Blink Reflex Test Research Articles

Clinical and electrophysiological prognostic factors in predicting poor outcomes in patients with idiopathic facial nerve paralysis

ObjectiveThis study was designed to verify whether one or more clinical and neurophysiological parameters could predict a poor prognosis in idiopathic facial paralysis. MethodsSeventy-three outpatients with unilateral idiopathic facial nerve paralysis who visited our hospital within 7 days of onset. All patients received treatment according to a standard therapy protocol and ocular care. Patients’ baseline characteristics were assessed before initiating treatment, including demographic characteristics, facial nerve function assessment and previous medical history. House-Brackmann (H-B) grading system was performed at baseline and six months after the onset. Electroneurography (ENoG) and blink reflex tests were conducted 7–10 days after the onset of paralysis. Sunnybrook Facial Grading System (SFGS) was conducted at baseline, days 7–10 post-onset when the electrophysiological tests were performed, and one month after the onset. ResultsAccording to the H-B grade at 6 months following the onset, 58 patients (79.5 %) had a good prognosis, while 15 patients (20.5 %) had a poor prognosis. The CMAP amplitudes in three facial muscles (frontalis, orbicularis oculi, and orbicularis oris) were decreased, and ENoG values were increased in the poor prognosis group compared with the good prognosis group (all p < 0.01). The results of the blink reflex study showed that the group with a poor prognosis had a longer R1 latency compared to the group with a good prognosis. Additionally, the group with a poor prognosis exhibited a higher rate of R1 absence on the affected side (both p < 0.01). The findings of conditional logistic regression indicated that the absence of R1 on the affected side, frontalis ENoG, orbicularis oculi ENoG, and orbicularis oris ENoG were predictive factors of a poor prognosis for facial nerve palsy. The receiver operating characteristic (ROC) curves showed that the SFGS at 1 month after onset of 55 is considered a critical cutoff value for poor prognosis, with a sensitivity of 86.7 % and specificity of 91.4 %. ConclusionElectroneurography (ENoG) and blink reflex tests acquired within 7–10 days after the onset of paralysis are significant and highly valuable for predicting the prognosis of idiopathic facial nerve paralysis. Higher ENoG values of the muscles innervated by the facial nerve and the absence of R1 on the affected side of the blink reflex are predictive factors for a poor prognosis. The SFGS is a clinical tool that plays an important role in evaluating the prognosis of idiopathic facial paralysis, particularly one month after onset.

A nationwide survey of facial onset sensory and motor neuronopathy in Japan

The epidemiology and etiology of facial onset sensory and motor neuronopathy (FOSMN), a rare syndrome that initiates with facial sensory disturbances followed by bulbar symptoms, remain unknown. To estimate the prevalence of FOSMN in Japan and establish the characteristics of this disease, we conducted a nationwide epidemiological survey. In the primary survey, we received answers from 604 facilities (49.8%), leading to an estimated number of 35.8 (95% confidential interval: 21.5–50.2) FOSMN cases in Japan. The secondary survey collected detailed clinical and laboratory data from 21 cases. Decreased or absent corneal and pharyngeal reflexes were present in over 85% of the cases. Electrophysiological analyses detected blink reflex test abnormalities in 94.1% of the examined cases. Immunotherapy was administered in 81% of cases and all patients received intravenous immunoglobulin. Among them, 35.3% were judged to have temporary beneficial effects evaluated by the physicians in charge. Immunotherapy tended to be effective in the early stage of disease. The spreading pattern of motor and sensory symptoms differed between cases and the characteristics of the motor-dominant and sensory-dominant cases were distinct. Cases with motor-dominant progression appeared to mimic amyotrophic lateral sclerosis. This is the first nationwide epidemiological survey of FOSMN in Japan. The clinical course of FOSMN is highly variable and motor-dominant cases developed a more severe condition than other types of cases. Because clinical interventions tend to be effective in the early phase of the disease, an early diagnosis is desirable.

Research on the Pathogenesis of Hemifacial Spasm through Electrophysiological Studies

The cause of hemifacial spasm (HFS) is commonly linked to vascular compression of the facial nerve at the root exit zone. Microvascular decompression has become the most effective treatment for HFS. However, despite numerous electrophysiological studies investigating factors such as ephaptic transmission, ectopic excitation between individual nerve fibers, and hyperexcitability of the facial motor nucleus, there is still debate about the exact pathogenesis of HFS. For over 40 years, researchers have been conducting electrophysiological studies in clinical settings to better understand the pathogenesis of HFS. These studies have employed techniques including the lateral spread response, blink reflex test, facial F-waves, and transcranial electrical stimulation. Although a peripheral nerve mechanism was historically considered most likely to be responsible for this condition, recent studies are increasingly pointing to a central mechanism as the primary culprit behind HFS. This article seeks to shed light on the pathogenesis of HFS by reviewing the key findings from electrophysiological studies carried out over the years.

