Pictorial Review of Cranial Nerve Denervation in the Head and Neck.

Of the twelve cranial nerves, nine supply motor innervation to the muscles of the head and neck. Loss of this motor nerve supply, or denervation, follows a series of predictable chronologic changes in the affected muscles. Although the length of time between each change is markedly variable, denervation is typically classified into three distinct time points: (a) acute, (b) subacute, and (c) chronic. These muscle changes produce characteristic findings on images, with contrast-enhanced MRI being the preferred modality for assessment. Imaging allows radiologists to not only identify denervation but also evaluate the extent of denervation and localize the potential site of insult. However, these findings may be easily mistaken for other diseases with similar manifestations, such as neoplasm, infection, and inflammatory conditions. As such, it is fundamental for radiologists to be familiar with cranial nerve anatomy and denervation patterns so that they can avoid these potential pitfalls and focus their imaging search on the pathway of the affected nerve. In this article, the anatomy and muscles innervated by motor cranial nerves in the head and neck, denervation, and the associated expected imaging patterns are reviewed, and examples of potential pitfalls and denervation mimics are provided. ©RSNA, 2024.

The Mechanism of Volume Regulation by Cervical Neuroforaminal Veins as was Previously Demonstrated for the Internal Vertebral Venous Plexus (IVVP) in the Cervical and Lumbar Region / Mecanismo de Regulación del Volumen por las Venas Neuroforaminales Cervicales como se Demostró Previamente para el Plexo Venoso Vertebral Interno (PVVI) en la Regiones Cervical y Lumbar

SUMMARY: Head and cervical spine movements cause narrowing or widening of neuroforamina. In healthy individuals these movements do not cause symptoms of radiculopathy. This implies a compensating volume-regulating mechanism of the neuroforamina. Such a mechanism has been postulated in the years before CT and MRI for the neuroforaminal veins. Dural sac indentations with emptying and refilling of the internal vertebral venous plexus (IVVP) were postulated in the lumbar region using myelography. Emptying of the IVVP occurs in the lumbar spine when moving towards maximal extension and refilling while moving towards maximal flexion. Such indentations have not been shown in the cervical region. With MRI this mechanism has been demonstrated during axial rotation in the C1-C2 segment. It consists of emptying and refilling of the IVVP and thus prevents dural sac compression. During spinal surgery, the IVVP and connecting neuroforaminal veins may be damaged. Because the clinical implications of dysfunction of this protecting mechanism of the IVVP and its neuroforaminal venous connections are not clear, the consequences of such damage are unknown. Therefore, these venous structures should be examined by studying the cervical spine in supine position and, if possible, in different postures (flexion, extension and axial rotation) using MRI with contrast-enhancement and fat suppression. These images may be a basis for future advancement of clinical care.

Los movimientos de la cabeza y la columna cervical provocan un estrechamiento o ensanchamiento de las neuroforaminas. En individuos sanos estos movimientos no causan síntomas de radiculopatía. Esto implica un mecanismo compensador de regulación del volumen de las neuroforaminas. Este mecanismo se ha postulado en los años anteriores a la TC y la RM para las venas neuroforaminales. Mediante mielografía se postularon hendiduras del saco dural con vaciado y llenado del plexo venoso vertebral interno (PVVI) en la región lumbar. El vaciado del PVVI se produce en la columna lumbar cuando se mueve hacia la máxima extensión y se rellena mientras se mueve hacia la máxima flexión. En la región cervical no se han observado tales depresiones. Con resonancia magnética se ha demostrado este mecanismo durante la rotación axial en el segmento C1-C2. Consiste en vaciar y rellenar la PVVI y así evitar la compresión del saco dural. Durante la cirugía de columna, la PVVI y las venas neuroforaminales que las conectan pueden dañarse. Debido a que las implicaciones clínicas de la disfunción de este mecanismo protector de la PVVI y sus conexiones venosas neuroforaminales no están claras, se desconocen las consecuencias de dicho daño. Por tanto, estas estructuras venosas deben examinarse estudiando la columna cervical en decúbito supino y, si es posible, en diferentes posturas (flexión, extensión y rotación axial) mediante resonancia magnética con contraste y supresión grasa. Estas imágenes pueden ser una base para futuros avances de la atención clínica.

Anatomical Insights on the Cervical Nerve for Contemporary Face and Neck Lifting: A Cadaveric Study.

