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Background: Clinical neurophysiology (CNP) involves the use of neurophysiological techniques to make an accurate clinical diagnosis, to quantify the severity, and to measure the treatment response. Despite several studies showing CNP to be a useful diagnostic tool in Movement Disorders (MD), its more widespread utilization in clinical practice has been limited. Objectives: To better understand the current availability, global perceptions, and challenges for implementation of diagnostic CNP in the clinical practice of MD. Methods: The International Parkinson and Movement Disorders Society (IPMDS) formed a Task Force on CNP. The Task Force distributed an online survey via email to all the members of the IPMDS between August 5 and 30, 2021. Descriptive statistics were used for analysis of the survey results. Some results are presented by IPMDS geographical sections namely PanAmerican (PAS), European (ES), African (AFR), Asian and Oceanian (AOS). Results: Four hundred and ninety‐one IPMDS members (52% males), from 196 countries, responded. The majority of responders from the AFR (65%) and PAS (63%) sections had no formal training in diagnostic CNP (40% for AOS and 37% for ES). The most commonly used techniques are electroencephalography (EEG) (72%) followed by surface EMG (71%). The majority of responders think that CNP is somewhat valuable or very valuable in the assessment of MD. All the sections identified "lack of training" as one of the biggest challenges for diagnostic CNP studies in MD. Conclusions: CNP is perceived to be a useful diagnostic tool in MD. Several challenges were identified that prevent widespread utilization of CNP in MD. [ABSTRACT FROM AUTHOR]

We proposed that the brain's electrical activity is composed of a sequence of alternating states with repeating topographic spectral distributions on scalp electroencephalogram (EEG), referred to as oscillatory macrostates. The macrostate showing the largest decrease in the probability of occurrence, measured as a percentage (reactivity), during sensory stimulation was labelled as the default EEG macrostate (DEM). This study aimed to assess the influence of awareness on DEM reactivity (DER). We included 11 middle cerebral artery ischaemic stroke patients with impaired awareness having a median Glasgow Coma Scale (GCS) of 6/15 and a group of 11 matched healthy controls. EEG recordings were carried out during auditory 1 min stimulation epochs repeating either the subject's own name (SON) or the SON in reverse (rSON). The DEM was identified across three SON epochs alternating with three rSON epochs. Compared with the patients, the DEM of controls contained more posterior theta activity reflecting source dipoles that could be mapped in the posterior cingulate cortex. The DER was measured from the 1 min quiet baseline preceding each stimulation epoch. The difference in mean DER between the SON and rSON epochs was measured by the salient EEG reactivity (SER) theoretically ranging from −100% to 100%. The SER was 12.4 ± 2.7% (Mean ± standard error of the mean) in controls and only 1.3 ± 1.9% in the patient group (P < 0.01). The patient SER decreased with the Glasgow Coma Scale. Our data suggest that awareness increases DER to SON as measured by SER. [ABSTRACT FROM AUTHOR]

Background and purpose: We evaluated the clinical and neurophysiological efficacy of rituximab (RTX) in a neurophysiologically homogeneous group of patients with monoclonal gammopathy and immunoglobulin M (IgM) anti‐myelin‐associated glycoprotein antibody (anti‐MAG) demyelinating polyneuropathy. Methods: Twenty three anti‐MAG‐positive polyneuropathic patients were prospectively evaluated before and for 2 years after treatment with RTX 375 mg/m2. The Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale (INCAT‐ds), modified INCAT sensory score (mISS), Medical Research Council sum score, Patients' Global Impression of Change scale were used, IgM levels were assessed and extensive electrophysiological examinations were performed before (T0) and 1 year (T1) and 2 years (T2) after RTX treatment. Results: At T1 and T2 there was a significant reduction from T0 both in mISS and in INCAT‐ds, with a p value < 0.001 in the inferential Friedman's test overall analysis. Ulnar nerve Terminal Latency Index and distal motor latency significantly changed from T0 to T1 and in the overall analysis (p = 0.001 and p = 0.002), and ulnar nerve sensory nerve action potential (SNAP) amplitude was significantly increased at T2 from T1, with a p value < 0.001 in the overall analysis. Analysis of the receiver‐operating characteristic curves showed that a 41.8% increase in SNAP amplitude in the ulnar nerve at T2 from T0 was a fair predictor of a mISS reduction of ≥2 points (area under the curve 0.85; p = 0.005; sensitivity: 90.9%, specificity: 83.3%). Conclusions: This study suggests that RTX is effective in patients with clinically active demyelinating anti‐MAG neuropathy over 2 years of follow‐up, and that some neurophysiological variables might be useful for monitoring this efficacy. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Neurogenic thoracic outlet syndrome (NTOS) is a heterogeneous and often disputed entity. An electrodiagnostic pattern of T1 > C8 axon involvement is considered characteristic for the diagnosis of NTOS. However, since the advent of high‐resolution nerve ultrasound (US) imaging, we have encountered several patients with a proven entrapment of the lower brachial plexus who showed a different, variable electrodiagnostic pattern. Methods: In this retrospective case series, 14 patients with an NTOS diagnosis with a verified source of compression of the lower brachial plexus and abnormal findings on their electrodiagnostic testing were included. Their medical records were reviewed to obtain clinical, imaging, and electrodiagnostic data. Results: Seven patients showed results consistent with the "classic" T1 axon > C8 pattern of involvement. Less typical findings included equally severe involvement of T1 and C8 axons, more severe C8 involvement, pure motor abnormalities, neurogenic changes on needle electromyography in the flexor carpi radialis and biceps brachii muscles, and one patient with an abnormal sensory nerve action potential (SNAP) amplitude for the median sensory response recorded from the third digit. Patients with atypical findings on electrodiagnostic testing underwent nerve imaging more often compared to patients with classic findings (seven of seven patients vs. five of seven respectively), especially nerve ultrasound. Discussion When there is a clinical suspicion of NTOS, an electrodiagnostic finding other than the classic T1 > C8 pattern of involvement does not rule out the diagnosis. High resolution nerve imaging is valuable to diagnose additional patients with this treatable condition. See Editorial on pages 4‐6 in this issue. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Neurophysiological patterns in patients with foodborne botulism are rarely described after the acute phase. We report data from a large Italian outbreak of botulism, with patients evaluated at different timepoints after poisoning. Methods: Eighteen male patients (mean age 47 ± 8.4 y) underwent 22 clinical and neurophysiological evaluations (4 patients were re‐evaluated). The resting compound muscle action potential (CMAP) amplitude, postexercise CMAP amplitude, CMAP change after high‐frequency (50 Hz) repetitive nerve stimulation (HFRNS), and motor unit action potentials (MUAPs) were assessed in the acute (4–8 days after poisoning; 5 patients), early post‐acute (32–39 days after poisoning; 5 patients), and late post‐acute (66–80 days after poisoning; 12 patients) phases. Results: In the acute, early post‐acute, and late post‐acute phases, respectively, reduced CMAP amplitudes were found in 100%, 20%, and 17% of patients; abnormal postexercise CMAP facilitation was observed in 100%, 40%, and 0% of patients; and pathological incremental responses to HFRNS were found in 80%, 50%, and 8% of patients. Baseline CMAP amplitudes, postexercise CMAP facilitation, and CMAP increases in response to HFRNS differed significantly between the acute and post‐acute phases. Small MUAPs were found in 100% of patients in the acute and early post‐acute phases and in 50% of patients in the late post‐acute phase. Discussion: The neurophysiological findings of foodborne botulism vary considerably according to the evaluation time point. In the post‐acute phase, different neurophysiological techniques must be applied to support a diagnosis of botulism. [ABSTRACT FROM AUTHOR]

