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Folia Morphologica 2023Anatomical variations can occasionally result in unexpected findings on physical examination. Here, we report two cases of seemingly unique connections between V2 and V3...
Anatomical variations can occasionally result in unexpected findings on physical examination. Here, we report two cases of seemingly unique connections between V2 and V3 parts of the trigeminal nerve. In these two cadaveric specimens, at the foramen ovale, small neural connections, confirmed with histology, were identified joining V2 to specifically, the motor root of V3. The findings of these two cadaveric specimens and the potential clinical ramifications are discussed.
Topics: Humans; Trigeminal Nerve; Skull Base; Cadaver
PubMed: 35380015
DOI: 10.5603/FM.a2022.0031 -
Journal of Veterinary Internal Medicine 2013Idiopathic headshaking (HSK) in horses is a distressing disorder in which the etiology and pathophysiology are unknown.
BACKGROUND
Idiopathic headshaking (HSK) in horses is a distressing disorder in which the etiology and pathophysiology are unknown.
HYPOTHESIS
Differences in sensory function of the trigeminal nerve exist between healthy and affected horses.
ANIMALS
Six healthy mature geldings and 6 mature geldings with idiopathic HSK.
METHODS
Prospective study. Sensory nerve action and somatosensory evoked potentials studies were performed. The stimulus site comprised the gingival mucosa dorsal to the maxillary canine. A pair of recording electrodes was placed along the sensory pathway of the trigeminal complex at the infraorbital nerve (R1), maxillary nerve (R2), spinal tract of trigeminal (R3), and somatosensory cortex (R4). Sensory nerve action potential latency (ms), amplitude (μV), duration (ms), area under the curve (μVms), and conduction velocity (m/s) were calculated.
RESULTS
Threshold for activation of the infraorbital branch of the trigeminal nerve was significantly different between 5 affected (≤ 5 mA) and 6 control horses (≥ 10 mA). After initiation of an action potential, there were no differences in all parameters measured and no differences between left and right sides. A horse with seasonal HSK tested during a time of no clinical manifestations showed a threshold for activation similar to control horses.
CONCLUSIONS AND CLINICAL IMPORTANCE
This study confirms involvement of the trigeminal nerve hyperexcitability in the pathophysiology of disease. Further, results might support a functional rather than a structural alteration in the sensory pathway of the trigeminal complex that can be seasonal. The horse could serve as a natural animal model for humans with idiopathic trigeminal neuralgia.
Topics: Animals; Area Under Curve; Electric Stimulation; Evoked Potentials, Somatosensory; Head; Horse Diseases; Horses; Male; Neural Conduction; Prospective Studies; Seasons; Trigeminal Nerve
PubMed: 24107198
DOI: 10.1111/jvim.12191 -
PloS One 2018Corneal anesthesia leads to chronic corneal injury. This anatomical study characterizes the donor nerve branches of the supratrochlear and supraorbital nerves used for...
PURPOSE
Corneal anesthesia leads to chronic corneal injury. This anatomical study characterizes the donor nerve branches of the supratrochlear and supraorbital nerves used for corneal neurotization.
METHODS
In 13 non-embalmed cadavers, the supratrochlear and supraorbital nerves were dissected and distances to anatomical landmarks measured. Cross-sections of supratrochlear and supraorbital donor nerves were harvested and histomorphometrically analyzed to assess the number of myelinated axons.
RESULTS
The donor axon counts were 3146 ± 1069.9 for the supratrochlear and 1882 ± 903 for the supraorbital nerve distal to the supraorbital notch. The supratrochlear nerve was dissected on the medial upper eyelid 2 cm lateral to the facial midline and the branch of the supraorbital nerve 1 cm medial to the mid-pupillary line.
CONCLUSION
The supraorbital and supratrochlear branches of the trigeminal nerve are potent donor nerves for corneal neurotization in the treatment of neuropathic keratopathy and can be reliably dissected using anatomical landmarks.
Topics: Axons; Cornea; Corneal Diseases; Humans; Nerve Transfer; Trigeminal Nerve
PubMed: 30379941
DOI: 10.1371/journal.pone.0206642 -
Chemical Senses Jan 2023The presence of a perceptual bias due to anxiety is well demonstrated in cognitive and sensory task for the visual and auditory modality. Event-related potentials, by...
The presence of a perceptual bias due to anxiety is well demonstrated in cognitive and sensory task for the visual and auditory modality. Event-related potentials, by their specific measurement of neural processes, have strongly contributed to this evidence. There is still no consensus as to whether such a bias exists in the chemical senses; chemosensory event-related potentials (CSERPs) are an excellent tool to clarify the heterogeneous results, especially since the Late Positive Component (LPC) may be an indicator of emotional involvement after chemosensory stimulation. This research examined the association between state and trait anxiety and the amplitude and latency of pure olfactory and mixed olfactory-trigeminal LPC. In this study, 20 healthy participants (11 women) with a mean age of 24.6 years (SD = 2.6) completed a validated questionnaire to measure anxiety (STAI), and CSERP was recorded during 40 pure olfactory stimulations (phenyl ethanol) and 40 mixed olfactory-trigeminal stimulations (eucalyptol). LPC latency and amplitude were measured at Cz (electrode located at midline central) for each participant. We observed a significant negative correlation between LPC latencies and the state anxiety scores for the mixed olfactory-trigeminal condition (r(18) = -0.513; P = 0.021), but not for the pure olfactory condition. We did not observe any effect on LPC amplitudes. This study suggests that a higher level of state anxiety is related to a more rapid perceptual electrophysiological response for mixed olfactory-trigeminal stimuli but not for pure odors.