Brainstem impairment in obstructive sleep apnoea and the effect of CPAP treatment: an electrophysiological blink reflex study

PurposeThis study aimed to evaluate the functionality of the brainstem structures through the blink reflex (BR) test in patients with obstructive sleep apnoea (OSA) and to assess the effects of continuous positive airway pressure (CPAP) treatment on BR responses.MethodsPatients with moderate-severe OSA and controls underwent BR testing. Patients with OSA who were adherent to CPAP therapy repeated BR testing at 6 months follow-up. CPAP adherence was defined as CPAP use for ≥ 4 hour per night on > 5 nights per week with residual apnoea-hypopnea index less than 5 events per hour.ResultsA total of 22 patients with OSA (86% male, mean age 57.8 ± 10.6 years) and 20 controls (60% male, mean age 55.3 ± 9.3 years) were included. Patients with OSA showed longer right and left R1 latency, as well as delayed right ipsilateral and contralateral R2 latencies compared to controls. Patients with OSA who were compliant with CPAP treatment (n = 16; 88% men, mean age 58.8 ± 9.7 years) showed a significant decrease in latency of the right ipsilateral and contralateral R2 responses at 6 months.ConclusionThis study showed an abnormal pattern of BR responses in patients with OSA, consistent with a significant impairment of brainstem functionality in OSA. CPAP treatment partially improved the BR responses, suggesting the importance of treating OSA.

Comparison of the Vestibular Evoked Myogenic Potential and the Blink Reflex in Cerebellar and Brainstem Infarction Patients

Objective: This study investigated whether the blink reflex could be substituted for the vestibular evoked myogenic potential (VEMP), which has some limitations for use in stroke patients.Methods: Thirty-four patients with cerebellar or brainstem ischemic stroke underwent VEMP and blink reflex testing. We compared the P13 latency of VEMP and the R1, R2, R2’ latency of the blink reflex in stroke patients. Statistical analysis was conducted using the Fisher exact test and independent t-test, with a p-value &lt; 0.05 indicating statistical significance.Results: In 29 stroke patients, excluding those with bilateral lesions, the VEMP and the blink test did not show a statistically significant relationship (p = 0.2701). In all 34 stroke patients participating in the study, including those with bilateral lesions, R2’ mean showed a statistically significant difference (p = 0.0081) according to the presence of normal or abnormal VEMP. Conclusion: R2’ of the blink reflex passes through more neural pathways and polysynaptic pathways than R1 and R2; therefore, it showed a more prominent difference between the normal and abnormal VEMP groups.

Effectiveness and safety of Korean medicine treatment based on the clinical practice guidelines in patients with acute peripheral facial palsy: A protocol for a multicenter, prospective, observational study.

Introduction:Peripheral facial palsy (PFP) results in weakness or paralysis of the affected side of the face. In Korea, there is a high demand for Korean medicine treatment for PFP. The clinical practice guidelines (CPGs) of Korean medicine for facial palsy were developed; however, there remains insufficient evidence to support the effectiveness and safety of Korean medicine treatment. Thus, this study aimed to evaluate the effectiveness and safety of Korean medicine treatment based on the CPGs in patients with acute PFP.Methods:This is a multicenter, prospective, observational study. The participants will be recruited from one Korean medicine hospital and eight Korean medicine clinics. The participants will receive Korean medicine treatments based on the CPGs, fill in survey questionnaires, and undergo electrophysiologic testing. The changes in House-Brackmann (H-B) grade, movement of the lip and eye, symptoms related to or accompanied by facial palsy, Facial Disability Index, EuroQol 5-dimension 5-level (EQ-5D-5L), and EuroQol Visual Analogue Scale (EQ-VAS), and the results of electromyography (EMG), electroneurography (ENoG), and Blink Reflex test will be analyzed. For the safety analysis, adverse events will be recorded, and for the feasibility analysis, the results of the Was It Worth It questionnaire will be assessed.Conclusion:We expect to draw real-world clinical data on the effectiveness and safety of Korean medicine treatment based on the CPGs in patients with acute PFP from this study. It would be the basis for complementing and improving the CPGs and provide the basis of clinical and policy decision-making.Trial registration:This study was approved by the Institutional Review Board of Kyung Hee University Korean Medicine Hospital (2021-06-005-001), and registered with the Korean Clinical Trial Registry (CRIS), Republic of Korea (KCT0006562).

