SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Facial nerve

77

Minmi is the only known genus of ankylosaurian dinosaur from Australia. Seven specimens are known, all from the Lower Cretaceous of Queensland. Only two of these have been described in any detail: the holotype specimen Minmi paravertebra from the Bungil Formation near Roma, and a near complete skeleton from the Allaru Mudstone on Marathon Station near Richmond, preliminarily referred to a possible new species of Minmi. The Marathon specimen represents one of the world’s most complete ankylosaurian skeletons and the best-preserved dinosaurian fossil from eastern Gondwana. Moreover, among ankylosaurians, its skull is one of only a few in which the majority of sutures have not been obliterated by dermal ossifications or surface remodelling. Recent preparation of the Marathon specimen has revealed new details of the palate and narial regions, permitting a comprehensive description and thus providing new insights cranial osteology of a basal ankylosaurian. The skull has also undergone computed tomography, digital segmentation and 3D computer visualisation enabling the reconstruction of its nasal cavity and endocranium. The airways of the Marathon specimen are more complicated than non-ankylosaurian dinosaurs but less so than derived ankylosaurians. The cranial (brain) endocast is superficially similar to those of other ankylosaurians but is strongly divergent in many important respects. The inner ear is extremely large and unlike that of any dinosaur yet known. Based on a high number of diagnostic differences between the skull of the Marathon specimen and other ankylosaurians, we consider it prudent to assign this specimen to a new genus and species of ankylosaurian. Kunbarrasaurus ieversi gen. et sp. nov. represents the second genus of ankylosaurian from Australia and is characterised by an unusual melange of both primitive and derived characters, shedding new light on the evolution of the ankylosaurian skull.

Concepts: Mammal, Cretaceous, Facial nerve, Dinosaur, Ankylosauridae, Ankylosauria, Thyreophora, Ornithischia

31

ABSTRACT OBJECTIVE: To review evidence published since the 2001 American Academy of Neurology (AAN) practice parameter regarding the effectiveness, safety, and tolerability of steroids and antiviral agents for Bell palsy. METHODS: We searched Medline and the Cochrane Database of Controlled Clinical Trials for studies published since January 2000 that compared facial functional outcomes in patients with Bell palsy receiving steroids/antivirals with patients not receiving these medications. We graded each study (Class I-IV) using the AAN therapeutic classification of evidence scheme. We compared the proportion of patients recovering facial function in the treated group with the proportion of patients recovering facial function in the control group. RESULTS: Nine studies published since June 2000 on patients with Bell palsy receiving steroids/antiviral agents were identified. Two of these studies were rated Class I because of high methodologic quality. CONCLUSIONS AND RECOMMENDATIONS: For patients with new-onset Bell palsy, steroids are highly likely to be effective and should be offered to increase the probability of recovery of facial nerve function (2 Class I studies, Level A) (risk difference 12.8%-15%). For patients with new-onset Bell palsy, antiviral agents in combination with steroids do not increase the probability of facial functional recovery by >7%. Because of the possibility of a modest increase in recovery, patients might be offered antivirals (in addition to steroids) (Level C). Patients offered antivirals should be counseled that a benefit from antivirals has not been established, and, if there is a benefit, it is likely that it is modest at best.

Concepts: Clinical trial, Virus, Evidence-based medicine, Cochrane Library, Antiviral drug, Antivirals, Facial nerve, Bell's palsy

28

Abstract Conclusion: The midline electroneurography (ENoG) method might reflect total facial nerve degeneration. Objective: We compared ENoG values in patients with facial palsy using two different methods, the midline method and five electroneurogram recordings, to reveal whether the ENoG value obtained with the midline method reflects total facial nerve degeneration. Methods: Forty patients with facial palsy were enrolled. Compound muscle action potentials (CMAPs) were recorded using the midline method, in which the anode was placed on the mental protuberance and the cathode was placed on the philtrum. Additionally, five electroneurogram recordings were obtained by placing the anode on the skin of the parietal region and five cathodes on the skin over five facial muscles (frontalis, orbicularis oculi, nasalis, orbicularis oris, and depressor anguli oris muscles). ENoG values recorded using the two methods were compared. Results: The ENoG values of the five facial muscles did not differ from those obtained using the midline method. The total ENoG value calculated by summing five CMAPs from five facial muscles, which is considered to reflect total facial nerve degeneration, was not significantly different from that using midline methods; moreover, a strong positive correlation coefficient (r = 0.87) was found between them.

