Peripheral Neuropathy in Patients with Hepatitis C Infection-Reversibility after HCV Eradication: A Single Center Study

Chronic hepatitis C virus (HCV) infection is characterized by a variety of extra-hepatic manifestations; peripheral neuropathy (PN) is one of the most common, especially when mixed cryoglobulinemia (MCG) is present. The prevalence and risk factors of HCV-related PN in the absence of MCG are largely unknown. We conducted a prospective, single-center study, examining the prevalence and reversibility of HCV-associated neuropathy in the absence of MCG. Nerve fiber density in the epidermis was evaluated through skin biopsy and electroneurography (ENG) before HCV-treatment initiation and 1 year post sustained virological remission (SVR). Forty HCV-infected individuals (nine HIV co-infected) with no other neuron-harming factors were included; four other HCV mono- and three HIV co-infected individuals were excluded due to presence of diabetes, B12 insufficiency, or neurotoxic drugs. Twelve consecutive controls with no neuron-harming conditions were also recruited; eight more were excluded due to meeting exclusion criteria. Four patients had ENG signs of polyneuropathy (two with HCV mono- and two with HIV co-infection), while seven more (five with HCV mono- and two with HIV co-infection) had signs of mono-neuropathy, leading to PN prevalences of 22.5% and 44% for mono- and co-infection, respectively (p value 0.179). The two patients with HCV mono-infection and polyneuropathy and the one with ulnar nerve damage showed ENG improvement 1 year post SVR. Regarding intraepidermal nerve density, HCV infection, irrespective of HIV co-infection, was correlated with a lower intraepidermal neuron density that improved 1 year post SVR (p value 0.0002 for HCV and 0.0326 for HCV/HIV co-infected patients). PN is common in HCV infection; successful eradication of HCV leads to PN improvement.

A Proposal for Neurography Referral in Patients with Carpal Tunnel Syndrome Based on Clinical Symptoms and Demographic Variables of 797 Patients

The clinical manifestation of median nerve entrapment at the carpal tunnel level is known as carpal tunnel syndrome (CTS). Electroneurography (ENG) is considered the gold standard in CTS evaluation. We conducted a retrospective study and analyzed some clinical and demographic variables, relating them to the degree of neuropathy using ENG, to better understand the role of ENG in this very common disease. We studied 816 patients referred to our service for neurographic evaluation. Their symptoms were classified as compatible with CTS (cCTS) (n = 646) and atypical for CTS (aCTS) (n = 170). A blind ENG was performed on 797 patients. Patient characteristics were coded as variables and analyzed to study whether they could predict neuropathy severity (sensory and motor involvement or grade ≥ 3 in our classification). We found a correlation between typical symptomatology, age over 50 years, male gender, positivity of Phalen's maneuver and Tinel's sign, and a neuropathy grade ≥ 3. We also found a correlation with CTS in the contralateral hand if the other hand showed neuropathy, despite the lack of symptoms in this hand. We propose a practical algorithm for ENG referral based on clinical symptoms, demographic factors, and neurophysiological variables.

Electroneurography Values Based on Degree of Facial Muscle Contraction Response to Electroacupuncture in Patients with Peripheral Facial Nerve Palsy: A Retrospective Study

Objective

Japanese acupuncture practice cannot easily predict the prognosis of patients with peripheral facial palsy. Electroneurography (ENoG) predicts prognosis in patients with peripheral facial palsy; however, the difference between ENoG values and degree of facial muscle contraction response (FMCR) to electroacupuncture stimulation (ES) targeting the affected facial nerve is unexplored. Therefore, an exploratory evaluation of the differences in ENoG values was conducted across the degrees of FMCR induced by ES targeting the affected facial nerve in patients with peripheral facial nerve palsy.

Methods

In total, 90 patients with peripheral facial nerve palsy were selected who underwent acupuncture treatment at the Department of Oriental Medicine, Saitama Medical University Hospital, between January 2005 and December 2014. The FMCR degree and ENoG values were assessed through patients' medical records. The patients were divided into excellent, moderate, and noresponse groups (65, 16, and 9 patients, respectively) according to the FMCR degree. The differences in ENoG values were analyzed among the groups.

Results

The ENoG values were 26.6% (10.4%-55.9%), 2.45% (0.35%-8.80%), and 2.00% (0.00%-5.10%) for the excellent, moderate, and no-response groups, respectively. These values significantly differed between the excellent group and the no-response (P < 0.01) and moderate (P < 0.01) groups.

Conclusion

The ENoG values varied according to degree of FMCR induced by ES targeting the facial nerve in patients with peripheral facial nerve palsy. This might allow to predict the prognosis based on the ES-induced FMCR.

