Spatial functional reorganizations can serve as potential biomarkers of post facial palsy synkinesis.

Facial palsy can result in a serious complication known as facial synkinesis, causing both physical and psychological harm to the patients. There is growing evidence that patients with facial synkinesis have brain abnormalities, but the brain mechanisms and underlying imaging biomarkers remain unclear. Here, we employed functional magnetic resonance imaging (fMRI) to investigate brain function in 31 unilateral post facial palsy synkinesis patients and 25 healthy controls during different facial expression movements and at rest. Combining surface-based mass-univariate analysis and multivariate pattern analysis, we identified diffused activation and intrinsic connection patterns in the primary motor cortex and the somatosensory cortex on the patient's affected side. Further, we classified post facial palsy synkinesis patients from healthy subjects with favorable accuracy using the support vector machine based on both task-related and resting-state functional magnetic resonance imaging data. Together, these findings indicate the potential of the identified functional reorganizations to serve as neuroimaging biomarkers for facial synkinesis diagnosis.

The Monocle Sign on 18 F-FDG PET Indicates Contralateral Peripheral Facial Nerve Palsy.

BACKGROUND: The aim of our study was to retrospectively analyze FDG PET/CT data in patients with facial nerve palsy (FNP) for the presence of the monocle sign. PATIENTS AND METHODS: A total of 85 patients with unilateral FNP were included into our study, thereof 73 with peripheral FNP and 12 with central FNP. FDG uptake (SUV max , SUV mean , total lesion glycolysis) was measured in both orbicularis oculi muscles (OOMs). FDG uptake of paretic and nonparetic muscles was compared in patients with FNP (Wilcoxon test and Mann-Whitney U test) and was also compared with FDG uptake in 33 patients without FNP (Mann-Whitney U test). SUV max ratios of OOM were compared. A receiver operating characteristic curve and Youden Index were used to determine the optimal cutoff SUV max ratio for the prevalence of contralateral peripheral FNP. RESULTS: The SUV max ratio of OOM was significantly higher in patients with peripheral FNP compared with patients with central FNP and those without FNP (1.70 ± 0.94 vs 1.16 ± 0.09 vs 1.18 ± 0.21, respectively; P < 0.001). The SUV max ratio of OOM yielded an area under the curve (AUC) of 0.719 (95% confidence interval, 0.630-0.809), with an optimal cutoff of 1.41, yielding a specificity of 94.4% and a sensitivity of 44.1% for identifying contralateral peripheral FNP. One hundred percent specificity is achieved using a cutoff of 1.91 (sensitivity, 29.4%). CONCLUSIONS: Asymmetrically increased FDG uptake of the OOM (the "monocle sign") indicates contralateral peripheral FNP. A nearly 2-fold higher SUV max represents a practically useful cutoff.

Ultrasonographic findings of facial muscles in patients with severe facial palsy who showed no improvement for more than 3 months on acute stage.

INTRODUCTION/AIMS: The study aimed to visualize the changes in the facial muscles of patients with severe facial palsy who showed no improvement for more than 3 months on acute stage. METHODS: The 102 patients with severe facial palsy over House-Brackmann grade IV or an 80% degenerative ratio on ENoG at the initial examination, who showed no improvement for more than 3 months on acute stage were indicated to undergo ultrasonography of the face to evaluate the facial muscles. RESULTS: Muscular degeneration was observed in 537/918 muscles (58.5%). Muscle volume shrinkage was observed in 209/918 muscles (22.8%). Fascial adhesions were observed in 209/918 muscles (22.7%). Among all the muscles assessed for degenerative changes, zygomaticus major/minor was the most affected by degenerative changes (91.2%). Degenerative changes were observed in the levator labii superioris muscle in 84.3% patients. The shrinkage was most frequently observed in the zygomaticus major muscle (61/102 patients [59.8%]), followed by the zygomaticus minor muscle (43.1%). Shrinkage of the levator labii suprioris was observed in 24.5% patients. The zygomaticus major/minor muscle had the highest proportion of fascial adhesions in 61.8% and 66.7% patients respectively. The levator labii suprioris muscle showed the lowest proportion of fascial adhesions, with only 7.8% patients being affected. DISCUSSION: This study confirmed that the zygomaticus major, zygomaticus minor, and levator labii suprioris muscles, which raise the corner of the mouth, are the first to degenerate in patients with severe facial paralysis. This study demonstrated that ultrasonography is a simple and non-invasive examination for facial paralysis.

The clinical availability of facial nerve enhancement in temporal bone MRI for the patients of idiopathic acute peripheral facial palsy.