BACKGROUND: Despite the significant roles it plays in the functions of the platysma and lower lip, the cervical branch of the facial nerve is often overlooked compared to other branches, but its consideration is critical for ensuring the safety of neck surgeries. OBJECTIVES: The aim of this study was to clarify the anatomical discrepancies associated with the cervical branch of the facial nerve to enhance surgical safety. METHODS: The study utilized 20 fresh-frozen hemiheads. A 2-stage surgical procedure was employed, beginning with an initial deep-plane facelift including extensive neck dissection, followed by a superficial parotidectomy on fresh-frozen cadavers. This approach allowed for a thorough exploration and mapping of the cervical nerve in relation to its surrounding anatomical structures. RESULTS: Upon exiting the parotid gland, the cervical nerve consistently traveled beneath the investing layer of the deep cervical fascia for a brief distance, traversing the deep fascia to travel within the areolar connective tissue before terminating anteriorly in the platysma muscle. A single branch was observed in 2 cases, while 2 branches were noted in 18 cases. CONCLUSIONS: The cervical nerve's relatively deeper position below the mandible's angle facilitates a safer subplatysmal dissection via a lateral approach for the release of the cervical retaining ligaments. Due to the absence of a protective barrier, the nerve is more susceptible to injuries from direct trauma or thermal damage caused by electrocautery, especially during median approaches.

Spinal accessory nerve anatomy in the posterior cervical triangle: A systematic review with meta-analysis.

This study aimed to investigate the anatomy of the spinal accessory nerve (SAN) in the posterior cervical triangle, especially in relation to adjacent anatomical landmarks, along with a systematic review of the current literature with a meta-analysis of the data. Overall, 22 cadaveric and three prospective intraoperative studies, with a total of 1346 heminecks, were included in the analysis. The major landmarks relevant to the entry of the SAN at the posterior border of the SCM muscle (PBSCM) were found to be the mastoid apex, the great auricular point (GAP), the nerve point (NP), and the point where the PBSCM meets the upper border of the clavicle. The SAN was reported to enter the posterior cervical triangle above GAP in 100% of cases and above NP in most cases (97.5%). The mean length of the SAN along its course from the entry point to its exit point from the posterior triangle of the neck was 4.07 ± 1.13 cm. The SAN mainly gave off 1 or 2 branches (32.5% and 31%, respectively) and received either no branches or one branch in most cases (58% and 23%, respectively) from the cervical plexus during its course in the posterior cervical triangle. The major landmarks relevant to the entry of the SAN at the anterior border of the TPZ muscle (ABTPZ) were found to be the point where the ABTPZ meets the upper border of the clavicle and the midpoint of the clavicle, along with the mastoid apex, the acromion, and the transverse distance of the SAN exit point to the PBSCM. The results of the present meta-analysis will be helpful to surgeons operating in the posterior cervical triangle, aiding the avoidance of the iatrogenic injury of the SAN.

Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery.

BACKGROUND: Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon's ability to monitor the at-risk nerve. METHODS: The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation. RESULTS: Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve's value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes. CONCLUSIONS: The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided.

Landmarks for the hypoglossal nerve within the anterior cervical triangle / Topografía del nervio hipogloso en el triángulo cervical anterior

SUMMARY: Cranial nerve injury is one of the neurologic complications following carotid endarterectomy. The hypoglossal nerve is one of the most frequently injured nerves during carotid endarterectomy. Guidelines suggest that proper anatomic knowledge is crucial to avoid cranial nerve injury. The aim of the present study is to provide landmarks for the localization of the hypoglossal nerve during carotid endarterectomy. 33 anterior cervical triangles of formalin-fixed adult cadavers were dissected. The "carotid axis" was defined and measured, the level of the carotid bifurcation within the carotid axis was registered. "High carotid bifurcation" was considered for those carotid bifurcation found in the upper 25 mm of the carotid axis. The distance between the hypoglossal nerve and the carotid bifurcation was measured (length 1). The relationship between the hypoglossal nerve and the posterior belly of the digastric muscle was registered. For caudal positions, the distance between hypoglossal nerve and posterior belly of the digastric muscle was determined (length 2). Carotid axis range 88.3 mm-155.4 mm, average 125.8 mm. Level of the carotid bifurcation within the carotid axis range 75.3 mm-126.5 mm, mean 102.5 mm. High carotid bifurcation was found in 19 cases (57 %). Length 1 ranged from 1.6 mm to 38.1, mean 17.5. Finally, in 29 specimens (87.8 %) the hypoglossal nerve was caudal to posterior belly of the digastric muscle, whereas in 4 cases (12.2 %) it was posterior. Length 2 ranged from 1 mm to 17.0 mm, mean 6.9 mm. Distances between the hypoglossal nerve and nearby structures were determined. These findings may aid the surgeon in identifying the hypoglossal nerve during carotid endarterectomy and thus prevent its injury.