Comparison of Motor Evoked Potentials Neuromonitoring Following Pre- and Postoperative Transcranial Magnetic Stimulation and Intraoperative Electrical Stimulation in Patients Undergoing Surgical Correction of Idiopathic Scoliosis

The relationships between the results of pre- and intraoperative motor evoked potential recordings during neuromonitoring and whether idiopathic scoliosis (IS) surgical correction improves the spinal efferent transmission have not been specified in detail. This study aims to compare the results of surface-recorded electromyography (EMG), electroneurography (ENG, M, and F-waves), and especially motor evoked potential (MEP) recordings from tibialis anterior muscle (TA) bilaterally in 353 girls with right idiopathic scoliosis (types 1-3 according to Lenke classification). It has not yet been documented whether the results of MEP recordings induced by transcranial single magnetic stimulus (TMS, pre- and postoperatively) and trains of electrical stimuli (TES; intraoperatively in T0-before surgery, T1-after pedicle screws implantation, and T2-after scoliosis curvature distraction and derotation following two-rod implantation) can be compared for diagnostic verification of the improvement of spinal cord neural transmission. We attempted to determine whether the constant level of optimal anesthesia during certain surgical steps of scoliosis treatment affects the parameters of MEPs recorded during neuromonitoring procedures. No neurological deficits have been observed postoperatively. The values of amplitudes but not latencies in MEP recordings evoked with TMS in IS patients compared before and after surgery indicated a slight improvement in efferent neural transmission. The results of all neurophysiological studies in IS patients were significantly asymmetrical and recorded worse on the concave side, suggesting greater neurological motor deficits at p = 0.04. The surgeries brought significant improvement (p = 0.04) in the parameters of amplitudes of sEMG recordings; however, the consequences of abnormalities in the activity of TA motor units were still reflected. ENG study results showed the symptoms of the axonal-type injury in peroneal motor fibers improving only on the concave side at p = 0.04, in parallel with F-wave parameters, which suggests that derotation and distraction might result in restoring the proper relations of the lumbar ventral roots in the spinal central canal, resembling their decompression. There were no significant differences detected in the amplitudes or latencies of MEPs induced with TMS or TES when comparing the parameters recorded preoperatively and intraoperatively in T0. The amplitudes of TES-evoked MEPs increased gradually at p = 0.04 in the subsequent periods (T1 and T2) of observation. A reduction in MEP latency at p = 0.05 was observed only at the end of the IS surgery. Studies on the possible connections between the level of anesthesia fluctuations and the required TMS stimulus strength, as well as the MEP amplitude changes measured in T0-T2, revealed a lack of relationships. These might not be the factors influencing the efferent transmission in spinal pathways beside the surgical procedures. Pre- (TMS-evoked) and intraoperative (TES-evoked) recordings are reliable for evaluating the patient's neurological status before and during surgical scoliosis correction procedures. An increase in MEP amplitude parameters recorded on both sides after scoliosis surgery proves the immediate improvement of the total efferent spinal cord transmission. Considering comparative pre- and postoperative sEMG and ENG recordings, it can be concluded that surgeries might directly result in additional lumbar ventral root decompression. We can conclude that MEP parameter changes are determined by the surgery procedures during neuromonitoring, not the anesthesia conditions if they are kept stable, which influences a decrease in the number of false-positive neuromonitoring warnings.

Vagus nerve stimulation using an endovascular electrode array

Objective. Vagus nerve stimulation (VNS), which involves a surgical procedure to place electrodes directly on the vagus nerve (VN), is approved clinically for the treatment of epilepsy, depression, and to facilitate rehabilitation in stroke. VNS at surgically implanted electrodes is often limited by activation of motor nerve fibers near and within the VN that cause neck muscle contraction. In this study we investigated endovascular VNS that may allow activation of the VN at locations where the motor nerve fibers are not localized.Approach. We used endovascular electrodes within the nearby internal jugular vein (IJV) to electrically stimulate the VN while recording VN compound action potentials (CAPs) and neck muscle motor evoked potentials (MEPs) in an acute intraoperative swine experiment.Main Results. We show that the stimulation electrode position within the IJV is critical for efficient activation of the VN. We also demonstrate use of fluoroscopy (cone beam CT mode) and ultrasound to determine the position of the endovascular stimulation electrode with respect to the VN and IJV. At the most effective endovascular stimulation locations tested, thresholds for VN activation were several times higher than direct stimulation of the nerve using a cuff electrode; however, this work demonstrates the feasibility of VNS with endovascular electrodes and provides tools to optimize endovascular electrode positions for VNS.Significance. This work lays the foundation to develop endovascular VNS strategies to stimulate at VN locations that would be otherwise too invasive and at VN locations where structures such as motor nerve fibers do not exist.