Significance of Blink Reflex as a Neurophysiological Marker of Diabetic Peripheral Neuropathy

Background: The cranial neuropathies incidence is higher in diabetic patients in comparison to healthy people. The III and VII cranial nerves are commonly affected, but trigeminal, glossopharyngeal, and vagus nerves are also affected. The blink reflex is a measure of the cranial and CNS conduction pathways. Method: The study included a group of 60 diabetic patients compared with 60 healthy individuals (non-diabetic) without any pain, paresthesia, or weakness in either limb. Objective: This research aims to assess the significance of the blink reflex in the early detection of cranial neuropathy in diabetic patients, as well as to compare the blink reflex abnormalities in diabetic patients with HbA1c, length of DM, and sural nerve amplitude. Results: A significant statistical difference between the cases and control was for (R.1) latency, (I.R.2) latency, (C.R.2) latency, (I.R.2) duration, and (C.R.2) duration with a p-value &lt;0.001. No statically significant correlation was found between the duration of diabetes mellitus and the blink reflex parameters. Regarding HbA1c, a significant positive association with (I.R.2) latency and (C.R.2) latency was noted (r = 0.3, p-value &lt;0.001), and also a strong negative correlation association was found with (I.R.2) duration and (C.R.2) duration (p-value &lt;0.001). Sural nerve amplitude correlated negatively with blink reflex latencies and positively with blink reflex duration Conclusion: The blink reflex test is an effective tool for diagnosing cranial neuropathy in individuals with diabetes without clinical symptoms or proof of CNS damage.

Electrodiagnostic findings in facial onset sensory motor neuronopathy (FOSMN)

ObjectiveTo determine the electrodiagnostic characteristics of facial onset sensory and motor neuronopathy (FOSMN). MethodsElectrophysiological data from 10 FOSMN patients in Newcastle-upon-Tyne and Sydney were reviewed. Relevant literature was reviewed. ResultsFindings on standard electrophysiological assessment were in broad agreement with those published: blink reflexes were abnormal in all but one patient; sensory nerve action potentials were reduced but compound muscle action potentials preserved; mixed acute and chronic neurogenic change was identified on needle electromyography in bulbar and cervico-thoracic muscles in approximately 50% of patients.Upper limb somatosensory evoked potential (SEP) central conduction times were increased (n = 4) and progressed on repeat testing (n = 3). Upper motor neuron dysfunction was revealed by several measures [ipsilateral motor evoked potentials (MEPs) (n = 1); reduced short interval intra-cortical inhibition on threshold-tracking transcranial magnetic stimulation (n = 2); absent beta-band intermuscular coherence (n = 3)]. ConclusionsElectrodiagnostic investigation of FOSMN should include blink reflex testing, SEPs and tests of upper motor neuron function. The combination of progressive lower motor neuron disease and upper motor neuron disease on neurophysiological investigation provides further support for the contention that FOSMN is a rare variant of motor neurone disease. SignificanceThese findings will aid the neurologist and neurophysiologist in making a confident diagnosis of FOSMN, thus expediting appropriate care.

Autonomic Function Tests, Heart Rate Variability, and Electrophysiological Evaluation in Patients With a Primary Episodic Headache: An Observational Study.

Cranial autonomic symptoms are typically associated with the trigeminal autonomic cephalalgias and also present in substantial cases of migraine. Autonomic nervous system dysfunctions are also been reported in headache disorders and postulated to promote headache attacks. This study was aimed to evaluate the parasympathetic and sympathetic autonomic functions tests in patients with a episodic primary headache and to investigate, if any, electrophysiological abnormalities in the blink reflex test and sympathetic skin response test in these patients. In this cross-sectional study, a total of 100 patients, 50 patients each of migraine and tension-type headache attending the neurology OPD and fulfilling the diagnostic criteria of headache disorders were enrolled. Autonomic functions tests were performed in the Department of Physiology, whereas electrophysiological tests were powered by the Editorial Manager and ProduXion Manager from Aries Systems Corporation performed in the Department of Neurology. Significant association ( P < 0.05) was observed in "blood pressure response to sustained handgrip" (sympathetic activity) and "heart rate response to Valsalva maneuver" (parasympathetic activity) among patients with migraine. Although the mean sympathetic skin response latency of patients with migraine was within the normal range, it was significantly prolonged in comparison with the control group. "Blood pressure response to sustained handgrip" and "heart rate variability" were found to be significantly ( P < 0.05) different in patients with a tension-type headache. The blink reflex test was observed to be normal in all patients with a headache. Patients with migraine showed a significant dysautonomia in category three of the Ewing battery for autonomic functional disability. Autonomic functional abnormality, both sympathetic and parasympathetic, does exist in patients with a primary episodic headache.