The functional anatomy of the anteromesial portion of the temporal lobe and its involvement in epilepsy can be explored by means of intracerebral electrical stimulations. Here, we aimed to expand the knowledge of its physiological and pathophysiological symptoms by conducting the first large‐sample systematic analysis of 1529 electrical stimulations of this anatomical region. We retrospectively analysed all clinical manifestations induced by intracerebral electrical stimulations in 173 patients with drug‐resistant focal epilepsy with at least one electrode implanted in this area. We found that high‐frequency stimulations were more likely to evoke electroclinical manifestations (p <.0001) and also provoked 'false positive' seizures. Multimodal symptoms were associated with EEG electrical modification (after discharge) (p <.0001). Visual symptoms were not associated with after discharge (p =.0002) and were mainly evoked by stimulation of the hippocampus (p =.009) and of the parahippocampal gyrus (p =.0212). 'False positive seizures' can be evoked by stimulation of the hippocampus, parahippocampal gyrus and amygdala, likely due to their intrinsic low epileptogenic threshold. Visual symptoms evoked in the hippocampus and parahippocampal gyrus, without EEG changes, are physiological symptoms and suggest involvement of these areas in the visual ventral stream. Our findings provide meaningful guidance in the interpretation of intracranial EEG studies of the temporal lobe. [ABSTRACT FROM AUTHOR]

Introduction: In everyday clinical neurophysiology practice, mononeuropathies are evaluated primarily by traditional electrodiagnostic testing. We sought to assess the additional benefit of neuromuscular ultrasound (US) in this scenario. Methods: All consecutive mononeuropathies undergoing combined US and electrodiagnostic evaluation over a 23‐mo period at a single neurophysiology practice were reviewed. Three independent examiners assessed how often US was: (a) "contributory" ‐ enabling a definite diagnosis not made by electrophysiology alone and/or impacting on the therapeutic decision, (b) "confirmatory" of the electrodiagnostic findings, but not adding further diagnostic or therapeutic information, or (c) "negative" ‐ missed the diagnosis. Results: There were 385 studies included. US was "contributory" in 36%, "confirmatory" in 61% and "negative" in 3%. Discussion: In this study of everyday neurophysiology practice, neuromuscular US contributed significant diagnostic or therapeutic information in over 1/3 of the investigations for common mononeuropathies. False negative US studies were uncommon in this setting. See Editorial on pages 437–438 in this issue. [ABSTRACT FROM AUTHOR]

Background and purpose: Some epilepsy syndromes (sleep‐related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2). Methods: The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library. Results: Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control. Conclusions: Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined. [ABSTRACT FROM AUTHOR]

