Trigeminal Nerve

The present study measured the position of the greater palatine foramen relative to adjacent anatomical landmarks in Brazilian skulls. The perpendicular distance of the greater palatine foramen to the midline maxillary suture in Brazilian skulls was about 14 mm and the distance of greater palatine foramen to the incisive foramen was approximately 36 mm. The distance of greater palatine foramen to the posterior border of the hard palate was approximately 3 mm, and the mean angle between the midline maxillary suture and the line from the incisive foramen and the greater palatine foramen was 22.71 degrees . In almost 70% of the cases, the greater palatine foramen opened in an anterior direction. The mean palatine length was approximately 52 mm. In the greater majority of the skulls (93.81%), the greater palatine foramina were opposite or distal to the maxillary third molar. These data will be helpful in comparing these skulls to those from various other regions as well as comparing sku...

GOALS:
To give an overview on the theoretical and practical applications of chemosensory event-related potentials.
METHODS:
Chemosensory event-related potentials (ERPs) may be elicited by brief and precisely defined odorous stimuli. Based on the principles of air-dilution olfactometry, a stimulator was developed in the late 1970s, which allows stimulation of the olfactory neuroepithelium and the nasal mucosa with no concomitant mechanical stimulation. Chemosensory ERPs were obtained after stimulation of the olfactory nerve (olfactory ERPs) or the trigeminal nerve (somatosensory or trigeminal ERPs). The characteristics of the stimulator for chemosensory research as well as the variables influencing the responses are discussed in this paper.
RESULTS:
Implementation and normative data from our department are reported with different clinical examples from otorhinolaryngologic clinic. The bulk of the evoked response consists of a large negative component (often referred to as N1), which occurs between 320 and 450 ms after stimulus onset. This component is followed by a large positive component, often referred to as P2, occurring between 530 and 800 ms after stimulus onset. Absence of olfactory ERPs and presence (even with subtle changes) of somatosensory ERPs is a strong indicator of the presence of an olfactory dysfunction.
CONCLUSIONS:
This review examines and discusses the methods of chemosensory stimulation as well as the electrophysiological correlates elicited by such stimuli. The clinical applications of chemosensory ERPs in neurology and otorhinolaryngology are outlined.

The facial nerve (CN VII) nerve follows a torturous and complex path from its emergence at the pontomedullary junction to its various destinations. It exhibits a highly variable and complicated branching pattern and forms communications with several other cranial nerves. The facial nerve forms most of these neural intercommunications with branches of all three divisions of the trigeminal nerve (CN V), including branches of the auriculotemporal, buccal, mental, lingual, infraorbital, zygomatic, and ophthalmic nerves. Furthermore, CN VII also communicates with branches of the vestibulocochlear nerve (CN VIII), glossopharyngeal nerve (CN IX), and vagus nerve (CN X) as well as with branches of the cervical plexus such as the great auricular, greater, and lesser occipital, and transverse cervical nerves. This review intends to explore the many communications between the facial nerve and other nerves along its course from the brainstem to its peripheral branches on the human face. Such connections may have importance during clinical examination and surgical procedures of the facial nerve. Knowledge of the anatomy of these neural connections may be particularly important in facial reconstructive surgery, neck dissection, and various nerve transfer procedures as well as for understanding the pathophysiology of various cranial, skull base, and neck disorders.

The percutaneous Hartel transoval route goes through an inverted pyramid, with an inferior summit and a superior base that includes three compartments. The danger of the inferior compartment is the parotid duct. The middle compartment contains many branches of the mandibular nerve. The superior compartment is crossed by the internal maxillary artery and its branches, as well as the auditory tube. The base of the pyramid presents not only the foramen ovale, but also the foramen lacerum, where the trocar may injure the internal carotid, and the foramen jugulare, where the trocar may meet the internal jugular vein and nerves of the pars nervosa (IX, X, XI). The trigeminal cave contains, within the trigeminal cistern, the trigeminal ganglion, extended backward by the triangular plexus (the target for thermocoagulation). These structures are undercrossed by the masticatory motor branch of the trigeminal nerve.

