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Turkish Journal of Medical Sciences Oct 2022Morphological differences that can lead the trigeminal nerve to neurovascular conflict and a new solitary pontine lesion are associated with the pathogenesis of...
BACKGROUND
Morphological differences that can lead the trigeminal nerve to neurovascular conflict and a new solitary pontine lesion are associated with the pathogenesis of trigeminal neuralgia (TN). In this case-control study, we aimed to contribute to the current discussions about the pathogenesis of TN by investigating the anatomical structures that may have an effect on the morphometric parameters of the trigeminal nerve.
METHODS
This study included 25 patients with TN followed up for pain in the Department of Algology, Faculty of Medicine, and 25 age- and gender-matched controls. We performed morphometric measurements including the length and volume of the trigeminal nerve, cerebellopontine cistern, pons, and posterior fossa in the MRIs of these individuals. Comparative analyses were performed for the mean of the affected and unaffected sides of the TN patients and the right, left, and both sides of the control group.
RESULTS
In patients with TN, on the affected side, length and volume of the trigeminal nerve and cerebellopontine cistern volume were found smaller than controls (p < 0.05). Pons volume was higher in patients with TN compared to controls (p < 0.05). The length of the affected nerve was significantly related to prepontine cistern length and cerebellopontine cistern volume (p < 0.05).
DISCUSSION
The cerebellopontine cistern volume has a significant impact on the morphometric characteristics of the trigeminal nerve. Especially, whether the increase in the volume of pons causes a decrease in the volume of cerebellopontine cistern should be clarified with further research.
Topics: Humans; Trigeminal Neuralgia; Case-Control Studies; Trigeminal Nerve; Pons; Magnetic Resonance Imaging
PubMed: 36422504
DOI: 10.55730/1300-0144.5503 -
Neurobiology of Disease May 2023The implications of neurogenic inflammation and neuroinflammation in the pathophysiology of migraine have been clearly demonstrated in preclinical migraine models... (Review)
Review
The implications of neurogenic inflammation and neuroinflammation in the pathophysiology of migraine have been clearly demonstrated in preclinical migraine models involving several sites relevant in the trigemino-vascular system, including dural vessels and trigeminal endings, the trigeminal ganglion, the trigeminal nucleus caudalis as well as central trigeminal pain processing structures. In this context, a relevant role has been attributed over the years to some sensory and parasympathetic neuropeptides, in particular calcitonin gene neuropeptide, vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide. Several preclinical and clinical lines of evidence also support the implication of the potent vasodilator and messenger molecule nitric oxide in migraine pathophysiology. All these molecules are involved in vasodilation of the intracranial vasculature, as well as in the peripheral and central sensitization of the trigeminal system. At meningeal level, the engagement of some immune cells of innate immunity, including mast-cells and dendritic cells, and their mediators, has been observed in preclinical migraine models of neurogenic inflammation in response to sensory neuropeptides release due to trigemino-vascular system activation. In the context of neuroinflammatory events implicated in migraine pathogenesis, also activated glial cells in the peripheral and central structures processing trigeminal nociceptive signals seem to play a relevant role. Finally, cortical spreading depression, the pathophysiological substrate of migraine aura, has been reported to be associated with inflammatory mechanisms such as pro-inflammatory cytokine upregulation and intracellular signalling. Reactive astrocytosis consequent to cortical spreading depression is linked to an upregulation of these inflammatory markers. The present review summarizes current findings on the roles of immune cells and inflammatory responses in the pathophysiology of migraine and their possible exploitation in the view of innovative disease-modifying strategies.
Topics: Humans; Neurogenic Inflammation; Neuroinflammatory Diseases; Migraine Disorders; Trigeminal Ganglion; Pituitary Adenylate Cyclase-Activating Polypeptide
PubMed: 36907522
DOI: 10.1016/j.nbd.2023.106072 -
Current Neuropharmacology 2021Trigeminal neuralgia is a chronic disease characterized by intense facial pain that is caused by trigeminal nerve affectation. It usually affects adults from 50 years of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Trigeminal neuralgia is a chronic disease characterized by intense facial pain that is caused by trigeminal nerve affectation. It usually affects adults from 50 years of age, and is more frequent in women. Additionally, it presents serious psychological effects that often lead to depression, which is why it is considered highly disabling. The therapeutic approach is based on the modification of nerve activity through electrical, surgical or chemical stimulation in specific regions of the nervous system.