RESUMEN: La lesión de pares craneales es una de las complicaciones neurológicas posteriores a la endarterectomía carotídea. El nervio hipogloso es uno de los nervios lesionados más frecuentemente durante la endarterectomía carotídea. Las guías de actuación clínica sugieren que el conocimiento anatómico adecuado es crucial para evitar lesiones de los nervios craneales. El objetivo del presente estudio fue proporcionar puntos de referencia para la ubicación del nervio hipogloso durante la endarterectomía carotídea. Se disecaron 33 triángulos cervicales anteriores de cadáveres adultos fijados en solución a base de formaldehído. Se definió y midió el "eje carotídeo", se registró el nivel de la bifurcación carotídea dentro del eje carotídeo. Se consideró una "bifurcación carotídea alta" para aquellas bifurcaciones carotídeas encontradas en los 25 mm superiores del eje carotídeo. Se midió la distancia entre el nervio hipogloso y la bifurcación carotídea (longitud 1). Se registró la relación entre el nervio hipogloso y el vientre posterior del músculo digástrico. Para las posiciones caudales, se determinó la distancia entre el nervio hipogloso y el vientre posterior del músculo digástrico (longitud 2). Rango del eje carotídeo 88,3 mm-155,4 mm, media 125,8 mm. Rango del nivel de la bifurcación carotídea dentro del eje carotídeo 75,3 mm-126,5 mm, media 102,5 mm. Se encontró una bifurcación carotídea alta en 19 casos (57 %). La longitud 1 osciló entre 1,6 mm y 38,1, con una media de 17,5. Finalmente, en 29 muestras (87,8 %) el nervio hipogloso fue caudal al vientre posterior del músculo digástrico, mientras que en 4 casos (12,2 %) fue posterior. La longitud 2 osciló entre 1 mm y 17,0 mm, con una media de 6,9 mm. Se determinaron las distancias entre el nervio hipogloso y las estructuras cercanas. Estos hallazgos pueden ayudar al cirujano a identificar el nervio hipogloso durante la endarterectomía carotídea y así prevenir su lesión.

Computed Tomography-Guided Radiofrequency Ablation of the Cervical Dorsal Root Ganglia in 27 Patients with Cervical and Occipital Postherpetic Neuralgia.

BACKGROUND Postherpetic neuralgia (PHN) is a common complication of herpes zoster virus infection that is associated with intense pain. The present study aimed to investigate the use of computed tomography (CT)-guided radiofrequency ablation (RFA) of the cervical dorsal root ganglia (DRG) for treatment of cervical and occipital PHN in 27 patients at a single center. MATERIAL AND METHODS Twenty-seven patients with PHN in the cervical and/or occipital region were enrolled. After imaging the area of PHN in the patients, axial scanning was performed on the upper cervical segment in the spinal scanning mode. The puncture path was defined and then RFA therapy (90°C for 180 s) was performed by targeting the corresponding intervertebral foramen. Patients were followed 2 days later and at 1, 3, 6, and 12 months after surgery. Observation at each follow-up visit included rating of pain on a visual analog scale (VAS) and assessment of complications and adverse events. RESULTS VAS scores significantly decreased in patients with PHN after RFA compared with their scores before RFA (P<0.05). Skin sensation decreased in the area that was originally painful and allodynia significantly diminished. CONCLUSIONS The findings from this small study from a single center showed that CT-guided percutaneous RFA of cervical DRG safely and effectively reduced cervical and occipital PHN in the short term.

Cervicogenic dizziness alleviation after coblation discoplasty: a retrospective study.