Background A review of Dr. Harvey Cushing’s surgical cases at the Johns Hopkins Hospital provided insight into his early work on trigeminal neuralgia (TN). There was perhaps no other affliction that captured his attention in the way that TN did, and he built a remarkable legacy of successful treatment. At the time, surgical interventions carried an operative mortality of 20%. Methods The Johns Hopkins Hospital surgical records from 1896–1912 were reviewed to contribute new cases to the 20 reports provided by Dr. Cushing in his early publications in 1900 and 1905. This review uncovered 123 TN cases, representing 168 interventions. Results At the start of his career, Cushing treated TN mainly through Gasserion ganglion extirpations and peripheral neurectomies; however, he nearly abandoned these methods in favor of sensory root avulsion after 1906 and did not perform alcohol injections until his later years at Hopkins. Overall, Cushing had a 0.6% mortality rate; additionally, 91% of patients were improved at the time of discharge. However, 26% of patients had a recurrence requiring further intervention by Cushing. Conclusion Modern day interventions of TN are reflective of the legacy left to us by Harvey Cushing, a pioneering forefather in neurosurgery. He pioneered the infra-arterial approach to excision of the Gasserion ganglion in face of problematic bleeding and later the use of sensory root avulsion to spare motor function. Through the evolution of his legacy and the refinement of original approaches, the quest to advance the treatment of TN took him along the trigeminal nerve from the periphery into the brain.

Following on from ecological theories of perception, such as the one proposed by [Gibson, J. J. (1966). The senses considered as perceptual systems. Boston: Houghton Mifflin] this paper reviews the literature on the multisensory interactions underlying the perception of flavor in order to determine the extent to which it is really appropriate to consider flavor perception as a distinct perceptual system. We propose that the multisensory perception of flavor may be indicative of the fact that the taxonomy currently used to define our senses is simply not appropriate. According to the view outlined here, the act of eating allows the different qualities of foodstuffs to be combined into unified percepts; and flavor can be used as a term to describe the combination of tastes, smells, trigeminal, and tactile sensations as well as the visual and auditory cues, that we perceive when tasting food.

Migraine and tension-type headaches have always plagued mankind. In spite of all the research dollars spent trying to determine the etiologies of these headaches, the neurology community still has not established a known cause of migraine and tension type headaches. This paper describes a study that was conducted for the U.S. Food and Drug Administration in which the efficacy of the Nociceptive Trigeminal Inhibition Tension Suppression System was evaluated and proved safe and efficacious in the reduction of medically diagnosed migraine and tension-type headache.

Nervio mixto que emerge sobre la cara anterior de la protuberancia como una raíz sensitiva grande y una raíz motora más pequeña. Su ganglio sensitivo (el ganglio semilunar, trigeminal o ganglio de Gasser) está situado en una depresión conocida como fosita de Gasser, cerca del vértice de la cara anterosuperior del peñasco del temporal. De este ganglio nacen las tres divisiones mayores del nervio, la rama oftálmica (V1), la rama maxilar superior (V2) y la rama mandibular (V3). V1 y V2 son netamente sensitivos, mientras que V3 es mixto, ya que el componente motor del nervio discurre con él.

BackgroundAtypical facial pain (AFP) is a throbbing pain situated deep in the eye and malar region, often radiating to the ear, neck, and shoulders. The pain generally is not within any dermatomal or anatomical boundaries. Atypical facial pain is distinct from trigeminal neuralgia and its variants. Therefore, the treatment of AFP should be specified. There is also no consensus in

Patients presenting with facial pain often have ineffective pain relief with medical therapy. Cases refractory to medical management are frequently treated with surgical or minimally invasive procedures with variable success rates. We report on the use of ultrasound-guided trigeminal nerve block via the pterygopalatine fossa in patients following refractory medical and surgical treatment. To present the immediate and long-term efficacy of ultrasound-guided injections of local anesthetic and steroids in the pterygopalatine fossa in patients with unilateral facial pain that failed pharmacological and surgical interventions. Academic pain management center. Prospective case series. Fifteen patients were treated with ultrasound-guided trigeminal nerve block with local anesthetic and steroids placed into the pterygopalatine fossa. All patients achieved complete sensory analgesia to pin prick in the distribution of the V2 branch of the trigeminal nerve and 80% (12 out of 15) achieved comp...

This study reports a review of the literature on the structural anatomy of the Vth, VIIth, VIIIth, IXth, and Xth cranial nerves, known to harbor dysfunction syndromes in humans. Because these dysfunctions are hypothesized to be caused by neurovascular conflicts at the root entry/exit zone and the transitional zone between central and peripheral myelinization, this investigation focused on the study and description of this junction. All the cranial nerves, except the optic and olfactory nerves, which are considered to be more a direct expansion of the central nervous system, have a transitional zone between central myelin (coming from oligodendrocytes) and peripheral myelin (produced by Schwann cells). The human studies reported in the literature argue in favor of a dome-shaped transitional zone directed to the periphery. It seems that this junctional region is situated more peripherally in sensory nerves than in motor nerves. The transitional zone is situated very peripherally for t...

