Sequelae of Major Trauma Patients with Maxillofacial Fractures.

OBJECTIVES: Sequelae after maxillofacial fractures are frequent and may affect the patient's quality of life. This study examined sequelae associated with maxillofacial fractures of severely traumatized patients focusing mainly on nerve injuries. METHODS: A retrospective study including trauma patients with relevant facial fractures admitted to our Trauma Center in the period 2011-2016. Presence of posttraumatic maxillofacial sequelae was identified by examining the medical records of the included patients. Focusing on facial sensory deficits and facial nerve paralysis, but also comprising data on diplopia, blindness, malocclusion, trismus, eye globe malposition, flattening of the malar, facial contour changes, and wound infections. RESULTS: Two-hundred-seventy-five severely traumatized patients were included, comprising 201 men (73%), with a median age of 40 years and ISS of 20. 163 (59%) patients only had assessments within 3 months from trauma of which 79 patients (48.5%) had facial complications at initial examination, mostly malocclusion and trismus. Most patients in this group had no or only minor sequelae at their last clinical assessment, mainly being sensory deficits. 112 (41%) patients had assessments both within and beyond 3 months of which 73 patients (65.2%) had facial complications at initial examination, while 91 patients (81%) had reported sequelae within 3 months decreasing to 47 patients (42%) at their last clinical assessment beyond 3 months from trauma, mostly sensory deficits. An improvement of most sequelae was observed. CONCLUSION: Objective sequelae were found to be quite common after maxillofacial fractures in severely traumatized patients, especially sensory deficits. However, most of the addressed sequelae seemed to improve over time.

Mini-Skin Incision for Carotid Endarterectomy: Neurological Morbidity and Health-related Quality of Life.

BACKGROUND: Cranial and cervical nerve (CCN) injury is recognized as a possible complication after carotid endarterectomy (CEA), which may result in minor local neurologic deficiencies and significant discomfort for the patient. The aim of this study is to investigate the effect of a mini-skin incision (<5 cm) on the CCN injury after CEA in comparison to standard longitudinal incision of 12-15 cm in a high volume center, and to evaluate health-related quality of life (HRQOL) outcomes in those patients who had undergone both types of the skin incision. METHODS: From January 2013 to December 2019, 446 CEAs (47.3%) were performed through a standard neck incision of 12-15 cm (group A), while 496 (52.7%) were performed through a mini-skin incision (<5 cm) (group B). Sixty-two patients underwent standard neck incision on one side and mini-skin incision on the other side (subgroup B). The main outcome measures were stroke, death, CCN injuries, cervical hematoma rates, and reinterventions. The HRQOL was assessed at baseline and after 30 days using Medical Outcomes Study Short-Form 36 and 6 disease-specific modified Likert scales. RESULTS: The stroke and death rate at 30 days was 1.12% in group A and 1% in group B (P = 1). The incidence of CCN deficits was significantly lower in group B (5.1%) in comparison to group A (13.4%) (P < 0.001). The cervical hematoma was more common after standard incision (4.9% vs. 1.2%, P = 0.02). HRQOL at 1 month showed that the outcomes after mini-skin incision were significantly better for less difficulty with eating/swallowing and neck pain (P < 0.01). CONCLUSIONS: CEA through a small incision (<5 cm) may reduce CCN complications without additional perioperative neurologic risks. As validated by patients with bilateral disease who experienced both surgical techniques, mini-skin incision is also associated with better HRQOL at 1 month, particularly with regard to eating/swallowing and neck pain.

Cranial nerve outcomes in regionally recurrent head & neck melanoma after sentinel lymph node biopsy.