OBJECTIVE: Little is known about the therapeutic relationship between coblation discoplasty and cervicogenic dizziness (CGD). CGD can be caused by abnormal proprioceptive inputs from compressed nerve roots, intradiscal mechanoreceptors and nociceptors to the vestibulospinal nucleus in the degenerative cervical disc. The aim was to analyze the efficacy of coblation discoplasty in CGD through intradiscal nerve ablation and disc decompression in a 12-month follow-up retrospective study. METHODS: From 2015 to 2019, 42 CGD patients who received coblation discolplasty were recruited as the surgery group, and 22 CGD patients who rejected surgery were recruited as the conservative group. Using intent-to-treat (ITT) analysis, we retrospectively analyzed the CGD visual analogue scale (VAS), neck pain VAS, CGD frequency score, and the CGD alleviation rating throughout a 12-month follow-up period. RESULTS: Compared with conservative intervention, coblation discoplasty revealed a better recovery trend with effect sizes of 1.76, 2.15, 0.92, 0.78 and 0.81 in CGD VAS, and effect sizes of 1.32, 1.54, 0.93, 0.86 and 0.76in neck pain VAS at post-operative 1 week, and 1, 3, 6, 12 months, respectively. The lower CGD frequency score indicated fewer attacks of dizziness until postoperative 3 months (p < 0.01). At post-operative 12 months, the coblation procedure showed increased satisfactory outcomes of CGD alleviation rating (p < .001, -1.00 of effect size). CONCLUSIONS: Coblation discoplasty significantly improves the severity and frequency of CGD, which is important inbridging unresponsive conservative intervention and open surgery.Key messagesThere is a correlation between the degenerative cervical disc and cervicogenic dizziness (CGD).CGD can be caused by abnormal proprioceptive inputs from a compressed nerve root and intradiscal mechanoreceptors and nociceptors to the vestibulospinal nucleus in the degenerative cervical disc.Cervical coblation discoplasty can alleviate CGD through ablating intradiscal nerve endings and decompressing the nerve root.

Neurological deterioration as a result of improper neck position detected by intraoperative neurophysiological monitoring in a cervical stenosis patient: A case report.

RATIONALE: Intraoperative neurophysiological monitoring (IONM) is widely used in spinal surgeries to prevent iatrogenic spinal cord injury (SCI). Most surgeons focus on avoiding neurological compromise intraoperatively, while ignoring the possibility of nerve damage preoperatively, such as neck positioning. Thus, this study aims to report a case with transient neurological deterioration due to improper neck position detected by IONM during cervical surgery. PATIENT CONCERNS: A 63-year-old male patient had been suffering from hypoesthesia of the upper and lower extremities for three years. DIAGNOSES: Severe cervical stenosis (C5-C7) and cervical ossification of a posterior longitudinal ligament. INTERVENTIONS: The cervical stenosis patient underwent an anterior cervical corpectomy decompression and fusion (ACDF) surgery with the assistance of IONM. When the lesion segment was exposed, the SSEP and MEP suddenly elicited difficulty indicating that the patient may have developed SCI. All the technical causes of IONM events were eliminated, and the surgeon suspended operation immediately and suspected that the IONM alerts were caused by cervical SCI due to the improper position of the neck. Subsequently, the surgeon repositioned the neck of the patient by using a thinner shoulders pad. OUTCOMES: At the end of the operation, the MEP and SSEP signals gradually returned to 75% and 80% of the baseline, respectively. Postoperatively, the muscle strength of bilateral biceps decreased from grade IV to grade III. Besides, the sensory disturbance of both upper extremities aggravated. However, the muscle power and hypoesthesia were significantly improved after three months of neurotrophic therapy and rehabilitation training, and no complications of nerve injury were found at the last follow-up visit. LESSONS: IONM, consisting of SSEP and MEP, should be applied throughout ACDF surgery from the neck positioning to suture incisions. Besides, in the ward 1to 2 days before operation, it is necessary for conscious patients with severe cervical stenosis to simulate the intraoperative neck position. If the conscious patients present signs of nerve damage, they can adjust the neck position immediately until the neurological symptoms relieve. Therefore, intraoperatively, the unconscious patient can be placed in a neck position that was confirmed preoperatively to prevent SCI.

In-Depth Look at the Anatomical Relationship of the Lesser Occipital Nerve, Great Auricular Nerve, and Spinal Accessory Nerve and Their Implication in Safety of Operations in the Posterior Triangle of the Neck.