End-to-Side vs. Free Graft Nerve Reconstruction-Experimental Study on Rats

The long history of regeneration nerve research indicates many clinical problems with surgical reconstruction to be resolved. One of the promising surgical techniques in specific clinical conditions is end-to-side neurorrhaphy (ETS), described and then repeated with different efficiency in the 1990s of the twentieth century. There are no reliable data on the quality of recipient nerve regeneration, possible donor nerve damage, and epineural window technique necessary to be performed. This research attempts to evaluate the possible regeneration after end-to-side neurorrhaphy, its quality, potential donor nerve damage, and the influence of epineural windows on regeneration efficiency. Forty-five female Wistar rats were divided into three equal groups, and various surgical technics were applied: A-ETS without epineural window, B-ETS with epineural window, and C-free graft reconstruction. The right peroneal nerve was operated on, and the tibial nerve was selected as a donor. After 24 weeks, the regeneration was evaluated by (1) footprint analysis every two weeks with PFI (peroneal nerve function index), TFI (tibial nerve function index), and SFI (sciatic nerve function index) calculations; (2) the amplitude and latency measurements of motor evoked potentials parameters recorded on both sides of the peroneal and tibial nerves when electroneurography with direct sciatic nerve electrical stimulation and indirect magnetic stimulation were applied; (3) histomorphometry with digital conversion of a transverse semithin nerve section, with axon count, fibers diameter, and calculation of axon area with a semiautomated method were performed. There was no statistically significant difference between the groups investigated in all the parameters. The functional indexes stabilized after eight weeks (PFI) and six weeks (TFI and SFI) and were positively time related. The lower amplitude of tibial nerve potential in groups A and B was proven compared to the non-operated side. Neurophysiological parameters of the peroneal nerve did not differ significantly. Histomorphometry revealed significantly lower diameter and area of axons in operated peroneal nerves compared to non-operated nerves. The axon count was at a normal level in every group. Tibial nerve parameters did not differ from non-operated values. Regeneration of the peroneal nerve after ETS was ascertained to be at the same level as in the case of free graft reconstruction. Peroneal nerves after ETS and free graft reconstruction were ascertained to have a lower diameter and area than non-operated ones. The technique of an epineural window does not influence the regeneration result of the peroneal nerve. The tibial nerve motor evoked potentials were characterized by lower amplitudes in ETS groups, which could indicate axonal impairment.

Electroneurological changes in peripheral nerves in patients post-COVID

Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze the changes in peripheral nervous system in case of COVID-19 survivors. In the presented study, 45 COVID-19 survivors who had nerve conduction study (NCS) were involved. Results were compared with control group consisting of healthy patients who had nerve conduction study before the COVID-19 pandemic. In our study group, neurophysiological abnormalities were present in the case of both sensory and motor nerve fibers. The most significant reduction of NCS parameters was observed in the case of sensory action potential amplitude of sural nerve. Moreover, that correlation was the most significant in the case of amplitude and conduction velocity in sensory and motor neuron fibers both in arms and legs. Those abnormalities were observed even 6 mo after COVID-19. Further investigation needs to be done regarding the polyneuropathies associated with human coronaviruses, and we should answer the question whether the virus directly damages peripheral nerves or factors mediating inflammatory response are responsible for the neural damage.NEW & NOTEWORTHY Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze changes in peripheral nervous system in case of COVID-19 survivors.

Clinical Onset of Action of Incobotulinum Toxin A Preparation

BACKGROUND

Many studies in vitro compared the onset of action, maximum efficacy, and duration of botulinum toxin type A (BoNT/A) preparations.

OBJECTIVE

In this study, we analyzed the onset of action of BoNT/A preparation free of complexing proteins in patients with upper limb spasticity post stroke up to 30 days after treatment.

METHODS

75 patients affected by Biceps Brachii spasticity were enrolled. Outcome measures were instrumental muscle tone modification (myometric measurement), improvement of Modified Ashworth Scale (MAS), improvement of elbow's passive extension, and improvement of compound muscle action potential (cMAP) evaluated by electroneurography. We analyzed data at t0 (pre-injection), t1 (1 day after), t2 (7 days after), t3 (14 days after), and t4 (30 days after).

RESULTS

All measurements decreased at t2, t3, and t4 with initial improvement at t2 and maximum improvement at t4; no statistical difference at t1 was found.

CONCLUSION

This study demonstrated the onset of Incobotulinumtoxin A efficacy started after 7 days; this rapid action and efficacy of BoNT/A preparation could improve an intensive rehabilitation program after some days post-injection. Early clinical onset of action could be by the absence of complexing proteins in the preparation.

Prospective Assessment of Risk Factors Influencing Facial Nerve Paresis in Patients after Surgery for Parotid Gland Tumors

Background and objectives: Facial weakness is the most important complication of parotid gland tumor surgery. The aims of this study are as follows: (1) assessment of the prevalence of postparotidectomy facial nerve dysfunction; (2) clinical and electrophysiological assessment of the facial nerve function before parotidectomy and at 1 and 6 months postoperatively; (3) assessment of the association of postoperative facial palsy with selected risk factors; and (4) assessment of the correlation between the results of clinical and neurophysiological assessments of facial nerve function. Materials and Methods: This study comprised 50 patients (aged 24-75 years) who underwent parotidectomy at the Department of Otolaryngology and Laryngological Oncology in Zabrze, Poland between 2015 and 2017. The evaluation included neurological, clinical and electrophysiological assessments of the facial nerve prior to surgery and at 1 and 6 months postoperatively. Results: No facial palsy was found preoperatively or 6 months postoperatively. Facial nerve dysfunction was found in 74% of patients 1 month postoperatively. In most cases (54%), paresis was mild or moderate (House-Brackmann grades II and III). The results of electrophysiological tests before parotidectomy were either normal or showed some mild abnormalities. We found a statistically significant correlation between the clinical assessment of the facial nerve function (based on the House-Brackmann scale) one month postoperatively and the latency of the CMAP response from the orbicularis oculi and orbicularis oris muscles. In all three studies, a statistically significant correlation was found between the amplitude of the compound muscle action potential (CMAP) of the orbicularis oris muscle and the degree of facial nerve weakness. Conclusions: The factors that may influence the risk of postoperative facial nerve paralysis (prolonged surgical time and the size and location of the tumor other than in the superficial lobe only) may indirectly suggest that surgery-related difficulties and/or surgeon experience could be crucial to surgery safety.

