Detailed anatomy of the motor and sensory roots of the trigeminal nerve and their neurovascular relationships: a magnetic resonance imaging study

2004 ◽  
Vol 101 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Indra Yousry ◽  
Bernhard Moriggl ◽  
Markus Holtmannspoetter ◽  
Urs D. Schmid ◽  
Thomas P. Naidich ◽  
...  

Object. The trigeminal nerve conducts both sensory and motor impulses. Separate superior and inferior motor roots typically emerge from the pons just anterosuperomedial to the entry point of the sensory root, but to date these two motor roots have not been adequately displayed on magnetic resonance (MR) images. The specific aims of this study, therefore, were to identify the superior and inferior motor roots, to describe their exact relationship to the sensory root, and to assess the neurovascular relationships among all three roots of the trigeminal nerve. Methods. Thirty-three patients and seven cadaveric specimens (80 sides) were studied using three-dimensional (3D) Fourier transform constructive interference in steady-state (CISS) imaging. The 33 patients were also studied by obtaining complementary time-of-flight (TOF) MR angiography sequences with and without contrast enhancement. At least one motor root was identified in all sides examined: in 51.2% of the sides a single motor root, in 37.5% two motor roots, and in 11.2% three motor roots. The superior cerebellar artery (SCA) and the anterior inferior cerebellar artery (AICA) contacted the sensory root in 45.5% of patients and 42.9% of specimens. The SCA often contacted the superior motor root (48.5% of patients and 50% of specimens) and less frequently the inferior motor root (26.5% of patients and 20% of specimens). Conclusions. Three-dimensional CISS and complementary 3D TOF MR angiography sequences reliably display sensory, superior motor, and inferior motor roots of the trigeminal nerve and their relationships to the SCA and AICA.

1996 ◽  
Vol 85 (6) ◽  
pp. 1050-1055 ◽  
Author(s):  
Philippe P. Maeder ◽  
Reto A. Meuli ◽  
Nicolas de Tribolet

✓ This study was undertaken to evaluate the capacity of three-dimensional (3-D) time-of-flight (TOF) magnetic resonance (MR) angiography with VoxelView (VV) 3-D volume rendering to detect and characterize intracranial aneurysms and to compare this rendering technique with that of maximum intensity projection (MIP). Forty patients with a total of 53 intracranial aneurysms (10 giant and subgiant, 43 saccular) were consecutively admitted to University Hospital, Lausanne, Switzerland, and investigated with 3-D TOF MR angiography. Source images of the 43 saccular aneurysms were processed with both MIP and VV. The aneurysm detection rate of the two techniques and their ability to characterize features of an aneurysm, such as its neck and its relation to the parent vessel, were compared. Intraarterial digital subtraction angiography was used as the gold standard to which these techniques could be compared and evaluated. Four aneurysms, less than 3 mm in size, were missed using MIP compared to three missed using VV. The representation of aneurysmal morphology using VV was superior to that found using conventional angiography in nine cases, equal in 16 cases, and inferior in seven cases. The representation of the aneurysm neck using VV was superior to MIP in 21 cases, equal in 17 cases, and inferior in one case; it was superior to that shown using conventional angiography in 10 cases, equal in 18 cases, and inferior in four cases. Time-of-flight MR angiography in conjunction with both MIP and VV 3-D reconstruction was able to visualize all aneurysms that were larger than 3 mm. Compared to MIP, VV provides a better definition of the aneurysm neck and the morphology of saccular aneurysms, making VV valuable for use in a preoperative diagnostic workup.


1971 ◽  
Vol 35 (5) ◽  
pp. 592-600 ◽  
Author(s):  
Kristin Gudmundsson ◽  
Albert L. Rhoton ◽  
Joseph G. Rushton

✓ Fifty trigeminal nerves were studied at autopsy under various magnifications. Two findings that could explain the preservation of sensation after rhizotomy of the main sensory root are: 1) anastomosis between the motor and sensory root in the majority of nerves, and 2) aberrant sensory rootlets that arose from the pons separately from the main sensory root in one half of the nerves. The motor root is composed of as many as 14 separately originating rootlets that usually join about 1 cm from the pons. At the pontine level, the first division fibers are usually dorsomedial and the third division fibers caudolateral within the main sensory root. However, the third division fibers may vary from being almost directly lateral to directly caudal to the first division fibers. This may explain the variability of sensory loss with partial section in the posterior fossa.