OBJECTIVE
To perform a meta-analysis of the scientific literature related to invasive and non-invasive electrical neuromodulation of trigeminal neuralgia, in order to assess their effects over pain and adverse effects.
METHODS
A literature search was conducted in 4 databases, followed by a manual search of articles on invasive or non-invasive electrical neuromodulation to control the pain of trigeminal neuralgia, including the last 15 years.
RESULTS
Regarding non-invasive methods, clinical trials did not present enough results in order to perform a meta-analysis. Regarding invasive methods, clinical trials meta-analysis showed no statistical differences between different treatment methods. In all cases, improvements in patients' pain were reported, although results regarding adverse effects were variable.
CONCLUSION
In the treatment of trigeminal neuralgia, the continuous radiofrequency provides better short and medium-term results, but pulsed radiofrequency shows less adverse effects after treatment, and has better results in the long-term.
Topics: Adult; Chronic Disease; Female; Humans; Neuralgia; Treatment Outcome; Trigeminal Nerve; Trigeminal Neuralgia
PubMed: 32727329
DOI: 10.2174/1570159X18666200729091314 -
Neurology India 2022The culprit of trigeminal neuralgia (TGN) may occur at any point between the nerve's root entry zone (REZ) and Meckel's cave. Meckel's cave meningoencephaloceles are... (Review)
Review
BACKGROUND
The culprit of trigeminal neuralgia (TGN) may occur at any point between the nerve's root entry zone (REZ) and Meckel's cave. Meckel's cave meningoencephaloceles are rare middle cranial fossa defects that usually remain asymptomatic but may contain prolapsed trigeminal nerve rootlets and result in TGN. Their management and surgical outcomes remain poorly understood.
OBJECTIVES
To perform a systematic review of clinical presentation and surgical outcomes of middle fossa defects presenting with trigeminal nerve-related symptoms.
MATERIALS AND METHODS
A systematic review was conducted in accordance with the PRISMA guidelines for all reports of middle cranial fossa defects causing trigeminal nerve-related symptoms. The pathophysiology, presentation, surgical management, and outcomes are discussed and illustrated with a case.
RESULTS
Initial search from inception to March 2021 identified 33 articles for screening. After applying inclusion and exclusion criteria, 6 articles were included representing a total of 8 cases in addition to our case (n = 9). All 9 patients were females and 33.3% (n = 3) presented with classic trigeminal neuralgia. "Empty sella" syndrome and radiologic signs of intracranial hypertension were present in 40%-62%. No patient presented with cerebrospinal fluid leak. The preferred treatment modality was surgical with subtemporal extradural repairs using combinations of autologous fat and muscle grafts and synthetic dura. Postoperative outcomes were only available in 55.5% (n = 5) of the cases, and nearly all reported complete symptom resolution, except for one case in which the meningoencephalocele wall was incised, along with trigeminal rootlets adhered to it. Our patient had immediate and durable symptom relief after a 4-year follow-up.
CONCLUSIONS
MEC containing prolapsed trigeminal nerve rootlets can cause typical trigeminal neuralgia from chronic pulsatile stress. This supports the hypothesis that the compressive or demyelinating culprit can locate more ventrally on the course of the trigeminal nerve. Subtemporal extradural surgical repairs can be safe, effective, and durable. Incising the MEC wall should be avoided as it may have trigeminal rootlets adhered to it.
Topics: Cranial Fossa, Middle; Dura Mater; Encephalocele; Female; Humans; Male; Meningocele; Trigeminal Nerve; Trigeminal Neuralgia
PubMed: 35864609
DOI: 10.4103/0028-3886.349629 -
Pain Physician Mar 2022The Gasserian ganglion (GG) is the primary neuronal aggregation area of the trigeminal nervous system and the epidural structure outside the central nervous system,...
BACKGROUND
The Gasserian ganglion (GG) is the primary neuronal aggregation area of the trigeminal nervous system and the epidural structure outside the central nervous system, thus, it has become the most commonly used target for minimally invasive treatment of trigeminal neuralgia (TN). Whether it is the classic trigeminal radiofrequency treatment or GG balloon compression therapy, the intervention target is the GG. The anatomy and imaging anatomy of the GG of the trigeminal nerve is of great importance in the minimally invasive treatment of TN.