BACKGROUND: Migraine surgery is an increasingly popular treatment option for migraine patients. The lesser occipital nerve is a common trigger point for headache abnormalities, but there is a paucity of research regarding the lesser occipital nerve and its intimate association with the spinal accessory nerve. METHODS: Six cadaver necks were dissected. The lesser occipital, great auricular, and spinal accessory nerves were identified and systematically measured and recorded. These landmarks included the longitudinal axis (vertical line drawn in the posterior), the horizontal axis (defined as a line between the most anterosuperior points of the external auditory canals) and the earlobe. Mean distances and standard deviations were calculated to delineate the relationship between the spinal accessory, lesser occipital, and great auricular nerves. RESULTS: The point of emergence of the spinal accessory nerve was determined to be 7.17 ± 1.15 cm lateral to the y axis and 7.77 ± 1.10 caudal to the x axis. The lesser occipital nerve emerges 7.5 ± 1.31 cm lateral to the y axis and 8.47 ± 1.11 cm caudal to the x axis. The great auricular nerve emerges 8.33 ± 1.31 cm lateral to the y axis and 9.4 ±1.07 cm caudal to the x axis. The decussation of the spinal accessory and the lesser occipital nerves was found to be 7.70 ± 1.16 cm caudal to the x axis and 7.17 ± 1.15 lateral to the y axis. CONCLUSION: Understanding the close relationship between the lesser occipital nerve and spinal accessory nerve in the posterior, lateral neck area is crucial for a safer approach to occipital migraine headaches, occipital neuralgia, and new daily persistent headaches and other reconstructive or cosmetic operations.

Selective nerve root block combined with posterior percutaneous cervical endoscopic discectomy for cervical spondylotic radiculopathy with double nerve root variation: A case report.

RATIONALE: The aim of this report is to present the technique of selective nerve root blockage combined with posterior percutaneous cervical endoscopic discectomy (PPECD) for cervical spondylotic radiculopathy (CSR). PATIENT CONCERNS: A 49-year-old female has pain in the skin area of the left scapular, pain in left elbow and limitation of left upper limb movement for 1.5 years. DIAGNOSIS: She was diagnosed with CSR and C6-7 double nerve root variation. INTERVENTIONS: We used selective nerve root block to determine the lesion segment and applied PPECD to relieve pressure on the patient's nerve roots. OUTCOMES: The pain symptoms disappeared after the patient was treated with C6-7 nerve root block. Endoscopic displayed C6-7 double nerve root variation on the left side of the spinal cord intraoperative. The neurological function was intact postoperatively and no recurrence of cervical disc herniation during the 5 months' follow-up period. The hospitalization time was 5 days, the operation time was 68.2 minutes and the bleeding volume was 52.6 ml. There was no change in cervical curvature and cervical disc height postoperatively. Japanese Orthopaedic Association score, SF-36 score and Visual Analogue Scale score improved significantly postoperatively. LESSONS: The application of selective nerve root blockage combined with PPECD for CSR could achieve satisfactory effect of position and decompression of the injured nerve root. Besides, we recommend that surgery be performed under general anesthesia to minimize patients' emotional stress and discomfort.

Electrical stimulation of the vagus nerve improves intestinal blood flow after trauma and hemorrhagic shock.

BACKGROUND: Gut damage after trauma/hemorrhagic shock contributes to multiple organ dysfunction syndrome. Electrical vagal nerve stimulation is known to prevent gut damage in animal models of trauma/hemorrhagic shock by altering the gut inflammatory response; however, the effect of vagal nerve stimulation on intestinal blood flow, which is an essential function of the vagus nerve, is unknown. This study aimed to determine whether vagal nerve stimulation influences the abdominal vagus nerve activity, intestinal blood flow, gut injury, and the levels of autonomic neuropeptides. METHODS: Male Sprague Dawley rats were anesthetized, and the cervical and abdominal vagus nerves were exposed. One pair of bipolar electrodes was attached to the cervical vagus nerve to stimulate it; another pair of bipolar electrodes were attached to the abdominal vagus nerve to measure action potentials. The rats underwent trauma/hemorrhagic shock (with maintenance of mean arterial pressure of 25 mmHg for 30 min) without fluid resuscitation and received cervical vagal nerve stimulation post-injury. A separate cohort of animals were subjected to transection of the abdominal vagus nerve (vagotomy) just before the start of cervical vagal nerve stimulation. Intestinal blood flow was measured by laser Doppler flowmetry. Gut injury and noradrenaline level in the portal venous plasma were also assessed. RESULTS: Vagal nerve stimulation evoked action potentials in the abdominal vagus nerve and caused a 2-fold increase in intestinal blood flow compared to the shock phase (P < .05). Abdominal vagotomy eliminated the effect of vagal nerve stimulation on intestinal blood flow (P < .05). Vagal nerve stimulation protected against trauma/hemorrhagic shock -induced gut injury (P < .05), and circulating noradrenaline levels were decreased after vagal nerve stimulation (P < .05). CONCLUSION: Cervical vagal nerve stimulation evoked abdominal vagal nerve activity and relieved the trauma/hemorrhagic shock-induced impairment in intestinal blood flow by modulating the vasoconstriction effect of noradrenaline, which provides new insight into the protective effect of vagal nerve stimulation.