1971 ◽  
Vol 34 (5) ◽  
pp. 643-646 ◽  
Author(s):  
Kamal Mousa Mira ◽  
Ibrahiem Abou Elnaga ◽  
Hassanein El-Sherif

✓ Nerve cells histologically similar to the ganglionic cells of the trigeminal nerve were observed in the proximal part of the sensory root and in the motor root of the human trigeminal nerve. They were also seen in the sensory root of the trigeminal nerve of the dog. Counting of the nerve fibers showed doubling of the number of nerve fibers in the three divisions compared with the fibers in the sensory root adjacent to the trigeminal ganglion. There was also an increase in the number of fibers within the sensory root as it courses centrally, while a decrease was seen in the number of fibers in the proximal part of the motor root. Intermediate nerve bundles were seen leaving the motor root near the pons and joining the sensory root centrally. The fibers of the sensory root corresponding to each peripheral division maintained their specific location in the sensory root during the whole course centrally.


1999 ◽  
Vol 91 (2) ◽  
pp. 276-283 ◽  
Author(s):  
Indra Yousry ◽  
Salvador Camelio ◽  
Martin Wiesmann ◽  
Urs D. Schmid ◽  
Bernhard Moriggl ◽  
...  

Object. The goal of this study was to identify reliably the cisternal segment of the abducent nerve by using the three-dimensional Fourier transform constructive interference in steady-state (3-D CISS) magnetic resonance (MR) imaging sequence to define landmarks that assist in the identification of the abducent nerve on MR imaging and to describe the nerve's relationship to the anterior inferior cerebellar artery (AICA).Methods. A total of 26 volunteers underwent 3-D CISS MR imaging, and 10 of these volunteers also underwent MR angiography in which a time-of-flight sequence was used to identify the facial colliculus, the abducent nerve and its apparent origin, Dorello's canal, and the AICA.The authors identified the abducent nerve with certainty in 96% of 3-D CISS sequences obtained in the axial and sagittal planes and in 94% obtained in the coronal plane. The nerve emerged from the pontomedullary sulcus in 94% of cases. The facial colliculus could always be identified, and Dorello's canal was identified in 94% of cases. In 76.6% of cases, the abducent nerve was seen to contact the AICA, which passed inferior to the nerve in 63.8% of cases and superior to it in 29.8%.Conclusions. The anatomical course of the abducent nerve and its relationship to the AICA and other blood vessels can be reliably identified using a 3-D CISS MR sequence with the facial colliculus and Dorello's canal serving as landmarks.


1998 ◽  
Vol 88 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Jesús Pujol ◽  
Gerardo Conesa ◽  
Joan Deus ◽  
Luis López-Obarrio ◽  
Fabián Isamat ◽  
...  

Object. The authors sought to evaluate the advantages and limitations of functional magnetic resonance (fMR) imaging when it was used regularly in the clinical context to identify the central sulcus. Methods. A 1.5-tesla MR system comprising a spoiled gradient recalled acquisition in the steady-state functional sequence and a cross-hand cancellation analysis method were used to evaluate 50 surgical candidates with centrally located space-occupying lesions in the brain. Three-dimensional (3-D) models of the patient's head and brain showing the relative position of the tumor and the eloquent cortex were obtained in each case. A selective and reproducible focal activation was found, indicating the probable central sulcus position in 41 patients (82%). Direct cortical stimulation confirmed the fMR findings in 100% of 22 intraoperatively assessed patients. Failure to identify the central sulcus occurred in 18% of cases and was mainly a consequence of intrinsic damage in the primary sensorimotor region that resulted in severe hand paresis. Conclusions. Although specific factors were identified that contributed to reduced sensitivity of fMR imaging in the clinical context, the present study supports functional assessment and 3-D representation of specific surgical situations as generally feasible in common practice.


2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 191-192 ◽  
Author(s):  
Lee Walton ◽  
Anna Hampshire ◽  
Paul Vaughan ◽  
David M. C. Forster ◽  
Andras A. Kemeny ◽  
...  

✓ The purpose of this paper was to note a potential source of error in magnetic resonance (MR) imaging. Magnetic resonance images were acquired for stereotactic planning for GKS of a vestibular schwannoma in a female patient. The images were acquired using three-dimensional sequence, which has been shown to produce minimal distortion effects. The images were transferred to the planning workstation, but the coronal images were rejected. By examination of the raw data and reconstruction of sagittal images through the localizer side plate, it was clearly seen that the image of the square localizer system was grossly distorted. The patient was returned to the MR imager for further studies and a metal clasp on her brassiere was identified as the cause of the distortion.