Presence of Varicella Zoster Virus DNA in Saliva May Be Associated with the Severity of Ramsay Hunt Syndrome

Background: The relationship between varicella zoster virus (VZV) collected from saliva and Ramsay Hunt syndrome (RHS) remains unclear. Therefore, this study aimed to investigate whether VZV DNA in saliva alters the clinical symptoms and prognosis of RHS. Methods: To measure the severity of clinical symptoms of 100 RHS patients, the initial House−Brackmann (HB) grade and associated symptoms were evaluated. The final HB grade at the end of treatment was measured to determine the prognosis. Electroneurography (ENoG) was performed on four facial muscles, including the frontalis, oculi, nasalis, and oris. Results: Salivary VZV DNA was isolated from 72 patients with RHS. The VZV DNA-positive group was 34.023 times more likely to have severe initial HB grade than the control group (95% CI, 3.21−359.68; p = 0.003). There were no significant differences in final HB grade. All ENoG values of the VZV DNA-positive group were significantly higher than those of the control group (frontalis, p = 0.003; oculi, p = 0.001; nasalis, p < 0.001; oris, p = 0.037). Conclusions: RHS patients with salivary VZV DNA have more severe clinical symptoms than the control group. There were no differences in prognosis and associated symptoms. A VZV DNA test using saliva samples of patients with RHS can evaluate the clinical symptoms and provide early confirmation of VZV infection, enabling timely treatment in a non-invasive way.

The Offprint of an Abnormal Pre-Parotidectomy Electrodiagnostic Finding in a Normally Functioning Facial Nerve: Correlation with Intraoperative Findings, Histology and Postoperative Facial Nerve Function

The aim of this study was to search for associations between an electrodiagnostically abnormal but clinically normal facial nerve before parotidectomy and the intraoperative findings, as well as the postoperative facial nerve function. The records of all patients treated for parotid tumors between 2002 and 2021 with a preoperative House–Brackmann score of grade I but an abnormal electrophysiologic finding were studied retrospectively. A total of 285 patients were included in this study, and 222 patients had a benign lesion (77.9%), whereas 63 cases had a malignant tumor (22.1%). Electroneurographic facial nerve involvement was associated with nerve displacement in 185 cases (64.9%) and infiltration in 17 cases (6%). In 83 cases (29.1%), no tumor–nerve interface could be detected intraoperatively. An electroneurographic signal was absent despite supramaximal stimulation in 6/17 cases with nerve infiltration and in 17/268 cases without nerve infiltration (p < 0.001). The electrophysiologic involvement of a normal facial nerve is not pathognomonic for a malignancy (22%), but it presents a rather rare (~6%) sign of a “true” nerve infiltration and could also appear in tumors without any contact with the facial nerve (~29%). Of our cases, two thirds of those with an anatomic nerve preservation and facial palsy had already directly and postoperatively recovered to a major extent in the midterm.

The Use of the Velocity Selective Recording Technique to Reveal the Excitation Properties of the Ulnar Nerve in Pigs

Decoding information from the peripheral nervous system via implantable neural interfaces remains a significant challenge, considerably limiting the advancement of neuromodulation and neuroprosthetic devices. The velocity selective recording (VSR) technique has been proposed to improve the classification of neural traffic by combining temporal and spatial information through a multi-electrode cuff (MEC). Therefore, this study investigates the feasibility of using the VSR technique to characterise fibre type based on the electrically evoked compound action potentials (eCAP) propagating along the ulnar nerve of pigs in vivo. A range of electrical stimulation parameters (amplitudes of 50 μA-10 mA and pulse durations of 100 μs, 500 μs, 1000 μs, and 5000 μs) was applied on a cutaneous and a motor branch of the ulnar nerve in nine Danish landrace pigs. Recordings were made with a 14 ring MEC and a delay-and-add algorithm was used to convert the eCAPs into the velocity domain. The results revealed two fibre populations propagating along the cutaneous branch of the ulnar nerve, with mean velocities of 55 m/s and 21 m/s, while only one dominant fibre population was found for the motor branch, with a mean velocity of 63 m/s. Because of its simplicity to provide information on the fibre selectivity and direction of propagation of nerve fibres, VSR can be implemented to advance the performance of the bidirectional control of neural prostheses and bioelectronic medicine applications.

Epidemiological, clinical, and electrophysiological findings in dogs and cats with traumatic brachial plexus injury: A retrospective study of 226 cases

Background

The imaging and electrodiagnostic (EDX) characteristics of traumatic brachial plexus injury (TBPI) are incompletely reported.

Objectives

To describe the epidemiological, clinical, and EDX characteristics of TBPIs in a series of cases in dogs and cats; to determine the association between clinical data, EDX findings, and clinical outcomes; and to assess the sensitivity and specificity of EDX studies to classify nerve lesions.

