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Objectives: Isolated dysarthria caused by stroke is a rare condition and generally seen in infratentorial lesions, especially in cerebellar lesions. Isolated dysarthria associated with supratentorial ischemic lesions are also very rare and, these conditions were shown in only a few cases. In this study, six patients characterized by IHP due to supratentorial ischemic lesions are presented., Patients and Methods: Physical examinations of patients were done by two different neurologists. The risk factors for stroke were determined. Localisations of lesions were identified by using magnetic resonance images(MRI). Corticolingual tract affection without sensorial and other corticospinal tract involvement was confirmed using Somatosensory evoked potentials(SEPs) and Transcranial Magnetic Stimulation(TMS)., Results: Unilateral lingual paresis was detected in all of the patients. The lesions were demonstrated on MRI slices. All lesions were on the same localization. The affection of the corticolingual tract without any other motor and sensory tract involvement was proven electrophysiologically., Conclusion: Corticospinal and corticobulbar fibers are very close to each other. Therefore common involvement is expected in cerebrovascular diseases. However, six patients with IHP caused by supratentorial ischemic lesions were reported in this study. Thus, a possible map of the corticolingual tract was drawn., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Fever of unknown origin (FUO) continues to present a clinical conundrum for even expert practitioners. The syndrome of FUO has over 200 possible etiologies. Burkitt lymphoma (BL) is a highly aggressive B-cell non-Hodgkin lymphoma with only 1,200 US adult cases reported annually. Fever, night sweats, and weight loss, otherwise known as B symptoms, are common early symptoms of BL. Nerve palsy, especially isolated hypoglossal nerve palsy (IHNP), is rarely seen as a presenting sign in any pathological condition. A case report of FUO and IHNP as the presenting manifestations of BL is presented. The rarity of IHNP and its clinical features delayed the recognition of this syndrome and emphasizes the value of a thorough understanding of the physical examination and the association of unusual clinical findings with a readily identifiable clinical syndrome.

Isolated hypoglossal nerve palsy is uncommon because of its intimate relationship with the other lower cranial nerves. Keane reported that tumours, predominantly malignant, were the most common cause of hypoglossal nerve palsy. We report a case of isolated idiopathic unilateral hypoglossal nerve palsy in a 45-year-old Caucasian male where no cause could be identified despite extensive investigations. There was uncertainty around prognosis at onset due to the rarity of this condition. In the absence of a cause, an early referral to the speech and language therapist was made and interestingly our patient made an almost complete recovery within 18 months of onset. In a small case series, it has been reported that though rare, idiopathic hypoglossal nerve palsy has an excellent outcome in most cases, similar to the more common idiopathic seventh cranial nerve palsy (Bell's Palsy).We recommend an early referral for physiotherapy in such cases., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Schwannoma of the hypoglossal nerve is rare. This case report documents an atypical abnormality of the cervical vestibular evoked myogenic potential (cVEMP) in a patient with schwannoma of the hypoglossal nerve. The observed abnormality was attributed to the proximity of the hypoglossal nerve to the spinal accessory nerve in the medullary cistern and base of the skull., Purpose: To report cVEMP abnormality in a patient with hypoglossal nerve schwannoma and provide an anatomical correlation for this abnormality., Research Design: Case report., Study Sample: A 44-yr-old woman., Data Collection: Pure-tone and speech audiometry, tympanometry, acoustic stapedial reflex, auditory brainstem response, and cVEMP testing were performed., Results: The audiological test results were normal except for the absence of cVEMP on the lesion side (right)., Conclusions: A cVEMP abnormality indicating a compromised spinal accessory nerve was observed in a patient with hypoglossal nerve schwannoma. This case report highlights the importance of recording cVEMP in relevant neurological conditions and provides clinical proof for the involvement of the spinal accessory nerve in the vestibulocollic reflex pathway., (American Academy of Audiology)

Competing Interests: Competing interests: None declared.