Prospective Assessment of Intraoperative Facial Nerve Monitoring in Patients Undergoing Partial Parotidectomy.

The most significant complication of parotid gland tumor surgery is facial weakness. This study compares the occurrence of transient facial palsy in patients with parotid gland tumors who underwent surgery without monitoring to those who underwent surgery with monitoring. The study's aim was to investigate facial nerve function in patients undergoing parotidectomy as well as the effect of intraoperative facial nerve monitoring and the effect of certain risk factors on the surgery and onset of postoperative facial palsy. This prospective study included 100 patients who underwent parotidectomy. The study cohort was divided into two groups. Group I included 50 patients who underwent surgery without neuromonitoring and group II included 50 patients who underwent surgery with neuromonitoring. The neurological assessment was conducted using the House–Brackmann scale. Preoperatively and one month postoperatively, electroneuronography (ENoG) and blink reflex tests were done. The analyses showed a significant reduction of the compound muscle action potential (CMAP) amplitude of the orbicularis oculi and orbicularis oris muscles and prolonged R1 and R2 blink reflex latencies 1 month after surgery. On neurological and electrophysiological studies, the rate of postoperative transient facial nerve dysfunction was significantly different between the groups. Significantly more patients, operated with use of facial nerve monitoring, presented postoperatively normal nerve function (i.e., House–Brackmann grade I) compared to those who underwent surgery without monitoring (78% and 26%, respectively; p < 0.001). Monitoring had a statistically significant impact on the prevalence of facial nerve conduction disorders in patients who underwent surgery, according to the blink reflex and ENoG studies. The duration of the surgical procedure was not affected by monitoring in any way. The clinical evaluation of facial nerve function (House–Brackmann scale) and some ENoG results 1 month after surgery were found to have a significant correlation. To summarize, using monitoring considerably reduced the negative impact of local factors and the prevalence of transient facial nerve palsy.

COVID-19 can cause blink reflex abnormalities.

Neurological symptoms and complications associated with coronavirus 2019 (COVID-19) are well known. It was aimed to evaluate the brainstem and trigeminal/facial nerves and the pathways between these structures in COVID-19 using the blink reflex test. Thirty patients with post COVID-19 (16 males, 14 females) and 30 healthy individuals (17 males, 13 females) were included in this prospective study. Individuals who previously had a positive nose swap polymerase chain reaction test for severe acute respiratory syndrome coronavirus 2 and whose previously clinical features were compatible with COVID-19 were included in the post COVID-19 patient group. Neurological examination of the participants should be normal. Blink reflex test was performed on all participants. R1, ipsilateral R2 (IR2), and contralateral R2 (CR2) waves obtained from the test were analyzed. The mean ages of healthy individuals and post COVID-19 patients were 34.0±6.4 and 38.4±10.6 years, respectively. Both age and gender were matched between the groups. R1, IR2, and CR2 latencies/amplitudes were not different between the two groups. The side-to-side R1 latency difference was 0.5±0.3 and 1.0±0.8 ms in healthy individuals and post COVID-19 patients, respectively (p=0.011). One healthy individual and 12 patients with post COVID-19 had at least one abnormal blink reflex parameter (p=0.001). This study showed that COVID-19 may cause subclinical abnormalities in the blink reflex, which includes the trigeminal nerve, the seventh nerve, the brainstem, and pathways between these structures.