1970 ◽  
Vol 33 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Richard L. Saunders ◽  
Ernest Sachs

✓ Microsurgical dissection of trigeminal nerves in autopsy specimens demonstrates that the so-called “accessory rootlets” are really a component of the motor root. This confirms Meckel's description of 1748.


2004 ◽  
Vol 100 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Toru Watanabe ◽  
Yoshiho Honda ◽  
Yukihiko Fujii ◽  
Miyako Koyama ◽  
Ryuichi Tanaka

Object. The purposes of this study were to evaluate the serial changes in diffusion anisotropy of the brain, probably reflecting axonal function in brain-dead patients, and thus to explore the possibility of quantitatively estimating the risk of brain death. Methods. Ten patients suffering from stroke with or without impending brain death and 10 healthy volunteers were studied using three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography with the aid of a 1.5-tesla MR imaging system. To detect changes in the diffusion anisotropy of neural bundles, the corticospinal tract was evaluated. Diffusion anisotropy of short axonal fibers decreased immediately after apparent brain death. Whereas the trichromatic coefficients of the corticospinal tract greatly diminished between 6 and 12 hours after apparent brain death, the coefficients of the corpus callosum and the optic radiation decreased in less time, that is, between 1 and 6 hours. The coefficients of these three bundles turned isotropic between 24 and 44 hours after apparent brain death. Conclusions. Results of 3DAC MR axonography revealed that diffusion anisotropy of neural bundles diminished between 1 and 12 hours after the onset of apparent brain death, probably depending on the length of the bundles, and disappeared between 24 and 44 hours after the onset of brain death, which might reflect dynamic changes of axonal structure and indirectly herald axonal dysfunction. These findings seem to be greatly helpful in establishing an appropriate method to estimate the risk of brain death quantitatively and in forming the basis of future definitions of brain death.


1995 ◽  
Vol 82 (2) ◽  
pp. 294-295 ◽  
Author(s):  
Alan Turtz ◽  
David Allen ◽  
Robert Koenigsberg ◽  
H. Warren Goldman

✓ The use of magnetic resonance (MR) angiography as a safe, accurate, and reliable substitute for invasive cerebral arteriography has been anticipated as refinements in this technique are introduced. We present the case of an unruptured, 11-mm pericallosal arterial aneurysm not visualized on high-resolution MR angiography. Although this case may be atypical, we caution against complete reliance on this test for exclusion of the presence of cerebral aneurysms.


2003 ◽  
Vol 99 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Jérôme Yelnik ◽  
Philippe Damier ◽  
Sophie Demeret ◽  
David Gervais ◽  
Eric Bardinet ◽  
...  

Object. The aim of this study was to correlate the clinical improvement in patients with Parkinson disease (PD) treated using deep brain stimulation (DBS) of the subthalamic nucleus (STN) with the precise anatomical localization of stimulating electrodes. Methods. Localization was determined by superimposing figures from an anatomical atlas with postoperative magnetic resonance (MR) images obtained in each patient. This approach was validated by an analysis of experimental and clinical MR images of the electrode, and the development of a three-dimensional (3D) atlas—MR imaging coregistration method. The PD motor score was assessed through two contacts for each of two electrodes implanted in 10 patients: the “therapeutic contact” and the “distant contact” (that is, the next but one to the therapeutic contact). Seventeen therapeutic contacts were located within or on the border of the STN, most of which were associated with significant improvement of the four PD symptoms tested. Therapeutic contacts located in other structures (zona incerta, lenticular fasciculus, or midbrain reticular formation) were also linked to a significant positive effect. Stimulation applied through distant contacts located in the STN improved symptoms of PD, whereas that delivered through distant contacts in the remaining structures had variable effects ranging from worsening of symptoms to their improvement. Conclusions. The authors have demonstrated that 3D atlas—MR imaging coregistration is a reliable method for the precise localization of DBS electrodes on postoperative MR images. In addition, they have confirmed that although the STN is the main target during DBS treatment for PD, stimulation of surrounding regions, particularly the zona incerta or the lenticular fasciculus, can also improve symptoms of PD.


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