Concepts: Cathode, Muscle, Correlation and dependence, Nerve, Facial nerve, Bell's palsy, Muscles of the head and neck, Orbicularis oris muscle

27

: Single-stage facial reanimation with a partial gracilis muscle coapted to the contralateral facial nerve seems an optimal surgical solution yet has not supplanted the two-stage approach. Insufficient obturator nerve length may limit reach to sizable contralateral facial nerve branches (possibly necessitating interposition nerve grafting), compromise optimal muscle positioning, or risk nerve coaptation under tension. This study evaluates whether retroperitoneal obturator nerve dissection would effectively lengthen the nerve, thus obviating the aforementioned limitations.

Concepts: Cranial nerves, Anatomy, Nerve, Facial nerve, Obturator nerve

27

BACKGROUND: . Bell’s palsy (BP) is the most frequent form of peripheral palsy of the facial nerve. Prognosis for recovery is good for most patients; in the remaining cases, different grades of residual impairment persist. Physical therapy, in association with drug administration, aims to improve outcomes. OBJECTIVE: . To assess the efficacy of early physical therapy in association with standard drug administration versus pharmacological therapy only, in terms of time to maximum gains and grade of recovery of function, and to examine who will most benefit from rehabilitation. METHODS: . From June 2008 to May 2010, 232 individuals were evaluated. The 87 patients meeting the eligibility criteria were randomly assigned to the experimental group (prednisone and valacyclovir plus physical therapy, n = 39) or the control group (pharmacological therapy, n = 48) within 10 days of onset. Intention-to-treat analyses were done. RESULTS: . The physical therapy had a significant effect on grade (P = .038) and time (P = .044) to recovery only in patients presenting with severe facial palsy (House-Brackmann [HB] grade V/VI). No significant differences were found between the study and control groups for outcome of synkinesis. CONCLUSION: . Physical therapy appears to be effective only in the more severe BP (baseline HB grade V/VI), whereas less severe BP (baseline HB grade IV) results in complete spontaneous recovery, regardless of physical therapy.

Concepts: Controlling for a variable, Scientific control, Pharmacology, Randomized controlled trial, Effectiveness, Efficacy, Facial nerve, Bell's palsy

26

This study describes the microsurgical anatomy of the middle cranial fossa approach using temporal bone three-dimensional (3D) computed tomography (CT) reconstruction, which should contribute to determining the drilling point for the internal auditory meatus (IAM) when bony landmarks are absent. Thirty temporal bone CT scans were reviewed retrospectively. We measured the shortest and longest distances to IAM from the petrous ridge, and measured the angle between the facial nerve and various labyrinth structures. Three-dimensional reconstructed images were obtained using high-resolution axial temporal bone CT (0.7-mm-thick slices, FOV 90 × 90, KVp 120, 305 mA, width 2,800, and level 800). The mean shortest and longest distances to IAM from the petrous ridge were 5.22 and 10.1 mm, respectively. The mean distance to the IAM from the cochlea was 9.91 mm. The mean angle between the IAM and superior semicircular canal was 47.21°, which was more acute than previously reported. The mean angle between the IAM and geniculate ganglion (GG) and external auditory canal was 113.8°, and the mean distance from the GG to the IAM was 15.44 mm. Understanding the 3D relationships among the microsurgical structures will help to decide the drilling point for the IAM when bony landmarks are absent. A preoperative evaluation might be useful for preserving important neurovascular structures while approaching the middle fossa.

Concepts: Skull, Auditory system, Temporal bone, Length, Ear canal, Facial nerve, Geniculate ganglion, Internal auditory meatus

26

The aim was to compare high-resolution computed tomography (HRCT) and thin-section magnetic resonance imaging (MRI) findings of facial nerve hemangioma. The HRCT and MRI characteristics of 17 facial nerve hemangiomas diagnosed between 2006 and 2013 were retrospectively analyzed. All patients included in the study suffered from a space-occupying lesion of soft tissues at the geniculate ganglion fossa. Affected nerve was compared for size and shape with the contralateral unaffected nerve. HRCT showed irregular expansion and broadening of the facial nerve canal, damage of the bone wall and destruction of adjacent bone, with “point”-like or “needle”-like calcifications in 14 cases. The average CT value was 320.9 ± 141.8 Hu. Fourteen patients had a widened labyrinthine segment; 6/17 had a tympanic segment widening; 2/17 had a greater superficial petrosal nerve canal involvement, and 2/17 had an affected internal auditory canal (IAC) segment. On MRI, all lesions were significantly enhanced due to high blood supply. Using 2D FSE T2WI, the lesion detection rate was 82.4 % (14/17). 3D fast imaging employing steady-state acquisition (3D FIESTA) revealed the lesions in all patients. HRCT showed that the average number of involved segments in the facial nerve canal was 2.41, while MRI revealed an average of 2.70 segments (P < 0.05). HRCT and MR findings of facial nerve hemangioma were typical, revealing irregular masses growing along the facial nerve canal, with calcifications and rich blood supply. Thin-section enhanced MRI was more accurate in lesion detection and assessment compared with HRCT.