Smell tests for clinical use have been developed in different countries, but no single test has gained general acceptance. The objectives of the study were to evaluate the smell outcomes in a Spanish population. A prospective study on healthy volunteers (n = 120) without olfactory disturbances was performed. The volunteers were differentiated by gender, age, and smoking habit groups. We used a new olfactory test, the Barcelona Smell Test 24 (BAST-24) that consists of 24 odours scoring smell detection, identification, and forced choice. Volunteers showed the highest scores on smell detection for both 1st (99%) and 5th cranial nerve (98%) odours. Spontaneous smell identification (54.7% and 59.3%) and forced choice (72.2% and 42.6%) scores were lower than those of smell detection, for both 1st and 5th cranial nerves respectively. On smell identification, volunteers scored higher in the left than in the right nostril. Females had better smell identification for both 1st and 5th cranial ...

The trigeminal nerve responds to a variety of nociceptive stimuli, including many chemicals that activate the olfactory system at lower concentrations. However, the mechanisms by which specific odorants activate the trigeminal nerve are largely undetermined. We used an integrative approach to determine whether TRPA1 channels were the target of eight olfactory stimuli known to activate the trigeminal nerve. In a mammalian cell line stably expressing the human TRPA1 channel, we observed significant increases in intracellular calcium levels upon application of α-terpineol, amyl acetate, benzaldehyde, and toluene. Notably, these responses were greatly reduced when these chemicals were applied in conjunction with the TRPA1 inhibitor HC-030031. To determine whether TRPA1 is required for detecting these odorants as irritants in vivo, we evaluated physiological and behavioral responses to these stimuli in mice lacking the TRPA1 channel. A decline in respiration was seen in wild-type but not TRPA1 knockout mice upon exposure to α-terpineol, benzaldehyde, and toluene. Furthermore, we observed either attenuated or absent avoidance behaviors in TRPA1 knockout mice compared to wild-type mice when exposed to α-terpineol, amyl acetate, and benzaldehyde. Our results show that TRPA1 is a molecular target for four different odorants—α-terpineol, amyl acetate, benzaldehyde, and toluene. Additionally, this study suggests that TRPA1 is required for detection of α-terpineol, benzaldehyde, and toluene as trigeminal irritants. However, TRPA1 is likely only one of multiple trigeminal receptors detecting amyl acetate.

Wobbly hedgehog syndrome (WHS) is a leading cause of neurologic disease in African pygmy hedgehogs (APHs; Atelerix albiventris). This study describes the signalment, clinical signs, gross, microscopic, and ultrastructural lesions of WHS in a cohort of 12 pet APHs. Microscopically, lesions consisted of status spongiosus of the white matter, typically bilateral and symmetrical, with myelin degeneration and loss that was accompanied by neuronal/axonal degeneration plus reactive microgliosis and mild, focal astrocytosis and astrogliosis. Lesions were most severe in the cerebellum and medulla oblongata, as well as cervical and thoracic spinal cord. Less affected areas were the corona radiata, corpus callosum, corpus striatum, internal capsule, and the mesencephalon. Ultrastructurally, the lesions consisted of splitting of the myelin sheath at the intraperiod line with subsequent focal expansion, resulting in status spongiosus, disruption, dilatation, rhexis, and phagocytosis. Based on th...

Trigeminal neuralgia is a common cause of facial pain. It has a significant impact on the quality of life and the socioeconomic functioning of the patient. The aim of this review is to provide recommendations for medical management of trigeminal neuralgia based on current evidence. Based upon the analyses of the literature combined with experience in pain management, symptoms, assessment, differential diagnosis, and treatment possibilities of trigeminal neuralgia are described and discussed. Recommendations for pain management are given and are displayed in a clinical practice algorithm. Treatment should be multidisciplinary. Various treatment options and their risks should be discussed with the patient. The first treatment of choice is carbamazepine or oxcarbazepine. In younger patients, the first choice of invasive treatment is probably microvascular decompression. For elderly patients, radiofrequency treatment of Gasserian ganglion is recommended and the technique is described in detail.