Diagnosis and management of diverse ocular conditions in cattle

The present clinical study on diagnosis and management of diverse ophthalmic conditions was carried out on 72 cattle at a cow shelter (Gaushala) at Jodhpur, Rajasthan. The aim of the study was to determine different affections of the eyeball and its adnexal structures in cattle. The incidence, case history, age, sex, breed, general health condition and clinical observations of various ocular affections were recorded in cattle along with their management during the period from Sept. 2018 to Sept. 2019. More than 400 cattle were screened for various ophthalmological disorders by a thorough clinical and ophthalmological examination viz. menace reflex test, corneal reflex test, pupillary light reflexes test, Schirmer's tear test, fluorescein dye test, obstacle course test, dazzle or photic blink reflex test, direct and indirect ophthalmoscopy and non-contact tonometry. Diverse ophthalmological disorders like lacerations of the eyelids, chronic conjunctivitis, corneal ulcers, corneal lacerations, infectious bovine keratoconjuctivitis, iris staphyloma, ocular proptosis, dermoids, glaucoma, cataract, retinal degeneration etc. were diagnosed and the relevant surgico-therapeutic treatment was done.

Reappraisal of the Prognostic Factors of Outcome and Recovery Time in Patients with Idiopathic Bell's Palsy: A Retrospective Single-Center Analysis.

Study Objectives: This retrospective study investigated prognostic factors and recovery time in patients with Bell’s palsy after different doses and durations of oral glucocorticoid treatments. Subjects and Methods: A total of 396 patients initially diagnosed with Bell’s palsy that had visited the Department of Neurology of Chang Gung Memorial Hospital, Taoyuan, a tertiary referral medical center in Taiwan, between January 2014 and December 2018 were included. Medical records, facial electroneurography (fENoG), and blink reflex (BR) tests were reviewed and analyzed. A favorable outcome was defined as patients who improved to grade ≤ II, and an unfavorable outcome was defined as patients who improved to grade ≥ III in 6 months according to the House–Brackmann (HB) grading system. Results: The rate of favorable outcomes was 89.4% (354 of 396 patients) at the 6-month follow-up. A favorable outcome (HB less than grade II) was associated with a delayed BR (odds ratio, OR, 5.38; 95% CI, 1.82 to 15.90) and fENoG values (the lesion side/the healthy side) over 33% (OR, 6.67; 95% CI, 3.02 to 14.71). The recovery time was significantly shorter for those with a delayed BR than for those with an absent BR and shorter for those with good fENoG values (>33%) than for those with poor values (≤33%). However, treatment without or with different doses and durations of oral glucocorticoid did not influence the final outcome or recovery time in this study. Conclusions: The fENoG and BR tests were significant and highly valuable examinations for predicting the final outcome. Moreover, age younger than 60 years, a delayed BR, and fENoG values > 33% were associated with shorter recovery times.

Comparison of nerve conduction study and transcranial magnetic stimulation for early diagnosis and prognosis prediction of idiopathic facial palsy.

Multiple electrophysiologic studies have been conducted in the evaluation of facial neuropathy. In our study, the diagnostic and prognostic values of nerve conduction studies (NCSs) and transcranial magnetic stimulation (TMS) were compared for idiopathic unilateral facial neuropathy. We recruited patients with newly diagnosed idiopathic unilateral facial neuropathy and performed a blink reflex test, facial NCSs, and TMS. The amplitude of facial compound muscle action potential (CMAP) and motor evoked potential (MEP) between the affected and unaffected sides of the face was compared. A total of 30 patients were enrolled in the final analysis. TMS yielded a better detection rate, and MEP reduction rate was significantly higher than CMAP reduction rate, early in the course of the disease. Poor prognosis was positively associated with the CMAP reduction rate. The cutoff value of the CMAP reduction rate in the prediction of poor prognosis was established as 0.42. Facial TMS could detect idiopathic unilateral facial neuropathy with a high sensitivity when used as an early diagnostic tool. Facial NCS could predict prognosis, and the CMAP reduction rate was significantly associated with poor short-term prognosis.

Optic, trigeminal, and facial neuropathy related to anti-neurofascin 155 antibody.