PURPOSE: This study is to evaluate the duration of facial nerve enhancement in gadolinium-enhanced temporal bone MRI after the onset of acute facial palsy. METHODS: Gd-enhanced MRI imagines were examined in 13 patients with idiopathic acute facial palsy within 14 days after the onset. The degree of facial nerve function was measured according to the House-Brackmann (H-B) grading system at their first visit at outpatient clinic. The follow-up MRI was taken about 16.5 months (7-24 months) after onset of disease. The degree of facial nerve enhancement was measured with signal intensity (SI) which was quantitatively analyzed using the region-of-interest (ROI) measurements for each segment of the facial nerve. SI was statistically analyzed by comparing SI values of contralateral site and ipsilateral site using the paired t test with SPSS program. RESULTS: The gadolinium enhancement was statistically increased at labyrinthine segment and geniculate ganglion area of facial nerve at initial temporal bone MRI. The gadolinium enhancement was statistically decreased at all the segments of facial nerve except tympanic segment (p < 0.05) at follow-up MRI. CONCLUSIONS: The facial nerve enhancement in Gd-enhanced MRI images prolonged more than 21 months of the onset. The newly developed pathologic lesions of acute facial palsy especially occur at the site of labyrinthine and geniculate ganglion.

Ultrasound-Guided Injections for Treatment of Facial Paralysis Sequelae: A Randomized Study on Body Donors.

BACKGROUND: Botulinum toxin injection is the accepted standard treatment for synkinesis and gustatory hyperlacrimation in patients with facial paralysis. However, poor injection accuracy can result in inconsistent treatment outcomes, variable treatment durations, and complications. Ultrasound guidance should increase injection accuracy in the facial region; however, this has not been proven. METHODS: Twenty-six hemifaces of nonembalmed cadavers were studied in a randomized split-face manner. Ink was injected with ultrasound or landmark guidance into the lacrimal gland and three common synkinetic muscles: the orbicularis oculi, depressor anguli oris, and mentalis. Injection accuracy was evaluated using several measures. RESULTS: Using ultrasound guidance, most ink (>50%) was found inside the correct target in 88% of cases, compared with 50% using landmark guidance ( P < 0.001). This was most pronounced in the lacrimal gland (62% versus 8%), depressor anguli oris (100% versus 46%), and mentalis (100% versus 54%) ( P < 0.05). All ink was found inside the correct target (no ink outside) in 65% using ultrasound guidance versus 29% without ( P < 0.001). Injection accuracy (any ink in target) was 100% when using ultrasound guidance versus 83% without ( P < 0.01). Twenty-three percent of the landmark-guided depressor anguli oris injections stained the facial artery ( P = 0.22). CONCLUSIONS: Ultrasound guidance significantly increased injection accuracy and reduced the amount of ink lost in the surrounding tissue compared with landmark guidance. Clinical trials are needed to explore the effects of ultrasound guidance on treatment outcome, duration, and complications in patients with facial paralysis.

Topographic Consideration on the Occurrence of Ipsilesional Facial Paresis in Lateral Medullary Infarction.

INTRODUCTION: The purpose of this study was to identify course of the corticobulbar tract and factors associated with the occurrence of facial paresis (FP) in lateral medullary infarction (LMI). METHODS: Patients diagnosed with LMI who were admitted to tertiary hospital were retrospectively investigated and divided into two groups based on the presence of FP. FP was defined as grade 2 or more by the House-Brackmann scale. Differences between the two groups were analyzed with respect to anatomical location of the lesions, demographic data (age, sex), risk factors (diabetes, hypertension, smoking, prior stroke, atrial fibrillation, and other cardiac risk factors for stroke), large vessel involvement on magnetic resonance angiography, other symptoms and signs (sensory symptoms, gait ataxia, limb ataxia, dizziness, Horner syndrome, hoarseness, dysphagia, dysarthria, nystagmus, nausea/vomiting, headache, neck pain, diplopia, and hiccup). RESULTS: Among 44 LMI patients, 15 patients (34%) had FP, and all of them had ipsilesional central-type FP. The FP group tended to involve upper (p < 0.0001) and relative ventral (p = 0.019) part of the lateral medulla. Horizontally large lesion was also related to the presence of FP (p = 0.044). Dysphagia (p = 0.001), dysarthria (p = 0.003), and hiccups (p = 0.034) were more likely to be accompanied by FP. Otherwise, there were no significant differences. CONCLUSION: The results of present study indicate that the corticobulbar fibers innervating the lower face decussate at the upper level of the medulla and ascend through the dorsolateral medulla, where the concentration of the fibers is densest near the nucleus ambiguus.