OBJECTIVE
To study the anatomy of the trigeminal nerve and multimodal image fusion, and to provide a basis for a clinical minimally invasive interventional treatment forTN.
STUDY DESIGN
Review, clinical research study.
SETTING
Department of Anesthesiology and Pain Medical Center, Jiaxing, China.
METHODS
Dissect the general structure of the trigeminal nerve and its positional relationship with adjacent structures, and use computed tomography (CT) and magnetic resonance imaging (MRI) to observe the trigeminal nerve, and then, perform a fusion of the CT/MR images.
RESULTS
The GG of the trigeminal nerve is located in Meckel's cave of the middle cranial fossa, and the 3 branches of the nerve fibers are intertwined. CT could only clearly show the bony structures adjacent to the GG, rather than the GG in the body, which was inconsistent with MR images. The bony structure was blurred, while the Meckel's cave and nerve roots, where the trigeminal nerve is located, could be clearly distinguished. Fusing the CT/MR images could provide 2 complementary advantages.
LIMITATIONS
It does not prove the the balloon position thought to be a "dumbbell" shape is adequate for the successful treatment.
CONCLUSION
Based on the anatomical structure and position of the trigeminal nerve, it is difficult to achieve highly selective branch treatment of TN with radiofrequency in the GG. For the treatment of TN with percutaneous microballoon compression on the GG, the balloon catheter should be placed in Meckel's cave. While it is not easy to insert into Meckel's cave, the depth of the balloon catheter should be that the distal end is flush with the top of the temporal bone petrous cone.
Topics: Humans; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Tomography, X-Ray Computed; Trigeminal Nerve; Trigeminal Neuralgia
PubMed: 35322984
DOI: No ID Found -
Neuromodulation : Journal of the... Aug 2021Subcutaneous trigeminal nerve field stimulation (sTNFS) is a neuromodulatory treatment for neuropathic trigeminal pain with the ability to reduce the intensity and...
INTRODUCTION
Subcutaneous trigeminal nerve field stimulation (sTNFS) is a neuromodulatory treatment for neuropathic trigeminal pain with the ability to reduce the intensity and frequency of pain attacks. However, hardware issues including lead migration, skin erosion, infection, so-called pocket pain at the site of the implanted neurostimulator are reported. Implantable wireless neurostimulation technology promises not only an even less invasive sTNFS treatment and thinner and more flexible electrodes better suited for facial implants, but also provides further advantages such as lack of an implantable neurostimulator and 3T magnetic resonance imaging compatibility.
MATERIAL AND METHODS
All patients who had received trial stimulation with a partially implantable sTNFS system were analyzed for ICHD-3 (3rd edition of the International Classification of Headache Disorders) diagnosis, success of trial stimulation, pre- and postoperative pain intensity, frequency of attacks, complications, and side-effects of sTNFS.
RESULTS
All patients (N = 3) responded to sTNFS (≥50% pain reduction) during the trial period. According to ICHD-3, N = 2 of the patients were classified with trigeminal neuralgia (TN) with concomitant persistent facial pain and N = 1 patient with multiple sclerosis associated TN. The time of the test period was 44 ± 31.24 days (mean ± SD). The average daily duration of stimulation per patient amounted 2.5 ± 2.2 hours (range 1-5). The pain intensity (defined on a visual analog scale) was reduced by 80% ± 17% (mean ± SD). Reduction or cessation in pain medication was observed in all patients. No surgical complications occurred in the long-term follow-up period of 18.84 ± 6 (mean ± SD) months.
CONCLUSION
The partially implantable sTNFS device seems to be safe, effective, and reliable. Compared to conventional devices, the equipment is not limited to the length of trial stimulation. Furthermore, the daily stimulation duration was much shorter compared to previous reports.
Topics: Electric Stimulation Therapy; Electrodes, Implanted; Humans; Pain, Intractable; Treatment Outcome; Trigeminal Nerve
PubMed: 34313358
DOI: 10.1111/ner.13478 -
Acta Neurochirurgica May 2024Based on a personal experience of 4200 surgeries, radiofrequency thermocoagulation is useful lesional treatment for those trigeminal neuralgias (TNs) not amenable to... (Review)
Review
Based on a personal experience of 4200 surgeries, radiofrequency thermocoagulation is useful lesional treatment for those trigeminal neuralgias (TNs) not amenable to microvascular decompression (idiopathic or secondary TNs). Introduced through the foramen ovale, behind the trigemnial ganglion in the triangular plexus, the needle is navigated by radiology and neurophysiological testing to target the retrogasserian fibers corresponding to the trigger zone. Heating to 55-75 °C can achieve hypoesthesia without anaesthesia dolorosa if properly controlled. Depth of anaesthesia varies dynamically sedation for cannulation and lesioning, and awareness during neurophysiologic navigation. Proper technique ensures long-lasting results in more than 75% of patients.
