Extracranial transport of brain lymphatics via cranial nerve in human.

Extracranial waste transport from the brain interstitial fluid to the deep cervical lymph node (dCLN) is not extensively understood. The present study aims to show the cranial nerves that have a role in the transport of brain lymphatics vessels (LVs), their localization, diameter, and number using podoplanin (PDPN) and CD31 immunohistochemistry (IHC) and Western blotting. Cranial nerve samples from 6 human cases (3 cadavers, and 3 autopsies) were evaluated for IHC and 3 autopsies for Western blotting. The IHC staining showed LVs along the optic, olfactory, oculomotor, trigeminal, facial, glossopharyngeal, accessory, and vagus nerves. However, no LVs present along the trochlear, abducens, vestibulocochlear, and hypoglossal nerves. The LVs were predominantly localized at the endoneurium of the cranial nerve that has motor components, and LVs in the cranial nerves that had sensory components were present in all 3 layers. The number of LVs accompanying the olfactory, optic, and trigeminal nerves was classified as numerous; oculomotor, glossopharyngeal, vagus, and accessory was moderate; and facial nerves was few. The largest diameter of LVs was in the epineurium and the smallest one was in the endoneurium. The majority of Western blotting results correlated with the IHC. The present findings suggest that specific cranial nerves with variable quantities provide a pathway for the transport of wastes from the brain to dCLN. Thus, the knowledge of the transport of brain lymphatics along cranial nerves may help understand the pathophysiology of various neurological diseases.

Hypoglossal and Glossopharyngeal Nerve Palsy After Anterior Cervical Decompression and Fusion: A Case Report.

CASE: A 69-year-old man underwent a C3-4 anterior cervical discectomy and fusion and developed postoperative hypoglossal and glossopharyngeal palsies that resolved with symptomatic treatment. CONCLUSION: Cranial nerve palsy is a rare and possibly under-reported injury after higher-level cervical spine surgery. Conscientious positioning and awareness of these nerves during surgical exposure are crucial to minimizing cranial nerve palsies. Proper workup to identify these palsies and differentiate them from other complications is necessary to guide proper treatment.

Ultrasound-guided selective glossopharyngeal nerve block: posterior mandibular ramus approach.

OBJECTIVE: Glossopharyngeal nerve block is a useful interventional technique for pain management of the head and neck. It is performed with landmark techniques or ultrasound guidance. We propose a novel ultrasound-guided glossopharyngeal nerve block technique. METHODS: This new approach was performed in 3 patients in their twenties and thirties. A needle was inserted deeply under the stylohyoid muscle through the sternocleidomastoid muscle. Subsequently, an ultrasound-guided nerve block was performed with 1 mL of 1% xylocaine. The performance of our technique was evaluated with 2 tests: a cold sensitivity test and a gag reflex test. RESULTS: The effect of the nerve block was observed in the posterior third of the tongue on both sides, the tonsils, and the pharyngeal region. The effect lasted for approximately 1.5 hour. Motor efferent block was not observed. CONCLUSIONS: We designated the technique as ultrasound-guided selective glossopharyngeal nerve block: posterior mandibular ramus approach. No complications occurred during the bilateral application. This novel approach can be performed at a very shallow position, compared with conventional methods. There is no damage to tissues other than the muscles, which reduces postoperative complications and patient distress. Although our technique requires further safety assessments and technical refinements, it could represent a simpler alternative to conventional methods in daily clinical practice.

Neuralgia del trigémino y del glosofaríngeo concomitantes, asíncronas y refractarias. Buena respuesta al abordaje quirúrgico en un tiempo / Concomitant, asynchronous and refractory trigeminal and glossopharyngeal neuralgia. Good response to surgical approach in one time

