Electroneurography in the acute stage of facial palsy as a predictive factor for the development of facial synkinesis sequela

Objective We investigated whether the value of ENoG is a predictive factor for the development of facial synkinesis in patients with facial palsy. Methods The degree of oral-ocular synkinesis was evaluated quantitatively by an asymmetry of the interpalpebral space width during the mouth movement (% eye opening). Twenty healthy volunteers without a history of facial palsy (12 men and 8 women; 25-65 years old; mean age: 42.3 ± 9.7 years) were included in the study to examine the normal range of % eye opening. Fifty-one patients with facial palsy including 38 with Bell palsy and 15 with herpes zoster oticus (28 men and 25 women; 11-86 years old; mean age: 54 ± 19 years) were enrolled to examine the relationship between the ENoG value 10-14 days after the onset of facial palsy, and the % eye opening 12 months later. Receiver operating characteristic (ROC) curve for the ENoG value was then used to decide the optimum cut-off value as a predictor of the development of oral-ocular synkinesis. Results We defined a % eye opening inferior to 85% as an index of the development of oral-ocular synkinesis. There was a significant correlation between the values of ENoG 10-14 days after the onset of facial palsy and those of % eye opening 12 months later (ρ=0.81, p<0.001). The area under the ROC curve for the ENoG value was the predictor for the development of oral-ocular synkinesis at 0.913 (95%CI: 0.831-0.996, p<.001). The optimum cut-off value of ENoG 10-14 days after the onset of facial palsy was 46.5% to predict the development of oral-ocular synkinesis 12 months after the onset of facial palsy (sensitivity 97.1% and specificity 77.5%). Conclusion The value of ENoG 10-14 days after the onset of facial palsy is a predictive factor for the development of facial synkinesis 12 months later. Since facial palsy patients with a ENoG value inferior to 46.5% have a high risk of developing synkinesis, they should receive the facial biofeedback rehabilitation with a mirror as a preventive therapy

When does facial synkinesis develop?

The objective of this study is to clarify when facial palsy patients with lower value of Electroneurography (ENoG) should begin the rehabilitation to prevent the development of facial synkinesis. For this purpose, we examined the relationship between the value of ENoG measured 10-14 days after facial palsy onset and the onset day of the development of oral-ocular synkinesis. Sixteen patients with facial palsy including 11 with Bell’s palsy and 5 with Ramsay Hunt syndrome (7 men and 9 women ; 15-73 years old ; mean age, 41.6 years) were enrolled in this study. There was no correlation between ENoG value and the onset day of the development of oral-ocular synkinesis (ρ = .09, p = .73). Oral-ocular synkinesis began to develop in 4.0 ± 0.7 months (mean ± SD ; range : 3.1-5.0 months) after facial palsy onset regardless of ENoG value. In conclusion, ENoG value cannot predict when facial synkinesis develops in patients with facial palsy. We recommend that facial palsy patients with a high risk for the development of synkinesis begin the biofeedback rehabilitation with mirror to prevent the development of facial synkinesis 3 months after facial palsy onset

Mechanism of robust circadian oscillation of KaiC phosphorylation in vitro

By incubating the mixture of three cyanobacterial proteins, KaiA, KaiB, and KaiC, with ATP in vitro, Kondo and his colleagues reconstituted the robust circadian rhythm of the phosphorylation level of KaiC (Science, 308; 414-415 (2005)). This finding indicates that protein-protein interactions and the associated hydrolysis of ATP suffice to generate the circadian rhythm. Several theoretical models have been proposed to explain the rhythm generated in this "protein-only" system, but the clear criterion to discern different possible mechanisms was not known. In this paper, we discuss a model based on the two basic assumptions: The assumption of the allosteric transition of a KaiC hexamer and the assumption of the monomer exchange between KaiC hexamers. The model shows a stable rhythmic oscillation of the phosphorylation level of KaiC, which is robust against changes in concentration of Kai proteins. We show that this robustness gives a clue to distinguish different possible mechanisms. We also discuss the robustness of oscillation against the change in the system size. Behaviors of the system with the cellular or subcellular size should shed light on the role of the protein-protein interactions in in vivo circadian oscillation