The value of radiographic features in predicting postoperative facial nerve function in vestibular schwannoma patients: A retrospective study and nomogram analysis.

OBJECTIVE: The purpose of this study was to identify significant prognostic factors associated with facial paralysis after vestibular schwannoma (VS) surgery and develop a novel nomogram for predicting facial nerve (FN) outcomes. METHODS: Retrospective data were retrieved from 355 patients who underwent microsurgery via the retrosigmoid approach for VS between December 2017 and December 2022. Univariate and multivariate logistic regression analysis were used to construct a radiographic features-based nomogram to predict the risk of facial paralysis after surgery. RESULTS: Following a thorough screening process, a total of 185 participants were included. The univariate and multivariate logistic regression analysis revealed that tumor size (p = 0.005), fundal fluid cap (FFC) sign (p = 0.014), cerebrospinal fluid cleft (CSFC) sign (p < 0.001), and expansion of affected side of internal auditory canal (IAC) (p = 0.033) were independent factors. A nomogram model was constructed based on these indicators. When applied to the validation cohort, the nomogram demonstrated good discrimination and favorable calibration. Then we generated a web-based calculator to facilitate clinical application. CONCLUSION: Tumor size, FFC and CSFC sign, and the expansion of the IAC, serve as good predictors of postoperative FN outcomes. Based on these factors, the nomogram model demonstrates good predictive performance.

Contrast-enhanced MRI findings of patients with acute Bell palsy within 7 days of symptom onset: A retrospective study.

The brain magnetic resonance imaging (MRI) findings seen in patients with Bell palsy are abnormal contrast enhancement of affected facial nerves. Previous studies were conducted on a few patients, mainly those who had experienced palsy for several weeks. This study investigated the diagnostic usefulness of MRI by examining MRI findings of acute Bell palsy (within 7 days of symptom onset) in a large cohort. Among the patients with Bell palsy (idiopathic unilateral facial palsy) who visited the hospital, 123 patients who underwent contrast-enhanced MRI of the internal auditory canal within 7 days of symptom onset were reviewed retrospectively. MRI examination results were investigated along with the patient's clinical symptoms and electrodiagnostic test results. Based on the MRI results, the frequency of abnormal contrast enhancement and contrast-enhanced areas were investigated. Of the 123 patients, 13 (11%) had normal brain MRI results, and 110 (89%) had abnormal findings. The frequency of abnormal contrast enhancement was not significantly associated with test timing (P = .56). Of the 110 patients with abnormal findings, 65 (59%) showed contrast enhancement in the labyrinthine segment and 36 (33%) in both the labyrinthine segment and geniculate ganglion. Most patients with Bell palsy who are in the acute phase showed abnormal contrast enhancement in their facial nerves, and similar findings were even observed in the examination conducted on the day of symptom onset. Brain MRI helps in the diagnosis of acute Bell palsy.

An interesting case of crossed syndrome: ipsilateral facial paralysis with contralateral glossoplegia.

BACKGROUND: Stroke is rarely accompanied with peripheral facial paralysis and supranuclear palsy of the hypoglossal nerve. Both sides of the motor cortex innervate the hypoglossal nucleus; therefore, unilateral lesions of the upper motor neurons rarely result in contralateral lingual paresis. We report a rare case of crossed syndrome with associated hyperacute peripheral hemifacial paralysis and contralateral lingual paresis after a lower pontine tegmentum ischemic stroke. CASE PRESENTATION: A 73-year-old man presented with symptoms of hyperacute peripheral hemifacial paralysis. Upon protrusion, the patient's tongue deviated to the contralateral side, without fasciculation or atrophy. Brain imaging showed focal ischemic stroke in the pontine tegmentum. However, lingual hemiparesis and multimodal neuroimaging findings differed. CONCLUSIONS: We suggest that cortico-hypoglossal fibers pass through the dorsal pontine. This case of crossed syndrome is a rare report of a lower pontine tegmentum ischemic stroke resembling an upper motor neuron lesion of the contralateral hypoglossal nerve.

Ventrolateral pontomedullary junction ischaemic stroke imitating isolated facial nerve palsy.

A 75-year-old woman presenting with unilateral lower motor neurone facial weakness was ultimately diagnosed with an ischaemic stroke at the pontomedullary junction affecting the facial nerve fascicles. Isolated, unilateral, upper and lower facial weakness is typically caused by lesions affecting the facial nerve, such as Bell's palsy, though rarely can be a manifestation of acute ischaemic stroke. It is important for neurologists and emergency providers to determine appropriately which patients with facial weakness require neuroimaging and which do not.