OBJECTIVE: Characterize long-term cranial nerve (CN) outcomes following sentinel lymph node biopsy (SLNB) based management for head and neck cutaneous melanoma (HNCM). METHODS: Longitudinal review of HNCM patients undergoing SLNB from 1997-2007. RESULTS: Three hundred fifty-six patients were identified, with mean age 53.5 ± 19.0 years, mean Breslow depth 2.52 ± 1.87 mm, and 4.9 years median follow-up. One hundred five (29.4%) patients had SLNB mapping to the parotid basin. Eighteen patients had positive parotid SLNs and underwent immediate parotidectomy / immediate completion lymph node dissection (iCLND), with six possessing positive parotid non-sentinel lymph nodes (NSLNs). Fifty-two of 356 (14.6%) patients developed delayed regional recurrences, including 20 total intraparotid recurrences: five following false negative (FN) parotid SLNB, three following prior immediate superficial parotidectomy, two following iCLND without parotidectomy, and the remaining 12 parotid recurrences had negative extraparotid SLNBs. Parotid recurrences were multiple (4.9 mean recurrent nodes) and advanced (n = 4 extracapsular extension), and all required salvage dissection including parotidectomy. Immediate parotidectomy/iCLND led to no permanent CN injuries. Delayed regional HNCM macrometastasis precipitated 16 total permanent CN injuries in 13 patients: 10 CN VII, five CN XI, and one CN XII deficits. Fifty percent (n = 10) of parotid recurrences caused ≥1 permanent CN deficits. CONCLUSIONS: Regional HNCM macrometastases and salvage dissection confer marked CN injury risk, whereas early surgical intervention via SLNB ± iCLND ± immediate parotidectomy yielded no CN injuries. Further, superficial parotidectomy performed in parotid-mapping HNCM does not obviate delayed intraparotid recurrences, which increase risk of CN VII injury. Despite lack of a published disease-specific survival advantage in melanoma, early disease control in cervical and parotid basins is paramount to minimize CN complications. LEVEL OF EVIDENCE: 4 (retrospective case series) Laryngoscope, 130:1707-1714, 2020.

Cranial nerve V2 and Vidian nerve trauma secondary to lateral pterygoid recess encephalocele repair.

BACKGROUND: The incidence of adverse sequelae related to trauma of cranial nerve V2 (V2) and the Vidian nerve (VN) during endoscopic pterygoid recess repair (PRR) of lateral sphenoid encephalocele is insufficiently reported in the medical literature. As part of our quality assessment and improvement program we sought to analyze the incidence and severity of V2 and VN injury during a 9-year experience (2010-2018) with PRR. METHODS: Hypoesthesia, paresthesia, and dry eye and their impact on patient quality of life were sought through chart review and a self-reported 0 to 5 Likert scale for each symptom. RESULTS: Thirty-five patients underwent repair of spontaneous cerebrospinal-fluid (CSF) rhinorrhea, with 11 consecutive patients undergoing endoscopic PRR. Mean follow-up for PRR was 32.5 months (range, 2.4 to 103.3 months). Although definitive management resulted in 100% success, 1 required secondary treatment. Eight patients were available for long-term follow-up (72.7%) and completed a symptom severity questionnaire using a Likert-scale. All patients observed either hypoesthesia, paresthesia, or dry eye of varying gradation (scale, 0 to 5). None described disabling symptoms, and some reported gradual improvement. Numbness, paresthesia, and dry eye were reported by 6 of 8 (75%), 5 of 8 (62.5%), and 4 of 8 (50%) patients, respectively. The mean Likert score among the 8 patients who completed this questionnaire noticing hypoesthesia, paresthesia, and dry eye was 2.6, 1.3, and 1.8, respectively. CONCLUSION: Meticulous surgical technique is paramount for successful PRR and minimizing nerve injury, yet the anatomic variation of the lateral pterygoid recess can be challenging, and neural injury is a real risk. Preoperatively, patients should be counseled that although V2 or VN injury is common, most patients describe resulting symptoms to be rarely bothersome.

Colon Interposition for Corrosive Esophageal Stricture: Single Institution Experience with 119 Cases.

