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Objective To test whether 1) quantitative analysis of EEG reactivity (EEG-R) using machine learning (ML) is superior to visual analysis, and 2) combining quantitative analyses of EEG-R and EEG background pattern increases prognostic value for prediction of poor outcome after cardiac arrest (CA). Methods Several types of ML models were trained with twelve quantitative features derived from EEG-R and EEG background data of 134 adult CA patients. Poor outcome was a Cerebral Performance Category score of 3–5 within 6 months. Results The Random Forest (RF) trained on EEG-R showed the highest AUC of 83% (95-CI 80–86) of tested ML classifiers, predicting poor outcome with 46% sensitivity (95%-CI 40–51) and 89% specificity (95%-CI 86–92). Visual analysis of EEG-R had 80% sensitivity and 65% specificity. The RF was also the best classifier for EEG background (AUC 85%, 95%-CI 83–88) at 24 h after CA, with 62% sensitivity (95%-CI 57–67) and 84% specificity (95%-CI 79–88). Combining EEG-R and EEG background RF classifiers reduced the number of false positives. Conclusions Quantitative EEG-R using ML predicts poor outcome with higher specificity, but lower sensitivity compared to visual analysis of EEG-R, and is of some additional value to ML on EEG background data. Significance Quantitative EEG-R using ML is a promising alternative to visual analysis and of some added value to ML on EEG background data.

Tremor is thought to be an effect of oscillatory activity within the sensorimotor network. To date, the underlying pathological brain networks are not fully understood. Disentangling tremor activity from voluntary motor output and sensorimotor feedback systems is challenging. To better understand the intrinsic sensorimotor fingerprint underlying tremor, we aimed to disentangle the sensorimotor system into driving (motor) and feedback/compensatory (sensory) neuronal involvement, and aimed to pinpoint tremor activity in essential tremor (ET) and tremor-dominant Parkinson's disease (PD) with a novel closed-loop approach. Eighteen ET patients, 14 tremor-dominant PD patients, and 18 healthy controls were included. An MR-compatible wrist manipulator was employed during functional MRI (fMRI) while muscle activity during (in)voluntary movements was concurrently recorded using electromyography (EMG). Tremor was quantified based on EMG and correlated to brain activity. Participants performed three tasks: an active wrist motor task, a passive wrist movement task, and rest (no wrist movement). The results in healthy controls proved that our experimental paradigm activated the expected motor and sensory networks separately using the active (motor) and passive (sensory) task. ET patients showed similar patterns of activation within the motor and sensory networks. PD patients had less activity during the active motor task in the cerebellum and basal ganglia compared to ET and healthy controls. EMG showed that in ET, tremor fluctuations correlated positively with activity in the inferior olive region, and that in PD tremor fluctuations correlated positively with cerebellar activity. Our novel approach with an MR-compatible wrist manipulator, allowed to investigate the involvement of the motor and sensory networks separately, and as such to better understand tremor pathophysiology. In ET sensorimotor network function did not differ from healthy controls. PD showed less motor-related activity. Focusing on tremor, our results indicate involvement of the inferior olive in ET tremor modulation, and cerebellar involvement in PD tremor modulation.

BACKGROUND: Hemifacial spasm is diagnosed on a clinical base, with certain atypical features alerting the physician for mimics. PHENOMENOLOGY SHOWN: Hemifacial neuromyotonia/myokymia characterized by tonic hemifacial contraction followed by multifocal undulating hemifacial twitches. EDUCATIONAL VALUE: These features are a red flag for (post-irradiation) facial neuromyotonia/myokymia which generally responds well to low dose carbamazepine. ispartof: TREMOR AND OTHER HYPERKINETIC MOVEMENTS vol:11 ispartof: location:England status: published

Objective To show that eye movement abnormalities differ between essential tremor (ET) and tremor dominant Parkinson’s disease (PD-T), and that these abnormalities reflect cerebellar dysfunction in ET and basal ganglia pathology in PD-T. Methods In this exploratory study, in 23 patients with ET, 21 age-matched patients with PD-T, and 19 age-matched healthy controls (HCs), we investigated visually guided saccades, antisaccades, and smooth pursuit eye movements (SPEM). Results While the ET group had a normal gain (saccade amplitude/target amplitude) and latency of saccades, the PD-T group had hypometric visually guided saccades, and a prolonged latency of visually guided saccades and antisaccades. The SPEM gain was similarly low in both ET and PD-T and was significantly lower in both patient groups than in the HC group. Conclusions In ET, SPEM gain was reduced in the presence of normal saccades, whereas in PD-T, the reduced SPEM gain was accompanied by delayed saccade initiation and hypometric saccades, in line with cerebellar dysfunction in ET and basal ganglia dysfunction in PD-T. Significance These findings support the presumed cerebellar pathology in ET. In addition, the difference in saccade features may contribute to the groundwork for a quantitative diagnostic test to differentiate between these disorders.