In the present report, we discuss the case of a 66-year-old woman with isolated unilateral hypoglossal paralysis due to cerebral infarction in the centrum semiovale. To date, it has hardly been discussed where the corticolingual tract passes through in the centrum semiovale. Brain magnetic resonance imaging revealed a small ischemic infarction in the contralateral centrum semiovale. We could demonstrate a route of the corticolingual tract., (Copyright © 2017. Published by Elsevier Inc.)

A 46-year-old woman with cervical disc herniation underwent C4-6 laminoplasty and C4-5 foraminotomy under general anesthesia. The patient complained of the tongue deviation toward the right after surgery. She underwent several examinations and was diag- nosed as right hypoglossal nerve palsy caused by peripheral nerve disorder. It was considered that the main damage was the external branch of hypoglossal nerve which was likely to occur as a complication of compression because of the location. The cause of hypoglossal nerve palsy was assumed to be possibly direct compression of the hypoglossal nerve by the tracheal tube. In prone position surgery, it is important to take care of pressure to the tongue because the intraoral space tends to be reduced by edema of the face and neck.

Introduction: Hereditary gelsolin amyloidosis (GA) is a rare condition caused by the gelsolin gene mutation. The diagnostic triad includes corneal lattice dystrophy (type 2), progressive bilateral facial paralysis, and cutis laxa. Detailed information on facial paralysis in GA and the extent of cranial nerve injury is lacking., Methods: 29 GA patients undergoing facial corrective surgery were interviewed, examined, and studied electroneurophysiologically., Results: All showed dysfunction of facial (VII) and trigeminal (V) nerves, two-thirds of oculomotor (III) and hypoglossal (XII) nerves, and half of vestibulocochlear (acoustic) (VIII) nerve. Clinical involvement of frontal, zygomatic, and buccal facial nerve branches was seen in 97%, 83%, and 52% of patients, respectively. Electromyography showed marked motor unit potential loss in facial musculature., Conclusions: Cranial nerve involvement in GA is more widespread than previously described, and correlates with age, severity of facial paralysis, and electromyographic findings. We describe a grading method for bilateral facial paralysis in GA, which is essential for evaluation of disease progression and the need for treatment., (© 2016 Wiley Periodicals, Inc.)

An increasingly reported entity, Lemierre's syndrome classically presents with a recent oropharyngeal infection, internal jugular vein thrombosis and the presence of anaerobic organisms such as Fusobacterium necrophorum. The authors report a normally fit and well 17-year-old boy who presented with severe sepsis following a 5-day history of a sore throat, myalgia and neck stiffness requiring intensive care admission. Blood cultures grew F. necrophorum and radiological investigations demonstrated left internal jugular vein, cavernous sinus and sigmoid sinus thrombus, left vertebral artery dissection and thrombus within the left internal carotid artery. Imaging also revealed two areas of acute ischaemia in the brain, consistent with septic emboli, skull base (clival) osteomyelitis and an extensive epidural abscess. The patient improved on meropenem and metronidazole and was warfarinised for his cavernous sinus thrombosis. He has an on-going left-sided hypoglossal (XIIth) nerve palsy., (2015 BMJ Publishing Group Ltd.)

Purpose: Occipital condyle syndrome (OCS) is a rare cause of headache. This study herein reports a case in which a unique headache and tongue deviation appear as symptoms of the first presentation of a malignant tumor., Case Report: A healthy 67-year-old male presented with a unilateral shooting pain in the occipital region, accompanied by slurred speech and difficulty swallowing. Neurological examinations later revealed atrophy and mild fasciculation of the tongue. The clinical symptoms and MRI results suggested OCS. Screening for tumor markers showed an elevated CEA. The chest CT revealed a lobulated soft-tissue mass in the lower left lobe, and a CTguided biopsy confirmed the diagnosis of adenocarcinoma. A whole body bone scan found multiple foci. The adenocarcinoma was graded pT2bN3M1b, stage IV. The headache improved with a prescription of prednisone, 60 mg to be taken daily. With three months of treatment, clinical examinations showed that the patient was free of pain and that there had been no progression of the atrophy or deviation of the tongue., Conclusion: The possible etiology of OCS includes a primary tumor or metastatic lesion that directly invades the base of the skull. Determining the underlying causes of OCS can be challenging, but MR imaging is currently the diagnostic tool of choice. An awareness of the features of OCS in healthy adults may be able to lead to earlier diagnosis of the underlying etiology and efficient relief of the symptoms.