The colon is an alternative graft organ for esophageal reconstruction. The present study reviewed our experience with the colon interposition for esophageal replacement following corrosive ingestion, to evaluate the outcomes of colon interposition based on our surgical experience. The clinical data of 119 patients who underwent colon interposition for esophageal replacement from January 2005 to March 2017 were retrospectively analyzed. The routes of the colon interposition were retrosternal in 119 (100%). The median operative time was 390 min (range: 290-610 min) and the median blood loss was 615 mL (range: 270-2500 mL). Of these 119 patients, the cervical anastomosis was performed at the hypopharynx (n=20, 16.8%), the larynx (n=3, 2.5%), and the cervical esophagus (n=96, 80.7%). Five patients experienced cervical anastomotic leakage (4 cases for esophagus-colon, and one for hypopharynx-colon). One patient experienced wound infection of the abdominal wall. Three patients had injury of recurrent laryngeal nerve and hoarseness. Three patients had stress ulcer with bleeding and treated with octreotide. Two patients suffered from incomplete intestinal obstruction. The postoperative follow-up was made for 12 months in all patients and all of them were alive. In conclusion, The colon is well-suited for esophageal reconstruction. The selection of the colon graft should be flexible and be based on the inspection of blood supply and the length needed. We must therefore make every effort to reduce the number of postoperative complications, and improve the quality of life for patients.

Electrical stimulation-based nerve location prediction for cranial nerve VII localization in acoustic neuroma surgery.

INTRODUCTION: Cranial nerve (CN) VII localization is a critical step during acoustic neuroma surgery because the nerve is generally hidden due to the tumor mass. The patient can suffer from Bell's palsy if the nerve is accidentally damaged during tumor removal. Surgeons localize CN VII by exploring the target area with a stimulus probe. Compound muscle action potentials (CMAPs) are elicited when the probe locates the nerve. However, false positives and false negatives are possible due to unpredictable tissue impedance in the operative area. Moreover, a single CMAP amplitude is not correlated with probe-to-nerve distance. OBJECTIVES: This paper presents a new modality for nerve localization. The probe-to-nerve distance is predicted by the proposed nerve location prediction model. METHODS: Input features are extracted from CMAP responses, tissue impedance, and stimulus current. The tissue impedance is calculated from the estimated resistance and capacitance of the tissue equivalent circuit. In this study, experiments were conducted in animals. A frog's sciatic nerve and gastrocnemius were used to represent CN VII and facial muscle in humans, respectively. Gelatin (2.8%) was used as a mock material to mimic an acoustic neuroma. The %NaCl applied to the mock material was used to emulate uncontrollable impedance of tissue in the operative area. RESULTS: The 10-fold cross-validation results revealed an average prediction accuracy of 86.71% and an average predicted error of 0.76 mm compared with the measurement data. CONCLUSION: The proposed nerve location prediction model could predict the probe-to-nerve distance across various impedances of the mock material.

Functional Recovery of Cranial Nerves in Patients with Traumatic Orbital Apex Syndrome.

OBJECTIVE: Traumatic orbital apex syndrome (TOAS) is a rare disease characterized by the damage of cranial nerves (CNs) II, III, IV, and VI. The aim of our study was to analyze the functional recovery of CNs in TOAS and discuss the management of these patients. METHODS: We retrospectively reviewed 28 patients with TOAS treated in the Department of Neurosurgery, Shanghai Changzheng Hospital from February 2006 to February 2016. Functional recovery of CNs was evaluated based on extraocular muscle movement and visual perception. Follow-up duration was at least 6 months. RESULTS: There were 26 males and 2 females with a mean age of 35.3 years. The most common cause of TOAS was traffic accident. CN IV suffered the lightest injury among CNs III, IV, and VI. CN II achieved obvious improvement at 3-month follow-up, while other CNs enjoyed evident improvement at 6-month follow-up. There was no significant difference between conservative treatment and surgical decompression. CONCLUSION: CNs passing through orbital apex region might recover to different degrees several months after proper management. Clinical decision should be individualized and surgical decompression could be considered with evidence of fracture, hematoma, or deformation.