Concepts: Medical imaging, Nuclear magnetic resonance, Radiography, Magnetic resonance imaging, Facial nerve, Geniculate ganglion, Greater petrosal nerve, Internal auditory meatus

2

Lyme disease is caused by a tick-borne spirochaete of the Borrelia species. It is associated with facial palsy, is increasingly common in England, and may be misdiagnosed as Bell’s palsy.Aim To produce an accurate map of Lyme disease diagnosis in England and to identify patients at risk of developing associated facial nerve palsy, to enable prevention, early diagnosis, and effective treatment.Design and setting Hospital episode statistics (HES) data in England from the Health and Social Care Information Centre were interrogated from April 2011 to March 2015 for International Classification of Diseases 10th revision (ICD-10) codes A69.2 (Lyme disease) and G51.0 (Bell’s palsy) in isolation, and as a combination.

Concepts: Epidemiology, Medical terms, Lyme disease, Borrelia burgdorferi, Borrelia, Spirochaetes, Facial nerve, Bell's palsy

1

A 54 year-old healthy woman presented to the emergency department with a right sided facial paralysis. About 3 weeks ago, she woke up and noticed an attached engorged tick in her right lower extremity. A week later, she noticed a mild to moderate right jaw pain which progressed to a severe right facial pain so she visited her doctor. On physical, II to XII cranial nerve examination was unremarkable. Doppler ultrasound did not show any vascular abnormalities in temporal artery. Her inflammatory markers were within normal limits (C-reactive protein:0.3mg/dL; sedimentation rate:6mm/h). Further brain imaging by MRI reveled no abnormalities. Lyme serology (antibodies against purified VlsE-1 and PepC10 antigens) was negative (index value 0.6;≤0.90 negative). Complete blood count and metabolic panel were within normal limits. Only objective physical finding was a right erythematous ear canal so the patient was prescribed a 7-day course of amoxicillin/clavulonic acid. Two days later, the rash in right leg increase in size. It was described as 4cm rash circular with erythematous edges, clearing and central erythema consistent with erythema migrans (EM) (bull’s eye). She was prescribed doxycycline 100mg orally twice a day. Five days later went to see a neurologist due to worsening right facial shooting pain. Patient had minimal gastrointestinal side effects from the antibiotic and continued taking it every 12hours without interruption. Physical exam revealed face symmetric, numbness in right chin in nerve distribution. She was diagnosed with possible Lyme cranial neuritis. Doxycycline was continued and pregabalin was started. On day #10 of doxycycline, she woke up and noticed that her right face was paralyzed and unable to close the right eye so she went to the local emergency department. The EM was improved from 4 to 2cm residual rash. Because of her headaches, a lumbar puncture and brain MRI were recommended. Cerebrospinal spinal fluid analysis revealed only 3 WBCs, protein 30.2g/dL, glucose 62mg/L, Lyme serology pair CSF fluid O.D.=0.114 (borderline), serum Lyme serology pair O.D.=0.409 (reactive), serum IgM western blot was positive (bands present: 23 and 41kDa), serum IgG western blot was indeterminate (bands: 41,58 and 93kDa), CRP remained less than 0.1mg/dL. MRI of brain showed new increased enhancement involving right facial nerve (Fig. 1). She was discharged on minocycline 100mg orally twice a day for 21 days. Two days later, her right side headaches improved significantly. The facial paralysis completely resolved after 1 week. At 3 months follow-up, she recovered completely without any complications.

Concepts: Lyme disease, Neurology, Cranial nerves, Cerebrospinal fluid, Lumbar puncture, Facial nerve, Bell's palsy, Erythema chronicum migrans

1

Preserving facial nerve function is a primary goal and a key decision factor in the comprehensive management of vestibular schwannoma and other cerebellopontine angle (CPA) tumors.

Concepts: Brain tumor, Tumor, Cranial nerves, Facial nerve, Bell's palsy, Schwannoma