ObjectiveTo characterize the frequency and patterns of optic, trigeminal, and facial nerve involvement by neuroimaging and electrophysiology in IgG4 anti‐neurofascin 155 antibody‐positive (NF155+) chronic inflammatory demyelinating polyneuropathy (CIDP).MethodsThirteen IgG4 NF155+ CIDP patients with mean onset age of 34 years (11 men) were subjected to neurological examination, blink reflex, and visual‐evoked potential (VEP) testing, and axial and/or coronal T2‐weighted head magnetic resonance imaging (MRI).ResultsAmong 13 patients, facial sensory impairment, facial weakness, and apparent visual impairment were observed in three (23.1%), two (15.4%), and two (15.4%) patients, respectively. All 12 patients tested had blink reflex abnormalities: absent and/or delayed R1 in 11 (91.7%), and absent and/or delayed R2 in 10 (83.3%). R1 latencies had strong positive correlations with serum anti‐NF155 antibody levels (r = 0.9, P ≤ 0.0001 on both sides) and distal and F wave latencies of the median and ulnar nerves. Absent and/or prolonged VEPs were observed in 10/13 (76.9%) patients and 17/26 (65.4%) eyes. On MRI, hypertrophy, and high signal intensity of trigeminal nerves were detected in 9/13 (69.2%) and 10/13 (76.9%) patients, respectively, whereas optic nerves were normal in all patients. The intra‐orbital trigeminal nerve width on coronal sections showed a significant positive correlation with disease duration.InterpretationSubclinical demyelination frequently occurs in the optic, trigeminal, and facial nerves in IgG4 NF155+ CIDP, suggesting that both central and peripheral myelin structures of the cranial nerves are involved in this condition, whereas nerve hypertrophy only develops in myelinated peripheral nerve fibers.

Clinical analysis of 12 cases of mixed connective tissue disease-associated trigeminal neuropathy

Objective: The aim of present study is to analyze clinical and laboratory features of mixed connective tissue disease (MCTD)-associated trigeminal neuropathy (TN). Methods: Clinical records of 12 cases of MCTD complicated with TN diagnosed in Peking University People's Hospital from January 2008 to October 2019 were analyzed retrospectively. Results: The present study included 12 cases, 1 males and 11 females, average age was(40±13)years. TN was developed before the diagosis of MCTD in 1 case. TN and MCTD were occurred simutaneously in 1 case. Raynaud phenomenon (12 cases), arthritis (10cases), edema of fingers (9cases), myositis (6 cases), and pulmonary involvement (11cases) were main cinical feature of MCTD-associate TN. Antinuclear antibody (ANA) and high titer anti-U1-RNP antibody could be detected in serum of all patients. Elevated erythrocyte sedimentation rate (ESR) and creatine kinase were found in serum of 7cases and 5cases, respectively. Blink reflex tests were positive in 6 cases. Neurological symptoms improve slowly without any progress by using glucocorticoid combined immunosuppressants or intravenous gamma globulin. Conclusions: TN is often associted with actived MCTD. Positive ANA and anti-U1-RNP antibody were common in MCTD-associated TN. Blink reflex test is essential to diagnose MCTD-associated TN. Intensive treatment of MCTD contributes to control the progress of TN.

Utility of preoperative electrophysiological testing of the facial nerve in patients with vestibular schwannoma.

PurposeThe aim of this study was to analyze the utility of various preoperative electrophysiological tests of the facial nerve CNVII in predicting CNVII function after vestibular schwannoma surgery.MethodsThis retrospective study included 176 patients who had preoperative facial nerve electroneurography and electrically evoked blink reflex testing. We defined the following variables: axonal degeneration of CNVII (AD-CNVII), trigeminal nerve damage (D-CNV), disturbances in the short-latency pathway of the blink reflex (D-BR), and any changes in electrophysiological test results (A-EMG).ResultsAD-CNVII, D-CNV, D-BR, and A-EMG were noted in 24%, 10%, 64%, and 71% of the patients, respectively. Negative D-CNV correlated with good CNVII function in early (p = 0.005) and long-term follow-up (p = 0.003) but was not an independent prognostic factor for postoperative facial muscles function. D-CNV appeared to be closely related to tumor size. D-BR was related to tumor size and had no predictive value. AD-CNVII (amplitude reduction of 50% or more compared to the healthy side) was an independent factor associated with increased risk of facial muscles weakness (p = 0.015 and p = 0.031 for early and late outcomes, respectively).ConclusionsFurther studies are needed to establish which tests and cut-off values are the most useful for predicting post-surgical facial nerve function.