Cranial Nerve Injury After Carotid Endarterectomy: Incidence, Risk Factors, and Time Trends.

OBJECTIVE/BACKGROUND: To review the incidence of post-carotid endarterectomy (CEA) cranial nerve injury (CNI), and to evaluate the risk factors associated with increased CNI risk. METHODS: The study was a meta-analysis. Pooled rates with 95% confidence intervals (CIs) were calculated for CNIs after primary CEA. Odds ratios (ORs) were calculated for potential risk factors. A fixed-effects model or a random effects model (Mantel-Haenszel method) was used for non-heterogeneous and heterogeneous data, respectively. Meta-regression analysis was performed to examine the influence of publication year upon CNI rate. RESULTS: Twenty-six articles, published between 1970 and 2015, were included in the meta-analysis, corresponding to 20,860 CEAs. Meta-analysis revealed that the vagus nerve was the most frequently injured cranial nerve (pooled injury rate 3.99%, 95% CI 2.56-5.70), followed by the hypoglossal nerve (3.79%, 95% CI 2.73-4.99). Fewer than one seventh of these injuries are permanent (vagus nerve: 0.57% [95% CI 0.19-1.10]; hypoglossal nerve: 0.15% [95% CI 0.01-0.39]). A statistically significant influence of publication year on the vagus and hypoglossal nerve injury rate was found, with the injury rate having decreased from about 8% to 2% and 1%, respectively, over the last 35 years. Urgent procedures (OR 1.59, 95% CI 1.21-2.10; p = .001), as well as return to the operating room for a neurological event or bleeding (OR 2.21, 95% CI 1.35-3.61; p = .002) were associated with an increased risk of CNI, whereas no statistically significant association was found between CNIs and the type of anaesthesia, the use of a patch, redo operation, and the use of a shunt. CONCLUSION: The vagus nerve appears to be the most frequently injured cranial nerve after CEA, followed by the hypoglossal nerve, with only a small proportion of these injuries being permanent. The CNI rate has significantly decreased over the past 35 years to a point indicating that CNIs should not be considered a major influencing factor in the decision making process between CEA and stenting.

Clinical and Electromyographic Characteristics of Unilateral Vocal Fold Paralysis With Lower Cranial Nerve Injury.

OBJECTIVES: The aim was to investigate the clinical and electromyographic characteristics of patients with unilateral vocal fold paralysis (UVFP) combined with lower cranial nerve injury. STUDY DESIGN: This is a case series with chart review. METHODS: Among 368 patients with idiopathic UVFP, 31 patients (8.4%) were eventually diagnosed with lower cranial nerve palsy after examinations of the head and neck, radiology, and electromyogram (EMG). The clinical and electromyographic characteristics of these patients were analyzed. RESULTS: Of the 31 patients, 27 patients exhibited obvious abnormal lower cranial nerve injury physical signs, and 4 patients showed atypical physical signs, identified by EMG. Ultimately, 41.9% (13/31) were diagnosed with idiopathic causes, 38.7% (12/31) with intracranial or skull-base lesions on radiology, 12.9% (4/31) with lower cranial neuritis, and 6.4% (2/31) with radiation-induced lower cranial nerve palsy. Among the cranial lesions, lesions of the jugular foramen region were the most common (50%, 6/12). All 26 patients who underwent EMG tests were confirmed to have vagus nerve impairments (11 complete and 15 incomplete) and accessory nerve impairments (16 complete and 10 incomplete), whereas only 13 patients (50%) exhibited hypoglossal nerve injuries (5 complete and 8 incomplete). CONCLUSIONS: For patients with clinically "idiopathic" UVFP, physical examinations of the lower cranial nerves are essential screening procedures. For patients with abnormal or suspicious physical signs, radiology should be performed to detect possible cranial or cervical lesions. EMG tests were strongly recommended to identify suspicious lower cranial nerve injury and its severity, and may help to predict the prognosis.