Key points: We explored the large variability in motor skill acquisition‐related effects on the primary and sensory cortices. Namely, we tested whether this variability depends on interindividual variance or the type of motor task investigated.We compared different motor‐learning tasks, i.e. model‐free vs. model‐based learning tasks, and their possible differential effects on the primary motor and sensory cortices by using transcranial magnetic stimulation techniques.The model‐free learning task induced an increase in corticospinal excitability and a reduction in the amplitude of somatosensory‐evoked potentials. Conversely, the model‐based learning tasks induced a decrease in intracortical inhibition.No correlations were found between neurophysiological changes and motor performance, indicating that this differential modulation may be secondary to the motor skill acquisition.The study results suggest differential motor skill acquisition‐related effects on cortical parameters, possibly due to the engagement of specific neurophysiological substrates. A large variability in learning‐related neurophysiological changes in the primary motor and sensory cortices has been observed. It is unclear whether these differential effects are due to the different tasks investigated or to interindividual variance. Only a few studies have assessed different motor‐learning tasks and their effects on neurophysiological features within the same group of participants, and several issues are unclear. Here, we compared the effects of different tasks within each individual. We investigated the effects on motor and sensory cortex parameters after a model‐free learning task, i.e. a ballistic motor task, compared with model‐based learning tasks, i.e. visuomotor‐learning tasks. Motor‐ and sensory‐evoked potentials, intracortical excitability as assessed by short‐interval intracortical inhibition, and sensorimotor interaction, i.e. short‐latency afferent inhibition, were recorded from 15 healthy subjects before and after the tasks. The ballistic motor task induced an increase in corticospinal excitability but did not change motor cortex intracortical inhibition or sensorimotor integration. In addition, it decreased the amplitude of cortical components of the somatosensory‐evoked potentials. The visuomotor‐learning tasks induced a reduction in motor cortex intracortical inhibition but did not modulate corticospinal and sensory cortex excitability or sensorimotor integration. This differential modulation is likely to be secondary to the motor skill acquisition, since no correlation was observed between neurophysiological changes and motor performance. Our results demonstrate differential motor skill acquisition‐related effects on cortical parameters, possibly reflecting the engagement of specific neurophysiological substrates, and contribute in‐depth knowledge of the mechanisms involved in different types of motor skill acquisition in humans. Key points: We explored the large variability in motor skill acquisition‐related effects on the primary and sensory cortices. Namely, we tested whether this variability depends on interindividual variance or the type of motor task investigated.We compared different motor‐learning tasks, i.e. model‐free vs. model‐based learning tasks, and their possible differential effects on the primary motor and sensory cortices by using transcranial magnetic stimulation techniques.The model‐free learning task induced an increase in corticospinal excitability and a reduction in the amplitude of somatosensory‐evoked potentials. Conversely, the model‐based learning tasks induced a decrease in intracortical inhibition.No correlations were found between neurophysiological changes and motor performance, indicating that this differential modulation may be secondary to the motor skill acquisition.The study results suggest differential motor skill acquisition‐related effects on cortical parameters, possibly due to the engagement of specific neurophysiological substrates. [ABSTRACT FROM AUTHOR]

Background: Alterations in large‐scale functional connectivity have widely been used to understand migraine pathophysiology and to find any imaging markers. The successful use of the Triple Network Model for many mental and neurological diseases has prompted us to consider chronic migraine under the prism of this model for the first time in the literature. Aim: To evaluate alterations in functional connectivity between large‐scale networks using resting‐state fMRI in chronic migraine patients and their correlation with clinical features within the boundaries of the Triple Network Model. Methods: Twenty‐five chronic migraine patients underwent 1,5T resting‐state functional magnetic resonance imaging (RS‐fMRI) scanning during the interictal phase and were compared to a group of 25 healthy controls. Functional connectivity was assessed using region‐of‐interest to region‐of‐interest (ROI‐to‐ROI) analysis between 8 networks and 15 subcortical areas, conventionally assigned to salience network. Results: Compare to healthy controls, patients had increased functional connectivity between salience network (SN) and sensorimotor network (SMN) and dorsal attention network (DAN), between nucleus accumbens and default mode network (DMN) and within DMN and also between thalamus and DAN. Decreased functional connectivity was registered between nucleus accumbens and DAN, and also within DAN. A higher depression scale score was positively correlated with an increase in FC within DMN. Conclusion: Taken together, our results show that patients with chronic migraine could be characterized by specific dysfunctional interactions between the SN, SMN, DAN, and DMN during resting state. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease patients may show a tremor that appears after a variable delay while the arms are kept outstretched (re-emergent tremor). The objectives of this study were to investigate re-emergent tremor pathophysiology by studying the role of the primary motor cortex in this tremor and making a comparison with rest tremor.Methods: We enrolled 10 Parkinson's disease patients with both re-emergent and rest tremor. Tremor was assessed by spectral analysis, corticomuscular coherence and tremor-resetting produced by transcranial magnetic stimulation over the primary motor cortex. We also recorded transcranial magnetic stimulation-evoked potentials generated by motor cortex stimulation during rest tremor, tremor suppression during wrist extension, and re-emergent tremor. Spectral analysis, corticomuscular coherence, and tremor resetting were compared between re-emergent tremor and rest tremor.Results: Re-emergent tremor showed significant corticomuscular coherence, causal relation between motor cortex activity and tremor muscle and tremor resetting. The P60 component of transcranial magnetic stimulation-evoked potentials reduced in amplitude during tremor suppression, recovered before re-emergent tremor, was facilitated at re-emergent tremor onset, and returned to values similar to those of rest tremor during re-emergent tremor. Compared with rest tremor, re-emergent tremor showed similar corticomuscular coherence and tremor resetting, but slightly higher frequency.Conclusions: Re-emergent tremor is causally related with the activity of the primary motor cortex, which is likely a convergence node in the network that generates re-emergent tremor. Re-emergent tremor and rest tremor share common pathophysiological mechanisms in which the motor cortex plays a crucial role. © 2020 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Objective: We attempted to determine whether clinical features could differentiate painful small‐fiber neuropathy related to primary Sj€ogren's syndrome (pSS‐SFN) from idiopathic SFN (idio‐SFN). Methods: Validated clinical questionnaires and neurophysiological investigations specific for pain and SFN assessment were performed in 25 patients with pSS‐SFN and 25 patients with idio‐SFN. Results: Patients with idio‐SFN had more frequent severe burning sensations and higher mean anxiety scores and daily pain intensity compared to patients with pSSSFN. Conversely, patients with pSS‐SFN had reduced electrochemical skin conductance measured by Sudoscan_, and almost half of them had the sensation of walking on cotton wool. Conclusion: Our results suggest that idio‐SFN more specifically involved small sensory fibers than pSS‐SFN, in which subtle dysfunction of larger sensory fibers and damage of distal autonomic sudomotor innervation may occur. A practical algorithm is proposed to help to differentiate SFN associated with pSS from idio‐SFN, based on information very easy to obtain by clinical interview. [ABSTRACT FROM AUTHOR]