Animals

One hundred and seventy‐five dogs and 51 cats with TBPI and EDX exploration of radial nerve, ulnar nerve, or both nerves.

Methods

Retrospective case series. All medical records were searched for dogs and cats presenting with TBPIs that underwent EDX exploration. Epidemiological, clinical, EDX, and follow‐up data were extracted. Association between clinical data, EDX findings, and clinical outcomes was explored.

Results

Forty‐six percent of affected animals were injured before 2 years of age and 57% of dogs weighed more than 20 kg. The radial compound muscle action potential (CMAP) amplitude for dogs and cats that had clinical improvement was higher than in animals without improvement (4.3 mV [0‐23.6] vs 0 mV [0‐2.4], respectively, P = .02). A discriminating radial CMAP amplitude threshold value of 5 mV had a specificity of 93% (95% CI [80‐100]) to predict recovery.

Conclusions and Clinical Importance

Electrodiagnostic studies, particularly measurement of radial CMAP amplitude, are valuable diagnostic tests to refine the prognosis of these animals.

Advanced Bioelectrical Signal Processing Methods: Past, Present, and Future Approach-Part III: Other Biosignals

Analysis of biomedical signals is a very challenging task involving implementation of various advanced signal processing methods. This area is rapidly developing. This paper is a Part III paper, where the most popular and efficient digital signal processing methods are presented. This paper covers the following bioelectrical signals and their processing methods: electromyography (EMG), electroneurography (ENG), electrogastrography (EGG), electrooculography (EOG), electroretinography (ERG), and electrohysterography (EHG).

Pintail Comb Injury as a Rare Cause of Penetrating Temporal Bone Trauma With Facial Paralysis

We present a case of novel penetrating temporal bone trauma with a pintail comb causing facial paralysis. We describe a 42-year-old woman with acute facial paralysis, hearing loss, and dizziness following accidental tympanic membrane puncture. The patient underwent middle ear exploration with tympanoplasty and was found to have an intact but severely edematous facial nerve. The patient demonstrated less than 90% degeneration under electroneuronography and was treated medically without decompression, and by 6 months had exhibited complete resolution of facial nerve dysfunction with normal hearing. This case report highlights a unique cause of penetrating temporal bone trauma and supports the utility of electroneuronography in predicting the likelihood of recovery and need for decompression in patients where the facial nerve has obvious signs of trauma but remains grossly intact.

Electrodiagnostic testing in acute facial palsy: Outcomes and comparison of methods

OBJECTIVE

To study the relationship between various electrodiagnostic modalities in acute facial palsy.

SETTING

Academic tertiary care center.

PATIENTS

One-hundred and six patients who presented with traumatic or non-traumatic acute facial paralysis (House-Brackmann, HB, grade 6/6) between 2008 and 2017 and underwent acute electrodiagnostic testing.

INTERVENTION

Electroneurography (ENoG) using nasolabial fold (NLF) or nasalis muscle (NM) methods, and volitional electromyography (EMG) in all patients.

MAIN OUTCOME MEASURES

Percent degeneration of ipsilateral facial nerve compound muscle action potentials (CMAP) on NLF- and NM-ENoG, presence or absence of muscle unit potentials (MUPs) on EMG.

RESULTS

Extent of facial nerve degeneration measured by NLF- and NM-ENoG were highly correlated (r = 0.85, P < .01) on each test and on serial testing. NLF- and NM-ENoG concordantly diagnosed ≥90% degeneration in 44 patients (80%), of whom 32 patients were diagnosed to have 100% degeneration by both methodologies. Absence of MUPs on EMG was 63% sensitive and 92% specific for ≥90% degeneration on ENoG, with a positive predictive value of 90%. For patients with Bell's palsy, percent degeneration on ENoG was also correlated to HB score at 1 year. Surgical decompression resulted in mean HB scores of 2.2 and 3.0 for patients with Bell's palsy and trauma, respectively.

CONCLUSIONS

NM-ENoG may be a valid and comparable method to NLF-ENoG for predicting the recovery of facial nerve function in acute paralysis. Absence of MUPs on EMG is a specific measure of severe degeneration and highly predictive of candidacy for surgical decompression.

LEVEL OF EVIDENCE

Level 3.

Muscle Activity Detectors-Surface Electromyography in the Evaluation of Abductor Hallucis Muscle

Despite the high availability of surface electromyography (sEMG), it is not widely used for testing the effectiveness of exercises that activate intrinsic muscles of foot in people with hallux valgus. The aim of this study was to assess the effect of the toe-spread-out (TSO) exercise on the outcomes of sEMG recorded from the abductor hallucis muscle (AbdH). An additional objective was the assessment of nerve conduction in electroneurography. The study involved 21 patients with a diagnosed hallux valgus (research group A) and 20 people without the deformation (research group B) who performed a TSO exercise and were examined twice: before and after therapy. The statistical analysis showed significant differences in the third, most important phase of TSO. After the exercises, the frequency of motor units recruitment increased in both groups. There were no significant differences in electroneurography outcomes between the two examinations in both research groups. The TSO exercise helps in the better activation of the AbdH muscle and contributes to the recruitment of a larger number of motor units of this muscle. The TSO exercises did not cause changes in nerve conduction. The sEMG and ENG are good methods for assessing this exercise but a comprehensive assessment should include other tests as well.