Introducción: La cirugía de descompresión microvascular (DMV) es el tratamiento de elección de una neuralgia craneal refractaria secundaria a compresión vascular. Las neuralgias simultáneas de dos pares craneales son extremadamente infrecuentes. Describimos un caso con neuralgia concomitante del trigémino (NT) y glosofaríngeo (NG) refractarias y secundarias a cruce neurovascular abordadas quirúrgicamente en un mismo tiempo. Caso clínico: Mujer de 65 años con NT derecho (inicialmente en V2-V3) desde 2004 con control regular con carboxamidas. Diecisiete años después empeoraron los paroxismos en V2-V3, aparecieron también en V1 y en el territorio del nervio glosofaríngeo derecho (oído derecho y fosa amigdalar al hablar y deglutir). La resonancia magnética cerebral mostró contacto arterial significativo entre arteria cerebelosa superior (ACS) con origen del V par craneal derecho y de la arteria cerebelosa antero-inferior (AICA) con el origen de pares craneales bajos derechos. Se realizó DMV de ambos pares craneales en un mismo tiempo quirúrgico mediante craniectomía retrosigmoidea, y se procedió a la liberación del V par craneal, en contacto íntimo con la ACS, y del IX par craneal en contacto con la AICA derecha, para lo que se puso teflón entre ellas. La paciente tuvo una resolución inmediata de los paroxismos trigeminales y una mejoría considerable en intensidad y frecuencia de los glosofaríngeos. A los 2 años de la intervención continúa la desescalada de tratamiento neuromodulador con buena respuesta.ConclusiónLa DMV en la NT y NG simultáneas es factible y puede ofrecer un buen resultado posquirúrgico. (AU)

INTRODUCTION: Microvascular decompression (MVD) surgery is the first choice treatment for refractory cranial neuralgia secondary to vascular compression. Simultaneous neuralgia of two cranial nerves is extremely rare. We describe a case of concomitant refractory trigeminal (TN) and glossopharyngeal (GN) neuralgia secondary to neurovascular crossover, treated surgically at the same time. CASE REPORT: 65-year-old woman with right TN (initially V2-V3) since 2004 with regular control with carboxamides. Seventeen years later, paroxysms worsened in V2-V3, also appearing in V1 and in the territory of the right glossopharyngeal nerve (right ear and tonsillar fossa when speaking and swallowing). Cerebral MRI showed significant arterial contact between the superior cerebellar artery (SCA) with the origin of the right V cranial nerve and the antero-inferior cerebellar artery (AICA) with the origin of the right lower CCNN. MVD of both cranial nerves was performed at the same surgical time by means of retrosigmoid craniectomy, releasing the V cranial nerve, in intimate contact with the SCA, and the IX cranial nerve in contact with the right AICA, interposing teflon between them. The patient had an immediate resolution of the trigeminal paroxysms and a dramatic improvement in intensity and frequency of glossopharyngeal paroxysms. Two years after the intervention, de-escalation of neuromodulator treatment continues with good response. CONCLUSION. MVD in simultaneous TN and GN is feasible and can offer a good post-surgical outcome. (AU)

Collet-Sicard syndrome: a scoping review.

Collet-Sicard syndrome (CSS) is the unilateral palsy of the cranial nerves (CN) IX, X, XI, and XII. To our knowledge, no review describes the characteristics of patients diagnosed with CSS. Therefore, this review aims to collect and describe all cases in the literature labeled as CSS. We performed a scoping review of the literature and conducted a database search in Embase and PubMed. We included articles and abstracts with case reports or case series of patients with CSS diagnosis. We classified the cases into two groups: "CSS", referring to patients presenting exclusively with IX-XII nerve involvement, and "CSS-plus", which corresponds to cases with CSS and other neurological impairments. We included 135 patients from 126 articles, of which 84 (67.7%) were male. The most common clinical manifestations reported were dysphagia and dysphonia. The most common etiology was tumoral in 53 cases (39.6%) and vascular in 37 cases (27.6%). The majority of patients showed partial or total improvement, with just over half receiving conservative treatment. The most frequent anatomic space was the jugular foramen (44.4%) and the parapharyngeal retrostyloid space (28.9%). Approximately 21% of the patients had other CN impairments, with the seventh and eighth CN most frequently compromised. We conclude that although there is a need for greater rigor in CSS reporting, the syndrome has a clear utility in identifying the localization of jugular foramen and parapharyngeal retrostyloid space pathology.

The glossopharyngeal nerve (IX cranial nerve pair): anatomical considerations and neuralgia: literature review / O nervo glossofaringeo (IX par de nervo craniano): considerações anatômicas e neuralgia: revisão da literatura

The glossopharyngeal nerve (IX cranial nerve) is a mixed nerve, with both motor and sensory function. This relates to the tongue and pharynx. Glossopharyngeal neuralgia is a rare nervous neuropathy, with poristic, lancinating and paritary crises, usually unilateral. The aim of the study was to review the literature on glossopharyngeal neuralgia of the nerve (IX cranial nerve), highlighting the anatomical aspects of this nerve and the possible causes and complications of neuralgia as well as forms of treatment. A literature review was carried out in the international Pubmed database. The literature review included 72 articles from 2015 to 2021. The keywords used were: "anatomy of glossopharyngeal neuralgia". Of the 72 articles, 7 were used for this literature review. Uncommon as nervous/glossophingeal etiologies and pathologies are neurological abnormalities/neurovarises and pathologies are neurovascular/neurovariseal lesions. Pharmacological treatment approaches mentioned in the literature were therapy with antiepileptics and antidepressants such as carbamazepine and gabapentin; a microvascular decompression; and gamma knife radiosurgery(AU)