Introduction: We evaluated diagnostic value of sensory tests during recovery from iatrogenic sensory neuropathy using intraoperatively verified nerve injury with subjective symptoms as gold standard.Methods: Inferior alveolar nerves were monitored neurophysiologically throughout mandibular osteotomy in 19 patients. Sensory disturbance was registered and sensation tested using clinical and quantitative sensory (QST) and neurophysiologic tests postoperatively at 1, 3, 6, and 12 months. Sensitivity, specificity, and predictive values were calculated for all tests.Results: The sensitivity of clinical tests was at best 37%, with 100% specificity, but they lost diagnostic value at chronic stages. Best diagnostic accuracy (highest combination of sensitivity and specificity) at different time points was achieved by combining neurophysiologic and thermal QST or tactile and thermal QST. The single most accurate test was sensory neurography.Conclusions: Neurography or combinations of neurophysiologic and quantitative tests enables most reliable early and late diagnosis. Clinical sensory examination is inadequate for accurate diagnosis. Muscle Nerve 59:342-347, 2019. [ABSTRACT FROM AUTHOR]

Abstract: A 59‐year‐old woman presented with progressive paresthesias of all of her limbs for 4 years, associated with neuropathic pain, tingling in the tongue and allodynia, consistent with small fiber neuropathy (SFN). Several systemic symptoms and signs were found on clinical examination and laboratory work‐up. Neurological investigations including neurophysiologic test and skin biopsy supported the diagnosis of SFN. Chronic exposure to N‐hexane was then disclosed and suspected to be the cause of the disease. Following the discontinuation of chronic N‐hexane exposure, the patient had a progressive improvement of all signs and symptoms, reinforcing the correlation between exposure to N‐hexane, and development of SFN. Exposure to N‐hexane may be considered as a novel reversible cause of SFN, which underlines the need to look for toxic etiologies in the diagnosis of SFN. [ABSTRACT FROM AUTHOR]

There is a need for quantitative, precise assessment of small fiber peripheral nerve function. We tested a customized camera device and protocol designed to quantify secretions of individual sweat glands (SGs). Testing was performed on 178 healthy controls and 20 neuropathy subjects. Sweating was stimulated on a 2.25 cm2 skin area by iontophoresis of pilocarpine. The camera imaged sweat from 50 to 400 sweat ducts. We calculated secretion rate of individual SGs, total sweat volume, and number of secreting SGs at four body sites. Neuropathy subjects were tested at the two distal sites to demonstrate the device's capability to detect abnormal sudomotor function. Normal ranges were calculated for each body site. Neuropathy subjects had lower sweat rates per SG, lower total sweat, and lower SG density. The normal values decreased with advancing age, were lower in females, and differed between body sites. There was good agreement with repeat testing. The device provides reliable, precise quantitative measures of sweat secretion from single SGs for characterization of sudomotor nerve function in healthy control subjects and in subjects with known peripheral neuropathy. The test combines the capabilities of existing tests of sudomotor function while providing additional capabilities. [ABSTRACT FROM AUTHOR]

Introduction: In this study we aimed to identify prognostic factors of ulnar neuropathy at the elbow (UNE) and developed a scoring system to establish the prognosis.Methods: We collected baseline clinical, electrophysiologic, and ultrasonographic data from 2 cohorts. The outcomes for all patients were determined on follow-up. Prognostic factors were determined using single and multiple variable analyses. A points system was developed to determine the risk for an unfavorable outcome.Results: Of the 220 patients with UNE 178 (81%) could be re-evaluated. Four variables were retained in the prediction model for a points system. An unfavorable outcome was associated with right-sided UNE, more severe weakness of the abductor digiti minimi (ADM), and more pronounced ulnar nerve thickening. A compound muscle action potential amplitude reduction across the elbow of ≥16% (particularly if ≥ 50%) was associated with a more favorable outcome.Conclusion: Outcome in UNE may be predicted by scoring 4 parameters. Muscle Nerve 55: 698-705, 2017. [ABSTRACT FROM AUTHOR]

Introduction: We studied patterns of nerve injury in pediatric common fibular (peroneal) neuropathy (CFN).Methods: A retrospective analysis was performed on data from 53 children with CFN at a pediatric electromyography laboratory.Results: Conduction block at the fibular head was present in 35% of patients. Deep fibular axonal loss was identified in 77%, while superficial fibular axonal loss was identified in 45%. The pathophysiology was predominantly axonal in 72%, mostly demyelinating in 6%, and mixed in 22%. Predominantly demyelinating lesions at the fibular head demonstrated sparing of the superficial fibular sensory nerve (P = 0.01, Fischer exact test). Predominantly axonal lesions had a moderate correlation between superficial and deep fibular axonal loss (Spearman r = 0.52; P = 0.0001).Conclusions: There is frequent axonal and fascicular injury in pediatric CFN, similar to adults. Deep and superficial fibular nerve involvements correlate in axonal lesions, whereas superficial fibular sensory fibers are often spared in demyelinating lesions. Muscle Nerve, 2016 Muscle Nerve 55: 693-697, 2017. [ABSTRACT FROM AUTHOR]