Objective: This cross-sectional study of acute ischemic stroke patients examined relationships between hypoglossal nerve conduction, sleep-disordered breathing (SDB), and its severity., Methods: Patients within 7 days of stroke underwent nocturnal respiratory monitoring with the ApneaLink device and hypoglossal nerve conduction studies., Results: Eighteen of 52 subjects (35% [95% confidence interval: 22%, 49%]) had an abnormal hypoglossal amplitude and 23 (44% [95% confidence interval: 30%, 59%]) had an abnormal hypoglossal latency. No differences were identified in hypoglossal nerve latency or amplitude between those with (n = 26) and without (n = 26) significant SDB, defined by an apnea-hypopnea index ≥ 15. However, hypoglossal nerve conduction latency was associated (linear regression p < 0.05) with SDB severity as reflected by the apnea-hypopnea index., Conclusions: Acute ischemic stroke patients have a high prevalence of hypoglossal nerve dysfunction. Further studies are needed to explore whether hypoglossal nerve dysfunction may be a cause or consequence of SDB in stroke patients and whether this association can provide further insight into the pathophysiology of SDB in this population.

Introduction: Neurological complications of infectious mononucleosis are rare. Various disorders have been described: meningitis, encephalitis, peripheral neuropathy. Isolated cranial nerve palsy has rarely been reported., Observation: A 16-year-old man was admitted for isolated and unilateral hypoglossal nerve palsy, four weeks after infectious mononucleosis. Cerebral MRI, cerebrospinal fluid study and electromyography were normal. IgM anti-VCA were positive. Two months later, without treatment, the tongue had almost fully recovered., Conclusion: To the best of our knowledge, only seven cases of isolated palsy of the hypoglossal nerve complicating infectious mononucleosis have been previously reported., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Objective: We report on vascular compression syndrome of the 12th cranial nerve (hypoglossal), an occurrence not previously reported, and demonstrate, through corresponding objective electrophysiological evidence, that microvascular decompression of the hypoglossal nerve root can cure hemilingual spasm., Clinical Presentation: A 52-year-old man had lower face muscle twitching and tongue spasms, which worsened with talking, chewing, or emotional stress. Carbamazepine offered only temporary relief, and relief from injections of botulinum toxin was insignificant. He was referred for surgical treatment. High-resolution magnetic resonance imaging of his posterior fossa contents revealed no obvious evidence of any compressive vessel along the facial nerve, but a compressive vessel along the hypoglossal nerve was apparent., Intervention: The presence of preoperative tongue spasms encouraged interoperative monitoring of tongue motor responses. The facial nerve exit zone was explored, but microsurgical inspection of the seventh/eighth cranial nerve complex did not reveal any compressive vessel. However, at the anterolateral aspect of the medulla oblongata, the hypoglossal nerve was clearly compressed and distorted laterally by a large tortuous vertebral artery. When the artery was mobilized away from the nerve, the abnormal late electromyographic response to transcranial electrical stimulation disappeared; immediately after shredded Teflon was interpositioned between the artery and the nerve, the abnormal spontaneous tongue fasciculation also disappeared. The patient has remained spasm free 6 months after surgery., Conclusion: Hemilingual spasm may be caused by vascular contact/compression along cranial nerve XII at the lower brainstem and belong to the same family of cranial nerve hyperactivity disorders as hemifacial spasm.