O nervo glossofaríngeo (IX par de nervo craniano) é um nervo misto, contendo função tanto motora como sensitiva. Este nervo relaciona-se com a língua e com a faringe. A neuralgia do nervo glossofaríngeo é uma neurapatia rara, sendo caracterizada por crises dolorosas, lancinantes e paroxísticas, geralmente unilaterais. O objetivo do estudo foi realizar uma revisão de literatura sobre a neuralgia do nervo glossofaríngeo (IX par de nervo craniano), destacando os aspectos anatômicos deste nervo e as possíveis causas e complicações da neuralgia bem como formas de tratamento. Foi realizada uma revisão da literatura na base de dados internacional Pubmed. A revisão da literatura incluiu 72 artigos no período de 2015 a 2021. As palavras-chave utilizadas foram: "anatomia da neuralgia do glossofaríngeo". Dos 72 artigos, 7 foram utilizados para esta revisão de literatura. Verificouse que a neuralgia do nervo glossofaríngeo é incomum e as etiologias mais encontradas foram compressão neurovascular/variações vasculares, patologias e traumas. As abordagens dos tratamentos mencionadas na literatura foram a terapia farmacológica da área com antiepilépticos e antidepressivos, como carbamazepina e gabapentina; a descompressão microvascular; e radiocirurgia com faca gama(AU)

Application of biomechanical principles to upper cervical spine anatomy to alleviate symptoms of intermittent cranial nerve IX irritation. Directions for successful self-management of headache post-concussion? A case series.

BACKGROUND: The neck has been implicated as a potential generator of symptoms such as dizziness and headache in individuals with persistent symptoms post concussion. Anatomically, the neck could also be a potential trigger for autonomic or cranial nerve symptoms. The glossopharyngeal nerve which innervates the upper pharynx is one possible autonomic trigger that might be affected by the upper cervical spine. CASE DESCRIPTION: This is a case series of three individuals with persistent post-traumatic headache (PPTH) and symptoms of autonomic dysregulation who also had signs of intermittent glossopharyngeal nerve irritation associated with certain neck positions or movements. Biomechanical principles were applied to anatomical research on the path of the glossopharyngeal nerve, in relation to the upper cervical spine and the dura mater, to alleviate these intermittent symptoms. The patients were provided techniques to be used as tools to immediately alleviate the intermittent dysphagia, which also alleviated the constant headache at the same time. As part of the overall long-term management program, patients were also taught daily exercises to improve upper cervical and dural stability and mobility. OUTCOME: The result was a decrease in intermittent dysphagia, headache, and autonomic symptoms in the long term in persons with PPTH following concussion. DISCUSSION: Autonomic and dysphagia symptoms may provide clues as to the origin of symptoms in a subgroup of individuals with PPTH.

Glossopharyngeal Neuralgia Characterized by Otalgia: A Retrospective Study.

Glossopharyngeal neuralgia (GPN) is an uncommon facial pain syndrome and is characterized by paroxysms of excruciating pain in the distributions of the auricular and pharyngeal branches of cranial nerves IX and X. Glossopharyngeal neuralgia characterized by otalgia alone is rare. Herein, the authors analyzed 2 patients with GPN with otalgia as the main clinical manifestation. The clinical features and prognosis of this rare group of patients with GPN were discussed. They both presented with paroxysmal pain in the external auditory meatus and preoperative magnetic resonance imaging suggested the vertebral artery were closely related to the glossopharyngeal nerves. In both patients, compression of the glossopharyngeal nerve was confirmed during microvascular decompression, and the symptoms were relieved immediately after surgery. At 11 to 15 months follow-up, there was no recurrence of pain. A variety of reasons can cause otalgia. The possibility of GPN is a clinical concern in patients with otalgia as the main complaint. The authors think the involvement of the glossopharyngeal nerve fibers in the tympanic plexus via Jacobson nerve may provide an important anatomic basis for GPN with predominant otalgia. Surface anesthesia test of the pharynx and preoperative magnetic resonance imaging is helpful for diagnosis. Microvascular decompression is effective in the treatment of GPN with predominant otalgia.

