is of paramount importance in selecting the optimum surgical approach and minimizing operative complications.

scholarly journals Comparison of normal facial nerve enhancement at 3T MRI using gadobutrol and gadopentetate dimeglumine

2017 ◽  
Vol 30 (6) ◽  
pp. 554-560 ◽  
Author(s):  
Rupa Radhakrishnan ◽  
Shamima Ahmed ◽  
Joshua Cole Tilden ◽  
Humberto Morales
Keyword(s):  
Facial Nerve ◽  
Contrast Agents ◽  
Spin Echo ◽  
Cranial Nerves ◽  
Gadopentetate Dimeglumine ◽  
Gradient Echo ◽  
3D Inversion ◽  
Post Contrast ◽  
Significant Difference ◽  
Facial Nerves

Background and purpose The facial nerve is unique among cranial nerves in demonstrating normal enhancement of particular segments. The effect of varying T1 relaxivities of gadolinium-based contrast agents on facial nerve enhancement is unclear. In this study, we assess differences in normal facial nerve enhancement with two different gadolinium-based contrast agents, gadobutrol and gadopentetate dimeglumine. In addition, we evaluate differences in facial nerve enhancement with spin-echo (SE) T1 versus 3D inversion recovery prepared fast spoiled gradient-echo (FSPGR) post-contrast sequences. Methods A total of 140 facial nerves in 70 individuals were evaluated (70 with gadobutrol and 70 with gadopentetate dimeglumine) by two blinded reviewers. Differences in enhancement of facial nerve segments between the two agents were analyzed. Differences in enhancement between SE T1 and FSPGR imaging were also evaluated. Results There was no significant difference in facial nerve enhancement between gadobutrol and gadopentetate dimeglumine. Enhancement was commonly observed in the geniculate, tympanic and mastoid segments (98%–100%) with either contrast agent; enhancement was less common in the labyrinthine segments (9%–14%) and lateral canalicular segment (2%–5%). There was a smaller enhancing proportion of labyrinthine and tympanic segments with FSPGR as compared to SE T1 images with gadobutrol. Conclusion There is no significant difference in overall enhancement of the facial nerve between gadobutrol and gadopentetate dimeglumine. Mild enhancement of the lateral canalicular portion of the facial nerve may be a normal finding. With FSPGR sequence, there is lesser perceived enhancement of the labyrinthine and tympanic segments of the facial nerve with gadobutrol.

scholarly journals Facial nerve preservation in stereotactic radiosurgery of tumors of the cerebellopontine cistern

2021 ◽  
Vol 23 (2) ◽  
pp. 57-65
Author(s):  
S. R. Ilyalov ◽  
K. M. Kvashnin ◽  
K. E. Medvedeva ◽  
A. A. Baulin ◽  
O. G. Lepilina ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Tumor Volume ◽  
Cranial Nerves ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Facial Paresis ◽  
Previous Surgery ◽  
Study Objective ◽  
The Mean

Introduction. Surgery has traditionally remained the main treatment for tumors of the cerebellopontine cistern but is associated with high risks of dysfunction of the cranial nerves. Radiosurgery is usually performed both as an adjuvant treatment and as an independent option.The study objective is to assess the safety of routine use of radiosurgery to preserve facial nerve function in the treatment of tumors of different origins located in the cerebellopontine cistern.Materials and methods. Since March 2018 to March 2020 there were 145 patients with tumors of cerebellopontine cistern (CPC) at the Center for High-Precision Radiology. Vestibilar schwannomas were detected in 116 (80 %) patients, in 37 cases - relapses or remains after surgery. The 22 patients had meningiomas, 6 after open surgery (WHO I). Trigeminal schwannomas - in 3 patients, facial schwannomas - in 2, jugular schwannomas - in 1 and metastasis of prostate cancer - in 1. 31 patients had facial paresis of different degrees after previous surgery. Among non-operated patients, facial paresis before radiosurgery was observed in only 1 patient. Radiosurgery was performed using the Leksell Gamma Knife Perfexion, the mean marginal dose was 12.2 Gy (11-15 Gy), the mean tumor volume was 3.98 cm3 (0.06-17.47 cm3).Results. Follow-up was performed in 85 patients. The mean follow-up was 359.3 days (91-776), the median follow-up was 367 days. Reduction of the tumor volume was detected in 27 patients, stabilization of the process in 15. The average decrease was 23.9 % (95 % CI 16.8-31.0 %). Transient postirradiation increase was observed in 30 patients only in the group of schwannomas and mean tumor volume increase was 53.7 % (95 % CI 38.5-68.9 %). In patients with previous surgery there were not cases of decline or regression facial paresis. Among patients who had not been operated on before radiosurgery, only in 1 case was the development of facial paresis (House-Brackman III) 5 months after irradiation, which amounted to 1.8 %. It should be especially noted that facial nerve function remained unchanged (House-Brackman I) in both patients with facial schwannomas. Also, not a single case of hemifacial spasm was identified.Conclusion. Radiosurgery of CPC tumors with a marginal dose from 12 to 15 Gy has a high degree of safety in relation to the facial nerve. This makes it possible to justify radiosurgery as alternative to traditional neurosurgical interventions.

scholarly journals Neuralgies of the lower cranial nerves: Microsurgical posterior fossa exploration

2004 ◽  
Vol 51 (4) ◽  
pp. 39-43 ◽  
Author(s):  
Branislav Antic ◽  
Predrag Peric ◽  
S. Ivanovic ◽  
M. Spaic
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Facial Nerve ◽  
Posterior Fossa ◽  
Trigeminal Nerve ◽  
Hemifacial Spasm ◽  
Microvascular Decompression ◽  
Cranial Nerves ◽  
Relief Rate ◽  
Lower Cranial Nerves

Neuralgias of the lower cranial nerves are trigeminal neuralgia (TN), glossopharingeal neuralgia (GphN), and geniculate neuralgia (GN). Microsurgical posterior fossa exploration with its variations microvascular decompression (MVD), partial sensory rhisotomy (PSR), and total sensory rhisotomy (TSR) is one of the most efficient ways of treating these neuralgias. It was performed 130 operations in 125 patients with TN, 3 in GphN patients, 1 in GN patient, 1 in GN/TN patients, 1 in GphN/GN patient, and 2 in GN/hemifacial spasm patients. Of total of 125 patients with TN, MVD was performed in 63, PSR in 18, and MVD+PSR in 44 cases. In 5 patients with recidivate TN PSR was performed. Of total 3 patients with GphN MVD was performed in 2 cases, and extirpation of a small meningeoma in 1 case (it was not seen on CT). In the patients with GN TSR of intermediate nerve was performed, in GN/TN patients TSR of intermediate nerve and PSR of trigeminal nerve was performed, in the GN/GphN patients MVD of glossopharingeal and TSR of intermediate nerve were performed, and in the GN/hemifacial spasm patients TSR of intermediate and MVD of facial nerve were performed. The results of TN patients are: excellent in 82,4%, good in 12%, and poor in 5,6% of patients. There is no difference in complete pain relief, rate of recurrence, and complications between MVD, MVD+PSR and PSR operative groups (p>0,05). Among patients with other neuralgias the following results are noted: excellent in 4, good in 3, and poor in 1 patient. Microsurgical posterior fossa exploration is the method of choice in the treatment of the neuralgias of the lower cranial nerves.

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