Introduction: The contribution of cranial and thoracic region electromyography (EMG) to diagnostic criteria for amyotrophic lateral sclerosis (ALS) has not been evaluated.Methods: Clinical and EMG data from each craniospinal region were retrospectively assessed in 470 patients; 214 had ALS. Changes to diagnostic classification in Awaji-Shima and revised El Escorial criteria after withdrawal of cranial/thoracic EMG data were ascertained.Results: Sensitivity for lower motor neuron involvement in ALS was highest in the cervical/lumbar regions; specificity was highest in cranial/thoracic regions. Cranial EMG contributed to definite/probable Awaji-Shima categorization in 1.4% of patients. Thoracic EMG made no contribution. For revised El Escorial criteria, cranial and thoracic data reclassified 1% and 5% of patients, respectively.Conclusion: Cranial EMG data make small contributions to both criteria, whereas thoracic data contribute only to the revised El Escorial criteria. However, cranial and thoracic region abnormalities are specific in ALS. Consideration should be given to allowing greater diagnostic contribution from thoracic EMG. Muscle Nerve 54: 378-385, 2016. [ABSTRACT FROM AUTHOR]

The clinical utility of routine electroencephalography ( EEG) after a first unprovoked seizure remains uncertain. Its diagnostic accuracy in identifying adults and children with new onset epilepsy was examined. A systematic review and meta-analysis of studies examining individuals who underwent routine EEG after a first unprovoked seizure and were followed for seizure recurrence for at least 1 year was performed. A 'positive' test was defined by the presence of epileptiform discharges ( ED). Pooled sensitivity and specificity estimates were calculated using a bivariate random effects regression model. In all, 3096 records were reviewed, from which 15 studies were extracted with a total of 1799 participants. Amongst adult studies, the sensitivity and specificity (95% confidence interval) of routine EEG were 17.3% (7.9, 33.8) and 94.7% (73.7, 99.1), respectively. Amongst child studies, the pooled sensitivity and specificity were 57.8% (49.7, 65.6) and 69.6% (57.5, 79.5), respectively. Based upon our positive likelihood ratios, and assuming a pre-test probability of 50%, an adult with ED on routine EEG after a first unprovoked seizure has a 77% probability of having a second seizure, whilst a child with similar findings has a 66% probability. Further studies are required to examine the impact of patient characteristics and EEG features on the diagnostic accuracy of routine EEG for new onset epilepsy. [ABSTRACT FROM AUTHOR]

Introduction: Acute bulbar, neck, and limb weakness carries several potential differential diagnoses. Although a diagnosis can often be established clinically, investigations such as electrodiagnostic and antibody testing can provide support for the clinical diagnosis and may aid in understanding the pathogenesis. A 65-year-old woman presented with acute bulbar, neck, and rapidly progressive bilateral upper limb weakness.Methods: Clinical evaluation, electrophysiological, and serological studies were undertaken.Results: Neurophysiology demonstrated proximal conduction block. A clinical diagnosis of pharyngeal-cervical-brachial weakness, a localized variant of Guillain-Barré syndrome, was made. The patient received treatment with intravenous immunoglobulin and made a remarkable recovery over the next month. She was found to have serum monospecific anti-GT1a antibodies.Conclusions: We report a case of pharyngeal-cervical-brachial weakness with monospecific anti-GT1a antibodies and discuss the differential diagnosis of acute bulbar, neck, and limb weakness. [ABSTRACT FROM AUTHOR]

This study assessed the functionality of vestibular, pursuit, and saccade circuitry in autism across a wide age range. Subjects were 79 individuals with autism (AUT) and 62 controls (CON) aged 5 to 52 years with IQ scores>70. For vestibular testing, earth-vertical axis rotation was performed in darkness and in a lighted visual surround with a fixation target. Ocular motor testing included assessment of horizontal saccades and horizontal smooth pursuit. No between-group differences were found in vestibular reflexes or in mean saccade velocity or accuracy. Saccade latency was increased in the AUT group with significant age-related effects in the 8-18 year old subgroups. There was a trend toward decreased pursuit gain without age effects. Normal vestibular-induced eye movements and normal saccade accuracy and velocity provide the most substantial evidence to date of the functional integrity of brainstem and cerebellar pathways in autism, suggesting that the histopathological abnormalities described in these structures may not be associated with intrinsic dysfunction but rather reflect developmental alterations related to forebrain cortical systems formation. Increased saccade latency with age effects adds to the extensive existing evidence of altered function and maturation of cortical systems in autism. [ABSTRACT FROM AUTHOR]