Manejo de la disfagia en pacientes con antecedente de infección severa por COVID-19 / Manejo de la disfagia en pacientes con antecedente de infección severa por COVID-19

de la deglución, los cuales representan todas las alteraciones del proceso fisiológico encargado de llevar el alimento desde la boca al esófago y después al estómago, salvaguardando siempre la protección de las vías respiratorias. OBJETIVO. Definir el manejo óptimo, de la disfagia en pacientes con antecedente de infección severa por COVID-19. METODOLOGÍA. Se realizó una revisión de la literatura científica en las bases de datos PubMed y Elsevier que relacionan el manejo de la disfagia y pacientes con antecedente de infección severa por SARS-CoV-2. Se obtuvo un universo de 134 artículos que cumplieron los criterios de búsqueda. Se seleccionaron 24 documentos, para ser considerados en este estudio. RESULTADOS. La incidencia de disfagia posterior a infección severa por SARS-CoV-2 fue del 23,14%, siendo la disfagia leve la más frecuente 48,0%. Los tratamientos clínicos más empleados en el manejo de la disfagia fueron rehabilitación oral y cambio de textura en la dieta en el 77,23% de los casos, mientras que el único tratamiento quirúrgico empleado fue la traqueotomía 37,31%. Un 12,68% de pacientes recuperó su función deglutoria sin un tratamiento específico. La eficacia de los tratamientos clínicos y quirúrgicos en los pacientes sobrevivientes de la infección severa por SARS-CoV-2 fue del 80,68%, con una media en el tiempo de resolución de 58 días. CONCLUSIÓN. La anamnesis es clave para el diagnóstico de disfagia post COVID-19. El tratamiento puede variar, desde un manejo conservador como cambios en la textura de la dieta hasta tratamientos más invasivos como traqueotomía para mejorar la función deglutoria.

INTRODUCTION. The difficulty to swallow or dysphagia is included within the problems of swallowing, which represent all the alterations of the physiological process in charge of carrying the food from the mouth to the esophagus, and then to the stomach, always taking into account the protection of the airways. OBJECTIVE. To define the optimal management, both clinical and surgical, for the adequate treatment of dysphagia produced as a consequence of severe SARS-CoV-2 infection. METHODOLOGY. A review of the scientific literature was carried out using both PubMed and Elsevier databases, which relate the management of dysphagia and patients with a history of severe SARS-CoV-2 infection. RESULTS. The incidence of dysphagia following severe SARS-CoV-2 infection was of 23,14%, with mild dysphagia being the most frequent 48,00%. The most frequently used clinical treatments for dysphagia management were oral rehabilitation and change in dietary texture in 77,23% of cases, while tracheotomy was the only surgical treatment used 37,31%. A total of 12,68% of patients recovered their swallowing function without specific treatment. The efficacy of clinical and surgical treatments in survivors of severe SARS-CoV-2 infection was 80,68%, with a mean resolution time of 58 days. CONCLUSION. An adequate medical history is key to the diagnosis of post-COVID-19 dysphagia. Treatment can range from conservative management such as changes in diet texture to more invasive treatments such as tracheotomy to improve swallowing function.

Ultrasound-Guided Glossopharyngeal Nerve Block for an Awake Intubation in a Patient Predicted to Have a Difficult Airway: A Case Report.

A peripheral nerve block may be used to improve patient tolerance of awake intubation. During an awake intubation, the glossopharyngeal, superior laryngeal, and recurrent laryngeal nerves can mediate discomfort, pain, cough, glottic closure, and gag reflexes. We describe the use of ultrasound-guided superior laryngeal, recurrent laryngeal, and glossopharyngeal nerve blocks to facilitate awake intubation in a patient predicted to have a difficult airway. The glossopharyngeal nerve block was performed via the parapharyngeal space approach targeting the distal glossopharyngeal nerve. This procedure resulted in an uneventful awake intubation.

Glossopharyngeal, Vagus and Accessory Nerves: Anatomy and Pathology.

The glossopharyngeal, vagus, and accessory nerves are discussed in this article, given their intimate anatomical and functional associations. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic due to various disease processes. This article aims to review these nerves' anatomy and demonstrates the imaging aspect of the diseases which most commonly affect them.

Institutional Patterns of Care of Diffuse Intrinsic Pontine Glioma.