Nationwide randomised trial evaluating elective neck dissection for early stage oral cancer (SEND study) with meta-analysis and concurrent real-world cohort.

BACKGROUND: Guidelines remain unclear over whether patients with early stage oral cancer without overt neck disease benefit from upfront elective neck dissection (END), particularly those with the smallest tumours. METHODS: We conducted a randomised trial of patients with stage T1/T2 N0 disease, who had their mouth tumour resected either with or without END. Data were also collected from a concurrent cohort of patients who had their preferred surgery. Endpoints included overall survival (OS) and disease-free survival (DFS). We conducted a meta-analysis of all six randomised trials. RESULTS: Two hundred fifty randomised and 346 observational cohort patients were studied (27 hospitals). Occult neck disease was found in 19.1% (T1) and 34.7% (T2) patients respectively. Five-year intention-to-treat hazard ratios (HR) were: OS HR = 0.71 (p = 0.18), and DFS HR = 0.66 (p = 0.04). Corresponding per-protocol results were: OS HR = 0.59 (p = 0.054), and DFS HR = 0.56 (p = 0.007). END was effective for small tumours. END patients experienced more facial/neck nerve damage; QoL was largely unaffected. The observational cohort supported the randomised findings. The meta-analysis produced HR OS 0.64 and DFS 0.54 (p < 0.001). CONCLUSION: SEND and the cumulative evidence show that within a generalisable setting oral cancer patients who have an upfront END have a lower risk of death/recurrence, even with small tumours. CLINICAL TRIAL REGISTRATION: NIHR UK Clinical Research Network database ID number: UKCRN 2069 (registered on 17/02/2006), ISCRTN number: 65018995, ClinicalTrials.gov Identifier: NCT00571883.

Relationship of the lobular branch of the great auricular nerve to the tympanoparotid fascia: Spatial anatomy for salvage during face and neck lift.

To enable selection of a safer suspension site to use in face and neck lifting procedures, the spatial relationship between the tympanoparotid fascia and the great auricular nerve should be clarified. In this study, we aimed to elucidate the position of the tympanoparotid fascia and the pathway of the lobular branch of the great auricular nerve traversing the tympanoparotid fascia. Twenty hemifaces from non-preserved bequeathed Korean cadavers (5 males, 7 females; mean age, 77.0 years) were dissected to determine the great auricular nerve distribution close to the tympanoparotid fascia of clinical significance for face and neck lift procedures. We observed the tympanoparotid fascia in all specimens (20 hemifaces). The tympanoparotid fascia was located anteriorly between the tragus and intertragic notch. Regarding the spatial relationship between the tympanoparotid fascia and the great auricular nerve, we found the sensory nerve entering the tympanoparotid fascia in all specimens (100%), and the depth from the skin was approximately 4.5 mm; in 65% of the specimens, the lobular branch was found to run close to the tympanoparotid fascia before going into the earlobe. Provided with relatively safer surface mapping to access the tympanoparotid fascia free of the lobular branch of the great auricular nerve, surgeons may better protect the lobular branch by anchoring the SMAS-platysma flap and thread to the deeper superior and anterior portions of the expected tympanoparotid fascia.

[Dissection and observation of a large unnamed nerve in the posterior cervical triangle].