Background: We investigated whether balance impairments caused by cerebellar disease are associated with specific sensorimotor processing deficits that generalize across all sensory modalities. Experiments focused on the putative cerebellar functions of scaling and coordinate transformation of balance responses evoked by stimulation of single sensory channels.Methods: Vestibular, visual, and proprioceptive sensory channels were stimulated in isolation using galvanic vestibular stimulation, moving visual scenery, and muscle vibration, respectively, in 16 subjects with spinocerebellar ataxia type 6 (SCA6) and 16 matched healthy controls. Two polarities of each stimulus type evoked postural responses of similar form in the forward and backward directions. Disease severity was assessed using the Scale for Assessment and Rating of Ataxia.Results: Impaired balance of SCA6 subjects during unperturbed stance was reflected in faster than normal body sway (P = 0.009), which correlated with disease severity (r = 0.705, P < 0.001). Sensory perturbations revealed a sensorimotor processing abnormality that was specific to response scaling for the visual channel. This manifested as visually evoked postural responses that were approximately three times larger than normal (backward, P < 0.001; forward P = 0.005) and correlated with disease severity (r = 0.543, P = 0.03). Response direction and habituation properties were no different from controls for all three sensory modalities.Conclusion: Cerebellar degeneration disturbs the scaling of postural responses evoked by visual motion, possibly through disinhibition of extracerebellar visuomotor centers. The excessively high gain of the visuomotor channel without compensatory decreases in gains of other sensorimotor channels provides a potential mechanism for instability of the balance control system in cerebellar disease. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction: The distribution of clinical and neurophysiological abnormalities in patients with early amyotrophic lateral sclerosis (ALS) was investigated in an attempt to delineate patterns of disease spread. Methods: Clinical and electrodiagnostic data were collected from 150 ALS patients and analyzed based on the clinical region of onset. Results: Asymmetry of clinical and neurophysiological abnormalities was more marked in upper limb-onset than lower limb-onset disease. Significant rostral-caudal gradients of clinical weakness were identified in bulbar- and lower limb-onset disease. Neurophysiological evidence of the ALS 'split-hand' pattern was evident irrespective of the region of disease onset. Limbs with and without evidence of clinical weakness demonstrated similar rates of abnormality on electromyography. Conclusions: These findings suggest a pattern of disease spread in ALS. This study may serve to guide ongoing development of disease quantitation biomarkers and the targeting of future neuroprotective strategies. Muscle Nerve 50: 894-899, 2014 [ABSTRACT FROM AUTHOR]

Aims Spinocerebellar ataxia type 3 ( SCA3) is an inherited spinocerebellar ataxia caused by the expansion of trinucleotide CAG repeats in the gene encoding ataxin-3. The clinical manifestations of SCA3 include peripheral neuropathy, which is an important cause of disability in a subset of patients. Although the loss of neurones in the dorsal root ganglion ( DRG) has been postulated to be the cause of this neuropathy, the precise mechanism remains to be elucidated. Methods To clarify the clinicopathological characteristics of SCA3-associated peripheral neuropathy, we performed nerve conduction studies and histopathological analyses. Nerve conduction studies were carried out in 18 SCA3 patients. Immunohistochemical analyses of the anterior and posterior roots of the spinal cord and peripheral nerves were performed in five SCA3 patients. We also employed immunohistochemistry and immunoelectron microscopy analyses with an anti-polyglutamine antibody. Results The mean sensory nerve action potentials of the SCA3 patients were half of the normal values. The motor conduction velocities were decreased, and the distal latencies were also significantly prolonged in the nerves studied relative to the those in normal controls. Histopathological analyses detected axonal sprouting and myelin thinning in all cases. Ataxin-3 aggregates were found in the cytoplasm of Schwann cells in all of the SCA3 patients examined but not in control subjects. Conclusions In addition to the previously reported neuronopathy, the results of the present study indicate that Schwann cells are involved in the formation of the pathogenic intracytoplasmic ataxin-3 protein aggregates in patients with SCA3-associated neuropathy. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction: Major advances in genetic analysis and neuroimaging have modified the traditional diagnostic approach for neuromuscular disorders. The purpose of this study was to investigate the role of electromyography (EMG) in the molecular era. Methods: We retrospectively surveyed reports of all EMG studies performed at Boston Children's Hospital from 2001 through 2011. Data were collected on study numbers, patient ages, referring provider subspecialty, study indication, electrophysiological diagnosis, and study utility. Results: A total of 2100 studies were performed. The volume increased from ∽160 to ∽250 studies/year. There was a trend toward studying older children. Neurologists, including neuromuscular specialists, constituted the major referral pool, whereas referrals from orthopedics increased steadily. Polyneuropathies followed by mononeuropathies were the most common indications and diagnoses. Fifty-seven percent of studies were normal. EMG provided meaningful information in 94% of cases. Conclusion: EMG continues to play a cardinal role in the diagnosis of pediatric neuromuscular disorders, although its practice paradigm is evolving. Muscle Nerve 50:244-249, 2014 [ABSTRACT FROM AUTHOR]

ABSTRACT Neuromuscular ultrasound involves the use of high-resolution ultrasound to image the peripheral nervous system of patients with suspected neuromuscular diseases. It complements electrodiagnostic studies well by providing anatomic information regarding nerves, muscles, vessels, tendons, ligaments, bones, and other structures that cannot be obtained with nerve conduction studies and electromyography. Neuromuscular ultrasound has been studied extensively over the past 10 years and has been used most often in the assessment of entrapment neuropathies. This review focuses on the use of neuromuscular ultrasound in 4 of the most common entrapment neuropathies: carpal tunnel syndrome, ulnar neuropathy at the elbow and wrist, and fibular neuropathy at the knee. Muscle Nerve 48:696-704, 2013 [ABSTRACT FROM AUTHOR]