Hereditary amyloidosis of the Finnish type (HAF, or familial amyloid polyneuropathy type IV) is an autosomal dominant disease that has been described most commonly in the Finnish population but has also been found in some other countries. Herein we report the first German family whose members suffer from this condition. There are no known Finnish ancestors. We performed clinical and electrophysiological examinations in 22 members of this family. All symptomatic family members suffered from facial palsy, and most of them had peripheral neuropathy. One patient had confirmed corneal lattice dystrophy. Additional symptoms were hypoglossal nerve involvement in 5 patients and oculomotor nerve palsy in 1 patient. The lips of all older patients appeared thickened. The causative G654A mutation in the gelsolin gene was found in all affected family members.

In the present offering, the authors provide evidence for the role of the hypoglossal motonucleus in causing a cranial nerve hyperactivity syndrome, namely hemilingual spasm. During a microvascular decompression operation to treat hemilingual spasm, transcranial stimulation elicited a delayed electromyographic (EMG) response from the tongue. This late volley of EMG activity occurred with a latency of approximately 40 ms, lasted approximately 50 ms, and disappeared when the offending vessel was displaced away from the exit zone of the hypoglossal nerve root along medulla oblongata. This late tongue EMG response resembles those found in facial muscles of the patients with hemifacial spasm (HFS). In HFS, electrical stimulation of a branch of facial nerve may elicit an EMG response with a latency of approximately 10 ms in muscles innervated by another branch of the nerve, followed by a variable volley of EMG activity that may last 100 ms or longer. This abnormal response, known as the lateral spread response, is a characteristic sign for hemifacial spasm that disappears after the offending vessel is moved off the facial nerve root. The results of the present study indicate that the EMG signs of hemilingual spasm are similar to those of HFS and that the tongue spasms are most likely caused by hyperactivity of the hypoglossal motonucleus. Based on the authors' knowledge, the above detailed electrophysiological findings related to hemilingual spasm have not been previously reported in the literature.

A neurovascular conflict (NC) consists of a pathological contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem. Even if NC of the V, VII and IX cranial nerve have been rarely described, to the best of our knowledge there is no report about the XII cranial nerve NC in the paediatric age. A three-year-old girl presented with right-sided tongue atrophy and fasciculation, of one-year-duration, consistent with a peripheral lesion of the right XII cranial nerve. Brain MRI and MRA documented a marked tortuosity of the vertebrobasilar arteries compressing the brainstem at the emergency of the XII cranial nerve, while the CT disclosed a concomitant osseous malformation of the cranio-cervical junction. The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in children, a neurovascular conflict. In this case a complete neuroimaging study is indicated.

The hypoglossal nerve provides motor innervation to the tongue, and may be affected by pathology at multiple locations along its pathway. Knowledge of its anatomy and careful examination of the tongue are important in the diagnosis of lesions and determination of appropriate testing. The hypoglossal nerve anatomy and physiology, clinical disorders, and the evaluation of the hypoglossal nerve are reviewed.

Background: Using the rat facial nerve axotomy model, the authors recently showed that manual stimulation of denervated whiskerpad muscles reduced the posttransectional polyinnervation at the neuromuscular junctions and promoted full recovery of vibrissal whisking., Objective: Prompted by implications for rehabilitation therapy, the authors examined whether manual stimulation of denervated supra- and infrahyoid muscles would also improve recovery after unilateral lesion on the hypoglossal nerve., Methods: Adult rats underwent transection of the right hypoglossal nerve. Half of the animals received no postoperative treatment, and the other half were subjected to daily manual stimulation of the suprahyoid/sublingual region for 2 months. Recovery was assessed by measuring the angle of tongue-tip deviation from the midline, degree of collateral axonal branching at the lesion site (counts after retrograde labeling with 2 fluorescent dyes), synaptic input to the hypoglossal motoneurons using synaptophysin immunocytochemistry, tongue-muscles motor representation in the cerebral cortex after c-Fos immunocytochemistry, and portion of polyinnervated neuromuscular junctions., Results: In animals receiving manual stimulation, the tongue-tip deviation was 37.0 +/- 49.37 degrees , whereas values in control nonstimulated rats were significantly higher (50.1 +/- 9.01 degrees ; P < .05; mean +/- SD). Improved recovery was not associated with reduced collateral axonal branching; there were also no differences in tongue-muscles representation in the motor cortex. However, manual stimulation restored the total synaptic input to levels in intact animals and reduced the proportion of polyinnervated neuromuscular junctions compared with nonstimulated animals., Conclusion: The data show that manual stimulation of denervated muscles improves functional outcome following peripheral nerve injury. This suggests immediate potential for enhancing clinical rehabilitation strategies.