Intraoperative electromyography has a favorable impact on facial nerve function in patients with parotid gland tumor

The aim of the present study was to evaluate the clinical usefulness of intraoperative neuromonitoring and its influence on surgery and especially the onset of facial nerve palsy. Important aspect was neurophysiological examination before and after removal of parotid gland tumor. The type, size and localization of the tumor were also examined. We included 72 patients into our study. The group of 50 patients, after parotid gland surgery without the use of neuromonitoring (group I) and the group of 24 patients operated with neuromonitoring of the facial nerve (group II). Each patient had clinical neurological examination performed, as well as the electrophysiological examination of the facial nerve before and 1 month after the surgery. Electrophysiological examination of the facial nerve included a blink reflex test and bilateral electroneurography (ENoG). In our results, one month after the surgery, the normal function of the facial nerve (grade I in House-Brackmann scale) was found in 87.5% of patients operated with neuromonitoring, whereas in patients operated without the monitoring, normal nerve function was found in 26% of patients. Interestingly, neurophysiological examination did not reveal any statistical differences in the values of latency and amplitude in patients before and after surgery in both groups. The average duration of operations without monitoring was 100.4 minutes, and with the use of neuromonitoring 86.25 minutes. The level of statistical significance was p = 0.052, however. In conclusion, the use of intraoperative facial nerve monitoring reduces the risk of temporary facial nerve palsy and may shorten time of the surgery.

Blink test results in patients with central sleep apnea syndrome

The aim of the study was to evaluate whether there was a problem in the interneuronal junctions of patients with central sleep apnea using the blink reflex test. Twenty-one (21) patients with central type apneas and/or hipopneas and 21 controls were recruited. The blink reflex test was performed and R1, R2 and contralateral R2 (R3) wave values of both groups were recorded in milliseconds (ms). The results of blink test in patients with central sleep apnea were right side R1 = 9.45 ± 4.35 ms, R2 = 33.35 ± 9.97 ms, R3 = 32.15 ± 10.05 ms and left side R1 = 9.90 ± 3.82 ms, R2 = 31.5 ± 10.5 ms, R3 = 29.00 ± 4.77 ms, (p = 0.49, p = 0.69, p = 0.60, respectively), whereas the results of blink test in controls were right side R1 = 9.25 ± 3.50 ms, R2 = 32.75 ± 11.4 ms, R3 = 32.50 ± 13.12 ms and left side R1 = 7.35 ± 2.6 ms, R2 = 27.75 ± 9.75 ms, R3 = 26.65 ± 14.5 ms. (p = 0.015, p = 0.04, p = 0.035, respectively). All left side (R1, R2, R3) blink reflex of the patients with central sleep apnea was statistically significant prolonged than controls. However, there was no statistically significant difference between women with central sleep apnea and controls regarding all right side (R1, R2, R3) blink reflex. There was statistically significant difference in R1, R2 and R3 waves of left sides blink reflex between two groups. The results may be related to central nervous system damage or/and degeneration in the interneuronal junctions of the brain stem in patients with central sleep apnea syndrome.

Neurophysiology and genetics of burning mouth syndrome.

Neuropathic mechanisms are involved in burning mouth syndrome (BMS), and variation of the dopamine D2 receptor (DRD2) gene contributes to experimental pain perception. We investigated whether neurophysiologic findings differ in BMS patients compared to healthy controls, and whether 957C>T polymorphism of the DRD2 gene influences thermal sensitivity or pain experience in BMS. Forty-five BMS patients (43 women), mean age 62.5years, and 32 healthy controls (30 women), mean age 64.8years, participated. Patients estimated pain intensity, interference, suffering and sleep with Numeric Rating Scale. Blink reflex tests of the supraorbital (SON), mental (MN) and lingual (LN) nerves, and thermal quantitative sensory testing were done. The results were analysed with ANOVA. DRD2 gene 957C>T polymorphism was determined in 31 patients, and its effects on neurophysiologic and clinical variables were analysed. Cool (p=0.0090) and warm detection thresholds (p=0.0229) of the tongue were higher in BMS patients than controls. The stimulation threshold for SON BR was higher in patients than in controls (p=0.0056). The latencies of R2 component were longer in BMS patients than in controls (p=0.0005) at the SON distribution. Habituation of SON BR did not differ between the groups. The heat pain thresholds were highest (p=0.0312) in homozygous patients with 957TT, who also reported most interference (p=0.0352) and greatest suffering (p=0.0341). Genotype 957CC associated with sleep disturbances (p=0.0254). Burning mouth syndrome patients showed thermal hypoesthesia within LN distribution compatible with small fibre neuropathy. The DRD2 957C>T genotype influences perception and experience of BMS pain. The results confirm earlier findings of neuropathic pain in BMS. The DRD2 957 C>T genotype influences perception and experience of clinical pain in BMS.