Parálisis facial alternobárica: a propósito de un caso y revisión de la literatura / Alternobaric facial palsy: case report and literature review

La parálisis o paresia facial alternobárica es una neuropraxia del séptimo nervio cra-neal debido a cambios de presión. Se produce en el contexto de una disfunción de la trompa de Eustaquio, una dehiscencia canal del nervio facial y cambios en la presión atmosférica. Se considera una rara complicación de barotrauma. Su prevalencia es difícil de estimar y, probablemente, se encuentre subreportada. La forma de presentación más habitual incluye paresia facial, plenitud aural, hipoacusia, otalgia, parestesias faciales y linguales. La mayoría de los episodios son transitorios, con una duración entre minutos y algunas horas, con recuperación posterior completa. Entre los diagnósticos diferenciales se encuentran causas periféricas y centrales de paresia facial, las cuales hay que sospechar ante la persistencia de los síntomas en el tiempo o ante la presencia de otros signos o síntomas neurológicos. La evaluación inicial debe incluir un examen otoneurológico completo. La tomografía computarizada de hueso temporal favorece la visualización de posibles dehiscencias del canal del facial. La prevención de nuevos episodios incluye la práctica de ecualización efectiva, la resolución de la disfunción de la trompa de Eustaquio y en algunos casos específicos, métodos alternativos de ventilación del oído medio como la colocación de tubos de ventilación. Una vez instalada la parálisis facial, si no se produce recuperación espontánea, el uso de corticoides es una opción. Se presenta un caso de paresia facial alternobárica recurrente y una revisión de literatura.

Alternobaric facial palsy or paralysis is a neuropraxia of the seventh cranial nerve due to pressure changes. It occurs in the context of Eustachian tube dysfunction, facial nerve canal dehiscence, and changes in atmospheric pressure. It is considered a rare complication of barotrauma. Its prevalence is difficult to estimated, and this condition is probably underreported. The most common form of presentation includes facial weakness, ear fullness or pressure, hearing loss, otalgia, facial and lingual paresthesias. Most episodes are transient, lasting from minutes to a few hours, with a subsequent complete recovery. Among the possible differential diagnoses are peripheral and central causes of facial paralysis, which must be suspected due to the persistence of symptoms over time or the presence of other neurological signs or symptoms. The initial evaluation should include a complete otoneurological examination. Computed tomography of the temporal bone is useful for the visualization of facial canal dehiscence. Prevention of further episodes includes practicing effective equalization, Eustachian tube dysfunction treatment, and in certain specific cases, alternative middle ear ventilation methods such as tympanostomy tubes. Once facial paralysis is established, if spontaneous recovery does not occur, the use of corticosteroids is considered an option. A case of recurrent alternobaric facial paresis and a review of the literature are presented.

"Uncrossed Central Facial Paralysis" Caused by Pontine Infarction: A Case Report.

INTRODUCTION: We report a patient with extraordinary pontine infarction-induced contralateral central facial palsy and weakened limb strength. CASE REPORT: This is a 66-year-old man with left arm movement difficulty for 10 days and worsening over the last 1 day. His left nasolabial fold flattening and left arm strength and sensory were decreased. He could not complete the finger-nose test well with his right hand. Magnetic resonance and magnetic resonance angiography tests confirmed his right pontine acute infarction but without large vessel stenosis or occlusion. CONCLUSION: "Uncrossed paralysis" patients may present with contralateral face and body weakness with pontine infarcts, if the infarct occurs above the level of the facial nucleus head, and may be simmilar with the higher level pontine lesions or cerebrum semisphere infarction, which need particular attention during clinical practice.

Magnetic resonance imaging findings of delayed facial palsy after dental procedures suggest viral reactivation as pathogenesis: a retrospective study.

PURPOSE: We hypothesize that delayed facial paralysis following dental procedures is also associated with viral reactivation. In this study, the brain magnetic resonance imaging (MRI) findings of patients were analyzed to identify the pathogenesis of facial nerve palsy after dental treatment. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients with unilateral facial nerve palsy and identified those diagnosed with delayed facial nerve palsy within 30 days of dental treatment. We assessed the clinical characteristics, electrodiagnostic findings, and imaging findings of these patients and looked for MRI findings that support a viral hypothesis for facial palsy. RESULTS: Among 924 patients with facial palsy, 11 (1.2%) had delayed facial paralysis following dental procedures. Patients developed facial palsy at an average of 3.2 days (1-11 days) after undergoing a dental procedure. The internal auditory canal MRI revealed abnormal enhancement of affected facial nerve in nine patients. The intensity and pattern of the enhancement were similar to those of Bell's palsy. CONCLUSIONS: Facial palsy can develop within the days following dental procedures, and the MRI results suggest that delayed facial palsy after dental treatment is related to viral reactivation-like Bell's palsy.