Excessive production of nitric oxide (NO) might have detrimental effects on the hypoxia-related neuropathology. This study aimed to test if mild hypoxic preconditioning (MHPC) would attenuate the pathological changes in the brainstem motoneurons having a different functional component after peripheral nerve crush injury (PNCI). Prior to PNCI treatment, young adult rats were caged in the mild hypoxic altitude chamber with 79Torr of the partial oxygen concentration ( pO(2)) (i.e., 0.5atm at 5500m in height) for 4 weeks to adapt the environmental changes. After that, all the animals having successfully crushed both the hypoglossal and vagus nerves (left-side) were allowed to survive for 3, 7, 14, 30 and 60 successive days in normoxic condition. Nicotinamine adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry revealed that MHPC reduces NADPH-d/nNOS expression in the hypoglossal nucleus (HN) and the dorsal motor nucleus of the vagus (DMN) at different time points after PNCI. The morphological findings were further ascertained by Western blot analysis of nNOS and nitrite assay for NO production. Both the morphological and quantitative results peaked at 7 days in HN, whereas for those in DMN were progressively increased up to 60 days following PNCI. The staining intensity of NADPH-d/nNOS(+) neurons, expression of nNOS protein, NO production levels as well as the neuronal loss in HN and DMN of MHPC rats following PNCI were attenuated, especially for those having a longer survival period over 14 days. The MHPC treatment might induce minute amounts of NO to alter the state of milieu of the experimental animals to protect against the PNCI.

Background: Occipital condyle syndrome is characterized by severe, unilateral, occipital headache and ipsilateral twelfth-nerve palsy. It is associated with skull-base metastasis., Cases: We identified two patients with sub-acute onset of severe, unilateral, occipital headache and ipsilateral tongue paralysis. The first patient was a 58-year-old woman with a history of limited stage small-cell lung cancer in clinical remission. The second patient was an otherwise healthy 36-year-old man. Neither patient had any other findings on general medical or neurological examination. One patient had only equivocal findings on initial magnetic resonance imaging (MRI), and the other patient's MRI was normal. Although initial work-up for metastatic disease was normal, the first patient developed severe bone pain over the next few months, and follow-up investigations demonstrated metastases to her spine, tibia, skull base and brain. The second patient improved initially, but was admitted to hospital three months later with constitutional symptoms and pancytopenia. Bone marrow and lymph node biopsies were consistent with Stage IVB Hodgkin's lymphoma., Conclusion: Occipital condyle syndrome can be the first presentation of disseminated malignancy. Initial imaging of the brain and skull base may be normal, and recognition of this syndrome warrants thorough investigation and close follow-up.

Hypoglossal neurinomas usually manifest with hemiatrophy and weakness of the tongue. A rare case of intracranial hypoglossal neurinoma without preoperative hypoglossal nerve dysfunction and its operative view are presented. A 36-year-old female who presented with headaches and vertigo was admitted to our hospital. The neurological examination revealed bilateral papilledema and mild truncal ataxia, although weakness and atrophy of the tongue were not observed. Magnetic resonance and computed tomography images demonstrated a large foramen magnum tumor without enlargement of the hypoglossal canal. Total removal of the tumor was performed via a lateral suboccipital craniotomy and C1 partial laminectomy. During the operation, two trunks were observed for the hypoglossal nerve at the entrance of the hypoglossal canal. The tumor arose from the caudal trunk, while the intact rostral trunk entered the hypoglossal canal normally. The tumor only developed intracranially, and since the rostral trunk of the hypoglossal nerve was intact, the patient did not present with hypoglossal nerve palsy preoperatively.