The combined microscopic-endoscopic technique for radical resection of cerebellopontine angle tumors.

OBJECT: The combined microscopic and endoscopic technique has shown significant advantages in the management of various lesions through different approaches. Endoscopic-assisted techniques have frequently been applied to cerebellopontine angle (CPA) surgery in the context of minimally invasive craniotomies. In this paper the authors report on the use of the endoscope in the CPA as a tool to increase the extent of resection, minimize complications, and preserve the function of the delicate CPA structures. They also describe a technique of the simultaneous use of the microscope and endoscope in the CPA and dissection of CPA tumors under tandem endoscopic and microscopic vision to overcome the shortcomings of introducing the endoscope alone in the CPA. The reliability of using the microscope alone in dissecting CPA tumors is evaluated, as is the effectiveness of the combined technique in increasing the resectability of various types of CPA tumors. METHODS: The authors conducted a retrospective analysis of 50 patients who underwent combined microscopic-endoscopic resection of CPA tumors by the senior author over a period of 3 years (February 2011 to February 2014) at Brigham and Women's Hospital, Harvard Medical School. The reliability of the extent of microscopic removal was evaluated with endoscopic exploration. Additional resection was performed with both microscopic and the combined microscopic-endoscopic technique. Endoscopically verified total resection was validated by intraoperative or postoperative MRI. The function of the cranial nerves was evaluated to assess the impact of the combined technique on their function. RESULTS: A tumor remnant was endoscopically identified in 69% of the 26 patients who were believed to have microscopic total resection. The utilization of the endoscopic visualization and dissection increased endoscopically verified total removal to 38 patients, and 82% of these patients had no sign of residual tumor on postoperative imaging. The technique was most effective with epidermoid tumors. There were a total of 17 new cranial nerve deficits in 10 patients. Preoperative fifth cranial nerve deficits improved in 52% and hearing improved in 29% of patients after surgery. CONCLUSIONS: This method provides simultaneous microscopic and endoscopic visualization and dissection techniques through skull-base approaches to CPA tumors. It overcomes some of the shortcomings of endoscopic-assisted surgery, further extends the surgical field, and increases the radicality of tumor resection with good functional outcomes.

Clinical relevance of cranial nerve injury following carotid endarterectomy.

OBJECTIVES: The benefit of carotid endarterectomy (CEA) may be diminished by cranial nerve injury (CNI). Using a quality improvement registry, we aimed to identify the nerves affected, duration of symptoms (transient vs. persistent), and clinical predictors of CNI. METHODS: We identified all patients undergoing CEA in the Vascular Study Group of New England (VSGNE) between 2003 and 2011. Surgeon-observed CNI rate was determined at discharge (postoperative CNI) and at follow-up to determine persistent CNI (CNIs that persisted at routine follow-up visit). Hierarchical multivariable model controlling for surgeon and hospital was used to assess independent predictors for postoperative CNI. RESULTS: A total of 6,878 patients (33.8% symptomatic) were included for analyses. CNI rate at discharge was 5.6% (n = 382). Sixty patients (0.7%) had more than one nerve affected. The hypoglossal nerve was most frequently involved (n = 185, 2.7%), followed by the facial (n = 128, 1.9%), the vagus (n = 49, 0.7%), and the glossopharyngeal (n = 33, 0.5%) nerve. The vast majority of these CNIs were transient; only 47 patients (0.7%) had a persistent CNI at their follow-up visit (median 10.0 months, range 0.3-15.6 months). Patients with perioperative stroke (0.9%, n = 64) had significantly higher risk of CNI (n = 15, CNI risk 23.4%, p < .01). Predictors for CNI were urgent procedures (OR 1.6, 95% CI 1.2-2.1, p < .01), immediate re-exploration after closure under the same anesthetic (OR 2.0, 95% CI 1.3-3.0, p < .01), and return to the operating room for a neurologic event or bleeding (OR 2.3, 95% CI 1.4-3.8, p < .01), but not redo CEA (OR 1.0, 95% CI 0.5-1.9, p = .90) or prior cervical radiation (OR 0.9, 95% CI 0.3-2.5, p = .80). CONCLUSIONS: As patients are currently selected in the VSGNE, persistent CNI after CEA is rare. While conditions of urgency and (sub)acute reintervention carried increased risk for postoperative CNI, a history of prior ipsilateral CEA or cervical radiation was not associated with increased CNI rate.