Imaging of Alternobaric Facial Palsy: An Etiologic Hypothesis.

OBJECTIVE: To report a case of alternobaric facial palsy (AFP) with a hyperpneumatized temporal bone and to review the relevant literature in order to propose a new facet of AFP pathogenesis. METHODS: A patient with a hyperpneumatized temporal bone was found to have recurrent episodes of facial palsy associated with air travel. Systematic review of PubMed, Cochrane Library, and Embase characterized all articles related to transient facial palsy associated with altitude changes or diving with a focus on demographics and imaging findings. RESULTS: A 25 year-old male was referred for recurrent facial palsy associated with commercial air travel. Imaging demonstrated a hyperpneumatized and well-aerated temporal bone. Total air cell volume was calculated to be 8.59 cc on the affected side. A systematic review of the literature identified 49 cases of AFP. Mean age was 34 years old and 80% were male. Twelve cases had imaging of the temporal bone for evaluation, of which 85% demonstrated at least 1 area of hyperpneumatization. Hyperpneumatization was most frequently encountered in the mastoid, zygomatic root, and inferior petrous apex. CONCLUSION: Hyperpneumatization of the temporal bone is critical to AFP etiology as it predicts higher middle ear pressure, if atmospheric pressure changes cannot be equilibrated, via reduced efficacy of normal tympanic membrane pressure buffering. This hypothesis helps to better account for the rarity of the condition and male preponderance.

Cholesterol granuloma in facial nerve canal presenting with facial nerve paralysis.

Cholesterol granulomas (CGs) are frequently found in the temporal bone, but their presence in the facial nerve has not been reported. We report a case of a 58-year-old woman who presented with left facial palsy caused by a CG that appeared to have originated in the facial nerve. Temporal bone computed tomography (CT) revealed soft tissue masses in the left middle ear spaces, and the facial canal was dilated from the genu to the vertical portion. Magnetic resonance imaging (MRI) revealed high signal intensity on T1-weighted images and partially high signal intensity on T2-weighted images, although no significant enhancement was observed on gadolinium-enhanced MRI. Surgical findings revealed CG in the middle ear spaces, but the facial canal remained intact and lacked continuity with the internal mass. Histopathological analysis verified the mass as a CG accompanied by cholesterol crystals. The mass was located within and continuous with the epineurium. These findings indicate that hemorrhage in the facial canal may have triggered the formation of the CG, causing left facial palsy due to increased pressure in the facial canal.

Exploratory Study of the Brain Response in Facial Synkinesis after Bell Palsy with Systematic Review and Meta-analysis of the Literature.

BACKGROUND: Facial synkinesis, characterized by unintentional facial movements paired with intentional movements, is a debilitating sequela of Bell palsy. PURPOSE: Our aim was to determine whether persistent peripheral nerve changes arising from Bell palsy result in persistent altered brain function in motor pathways in synkinesis. DATA SOURCES: A literature search using terms related to facial paralysis, Bell palsy, synkinesis, and fMRI through May 2021 was conducted in MEDLINE and EMBASE. Additionally, an fMRI study examined lip and eyeblink movements in 2 groups: individuals who fully recovered following Bell palsy and individuals who developed synkinesis. STUDY SELECTION: Task-based data of the whole brain that required lip movements in healthy controls were extracted from 7 publications. Three studies contributed similar whole-brain analyses in acute Bell palsy. DATA ANALYSIS: The meta-analysis of fMRI in healthy control and Bell palsy groups determined common clusters of activation within each group using activation likelihood estimates. A separate fMRI study used multivariate general linear modeling to identify changes associated with synkinesis in smiling and blinking tasks. DATA SYNTHESIS: A region of the precentral gyrus contralateral to the paretic side of the face was hypoactive in synkinesis during lip movements compared with controls. This region was centered in a cluster of activation identified in the meta-analysis of the healthy controls but absent from individuals with Bell palsy. LIMITATIONS: The meta-analysis relied on a small set of studies. The small sample of subjects with synkinesis limited the power of the fMRI analysis. CONCLUSIONS: Premotor pathways show persistent functional changes in synkinesis first identifiable in acute Bell palsy.