Carotid and vertebral artery dissection is one of the major causes of ischemic stroke in young patients and diagnosing it remains a challenge for the clinician due to its variable clinical presentation. We report the case of a 57-years old man admitted to the emergency department complaining of dysphagia and a hoarse voice. Physical examination revealed a left deviation of his tong and some weakness of the left side of his soft palate. A gastroscopy and a cervical tomodensitometry revealed the presence of an important dilation of his upper oesophagus. A cerebral magnetic resonance was performed, showing en excentric high signal intensity on the left carotid artery, and the MR angiography confirmed the presence of an acute dissection on the left internal carotid artery. Our patient suffered of a left carotid artery dissection presenting with ipsilateral Xth and XIIth nerve palsies. His main symptom was a dysphagia due to a dilation of his upper oesophagus; the pneumogastric nerve being responsible for the parasympathic innervation of the upper muscles of the oesophagus.

Ipsilateral headache associated with hypoglossal nerve palsy is uncommon and is usually reported to be secondary to internal carotid artery dissection. Herein, we report three idiopathic cases of berign ipsilateral headache with hypoglossal nerve palsy.

The Miller Fisher syndrome, Guillain-Barre syndrome and Bickerstaff's brainstem encephalitis are related conditions in which anti-GQ1b antibody positivity occur in varied frequencies. This report demonstrates the presence of corticobulbar and corticospinal dysfunction in BBE, by means of a novel transcranial magnetic stimulation technique. It further supports the presence of protean manifestations in anti-GQ1b IgG antibody-positive spectrum of disorders.

Disrupted peripheral nerves are typically sutured as spontaneous recovery does not always occur. However, the molecular mechanisms involved in nerve regeneration following end-to-end nerve suture are obscure. Here, we investigated effects of end-to-end nerve suture after peripheral nerve transection on motor neurons, using the C57BL/6J mouse hypoglossal nerve injury model. In this animal model, 60-80% of injured motor neurons gradually progress to neuronal death, while the remaining injured neurons survive and regenerate. Mice were divided into the Cut and Suture groups. In the Cut group, the right hypoglossal nerve was transected. In the Suture group, the right hypoglossal nerve was transected and then was repaired using end-to-end nerve suture. We assessed differences between the Cut and Suture groups by analyzing the neuronal survival rate by thionine staining and the nerve terminal regeneration rate by vesicular acetylcholine transporter (VAChT) immunohistochemistry, which is a marker for cholinergic presynaptic terminal. We found that 82.9% of motor neurons survived in the Suture group, whereas only 39.2% of motor neurons did in the Cut group 56 days after surgery. At that time point, 86% of presynaptic terminals compared to controls were regenerated in the Suture group, and 21% were regenerated in the Cut group. These results demonstrate that peripheral nerve suture prevented death of nerve-transected motor neurons and promoted nerve regeneration. We also examined expression profiles of major survival and death signal-associated genes in hypoglossal nuclei using in situ hybridization and real-time polymerase chain reaction (PCR). Although most of the survival- and death-associated genes were regulated in a similar manner in both groups, expression of BH3-only protein Noxa mRNA was significantly lower in the Suture than in the Cut group. A significant suppression of Noxa expression by the Suture may be a major reason why nerve suture induces survival and regeneration of nerve-injured motor neurons.

We examined changes in the expression of Smad family members, which transduce signals from TGF-beta superfamily ligands, following hypoglossal nerve injury. RT-PCR and in situ hybridization revealed that Smad1, 2, 3 and 4 mRNAs were significantly up-regulated in injured side, whereas Smad8 mRNA was down-regulated. Immunohistochemistry and Western blotting analysis confirmed the alterations of Smad1, 2 and 4 in injured neurons. These results suggest that the Smad signaling may be important for nerve regeneration.