Topics: Trigeminal Neuralgia; Humans; Electrocoagulation; Trigeminal Nerve; Foramen Ovale; Trigeminal Ganglion; Microvascular Decompression Surgery; Treatment Outcome
PubMed: 38727725
DOI: 10.1007/s00701-024-06074-2 -
Journal of Neurophysiology Feb 2020Blinking sustains the corneal tear film generated by sexually dimorphic lacrimal and meibomian glands. Our study examines whether trigeminal control of blinking is also...
Blinking sustains the corneal tear film generated by sexually dimorphic lacrimal and meibomian glands. Our study examines whether trigeminal control of blinking is also sexually dimorphic by investigating trigeminal reflex blinking, associative blink modification, and spontaneous blinking in male and female rats before and after unilateral dry eye caused by exorbital gland removal. Before gland removal, female rats exhibited a lower threshold for evoking trigeminal reflex blinks, a weaker effect of associative blink modification, and longer-duration spontaneous blinks than males. Spontaneous blink rate, reflex blink excitability, and occurrence of blink oscillations did not differ between the sexes. Reanalysis of previous data showed that humans showed the same blink sexual dimorphisms as rats. During the first 2 wk of dry eye, trigeminal blink circuit excitability and blink oscillations steadily rose in male rats, whereas excitability and blink oscillations did not change in females. Following dry eye, spontaneous blink duration increased for both males and females, whereas spontaneous blink rate remained constant for males but decreased for females. The associative modification treatment to depress trigeminal blink amplitude initially produced blink depression in males that converted to blink potentiation as trigeminal excitability rose, whereas females exhibited progressively more blink depression. These data indicated that dry eye increased excitability in male trigeminal reflex blink circuits at the expense of circuit modifiability, whereas trigeminal modifiability increased in females. This increased modifiability of female trigeminal blink circuits with dry eye may contribute to the preponderance of females developing the focal dystonia, benign essential blepharospasm. All the elements controlling the corneal tear film are sexually dimorphic. Blinking, which smooths and maintains the tear film, also exhibits sex differences. Dry eye increases the sexual dimorphisms of blinking, including increased exaggeration of excitability in males and enhanced modifiability of the female trigeminal complex. This increased modifiability may explain female predominance in the development of the focal dystonia, benign essential blepharospasm.
Topics: Animals; Blepharospasm; Blinking; Dry Eye Syndromes; Female; Male; Rats; Rats, Sprague-Dawley; Sex Characteristics; Trigeminal Nerve
PubMed: 31940243
DOI: 10.1152/jn.00635.2019 -
Cephalalgia : An International Journal... Nov 2019The trigeminal ganglion is unique among the somatosensory ganglia regarding its topography, structure, composition and possibly some functional properties of its... (Review)
Review
INTRODUCTION
The trigeminal ganglion is unique among the somatosensory ganglia regarding its topography, structure, composition and possibly some functional properties of its cellular components. Being mainly responsible for the sensory innervation of the anterior regions of the head, it is a major target for headache research. One intriguing question is if the trigeminal ganglion is merely a transition site for sensory information from the periphery to the central nervous system, or if intracellular modulatory mechanisms and intercellular signaling are capable of controlling sensory information relevant for the pathophysiology of headaches.
METHODS
An online search based on PubMed was made using the keyword "trigeminal ganglion" in combination with "anatomy", "headache", "migraine", "neuropeptides", "receptors" and "signaling". From the relevant literature, further references were selected in view of their relevance for headache mechanisms. The essential information was organized based on location and cell types of the trigeminal ganglion, neuropeptides, receptors for signaling molecules, signaling mechanisms, and their possible relevance for headache generation.