Topics: Adult; Female; Humans; Young Adult; Anxiety; Evoked Potentials; Odorants; Phenylethyl Alcohol; Smell; Trigeminal Nerve; Male
PubMed: 36976248
DOI: 10.1093/chemse/bjad010 -
Cephalalgia : An International Journal... Mar 2019Migraine is a complex neurologic disorder that leads to significant disability, yet remains poorly understood. (Review)
Review
PREMISE
Migraine is a complex neurologic disorder that leads to significant disability, yet remains poorly understood.
PROBLEM
One potential triggering mechanism in migraine with aura is cortical spreading depression, which can activate the trigeminal nociceptive system both peripherally and centrally in animal models. A primary neuropeptide of the trigeminal system is calcitonin gene-related peptide, which is a potent vasodilatory peptide and is currently a major therapeutic target for migraine treatment. Despite the importance of both cortical spreading depression and calcitonin gene-related peptide in migraine, the relationship between these two players has been relatively unexplored. However, recent data suggest several potential vascular and neural connections between calcitonin gene-related peptide and cortical spreading depression.
CONCLUSION
This review will outline calcitonin gene-related peptide-cortical spreading depression connections and propose a model in which cortical spreading depression and calcitonin gene-related peptide act at the intersection of the vasculature and cortical neurons, and thus contribute to migraine pathophysiology.
Topics: Animals; Calcitonin Gene-Related Peptide; Calcitonin Gene-Related Peptide Receptor Antagonists; Cortical Spreading Depression; Humans; Migraine Disorders; Receptors, Calcitonin Gene-Related Peptide; Trigeminal Nerve; Vasodilation
PubMed: 29695168
DOI: 10.1177/0333102418774299 -
Neurology India 2022To study the trigeminal nerve tractography and assessment of diffusion tensor imaging (DTI) parameters by comparing the values of fractional anisotropy (FA) of...
AIMS
To study the trigeminal nerve tractography and assessment of diffusion tensor imaging (DTI) parameters by comparing the values of fractional anisotropy (FA) of trigeminal (V) nerve on the affected side with that of the unaffected opposite side.
MATERIALS AND METHODS
Prospective comparative study done for one year included 30 patients who presented with trigeminal neuralgia and 30 controls who did not have any present or past history of neurological or neurosurgical symptoms were enrolled in the study.
RESULTS
Most common age of presentation of TN is >50 years, and the commonly involved branch is V2 (maxillary branch of the trigeminal nerve). Most of the patients were having symptoms for more than 1 year. The superior cerebellar artery was the most common vessel compressing the V nerve at the root entry zone (REZ), followed in the order by anterior inferior cerebellar artery and petrosal vein. Neurovascular compression (NVC) was more commonly seen in the study group when compared with the control group. In all the patients in the study group, fractional anisotropy (FA) was decreased on the affected side as compared to the unaffected side. In the study group, 10 patients were having NVC on both sides, but FA was significantly decreased only on the affected side. No significant difference in FA values at the REZ of bilateral V nerves in the control group.
CONCLUSION
DTI metrics of the trigeminal nerve is a very helpful imaging technique in patients with trigeminal neuralgia. It not only helps in anatomical imaging but also reinforces the association between NVC and TN.
Topics: Benchmarking; Diffusion Tensor Imaging; Humans; Magnetic Resonance Imaging; Middle Aged; Prospective Studies; Trigeminal Nerve; Trigeminal Neuralgia
PubMed: 35263894
DOI: 10.4103/0028-3886.338701 -
British Medical Journal Feb 1969
Topics: Adult; Humans; Male; Occupational Diseases; Peripheral Nervous System Diseases; Psychophysiologic Disorders; Taste; Trichloroethylene; Trigeminal Nerve
PubMed: 4303442
DOI: 10.1136/bmj.1.5641.422 -
Neurologia Medico-chirurgica Feb 2022Trigeminal neuralgia (TN) is often caused by various vein forms. Herein, we report two cases of vein-related TN. In the first case, the vein of the cerebellopontine...
Trigeminal neuralgia (TN) is often caused by various vein forms. Herein, we report two cases of vein-related TN. In the first case, the vein of the cerebellopontine fissure (VCPF), along with the thickened surrounding arachnoid, clung to the trigeminal nerve. As the perfusion range of this vein was expected to be wide and its injury might cause extensive venous infarction, the anchor between the trigeminal nerve and the vein was carefully dissected and the vein was successfully transposed. In the second case, the involvement of the vein of the middle cerebellar peduncle (VMCP), which penetrates the nerve bundle of the trigeminal nerve, was suspected. Because vein transposition was impossible, the vein was transected at the nerve penetration site after confirming that there was sufficient collateral venous outflow. The superior petrosal vein and its tributaries are the primary causative veins of vein-related TN, and their contact patterns are infinite. Moreover, their perfusion range and the presence or absence of collateral venous outflow vary from case to case. Therefore, it is necessary to judge the perfusion range as well as collateral venous outflow based on preoperative images and intraoperative findings and to determine the appropriate treatment method for each case.