OBJECTIVE: To characterize the anatomical features of a large unnamed nerve in the posterior cervical triangle and clarify its relationship with the lesser occipital nerve. METHODS: We dissected 31 adult formalin-fixed cadaver head and neck specimens (62 sides). The lateral cervical region, the anterior cervical region, the sternocleidomastoid region, and the occipital region were dissected to define the anatomical features of the unnamed nerve. RESULTS: This unnamed nerve was identified in the posterior cervical triangle in 96.8% of the specimens. The main trunk of the nerve had a diameter of about 3 mm with a length of around 10 cm. The nerve arose from the anterior branch of the second cervical nerve (C2, C2-3), entered the posterior cervical triangle at 1-3 cm above the accessory nerve, and continued to ascend along or in parallel with the posterior border of the sternocleidomastoid muscle. It passed between the attachments of the sternocleidomastoid and the trapezius to the occiput and divided into 3-5 branches, which innervated the skin area between the lesser and greater occipital nerves. CONCLUSIONS: We identified a large unnamed nerve in the posterior cervical triangle, for which we coined the name "long occipital nerve" based on its unique anatomical features. The discovery of this nerve can be important for local surgery and for diagnosis and treatment of related diseases.

The course of lower cranial nerves within the neck: a cadaveric dissection study.

PURPOSE: To evaluate the course of lower cranial nerves (CNs) within the neck in relation to surrounding structures and anatomic landmarks via a cadaveric dissection study. METHODS: A total of 70 neck dissections (31 bilateral, 8 unilateral) were performed on 39 adult fresh cadavers [mean (SD) age: 38.5 (11.2) years, 29 male, 10 female] to identify the course of lower CNs [spinal accessory nerve (SAN), vagus nerve and hypoglossal nerve] within the neck in relation to surrounding structures [internal jugular vein (IJV), common carotid artery (CCA)] and distance to anatomical landmarks (cricoid cartilage, hyoid bone, digastric muscle). RESULTS: SAN travelled most commonly anterior to IJV (51.4%) at the level of jugular foramen, while travelling lateral to IJV at the post belly of digastric (55.7%) and inferior to digastric muscle (90%) in most neck dissections. Vagus nerve travelled lateral to CCA in majority (94.3%) of dissections, while medial (2.9%), posterolateral (1.4%) and posterior (1.4%) positions were also noted. Average distance of hypoglossal nerve was 27.7 (9.7) mm to carotid bifurcation, 9.3 (3.9) mm to hyoid bone, and 54.7 (18.0) mm to the inferior border of cricoid cartilage. CONCLUSION: In conclusion, our findings indicate that anatomic variations are not rare in the course of lower CNs within the neck in relation to adjacent structures, and awareness of these variations together with knowledge of distance to certain anatomic landmarks may help the surgeon to identify lower CNs during neck surgery and prevent potential nerve injuries.

Prevalence of the right nonrecurrent inferior laryngeal nerve in a series of 100 total thyroidectomies / Prevalencia del nervio laríngeo inferior derecho no recurrente en una serie de 100 tiroidectomías totales

SUMMARY: The right nonrecurrent inferior laryngeal nerve (NRILN) is a rare occurrence generally associated with an aberrant right subclavian artery. Its prevalence ranges from 0.3 to 1.8 %. It is found mainly in thyroid surgeries, the most frequently performed cervical surgeries. This neural anomaly is almost never diagnosed preoperatively. Dysphagia may be a warning symptom, sometimes being incorrectly related to esophageal compression due to a goiter or thyroid cancer. The postoperative diagnosis of an accompanying aberrant right subclavian artery should be done to confirm the clinical picture and inform the patient of any possible future medical/ surgical procedures. The aim of this work is to determine the prevalence of the NRILN in patients undergoing total thyroidectomy in two reference centers for head and neck surgery in Paraguay. Prospective cross-sectional study in a series of 100 consecutive total thyroidectomies in the INCAN and the ORL Service in the Hospital Central of the IPS. 100 patients underwent a total thyroidectomy, 90 of whom were women. The average age was 47 years. 6 % also underwent a neck dissection for thyroid cancer. The preoperative diagnosis was multinodular goiter (MNG) in 84 cases and thyroid cancer in the remaining 16 (16 %). In one man aged 47 years (1 %) operated on for MNG and presenting slight to solid dysphagia, there was difficulty finding the right NRILN. It was located at the level of the lower edge of the inferior pharyngeal constrictor and its downward anomalous course was proven. Postoperatively, after confirmation of the diagnosis that the thyroid pathology was benign, a color echo-Doppler and a CT angiography corroborated the diagnosis of an associated aberrant right subclavian artery. Given the difficulty in locating the recurrent inferior laryngeal nerve in thyroid surgery, it is advisable to consider the possibility that it may be nonrecurrent and should be looked for at the level of its entrance to the larynx below the inferior constrictor. In such cases it is recommended that the patient be examined postoperatively to rule out an associated vascular anomaly. A tomography study of each patient with a thyroid pathology and dysphagia could contribute to the diagnosis of the vascular anomaly and maximize precautions in the nerve dissection, including use of a neurostimulator. The NRILN is a rare entity. In this case study, it represents 1 % of the patients operated on for thyroid pathology in the INCAN and IPS in a 1-year period (July 2016 - June 2017).