Purpose Traumatic brain injury ( TBI) is an important cause of morbidity and mortality in children, and early posttraumatic seizures ( EPTS) are a contributing factor to ongoing acute damage. Continuous video- EEG monitoring ( cEEG) was utilized to assess the burden of clinical and electrographic EPTS. Methods Eighty-seven consecutive, unselected (mild - severe), acute TBI patients requiring pediatric intensive care unit ( PICU) admission at two academic centers were monitored prospectively with cEEG per established clinical TBI protocols. Clinical and subclinical seizures and status epilepticus ( SE, clinical and subclinical) were assessed for their relation to clinical risk factors and short-term outcome measures. Key Findings Of all patients, 42.5% (37/87) had seizures. Younger age (p = 0.002) and injury mechanism (abusive head trauma - AHT, p < 0.001) were significant risk factors. Subclinical seizures occurred in 16.1% (14/87), while 6.9% (6/87) had only subclinical seizures. Risk factors for subclinical seizures included younger age (p < 0.001), AHT (p < 0.001), and intraaxial bleed (p < 0.001). SE occurred in 18.4% (16/87) with risk factors including younger age (p < 0.001), AHT (p < 0.001), and intraaxial bleed (p = 0.002). Subclinical SE was detected in 13.8% (12/87) with significant risk factors including younger age (p < 0.001), AHT (p = 0.001), and intraaxial bleed (p = 0.004). Subclinical seizures were associated with lower discharge King's Outcome Scale for Childhood Head Injury (KOSCHI) score (p = 0.002). SE and subclinical SE were associated with increased hospital length of stay (p = 0.017 and p = 0.041, respectively) and lower hospital discharge KOSCHI (p = 0.007 and p = 0.040, respectively). Significance cEEG monitoring significantly improves detection of seizures/SE and is the only way to detect subclinical seizures/ SE. cEEG may be indicated after pediatric TBI, particularly in younger children, AHT cases, and those with intraaxial blood on computerized tomography ( CT). [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction Manual laborers are at increased risk for carpal tunnel syndrome ( CTS), and a combination of history, physical examination, and nerve conduction studies is often used to screen for CTS in this population. Neuromuscular ultrasound may be a better screening tool, because it is painless. In this study we compare the accuracy of nerve conduction studies and ultrasound for CTS screening. Methods Five hundred thirteen manual laborers were screened prospectively for CTS using nerve conduction studies and neuromuscular ultrasound, and the accuracy of the 2 techniques was compared using the Katz hand diagram as the diagnostic standard. Results The ROC curves for the 2 techniques were not significantly different ( P = 0.542), indicating that the approaches had similar diagnostic accuracy. Conclusions Neuromuscular ultrasound is a painless technique that has diagnostic accuracy similar to nerve conduction studies and can be used to screen large populations at risk for CTS. Muscle Nerve, 2013 [ABSTRACT FROM AUTHOR]

Introduction: The most common etiology of hypercapnic respiratory failure is chronic obstructive pulmonary disease (COPD). However, the differential diagnosis also includes neuromuscular disorders. We studied the specificity of reduced amplitude phrenic nerve compound motor action potential (CMAP) to diagnose neuromuscular disorders. Methods: A group of patients with advanced COPD were recruited prospectively and compared with controls. Phrenic nerve CMAPs were measured bilaterally using supraclavicular surface stimulation and bipolar recording (G1: 5 cm above the xiphoid; G2: 16 cm from G1). Results: A group of 20 patients (15 men) and a group of 29 controls (15 men) were included. Phrenic nerve CMAPs of patients with COPD had significantly longer latency and higher amplitude. Conclusion: Our study demonstrates that patients with hypercapnic respiratory failure and reduced phrenic nerve CMAP amplitude most probably have a neuromuscular disorder affecting the diaphragm and not COPD or another lung disorder. Muscle Nerve 47: 504-509, 2013 [ABSTRACT FROM AUTHOR]

Introduction: Muscle magnetic resonance imaging (MRI) is an innovative tool for exploring focal neuropathies. However, its usefulness in mild, proximal, or chronic lesions, when electromyography (EMG), the current 'gold standard' sensitivity is inadequate, has yet to be studied. Methods: Clinical, MRI, and EMG examinations were performed in 113 muscles of 17 consecutive patients with clinically diagnosed lower limb focal neuropathies. The sensitivity and specificity of MRI and EMG were evaluated in relation to disease duration, severity, and anatomical location. Results: Muscle MRI was highly sensitive for the detection of denervated muscle, and, unlike EMG, its sensitivity did not decrease regardless of the anatomical location, duration, or severity of the neuropathy. Five MRI false positives were noted, including three in the thigh muscles. Conclusions: Muscle MRI is an alternative tool to EMG in proximal, mild, or chronic clinical diagnoses of lower limb focal neuropathies. However, it also seems prone to false-positive results, particularly in proximal muscles. Muscle Nerve, 2012 [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

Based on its efficacy in treating neuropathic pain, gabapentin may be effective for the treatment of carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the efficacy of gabapentin for symptom relief in CTS. We conducted a randomized, double-blinded, placebo-controlled trial recruiting patients with newly diagnosed idiopathic CTS of more than a period of three months. Diagnosis was based on characteristic symptoms with electrophysiological confirmation. Patients were randomly assigned to an active group receiving gabapentin (starting dose 300 mg once daily to a target of 900 mg daily) or a placebo group. Primary end-point was the global symptom score (GSS), which was measured at baseline, two, and eight weeks. There was no significant difference in baseline variables between the two treatment groups. Hundred and forty patients were enrolled in the study, of whom 71 were randomly assigned to gabapentin group and 69 assigned to placebo group. Both gabapentin and placebo produced significant improvement in symptoms at two and eight weeks. The GSS at 2 and 8 weeks was 16.4 (SD 9.4) and 13.4 (SD 9.7), respectively, in the active group versus 14.9 (SD 9.0) and 12.5 (SD 8.9) in the control group ( P < 0.01). But by eight weeks, the mean reduction in symptom severity of patients on gabapentin [−10.4 (SD 10.8)] was not significant when compared with placebo [−8.7 (SD 8.1), P < 0.39]. Adverse events were not severe and included dizziness, somnolence, and headache. Gabapentin did not produce a significant reduction in symptom severity compared with placebo over an eight-week period. [ABSTRACT FROM AUTHOR]