Topics: Cerebral Veins; Humans; Microvascular Decompression Surgery; Trigeminal Nerve; Trigeminal Neuralgia; Vascular Surgical Procedures
PubMed: 34732593
DOI: 10.2176/nmc.tn.2021-0154 -
Turkish Neurosurgery 2020To evaluate the relationship between trigeminal neuralgia (TN) and potential magnetic resonance imaging (MRI)-related measurements in patients with TN.
Significance of the Cerebellopontine Cistern Cross-Sectional Area and Trigeminal Nerve Anatomy in Trigeminal Neuralgia: An Anatomical Study Using Magnetic Resonance Imaging.
AIM
To evaluate the relationship between trigeminal neuralgia (TN) and potential magnetic resonance imaging (MRI)-related measurements in patients with TN.
MATERIAL AND METHODS
Retrospective analysis of 104 patients with TN was performed. MRI studies of 98 healthy controls were included in the study to compare the parameters with TN patients’ measurements. MRI measurements of cerebellopontine cistern (CPC) cross-sectional area, trigeminal-pontine angle (TPA) width, and trigeminal nerve cisternal segment length and thickness were assessed on both symptomatic and asymptomatic sides using 1.5T MRI with constructive interference in steady-state sequences. The images were interpreted by two radiologists blinded to the affected sides of the patients.
RESULTS
There were significant differences between the symptomatic and asymptomatic sides in terms of mean trigeminal nerve length (8.8 ± 2.34 mm vs. 9.39 ± 2.29 mm; respectively, p=0.001) and thickness (20.9 ± 9.6 mm2 vs. 25 ± 9.98 mm2, respectively; p < 0.001). The median cerebellopontine cistern cross-sectional area was considerably lower on the symptomatic side compared with the asymptomatic side [201 mm2 (interquartile range=93) vs. 224.5 mm2 (interquartile range=77), respectively; p < 0.001]. There were no significant differences between the trigeminal-pontine angle width on either side (38.32 ± 10.38 vs. 38.78 ± 10.9, respectively; p=0.679). There were no statistically significant differences between the right and left sides regarding these parameters in the control group.
CONCLUSION
Smaller CPC cross-sectional area, trigeminal nerve length, and trigeminal nerve thickness on MRI were demonstrated to commonly exist on the symptomatic side in patients with TN. We suggest that this narrow space may increase the risk of vascular compression on the nerve.
Topics: Adult; Aged; Cerebellopontine Angle; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Pons; Retrospective Studies; Trigeminal Nerve; Trigeminal Neuralgia
PubMed: 32091126
DOI: 10.5137/1019-5149.JTN.27735-19.2 -
Anatomical Record (Hoboken, N.J. : 2007) Apr 2013Modern crocodylians possess a derived sense of face touch, in which numerous trigeminal nerve-innervated dome pressure receptors speckle the face and mandible and sense...
Modern crocodylians possess a derived sense of face touch, in which numerous trigeminal nerve-innervated dome pressure receptors speckle the face and mandible and sense mechanical stimuli. However, the morphological features of this system are not well known, and it remains unclear how the trigeminal system changes during ontogeny and how it scales with other cranial structures. Finally, when this system evolved within crocodyliforms remains a mystery. Thus, new morphological insights into the trigeminal system of extant crocodylians may offer new paleontological tools to investigate this evolutionary transformation. A cross-sectional study integrating histological, morphometric, and 3D imaging analyses was conducted to identify patterns in cranial nervous and bony structures of Alligator mississippiensis. Nine individuals from a broad size range were CT-scanned followed by histomorphometric sampling of mandibular and maxillary nerve divisions of the trigeminal nerve. Endocast volume, trigeminal fossa volume, and maxillomandibular foramen size were compared with axon counts from proximal and distal regions of the trigeminal nerves to identify scaling properties of the structures. The trigeminal fossa has a significant positive correlation with skull length and endocast volume. We also found that axon density is greater in smaller alligators and total axon count has a significant negative correlation with skull size. Six additional extant and fossil crocodyliforms were included in a supplementary scaling analysis, which found that size was not an accurate predictor of trigeminal anatomy. This suggests that phylogeny or somatosensory adaptations may be responsible for the variation in trigeminal ganglion and nerve size in crocodyliforms.
Topics: Adaptation, Physiological; Alligators and Crocodiles; Animals; Biological Evolution; Cephalometry; Face; Imaging, Three-Dimensional; Mandibular Nerve; Maxillary Nerve; Mechanotransduction, Cellular; Pressoreceptors; Pressure; Tomography, X-Ray Computed; Touch; Touch Perception; Trigeminal Ganglion; Trigeminal Nerve
PubMed: 23408584
DOI: 10.1002/ar.22666