[Diseases with peripheral motor symptoms]

Diseases with peripheral motor symptoms are a rare, but important subgroup of the all peripheral neuropathies, radiculopathies and neuronopathies. In these mostly progressive neuropathies, the clinical features include pure motor symptoms with weakness and wasting of the striated muscles. The differentiation of these diseases is frequently a challenge for qualified clinical neurologists. A careful history taking, the disease time course, the findings of routine clinical physical examination and the electrophysiological studies are all necessary in the diagnostic procedure. The aim of this publication is to overview the clinical characteristics of the pure motor peripheral neuropathies, to consider the diagnostic steps and the differential diagnosis, and finally to summarize the treatment options.

Polyneuropathy in Acute Lymphoblastic Leukemia Long-Term Survivors: Clinical and Electrophysiological Characteristics With the Impact of Radiotherapy

Introduction: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer with one of the highest survival rates. Long-term complications that occur after intensive oncological treatment often impair normal daily functioning. However, existing data on peripheral nervous system condition in ALL survivors remain conflicting. Materials and Methods: The study group consisted of 215 ALL survivors. Patients were treated with New York (NY, n = 45), previous modified Berlin-Frankfurt-Münster (pBFM, n = 64), and BFM95 (n = 106) protocols. Time elapsed between the end of the treatment and the control examination varied from 0.3 to 20.9 years. The analyzed patients underwent a neurophysiological analysis with electroneurography (ENG) of motor (median and peroneal) and sensory (median and sural) nerves as well as electromyography (EMG) of tibialis anterior, vastus lateralis, and interosseous I muscles. To estimate the influence of radiotherapy on recorded neurophysiological responses, a joint analysis of NY, and pBFM groups was performed. Results: Clinical symptoms of polyneuropathy were noted among 102 (47.4%) children during the ALL therapy and in 111 (51.6%) during follow-up. At the time of treatment, polyneuropathy was diagnosed in 57.8% participants from NY group, 35.9%-pBFM and 50.0%-BFM95 (p = 0.145). A significantly higher incidence of polyneuropathy was observed during a follow-up in the NY group (68.9%; p < 0.001 vs. pBFM, p = 0.002 vs. BFM95). The most frequent abnormality within all the protocols was demyelination (NY: 44.4%, pBFM: 59.4%, BFM95: 41.5%), in contrast to the least frequently registered isolated axonal changes. The negative influence of oncological treatment on neurophysiological parameters in ALL survivors was observed. Complex disorders of motor nerves, sensory nerves, and motor unit potentials were registered. Motor-sensory neuropathy was the most frequently found pathology in all analyzed protocols. The harmful effect of radiotherapy was also observed in EMG results. Conclusions: Detailed neurophysiological analysis in long-term childhood ALL survivors has shown generalized abnormalities in registered parameters. To our knowledge, the current study is the largest and one of the most comprehensive ones among those examining disturbances in ENG and EMG in this group of patients. Moreover, we are the first ones to demonstrate the negative influence of radiotherapy on peripheral nerve conduction parameters.

Electroneurography value as an indicator of high risk for the development of moderate-to-severe synkinesis after Bell's palsy and Ramsay Hunt syndrome

Background: The degree of distress caused by the sequelae of peripheral facial nerve palsy usually depends on the severity of synkinesis. Objective: To clarify whether electroneurography (ENoG) can predict the severity of synkinesis after peripheral facial nerve palsy. Materials and methods: One-hundred and fourteen patients treated for facial nerve palsy at our hospital from April 2014-September 2016 were retrospectively reviewed. ENoG was performed 10-16 days after symptom onset. Patients were classified into Groups A (ENoG value 10%-20%, n = 9) and B (ENoG value <10%, n = 21). Eight months after symptom onset, electrophysiological and symptomatic outcomes were evaluated as the aberrant regeneration ratio of the blink reflex and the total synkinesis score of the Sunnybrook facial grading system, respectively. The outcomes of the groups were compared. Results: Group B had a significantly higher median aberrant regeneration ratio (0% versus 87%, p=.015), median total synkinesis score (1 versus 3, p < .001), and incidence of moderate-to-severe synkinesis (0% versus 57.2%, p=.003) than did Group A. Conclusions and significance: Patients with an ENoG value of <10% have higher risks of aberrant regeneration and moderate-to-severe synkinesis than those with an ENoG value of 10%-20%. Patients with ENoG values of <10% may require rehabilitation to prevent synkinesis.

Neurophysiological study of the radial nerve variant in the innervation of the dorsomedial surface of the hand

INTRODUCTION

Sensory innervation of the dorsomedial surface of the hand usually depends on the dorsal ulnar nerve (DUN). Innervation in this area by the superficial radial nerve (SRN) has been described as a normal variant.

METHODS

We studied 358 patients using nerve conduction of the DUN and SRN with dorsomedial recording. Each hand was classified into usual innervation (only DUN response), mixed variant (response of both nerves), or complete variant (only SRN response).