RESUMEN: El nervio laríngeo inferior no recurrente (NLINR) del lado derecho es una entidad rara asociada generalmente a una arteria lusoria. Su prevalencia oscila entre el 0,3 al 1,8 %. Su hallazgo se da sobre todo en cirugías tiroideas, al ser éstas las cirugías cervicales más frecuentemente realizadas. El diagnóstico preoperatorio de esta anomalía nerviosa es realizado en contadas ocasiones. La disfagia puede ser un síntoma de alerta ante esta situación, siendo a veces erróneamente relacionada con la compresión esofágica por un bocio o cáncer tiroideo. El diagnóstico postoperatorio de arteria lusoria acompañante debería realizarse para certificar el cuadro e informar al paciente ante eventuales procedimientos médico-quirúrgicos futuros. El objetivo de este trabajo consisitó en determinar la prevalencia del nervio laríngeo inferior no recurrente en los pacientes operados de tiroidectomía total en dos centros de referencia en cirugía de cabeza y cuello del Paraguay.Estudio prospectivo de corte transversal en una serie de 100 tiroidectomías totales consecutivas, operados en el INCAN y el Servicio de ORL del Hospital Central del IPS. Fueron sometidos a tiroidectomía total 100 pacientes, de los cuales 90 fueron del sexo femenino. La edad promedio fue de 47años. En 6% se realizó además vaciamiento cervical por cáncer de tiroides. El diagnóstico preoperatorio fue bocio multinodular (BMN) en 84 casos y cáncer de tiroides en los restantes 16 (16%). En un varón de 47 años, (1%) operado por bocio multinodular, y que refería disfagia leve a sólidos, se tuvo dificultad para encontrar al nervio laríngeo inferior derecho. Siendo el mismo localizado a nivel del margen inferir del constrictor inferior de la faringe y comprobándose su trayecto anómalo descendente. En el postoperatorio, una vez confirmado el diagnóstico de benignidad de la patlogía tiroidea, se realizó un ecodoppler color y una angiotomografía que corroboraron el diagnóstico de arteria lusoria asociada. Ante la dificultad en localizar al nervio laríngeo inferior recurrente en una cirugía tiroidea, es conveniente considerar la posibilidad de que el mismo sea no recurrente e ir a buscarlo a nivel de su ingreso a la laringe por debajo del constrictor inferior. En estos casos conviene estudiar al paciente en el postoperatorio para descartar una anomalía vascular asociada. El estudio tomográfico en todo paciente portador de patología tirroidea y disfagia podría contribuir al diagnóstico de la anomalía vascular y extremar los recaudos en la disección del nervio, incluso utilizando el neuroestimulador. El NLINR es una entidad rara. En esta casuística representa el 1 % de los pacientes operados por patología tiroidea en el INCAN e IPS en el periodo de 1 año (julio 2016/ junio 2017).

POSTERIOR PENETRATING INJURY OF THE NECK: A CASE REPORT.

- A 45-year-old male patient was admitted to the emergency unit due to posterior stab wound of the neck. The knife was directed diagonally from the left to the right side of the neck in the dorsoventral axis. The patient was fully conscious upon admission with pain and paresthesia along the upper right extremity. The patient underwent computed tomography (CT) and CT angiography scan of the neck, which revealed the knife blade piercing the left sided neck muscles and through the intervertebral ligaments of the C IV/C V in direction to the contralateral internal carotid artery, vertebral artery and the C5 nerve root. The patient underwent an urgent surgery according to the radiographs. Electromyography was performed during the early postoperative care and revealed an acute lesion of the right-sided C5 nerve root. Postoperative follow-up magnetic resonance imaging revealed intact brachial plexus bundles at the site of injury. Symptoms of reduced muscle strength and limited range of motion of the upper right extremity prevailed. Penetrating neck injuries represent a rare entity of all trauma injuries. Meticulous preoperative radiographs revealed close proximity of the knife blade tip to the right-sided vertebral artery and common carotid artery. Limited abduction at the right shoulder during postoperative period correlated to the C5 nerve root injury.