Background and purpose: Sensory neuron diseases (SND) represent a specific subgroup of peripheral nervous system disorders that are becoming increasingly recognized. We aimed to analyze clinical, neurophysiological, and MRI features in patients with SND. Methods: We reviewed clinical and electrophysiological data of 20 individuals fulfilling SND criteria. Patients underwent an additional neurological evaluation and cervical spine MRI. Results: Sensory neuron diseases was associated with dysimmune conditions in six, hepatitis C in one, B12 deficiency in another, and in one patient SND was related to organophosphate intoxication. In the remaining eleven, it was considered as idiopathic. Nineteen patients experienced sensory symptoms. Worse ataxia was related with longer disease duration ( P = 0.02). Early CSF assessment was related to higher protein level ( P = 0.008). All patients showed widespread impairment in sensory nerve action potential amplitudes. High signal intensity in the posterior columns was observed in most patients when MRI was performed more than 3 years after disease onset. Discussion: Sensory neuron diseases usually presents with sensory symptoms and ataxia. A high index of suspicion is important because inflammatory changes might be more prominent initially, a period when immunotherapy could be more valuable. Early diagnosis should be based mainly on electrophysiological and clinical grounds, as MRI may be normal initially. [ABSTRACT FROM AUTHOR]

The subsequent clinical course of patients examined in the EMG laboratory has not been adequately studied before. It is not known how EMG findings in practice affect patients’ final diagnosis, treatment and outcome. The aim of the present study was to test the hypothesis that EMG results have an important impact on the choice of patients’ treatment and on outcome. Three years after EMG examination, a short questionnaire asking about initial symptoms, the final diagnosis, treatment and current symptoms was sent to 300 consecutive EMG patients. Responses concerning 186 of them (39% men) were received either from patients and/or from their referring physicians. Information obtained during EMG examination was also added. Data was analyzed using methods of bivariate and multivariate statistics. We found that patients with a pathologic EMG had a better clinical outcome 3 years later. Pathologic EMG has an independent effect, pointing to more favorable disease courses, which was further improved by more active treatment approaches received by these patients. The study demonstrated the important impact of EMG findings on the treatment choice and clinical outcome in population consisting mainly of patients with carpal tunnel syndrome and radiculopathy. Studies in other patient populations are needed. [ABSTRACT FROM AUTHOR]

Purpose: To study the relation between the spike frequency during intraoperative electrocorticography (ECoG) under general anesthesia with isoflurane and that during extraoperative ECoG monitoring in children with intractable neocortical epilepsy. Methods: Twenty-one children (age, 1–16 years; 15 boys and six girls) who underwent intraoperative and extraoperative ECoG monitoring with subdural electrode arrays were studied. The spike frequency and the spatial pattern of spike frequency were compared between intraoperative and extraoperative ECoGs for each patient (by using Wilcoxon signed-ranks and Spearman's rank correlation, respectively). Results: In 15 of 21 patients, the spike frequency was significantly lower during intraoperative than during extraoperative ECoG (mean z =–6.3; p < 0.001). In four of 21 patients, no significant difference was found in the spike frequency between intraoperative and extraoperative recordings. In two of 21 patients, spike frequency reached one spike/min neither during intraoperative nor extraoperative recording; therefore appropriate comparison of spike frequency was not possible. A significant positive correlation in the spike-frequency pattern was seen between intraoperative and extraoperative recordings in nine of nine cases who had ≥10 spikes/min during intraoperative ECoG (mean rho = 0.62; p < 0.01), in five of six cases with one to nine spikes/min (mean rho = 0.50; p < 0.01), and in none of five cases with less than one spike/min (mean rho = 0.13). Conclusions: General anesthesia often decreases the spike frequency in children with neocortical epilepsy, yet intraoperative ECoG can reliably reflect the awake interictal spiking pattern when spike frequency exceeds one spike/min during intraoperative ECoG recording. [ABSTRACT FROM AUTHOR]

Summary: Purpose: We studied the relation between quantitative interictal subdural EEG data and visually defined ictal subdural EEG findings in children with intractable neocortical epilepsy, and determined whether interictal EEG data are predictive of ictal EEG onset zones. Methods: Thirteen children (aged 1.2–15.4 years) underwent prolonged intracranial EEG recording, using 48- to 120-channel subdural electrodes. Three distinct 10-min segments of the continuous interictal EEG recording were selected for each patient, and the spike frequency for each channel was determined by using an automatic spike-detection program. Subsequently the average spike frequency of each electrode was compared with ictal assessment (onset, spread, and no early ictal involvement). In addition, 50 distinct interictal spikes were averaged for each patient, and the amplitude and latency after the leading spike (averaged spike showing the earliest peak) were measured for each electrode and analyzed with respect to ictal EEG findings. Results: Reproducibility of the spike-frequency pattern derived from three 10-min segments was high (Kendall's W, 0.85 ± 0.08). Electrodes showing the highest spike frequency, the highest spike amplitude, and the leading spike were found to be a part of the seizure onset in 13 of 13, 12 of 13, and 10 of 13 cases, respectively. There was significant correlation between ictal assessment and spike frequency as well as spike amplitude. A receiver operating characteristics analysis showed that a cutoff threshold at 14% of the maximal spike frequency resulted in a specificity of 0.90 and a sensitivity of 0.77 for the detection of seizure-onset electrodes. Conclusions: Quantitative interictal subdural EEG may predict ictal-onset zones in children with intractable neocortical epilepsy. [ABSTRACT FROM AUTHOR]

A response by G. Koch and F. Sallustio to a letter to the editor regarding their article "Transcranial direct current stimulation of the affected hemisphere does not accelerate recovery of acute stroke patients" that was published in the 2012 issue is presented.