Microvascular decompression for hemifacial spasm in patients >65 years of age: an analysis of outcomes and complications.

INTRODUCTION: Few data are available to quantify the risks and benefits of microvascular decompression (MVD) in elderly patients with hemifacial spasm. METHODS: Twenty-seven patients >65 years of age and 104 younger patients who underwent MVD for hemifacial spasm (HFS) over a 3-year period were analyzed retrospectively and compared. RESULTS: Twenty-six (96.3%) elderly patients and 93 of 104 (89.4%) young patients reported a spasm-free status at a mean follow-up of 26.5 months after MVD. No significant difference in spasm-free status was noted. Cranial nerve complications and other major complications were compared, with no significant differences observed. CONCLUSIONS: Although this study does not offer definitive inclusion or exclusion criteria or clearly establish the safety of MVD for HFS in the elderly, our experience suggests that many elderly patients with HFS can undergo MVD safely, with outcomes and risk profiles similar to those of younger patients.

Galanin protects against nerve injury after shear stress in primary cultured rat cortical neurons.

The neuropeptide galanin and its receptors (GalR) are found to be up-regulated in brains suffering from nerve injury, but the specific role played by galanin remains unclear. This study aimed to explore the neuroprotective role of galanin after shear stress induced nerve injury in the primary cultured cortical neurons of rats. Our results demonstrated that no significant changes in cell death and viability were found after galanin treatment when subjected to a shear stress of 5 dyn/cm(2) for 12 h, after increasing magnitude of shear stress to 10 dyn/cm(2) for 12 h, cell death was significantly increased, while galanin can inhibit the nerve injury induced by shear stress with 10 dyn/cm(2) for 12 h. Moreover, Gal2-11 (an agonist of GalR2/3) could also effectively inhibit shear stress-induced nerve injury of primary cultured cortical neurons in rats. Although GalR2 is involved in the galanin protection mechanism, there was no GalR3 expression in this system. Moreover, galanin increased the excitatory postsynaptic currents (EPSCs), which can effectively inhibit the physiological effects of shear stress. Galanin was also found to inhibit the activation of p53 and Bax, and further reversed the down regulation of Bcl-2 induced by shear stress. Our results strongly demonstrated that galanin plays a neuroprotective role in injured cortical neurons of rats.

Pregabalin suppresses nociceptive behavior and central sensitization in a rat trigeminal neuropathic pain model.