RESULTS

Mixed innervation was found in 14.2% of hands and complete innervation was found in 6.8% of hands, mostly unilaterally. No statistically significant differences were observed in age, sex, or clinical suspicion between usual and variant innervation. The potential amplitude after SRN stimulation was greater in the complete variant.

DISCUSSION

It is important to know the characteristics of this variant in order to avoid diagnostic errors and to prevent iatrogenic lesions in surgery performed on the dorsum of the wrist. Muscle Nerve 58: 732-735, 2018.

Prognostic factors of Bell's palsy and Ramsay Hunt syndrome

The aim of this study was to compare clinical characteristics, electroneurography (ENoG) results, and functional outcomes of patients with Bell's palsy (BP) and Ramsay Hunt syndrome (RHS).Around 57 patients with BP and 23 patients with RHS were enrolled in this study from January 2010 and September 2015. Both clinical characteristics and ENoG results were recorded at hospital admission. The evaluations of functional outcomes were conducted with House-Brackmann (H-B) grading system at 6-month follow-up.There were no significant differences in age, gender proportion, initial H-B grades, time before commencement of treatment and the presence of comorbid disease in 2 groups. However, the final H-B grades at 6-month follow-up were significantly better in BP patients than RHS patients. The results of ENoG showed that degeneration index (DI) was significantly higher in the RHS group than the BP group. But no significant difference was found in the value of prolonged latency time (PLT) between the 2 groups. In multivariate analysis, age and ENoG DI were independently associated with functional outcome of recovery in the BP group (OR 0.167, 95% CI 0.038-0.622, P = 0.009 and OR 0.289 95% CI 0.107-0.998, P = 0.050, respectively). However, in the RHS group, only ENoG DI was related to the final H-B grades (OR 0.067, 95% CI 0.005-0.882, P = 0.040). Spearman's rank correlation analysis showed that higher age and ENoG DI were related to poorer prognosis in 2 groups (P < 0.05). PLT was related to functional outcomes only in the BP group (rs = 0.460, P < 0.001). The receiver operating characteristic (ROC) of ENoG DI analysis revealed that the cutoff value was 67.0% for BP prognosis and 64.5% for RHS prognosis. What's more, patients with hypertension or diabetes mellitus had both higher final H-B grade and ENoG DI than those without the same comorbidity.Patients with RHS had poorer prognosis than those with BP. Some factors including age, ENoG DI, and the presence of disease influenced recovery from BP and RHS. The present study demonstrated that BP patients with ENoG DI < 67.0% and RHS patients with ENoG DI < 65.5% had a greater opportunity for recovery within half a year.

Lesions involving the jugular foramen: clinical characteristics and surgical management

CONCLUSION

Lesions involving the jugular foramen (JF) present as various diagnoses. Pulsatile tinnitus is more common in glomus jugulare (GJ) tumors, whereas otalgia and facial nerve paresis are more prevalent in temporal bone malignancies (TBMs). Preoperative facial nerve electroneurography (ENoG) was significantly correlated with postoperative facial nerve function.

OBJECTIVE

To describe the diagnosis and surgical management of lesions involving the JF.

METHODS

The charts were reviewed for 38 patients who had lesions involving the JF, including 14 patients with TBMs, 11 with GJ tumors, 7 with cholesteatomas, 2 with facial nerve schwannomas, 2 with JF schwannomas, and 2 with cholesterol granulomas. The follow-up data were recorded.

RESULTS

The most frequent symptoms included hearing loss (89.47%), followed by otorrhea (47.37%) and pulsatile tinnitus (39.47%). With respect to TBMs, 57.14% of patients complained of otorrhea and otalgia, and 50.00% presented with facial nerve paresis. Among the 13 patients with facial nerve paresis, 53.85% were diagnosed with TBMs. Regarding GJ tumors, 81.82% had pulsatile tinnitus and hearing loss. Among the 25 patients with normal preoperative facial nerve function, the mean facial nerve ENoG reduction was 29.48 ± 29.15%, and the mean postoperative facial nerve score was 77.48 ± 33.13. The correlation coefficient was -0.973 (p = 0.000).

Steroid plus antiviral treatment for Bell's palsy

OBJECTIVES

The effectiveness of antiviral agents for the treatment of Bell's palsy is uncertain. We evaluated whether a steroid with an antiviral agent (S + A group) provided better recovery outcomes than a steroid alone (S group) in patients with Bell's palsy.

SUBJECTS AND DESIGN

A total of 1342 patients diagnosed with Bell's palsy who visited the Kyung Hee Medical Center in Seoul, Korea, from 2002 to 2012 were included in this study. Patients in the S + A group were treated with prednisolone and antiviral agents (n = 569) and those in the S group with prednisolone alone (n = 773). Outcomes were measured using the House-Brackmann (HB) scale according to age, initial disease severity, electroneurography (ENoG) findings and underlying comorbidities.