ラムゼイ・ハント症候群症例の前庭蝸牛神経MRI造影効果と前庭蝸牛機能障害との関係

Objective: The correlation between enhancement of the vestibulocochlear nerves on gadolinium-enhanced magnetic resonance imaging (MRI) and vestibulocochlear functional deficits was examined in patients with Ramsay Hunt syndrome (RHS). Methods: Nineteen patients with RHS who showed herpes zoster oticus, peripheral facial palsy, and vertigo were enrolled. Canal paresis (CP) in the caloric test, abnormal response to ocular and cervical vestibular myogenic potentials (oVEMP and cVEMP), and refractory sensorineural hearing loss were evaluated. MRI images perpendicular to the internal auditory canal were reconstructed to identify the superior (SVN) and inferior vestibular nerves (IVN) and the cochlear nerve (CV). The signal intensity increase (SIinc) of the four-nerve enhancement was calculated as an index. Results: Among RHS patients, 79%, 53%, 17% and 26% showed CP in the caloric test, abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, respectively. SIinc rates of the SVN were significantly increased in RHS patients with CP in the caloric test, and with abnormal responses to oVEMP and cVEMP. SIinc rates of the SVN tended to increase in RHS patients with refractory sensorineural hearing loss ( p = 0.052). SIinc rates of the IVN were significantly increased in RHS patients with abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, but not in those with CP in the caloric test. SIinc rates of the CN were significantly increased in RHS patients with CP in the caloric test, abnormal response to oVEMP and refractory sensorineural hearing loss, but not in those with abnormal response to cVEMP. Conclusion: In patients with RHS, the origin of vertigo may be superior vestibular neuritis, which is affected by reactive varicella-zoster virus from the geniculate ganglion of the facial nerve through the faciovestibular anastomosis. The results also suggested that in some RHS patients, inferior vestibular neuritis contributes to the development of vertigo and that the origin of refractory sensorineural hearing loss is cochlear neuritis

Ictal direct current shifts contribute to defining the core ictal focus in epilepsy surgery

難治てんかん焦点の新しいバイオマーカー「発作時DC電位」 --国内5施設の共同研究での世界初の成果--. 京都大学プレスリリース. 2022-09-05.Identifying the minimal and optimal epileptogenic area to resect and cure is the goal of epilepsy surgery. To achieve this, EEG analysis is recognized as the most direct way to detect epileptogenic lesions from spatiotemporal perspectives. Although ictal direct-current shifts (icDCs; below 1 Hz) and ictal high-frequency oscillations (icHFOs; above 80 Hz) have received increasing attention as good indicators that can add more specific information to the conventionally defined seizure-onset zone, large cohort studies on postoperative outcomes are still lacking. This work aimed to clarify whether this additional information, particularly icDCs which is assumed to reflect extracellular potassium concentration, really improve postoperative outcomes. To assess the usefulness in epilepsy surgery, we collected unique EEG datasets recorded with a longer time constant of 10 sec using an alternate current amplifier. 61 patients [15 with mesial temporal lobe epilepsy and 46 with neocortical epilepsy] who had undergone invasive presurgical evaluation for medically refractory seizures at five institutes in Japan, were retrospectively enrolled in this study. Among intracranially implanted electrodes, the two core electrodes of both icDCs and icHFOs were independently identified by board-certified clinicians based on unified methods. The occurrence patterns, such as their onset time, duration, and amplitude (power) were evaluated to extract the features of both icDCs and icHFOs. Additionally, we examined whether the resection ratio of the core electrodes of icDCs and icHFOs independently correlated with favorable outcomes. A total of 53 patients with 327 seizures were analyzed for wide-band EEG analysis, and 49 patients were analyzed for outcome analysis. icDCs were detected in the seizure-onset zone more frequently than icHFOs among both patients (92% vs. 71%) and seizures (86% vs. 62%). Additionally, icDCs significantly preceded icHFOs in patients exhibiting both biomarkers, and icDCs occurred more frequently in neocortical epilepsy patients than in mesial temporal lobe epilepsy patients. Finally, although a low corresponding rate was observed for icDCs and icHFOs (39%) at the electrode level, complete resection of the core area of icDCs significantly correlated with favorable outcomes, similar to icHFO outcomes. Our results provide a proof of concept that the independent significance of icDCs from icHFOs should be considered as reliable biomarkers to achieve favorable outcomes in epilepsy surgery. Moreover, the different distribution of the core areas of icDCs and icHFOs may provide new insights into the underlying mechanisms of epilepsy, in which not only neurons but also glial cells may be actively involved via extracellular potassium levels

Elucidating the Ticking of an In Vitro Circadian Clockwork

A biochemical oscillator can be reconstituted in vitro with three purified proteins, that displays the salient properties of circadian (daily) rhythms, including self-sustained 24-h periodicity that is temperature compensated. We analyze the biochemical basis of this oscillator by quantifying the time-dependent interactions of the three proteins (KaiA, KaiB, and KaiC) by electron microscopy and native gel electrophoresis to elucidate the timing of the formation of complexes among the Kai proteins. The data are used to derive a dynamic model for the in vitro oscillator that accurately reproduces the rhythms of KaiABC complexes and of KaiC phosphorylation, and is consistent with biophysical observations of individual Kai protein interactions. We use fluorescence resonance energy transfer (FRET) to confirm that monomer exchange among KaiC hexamers occurs. The model demonstrates that the function of this monomer exchange may be to maintain synchrony among the KaiC hexamers in the reaction, thereby sustaining a high-amplitude oscillation. Finally, we apply the first perturbation analyses of an in vitro oscillator by using temperature pulses to reset the phase of the KaiABC oscillator, thereby testing the resetting characteristics of this unique circadian oscillator. This study analyzes a circadian clockwork to an unprecedented level of molecular detail