UNLABELLED: The aim of this study was to determine whether pregabalin affects nociceptive behavior and central sensitization in a trigeminal neuropathic pain model. A partial infraorbital nerve transection (p-IONX) or sham operation was performed in adult male rats. Nociceptive withdrawal thresholds were tested with von Frey filaments applied to the bilateral vibrissal pads pre- and postoperatively. On postoperative day 7, the behavioral assessment was conducted before and at 30, 60, 120, and 180 minutes after and 24 hours after pregabalin (.1, 1, 10, 100 mg/kg intraperitoneally) or saline injection. The effects of pregabalin or saline were also examined on the mechanoreceptive field and response properties of nociceptive neurons recorded in the medullary dorsal horn at postoperative days 7 to 10. Reduced withdrawal thresholds reflecting bilateral mechanical allodynia were observed in p-IONX rats until postoperative day 28, but not in sham-operated rats. At postoperative day 7, pregabalin significantly and dose-dependently reversed the reduced mechanical withdrawal thresholds in p-IONX rats. Pregabalin also attenuated central sensitization of the neurons, as reflected in reversal of their reduced activation threshold, increased responses to pinch/pressure, and enhanced stimulus-response function. This study provides the first documentation that pregabalin attenuates the mechanical allodynia and central sensitization that characterize this trigeminal neuropathic pain model, and supports its clinical use for treating craniofacial neuropathic pain. PERSPECTIVE: Trigeminal nerve injury in rats produced facial mechanical hypersensitivity and trigeminal central sensitization of medullary dorsal horn neurons that were markedly attenuated by systemically administered pregabalin, suggesting its potential clinical utility for orofacial neuropathic pain.

Exploring vocal recovery after cranial nerve injury in Bengalese finches.

Songbirds and humans use auditory feedback to acquire and maintain their vocalizations. The Bengalese finch (Lonchura striata domestica) is a songbird species that rapidly modifies its vocal output to adhere to an internal song memory. In this species, the left side of the bipartite vocal organ is specialized for producing louder, higher frequencies (≥2.2kHz) and denervation of the left vocal muscles eliminates these notes. Thus, the return of higher frequency notes after cranial nerve injury can be used as a measure of vocal recovery. Either the left or right side of the syrinx was denervated by resection of the tracheosyringeal portion of the hypoglossal nerve. Histologic analyses of syringeal muscle tissue showed significant muscle atrophy in the denervated side. After left nerve resection, songs were mainly composed of lower frequency syllables, but three out of five birds recovered higher frequency syllables. Right nerve resection minimally affected phonology, but it did change song syntax; syllable sequence became abnormally stereotyped after right nerve resection. Therefore, damage to the neuromuscular control of sound production resulted in reduced motor variability, and Bengalese finches are a potential model for functional vocal recovery following cranial nerve injury.

Axon degeneration and regeneration: insights from Drosophila models of nerve injury.

Axon degeneration is the pivotal pathological event of acute traumatic neural injury as well as many chronic neurodegenerative diseases. It is an active cellular program and yet molecularly distinct from cell death. Much effort is devoted toward understanding the nature of axon degeneration and promoting axon regeneration. However, the fundamental mechanisms of self-destruction of damaged axons remain unclear, and there are still few treatments for traumatic brain injury (TBI) or spinal cord injury (SCI). Genetically approachable model organisms such as Drosophila melanogaster, the fruit fly, have proven exceptionally successful in modeling human neurodegenerative diseases. More recently, this success has been extended into the field of acute axon injury and regeneration. In this review, we discuss recent findings, focusing on how these models hold promise for accelerating mechanistic insight into axon injury and identifying potential therapeutic targets for TBI and SCI.

Chorda tympani nerve modulates the rat's avoidance of calcium chloride.

Calcium intake depends on orosensory factors, implying the presence of a mechanism for calcium detection in the mouth. To better understand how information about oral calcium is conveyed to the brain, we examined the effects of chorda tympani nerve transection on calcium chloride (CaCl(2)) taste preferences and thresholds in male Wistar rats. The rats were given bilateral transections of the chorda tympani nerve (CTX) or control surgery. After recovery, they received 48-h two-bottle tests with an ascending concentration series of CaCl(2). Whereas control rats avoided CaCl(2) at concentrations of 0.1mM and higher, rats with CTX were indifferent to CaCl(2) concentrations up to 10mM. Rats with CTX had significantly higher preference scores for 0.316 and 3.16 mM CaCl(2) than did control rats. The results imply that the chorda tympani nerve is required for the normal avoidance of CaCl(2) solution.

[Damage to craniocerebral nerves in reconstructive surgery of carotid arteries].