RESULTS

The rate of recovery (HB grades I and II) with initially severe Bell's palsy (HB grades V and VI) was higher in the S + A than in the S group (P = 0.001). However, the rates of recovery were similar with initially moderate palsy (HB grades II-IV) (P = 0.502). In patients classified according to age and ENoG-determined severity of palsy, the overall recovery rate was higher in the S + A than in the S group, but the differences were not statistically significant (P > 0.05 for both). The recovery rate without diabetes mellitus (DM) and hypertension (HTN) was higher in the S + A group than in the S group (P = 0.031). But in the patients with HTN and DM, the difference in recovery rates between the S + A and S groups was not statistically significant (P = 0.805).

CONCLUSIONS

Treatment with a steroid plus antiviral agent resulted in significantly higher recovery rates than steroid therapy alone in patients with initially severe Bell's palsy and without either HTN or DM, and a nonsignificant trend towards higher recovery rates in all patients with Bell's palsy in this study. Antiviral agents may therefore help in the treatment of Bell's palsy.

Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study

BACKGROUND

An association between massive rotator cuff tear (RCT) and suprascapular nerve neuropathy has previously been suggested. The anatomic course of the suprascapular nerve is relatively fixed along its passage. Thus, injury to the nerve by trauma, compression, and iatrogenic reasons is well documented. However, the association between retraction of the RCT and development of neuropathy of the suprascapular nerve remains unclear. We aimed to prospectively evaluate the suprascapular nerve for preoperative neurodiagnostic abnormalities in shoulders with massive RCT.

METHODS AND MATERIALS

A prospective study was performed in 2 centers. Fifty patients with retracted tears of both supraspinatus and infraspinatus were evaluated. This was confirmed with preoperative computed tomography arthrography, and the fatty infiltration of the affected muscles was graded. Forty-nine preoperative electromyograms were performed in a standardized fashion and the results analyzed twice.

RESULTS

Of 49 shoulders, 6 (12%) had neurologic lesions noted on electromyography: 1 suprascapular nerve neuropathy, 1 radicular lesion of the C5 root, 1 affected electromyogram in the context of a previous stroke, and 3 cases of partial axillary nerve palsy with a history of shoulder dislocation. No difference or diminution of the latency or amplitude of the electromyographic curve was found in the cases that presented significant fatty infiltration.

CONCLUSION

This study did not detect a suprascapular lesion in the majority of cases of massive RCT. With a low association of neuropathy with massive RCT, we find no evidence to support the routine practice of suprascapular nerve release when RCT repair is performed.

Value of electroneurography as a prognostic indicator for recovery in acute severe inflammatory facial paralysis: a prospective study of Bell's palsy and Ramsay Hunt syndrome

OBJECTIVES/HYPOTHESIS

To evaluate the prognostic and predictive value of electroneuronography (ENoG) in acute severe inflammatory facial paralysis, including Bell's palsy and Ramsay Hunt syndrome (RHS).

STUDY DESIGN

Prospective observational study.

METHODS

Patients with acute severe facial paralysis of House-Brackmann (H-B) grade IV or worse and diagnosed with Bell's palsy or RHS were enrolled from August 2007 to July 2011. After treatment with oral corticosteroid, antiviral agent, and protective eye care, patients were followed up until recovery or 12 months from onset.

RESULTS

Sixty-six patients with Bell's palsy and 22 with RHS were included. Multiple logistic regression analysis showed significant effect of ENoG value on recovery in both Bell's palsy and RHS. Values of ENoG were significantly worse in RHS than Bell's palsy. Chance of early recovery within 6 weeks after correction of ENoG effect was still significantly worse in RHS. Logistic regression analysis showed 90% chance of recovery within 6 months, expected with ENoG values of 69.2% degeneration (Bell's palsy) and 59.3% (RHS). The receiver operating characteristics (ROC) curves showed ENoG values of 82.5% (Bell's palsy) and 78.0% (RHS) as a critical cutoff value of nonrecovery until 1 year, with the best sensitivity and specificity.

CONCLUSIONS

A higher chance of recovery was expected with better ENoG in Bell's palsy and RHS. Based on our data, nonrecovery is predicted in patients with ENoG value greater than 82.5% in Bell's palsy, and 78% in RHS.

LEVEL OF EVIDENCE

4.

Clinical and functional assessment of dysautonomia and its correlation in Alzheimer's disease

The aims were to assess dysautonomia in Alzheimer's Disease (AD), clinically and electrophysiologically, using sympathetic skin response (SSR) test and R-R interval variation (RRIV) test and to analyze the relationship between symptoms of dysautonomia and SSR/RRIV results. A tota of 54 patients with AD and 37 controls were evaluated using Autonomic Symptoms Questionnaire and SSR/RRIV test. Clinical dysautonomia was observed in 66% of patients (eg, orthostatic hypotension in 34.5%, constipation in 17.2%, urinary incontinence in 13.8%). The SSR test was abnormal in 26%, but the RRIV test was abnormal in 97.7% of cases; there was significant difference in RRIV test results between AD and controls (R mean 8.05% and 14.6%, respectively). In AD, clinical dysautonomia occurs at a various degree, and the abnormal SSR and RRIV test results were not always related to the presence of clinical dysautonomia; this observation points that the tests could be used as a useful tool in the assessment of subclinical dysautonomia.