Background and Aim: Despite recent advances, the outcomes of diffuse intrinsic pontine glioma (DIPG) remain dismal. This is a retrospective study to understand the pattern of care and its impact on DIPG patients diagnosed over 5 years in a single institute. Subjects and Methods: DIPGs diagnosed between 2015 and 2019 were retrospectively reviewed to understand the demographics, clinical features, patterns of care, and outcomes. The usage of steroids and response to treatment were analyzed as per the available records and criteria. The re-irradiation cohort was propensity matched with patients with a progression-free survival (PFS) >6 months treated with supportive care alone based on PFS and age as a continuous variable. Survival analysis was performed using the Kaplan-Meier method, and Cox regression model was used to identify any potential prognostic factors. Results: One hundred and eighty-four patients were identified with demographic profiles similar to western population-based data in the literature. Of them, 42.4% were residents from outside the state of the institution. About 75.2% of patients completed their first radiotherapy treatment, of which only 5% and 6% had worsening clinical symptoms and persistent need for steroids 1 month posttreatment. On multivariate analysis, Lansky performance status <60 (P = 0.028) and cranial nerve IX and X (P = 0.026) involvement were associated with poor survival outcomes while receiving radiotherapy with better survival (P < 0.001). In the cohort of patients receiving radiotherapy, only re-irradiation (reRT) was associated with improved survival (P = 0.002). Conclusion: Many patient families still do not choose radiotherapy treatment, although it has a consistent and significant positive association with survival and steroid usage. reRT further improves outcomes in the selective cohorts. Involvement of cranial nerves IX and X needs improved care.

Glossopharyngeal neuralgia as initial symptom in combined hyperactive dysfunction syndrome: case report.

OBJECTIVES: Hyperactive dysfunction syndrome (HDS) is defined as symptoms arising from overactivities in cranial nerves, like trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN). A combination of these cranial nerve neuralgias, that might or might not occur in one or both sides, either synchronously, or metachronously is called combined hyperactive dysfunction syndrome (CHDS). CASE PRESENTATION: We presented a 73 years-old male patient with CHDS presenting with GPN as the initial symptom, with total relief from GPN, TN, and HFS after microvascular decompression. Up to date, only nine patients have been reported in the literature with symptomatic. CONCLUSIONS: TN-HFS-GPN. Our case is the first case with GPN as the initial symptom. The combination of arterial and venous origin of the offending vessels makes the case picturesage.

The Location of the Parasympathetic Fibres within the Vagus Nerve Rootlets: A Case Report and a Review of the Literature.

The vagus nerve has motor, sensory, and parasympathetic components. Understanding the nerve's internal anatomy, its variations, and relationship to the glossopharyngeal nerve are crucial for neurosurgeons decompressing the lower cranial nerves. We present a case report demonstrating the location of the parasympathetic fibres within the vagus nerve rootlets. A 47-year-old woman presented with a 1-year history of medically refractory left-sided glossopharyngeal neuralgia and a more recent history of left-sided hemi-laryngopharyngeal spasm. magnetic resonance imaging showed her left posterior inferior cerebellar artery distorting the lower cranial nerves on the affected left side. The patient consented to microvascular decompression of the lower cranial nerves with possible sectioning of the glossopharyngeal and upper sensory rootlets of the vagus nerve. During surgery, electrical stimulation of the most caudal rootlet of the vagus nerve triggered profound bradycardia. None of the more rostral rootlets had a similar parasympathetic response. This case is the first demonstration, to our knowledge, of the location of the cardiac parasympathetic fibres within the human vagus nerve rootlets. This new understanding of the vagus nerve rootlets' distribution of pure sensory (most rostral), motor/sensory (more caudal), and parasympathetic (most caudal) fibres may lead to a better understanding and diagnosis of the vagal rhizopathies. Approximately 20% of patients with glossopharyngeal neuralgia also have paroxysmal cough. This could be due to the anatomical juxtaposition of the IXth cranial nerve with the rostral vagal rootlets with pure sensory fibres (which mediate a tickling sensation in the lungs). A subgroup of patients with glossopharyngeal neuralgia have neuralgia-induced syncope. The cause of this rare condition, "vago-glossopharyngeal neuralgia," has been debated since it was first described by Riley in 1942. Our case supports the theory that this neuralgia-induced bradycardia is reflexively mediated through the brainstem with afferent impulses in the IXth and efferent impulses in the Xth cranial nerve. The rarer co-occurrence of glossopharyngeal neuralgia with hemi-laryngopharyngeal spasm (as seen in this case) may be explained by the proximity of the IXth nerve with the more caudal vagus rootlets which have motor (and probably sensory) supply to the throat. Finally, if there is a vagal rhizopathy related to compression of its parasympathetic fibres, one would expect it to be at the most caudal rootlet of the vagus nerve.