Objective: Cadaveric dissections were performed to review the intracranial and extracranial course of the hypoglossal nerve. The neurological significance of a newly defined "triple cross" of the hypoglossal nerve is discussed., Materials and Methods: 10 cadaveric heads (left and right; 20 sides) were dissected using microsurgical techniques., Results: In the cisternal segment of hypoglossal nerve, the diameter of the rostral trunk amounted to 155-680 microm (mean 435 microm), and the caudal trunk to 210-820 microm (mean 482 microm). The roots formed three trunks in 20% of the hypoglossal nerves and two trunks in the rest. As a first cross, the anterior medullary segment of the vertebral artery crossed the hypoglossal nerve roots in 14 of 20 sides (70%). As a rare variation, the vertebral artery extended medial to the nerve (25%) or between its roots (5%). The second cross was found between the descendens hypoglossus and the occipital artery (75%), sternocleidomastoid artery and vein complex (15%) and external carotid artery (10%). The third cross was shown in the submandibular triangle between the lingual hypoglossus and its drainage vein; vena committans nervus hypoglossus., Conclusion: Throughout its way, the hypoglossal nerve passes over vascular structures in three crossing points which may serve as a probable cause of hypoglossal nerve entrapment disorders.

The hypoglossal (XII) nerve is made up of functionally different nerve branches: the medial branch related to protrusion of the tongue and the lateral branch related to its retraction. The present study was performed to determine the effects of facial (VII) and XII nerve injuries on the survival and growth of rats in which the unilateral or bilateral VII and XII nerve components (main trunk, XII-trunk; medial branch, XII-med; lateral branch, XII-lat) had been resected at different developmental stages. In the suckling period, unilateral as well as bilateral injuries in the XII-trunk or XII-med nerve produced disturbed milk intake, lower survival rates and growth retardation in the nerve-injured rats. In the transition and mastication periods, only bilateral injury in the XII-trunk or XII-med nerve produced disturbed food intake followed by lower survival rates and growth retardation in those animals. The unilateral XII-lat nerve injury did not have significant effects on milk and food intake, whereas the bilateral injury caused disturbance in milk intake especially at the early neonatal stage. The unilateral VII nerve injury at the early neonatal stage caused deteriorating effects on food intake resulting in lower survival rate and severe growth retardation in the nerve-injured rats. The results indicate that the survival and growth of XII and VII nerve-resected rats differ considerably depending on the nerves injured and the developmental ages of the animals at the time of nerve insult.

To identify proteins implicated in peripheral nerve regeneration, we performed two-dimensional polyacrylamide gel electrophoresis and subsequent mass spectrometry analysis using nerve-injured hypoglossal nuclei of rat. We have identified annexin III (ANX III/ANX A3) as an induced protein after rat hypoglossal nerve injury. ANX III is known as a Ca2+-dependent phospholipid-binding protein, but its physiological function is mostly unknown. By in situ hybridization and immunohistochemistry, we demonstrated that ANX III expression was induced specifically in activated (axotomy-stimulated) microglia after nerve injury. ANX III was the most prominent ANX expressed in microglia of the major ANX family members (ANX I-VI). Hybridization signals for other ANX mRNAs (II, IV, V, and VI) were mainly observed in neuronal cells, and no significant hybridization signal for ANX I mRNA was detected in hypoglossal nuclei. In cultured microglia, ATP treatment induced ANX III translocation to the ruffling membrane where F-actin was accumulated. Further in vitro studies revealed that ANX III was not secreted and had F-actin binding activity in a Ca2+-dependent manner. These results suggest that ANX III may be a Ca2+-dependent mediator between phospholipids and F-actin in microglia stimulated by peripheral nerve injury., (Copyright 2006 Wiley-Liss, Inc.)