Reconstructive operations on aortic arch branches appear to be the most efficient method of preventing acute and chronic impairments of cerebral circulation. Iatrogenic lesions of the craniocerebral nerves deteriorate the course of the immediate, and especially the remote postoperative period, decreasing quality of life and social status of the patients after endured carotid reconstructions. The authors analysed herein the outcomes in a total of 562 patients after endured carotid artery surgery for atherosclerosis or pathological tortuosity. The authors examined the incidence rate, patterns and risk factor of damage to the craniocerebral nerves in all the patients. Comprehensive prevention of damage to the craniocerebral nerves was carried out in a total of 412 patients from the Study Group and was aimed at excluding or decreasing intensity of the eff ect of the eliminable risk factors. The proposed measures made it possible to decrease the rate of lesions of craniocerebral nerves from 18.7 to 6.9% and to substantially improve the postoperative patients' quality of life.

Curcumin protects the dorsal root ganglion and sciatic nerve after crush in rat.

The goal of this study was to quantify the histological changes in the dorsal root ganglion (DRG) and the sciatic nerve in rats subjected to sciatic nerve crush (SNC) following curcumin treatment. The rats were divided into four groups, each including five animals, and underwent the following intervention: group I: control animals which received olive oil; group II: sham-operated animals whose skin of the posterior thigh was opened, sutured, and received the vehicle; group III: SNC animals which received the vehicle; and group IV: SNC plus curcumin (100 mg/kg/day) solved in the vehicle. On the 28th day, the fifth lumbar DRG and sciatic nerve were removed. Volume of the ganglion, mean cell volume, total volume of DRG cells (A- and B-cells), and total surface of DRG cells, total number, diameter, and area of the myelinated nerve fibers were estimated using stereological methods. Except for the volume of the ganglion, all other parameters were decreased after nerve crush. In curcumin-treated rats, these parameters decreased, but to a lesser extent, and the values were significantly higher than in the non-treated SNC group (p<0.04). It can be concluded that in rats after crush, curcumin has a protective effect on the DRG and sciatic nerve.

Cranial nerve monitoring during subpial dissection in temporomesial surgery.

OBJECTIVE: Cranial nerves (CNs) crossing between the brainstem and skull base at the level of the tentorial hiatus may be at risk in temporomesial surgery involving subpial dissection and/or tumorous growth leading to distorted anatomy. We aimed to identify the surgical steps most likely to result in CN damage in this type of surgery. METHODS: Electromyographic responses obtained with standard neuromonitoring techniques and a continuous free-running EMG were graded as either contact activity or pathological spontaneous activity (PSA) during subpial resection of temporomesial structures in 16 selective amygdalohippocampectomy cases. Integrity of peripheral motor axons was tested by transpial/transarachnoidal electrical stimulation while recording compound muscle action potentials from distal muscle(s). RESULTS: Continuous EMG showed pathological activity in five (31.2%) patients. Nine events with PSA (slight activity, n = 8; strong temporary activity, n = 1) were recorded. The oculomotor nerve was involved three times, the trochlear nerve twice, the facial nerve once, and all monitored nerves on three occasions. Surgical maneuvers associated with PSA were the resection of deep parts of the hippocampus and parahippocampal gyrus (CN IV, twice; CN III, once), lining with or removing cotton patties from the resection cavity (III, twice; all channels, once) and indirect exertion of tension on the intact pia/arachnoid of the uncal region while mobilizing the hippocampus and parahippocampal gyrus en bloc (all channels, once; III, once). CMAPs were observed at 0.3 mA in two patients and at 0.6 mA in one patient, and without registering the exact amount of intensity in three patients. CONCLUSION: The most dangerous steps leading to cranial nerve damage during mesial temporal lobe surgery are the final stages of the intervention while the resection is being completed in the deep posterior part and the resection cavity is being lined with patties. Distant traction may act on nerves crossing the tentorial hiatus via the intact arachnoid.