Anatomy of small canals around the jugular foramen: Special reference to Jacobson's and Arnold's nerves.

The jugular foramen harbors anatomically complex bony, venous and neural structures. It is closely associated with small canals including the mastoid, tympanic, and cochlear canaliculi, and the stylomastoid foramen. The minute intraosseous branches of Arnold's and Jacobson's nerves (<1 mm in length) remain difficult to study with current imaging techniques, and cadaveric dissection is the most reliable approach. Our aim was to examine the variations of Jacobson's and Arnold's canaliculi and nerves and to provide detailed cadaveric graphics. To reveal the anatomical structures of small canals around the jugular foramen, 25 sides of dry skulls and 14 sides of cadaveric heads were examined. Intraosseous branches varied more in Arnold's nerve than Jacobson's nerve. In our cadaveric dissection, all specimens formed a single canal for Jacobson's nerve connecting the jugular foramen to the tympanic cavity. The intraosseous course of Arnold's nerve varied in its communication with the facial nerve. A descending branch crossing the facial nerve was identified in five of 14 sides, an ascending branch in 13. In two specimens, an ascending branch clearly reached the base of the stapedius muscle. Classical anatomical studies of cadavers remain a supplementary tool for analyzing these tiny structures. The present study confirms Gray's findings of 1913. Variations of these nerves could be even more complex than previously reported. Our study provides additional information regarding the anatomy of Jacobson's and Arnold's nerves.

Refractory glossopharyngeal neuralgia successfully treated with onabotulinumtoxinA: A case report.

BACKGROUND: Glossopharyngeal neuralgia is a rare but severe and disabling pain condition often caused by vascular compression of the glossopharyngeal nerve. Treatment is similar to that of trigeminal neuralgia, but some patients may be refractory to both medical and surgical approaches. Here we present a case of refractory glossopharyngeal neuralgia that responded well to onabotulinumtoxinA (BTX-A). CASE: We report a case of a 65-year-old man with well-controlled human immunodeficiency virus disease with glossopharyngeal neuralgia symptoms since 2015. He had partial response to medications but was limited by side-effects. He underwent microvascular decompression twice with initial relief both times, but experienced recurrence of attacks 1-3 years after each surgery. He was treated with BTX-A using the chronic migraine PREEMPT protocol (i.e., 31-39 injection sites in head and neck muscles), which led to significant relief of his glossopharyngeal neuralgia pain. CONCLUSIONS: This is the first case to our knowledge of glossopharyngeal neuralgia treated with BTX-A. BTX-A can be an effective treatment for glossopharyngeal neuralgia, even when injections are not administered directly over the sensory distribution of the glossopharyngeal nerve.

Terminal field volume of the glossopharyngeal nerve in adult rats reverts to prepruning size following microglia depletion with PLX5622.

Programmed reduction of synapses is a hallmark of the developing brain, with sensory systems emerging as useful models with which to study this pruning. The central projections (terminal field) of the gustatory glossopharyngeal nerve (GL) of the rat are a prime example of developmental pruning, undergoing an approximate 66% reduction in volume from postnatal day 15 (P15) to P25. Later in adulthood, developmental GL pruning can be experimentally reversed, expanding to preweaning volumes, suggesting mature volumes may be actively maintained throughout the life span. Microglia are central nervous system glia cells that perform pruning and maintenance functions in other sensory systems, including other gustatory nerves. To determine their role in GL pruning, we depleted microglia from Sprague-Dawley rat brains from P1 to P40 using daily intraperitoneal injections of the colony-stimulating factor 1 receptor inhibitor PLX5622. This prevented GL developmental pruning, resulting in preweaning terminal field volumes and innervation patterns persisting through P40, 2 weeks after pruning is normally completed. These findings show microglia are necessary for developmental GL pruning. Ceasing PLX5622 treatments at P40 allowed microglia repopulation, and within 4 weeks the GL terminal field had reduced to control volumes, indicating that pruning can occur outside of the typical developmental period. Conversely, when microglia were depleted in adult rats, GL terminal fields expanded, reverting to sizes comparable to the neonatal rat. These data indicate that microglia are required for GL pruning and may continue to maintain the GL terminal field at a reduced size into adulthood.