RESULTS
The trigeminal ganglion consists of clusters of sensory neurons and their peripheral and central axon processes, which are arranged according to the three trigeminal partitions V1-V3. The neurons are surrounded by satellite glial cells, the axons by Schwann cells. In addition, macrophage-like cells can be found in the trigeminal ganglion. Neurons express various neuropeptides, among which calcitonin gene-related peptide is the most prominent in terms of its prevalence and its role in primary headaches. The classical calcitonin gene-related peptide receptors are expressed in non-calcitonin gene-related peptide neurons and satellite glial cells, although the possibility of a second calcitonin gene-related peptide receptor in calcitonin gene-related peptide neurons remains to be investigated. A variety of other signal molecules like adenosine triphosphate, nitric oxide, cytokines, and neurotrophic factors are released from trigeminal ganglion cells and may act at receptors on adjacent neurons or satellite glial cells.
CONCLUSIONS
The trigeminal ganglion may act as an integrative organ. The morphological and functional arrangement of trigeminal ganglion cells suggests that intercellular and possibly also autocrine signaling mechanisms interact with intracellular mechanisms, including gene expression, to modulate sensory information. Receptors and neurotrophic factors delivered to the periphery or the trigeminal brainstem can contribute to peripheral and central sensitization, as in the case of primary headaches. The trigeminal ganglion as a target of drug action outside the blood-brain barrier should therefore be taken into account.
Topics: Adenosine Triphosphate; Afferent Pathways; Animals; Calcitonin Gene-Related Peptide; Calcitonin Gene-Related Peptide Receptor Antagonists; Cytokines; Headache; Humans; Intercellular Signaling Peptides and Proteins; Migraine Disorders; Nerve Growth Factors; Neuropeptides; Nitric Oxide; Nociception; Rats; Receptors, Calcitonin Gene-Related Peptide; Receptors, Neuropeptide; Sensory Receptor Cells; Signal Transduction; Trigeminal Ganglion
PubMed: 29989427
DOI: 10.1177/0333102418786261 -
Brain Stimulation 2023Trigeminal nerve stimulation (TNS) has been proposed as a promising intervention for coma awakening. However, the effect of TNS on patients with prolonged disorders of... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Trigeminal nerve stimulation (TNS) has been proposed as a promising intervention for coma awakening. However, the effect of TNS on patients with prolonged disorders of consciousness (pDoC) is still unclear.
OBJECTIVE
This study aimed to investigate the therapeutic effects of TNS in pDoC caused by stroke, trauma, and anoxia.
METHODS
A total of 60 patients (male =25, female =35) aged over 18 who were in a vegetative state or minimally conscious state were randomly assigned to the TNS (N = 30) or sham TNS (N = 30) groups. 4 weeks of intervention and a followed up for 8 weeks were performed. The Glasgow Coma Scale (GCS) and Coma Recovery Scale-Revised (CRS-R) scores as primary outcomes were assessed at baseline and at 2, 4, 8, and 12 weeks.
RESULTS
The score changes in the TNS group over time for CRS-R (2-week: mean difference = 0.9, 95% CI = [0.3, 1.5], P = 0.006; 4-week: 1.6, 95% CI = [0.8, 2.5], P < 0.001; 8-week: mean difference = 2.4, 95% CI = [1.3, 3.5], P < 0.001; 12-week: mean difference = 2.3, 95% CI = [1.1, 3.4], P < 0.001) and GCS (4-week: mean difference = 0.7, 95% CI = [0.3, 1.2], P = 0.002; 8-week: mean difference = 1.1, 95% CI = [0.6, 1.7], P < 0.001; 12-week: 1.1, 95% CI = [0.5, 1.7], P = 0.003) were higher than those in the sham group. 18-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) revealed that the metabolism of the right parahippocampal cortex, right precuneus, and bilateral middle cingulate cortex was significantly increased in TNS group.
CONCLUSION
The results of this study indicate that TNS could increase local brain metabolism and may promote functional recovery in patients with prolonged disorders of consciousness.
REGISTRATION INFORMATION
Name of the registry: Chinese Clinical Trial Registry.
REGISTRATION NUMBER
ChiCTR1900025573. The date that the study was submitted to a registry: 2019-09-01. The date when the first patient was enrolled was 2021-01-20.
Topics: Humans; Male; Female; Adolescent; Adult; Treatment Outcome; Coma; Consciousness Disorders; Consciousness; Persistent Vegetative State; Trigeminal Nerve
PubMed: 37182683
DOI: 10.1016/j.brs.2023.05.002