Background: Usefulness of transcervical approach to hypoglossal schwannoma with paraspinal extension is described herein., Case Description: A 54-year-old woman presented with gradually worsening left hypoglossal nerve palsy. The findings were of a tumor lying in the left hypoglossal canal and paraspinal region and were consistent with hypoglossal schwannoma. Subtotal intracapsular removal of the tumor was performed via transcervical approach. The symptoms improved, and no additional symptoms were noted., Conclusion: The transcervical approach and intracapsular removal of the tumor under electrophysiological monitoring provided for successful minimally invasive surgery in this case of hypoglossal schwannoma.

The previous companion paper describes the initial (seed) schema architecture that gives rise to the observed prey-catching behavior. In this second paper in the series we describe the fundamental adaptive processes required during learning after lesioning. Following bilateral transections of the hypoglossal nerve, anurans lunge toward mealworms with no accompanying tongue or jaw movement. Nevertheless anurans with permanent hypoglossal transections eventually learn to catch their prey by first learning to open their mouth again and then lunging their body further and increasing their head angle. In this paper we present a new learning framework, called schema-based learning (SBL). SBL emphasizes the importance of the current existent structure (schemas), that defines a functioning system, for the incremental and autonomous construction of ever more complex structure to achieve ever more complex levels of functioning. We may rephrase this statement into the language of Schema Theory (Arbib 1992, for a comprehensive review) as the learning of new schemas based on the stock of current schemas. SBL emphasizes a fundamental principle of organization called coherence maximization, that deals with the maximization of congruence between the results of an interaction (external or internal) and the expectations generated for that interaction. A central hypothesis consists of the existence of a hierarchy of predictive internal models (predictive schemas) all over the control center-brain-of the agent. Hence, we will include predictive models in the perceptual, sensorimotor, and motor components of the autonomous agent architecture. We will then show that predictive models are fundamental for structural learning. In particular we will show how a system can learn a new structural component (augment the overall network topology) after being lesioned in order to recover (or even improve) its original functionality. Learning after lesioning is a special case of structural learning but clearly shows that solutions cannot be known/hardwired a priori since it cannot be known, in advance, which substructure is going to break down.

The hypoglossal nerve or Twelfth-nerve palsy is a rare damage with different causes: tumors or metastases in skull base, cervicals tumors, schwannoma, dissection or aneurysm carotid arteries, stroke, trauma, idiopathic cause, radiation, infections (mononucleosis) or multiple cranial neuropathy. Tumors were responsible for nearly half of the cases in different studies. We studied a female with hypoglossal nerve acute palsy. We made a differential diagnostic with others causes and a review of the literature.

Cervical paragangliomas are rare tumors derived from neural crest cells. Anatomic imaging techniques rely upon the characteristic spatial relations and the high vascularity of this tumor. Results of computed tomography (CT), magnetic resonance imaging (MRI), and arteriography initially led us to the preoperative diagnosis of cervical paraganglioma. In our case, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET), a type of functional imaging, was also carried out and demonstrated abnormally increased tracer uptake; this approach was thus successful for visualizing paraganglioma. FDG PET imaging may be useful in the detection of benign paraganglioma. On surgical exploration of the neck, the tumor was found to arise from the vagus nerve, whereas the hypoglossal nerve was encompassed by the tumor in its upper portion. The intraoperative findings suggested the possibility that the tumor had arisen from the hypoglossal nerve.

An 18 year old man with congenital basilar invagination developed multiple lower cranial nerve (CN) palsies including CN IX to XII after a traffic accident. Computed tomography of his skull base revealed a two part atlas Jefferson fracture. Normally, lower cranial nerves (CN IX-XII) pass through a space between the styloid process and the atlas transverse process. Atlas burst fractures rarely cause neurological deficits because of a greater transverse and sagittal diameter of the spinal canal at the atlas, and a tendency of the lateral masses to slide away from the cord after injury. However, when associated with a rare condition-congenital basilar invagination-atlas fractures can compromise the space and make CN IX-XII more vulnerable to compression injury. This report discusses the correlation between the anatomical lesions and clinical features of this patient.