Background and purpose Median nerve somatosensory evoked potential (SEP) recordings play an important role in outcome algorithms in comatose patients after cardiopulmonary resuscitation. Knowledge of technical difficulties, clinical implications and uniform interpretation of SEP recordings is crucial. The aim of this study was to evaluate the skills of neurologists to interpret SEP recordings in post-anoxic patients. Methods Nationwide Dutch clinical neurophysiology examinations from 2007, 2008 and 2011, containing SEP related questions, were analysed. Participants were classified as neurology residents, neurologists with less than 10 years of experience, neurologists with more than 10 years of experience and clinical neurophysiologists. End-points were the knowledge of all participants about SEP recordings per year as well as improvement in knowledge over the years, as reflected by the test scores. Results A total of 194 participants completed the examination in 2007, 200 in 2008 and 263 in 2011. Between 2007 and 2008, all groups of respondents showed a significant increase in percentage of correct answers to SEP questions. Sixty-six participants completed all three examinations. The SEP score of this group improved in 2008 [75%, interquartile range (IQR) 50–75, P

Background Essential tremor (ET) is the most common tremor disorder. It has been repeatedly shown that the olivocerebellar system is involved in ET, consisting of the inferior olive nucleus (ION), dentate nucleus (DN) and cerebellar cortex. Impairment of the central timing mechanism in ET has been suggested. The olivocerebellar system plays an important role in motor timing. In order to study the functional involvement of this system in ET, we employed a task involving motor timing during functional MRI (fMRI). Methods Thirty propranolol sensitive ET patients with familial upper limb tremor and 30 healthy controls were included. T2 ∗ -weighted EPI sequences were acquired (180 volumes, TR: 2s, voxel size: 3.5 × 3.5 × 3.5 mm, 3TMRI). The task consisted of alternating rest and finger tapping (rate of 2 Hz) blocks. Task performance was measured by electromyography. Analysis was performed in SPM8 (standard preprocessing, normalization according to the spatially unbiased infra-tentorial template, 4 mm smoothing kernel). The left ION was localized with a conjunction analysis of patients and controls. For this abstract, quantified tapping performance is not yet incorporated. Results Within-group random-effects analysis restricted to the brainstem and cerebellum showed activations throughout the cerebellum (bilateral lobules V, VI, VIIIA) and in both left and right ION. Preliminary between-group analysis of the ION and CB right lobule VI showed significantly higher activations in controls compared to ET patients. Conclusions Exploratory analysis suggests altered activity in the olivocerebellar system in ET patients compared to controls during a motor timing task. Inclusion of task performance and effective connectivity analysis will be carried out to aid us in discriminating between altered activity due to task performance and pathological motor timing related to ET. Understanding the role of the olivocerebellar system in ET is of great importance for unraveling the mechanism of tremor genesis.

Objective: The aim of the present study is to investigate cortical excitability in patients with DYT 11 positive Myoclonus-Dystonia (M-D), using transcranial magnetic stimulation (TMS).Methods: Silent period, motor evoked potential (MEP) recruitment curve short interval intracortical, inhibition (SICI), intracortical facilitation (ICF) and short interval intracortical facilitation (SICF), with short interstimulus intervals (ISIs) ranging from 1.2 to 3.2 ms, were studied in 15 DYT 11-positive M-D patients and their matched controls. In four patients and matched controls peripheral double pulse electrical nerve stimulation was performed.Results: All TMS parameters of cortical excitability were normal compared to healthy controls. In the SICF protocol we observed more variable and polyphasic MEPs in M-D patients. Cross-covariance analysis of MEP area revealed a significant correlation difference at ISI 2.2 and 2.8 ms. This increased variability was not seen in other TMS protocols or with peripheral nerve stimulation.Conclusions: In contrast with other types of dystonia, no changes in cortical excitability were found in DYT 11 patients. Our findings suggest that M-D is both clinically and pathophysiologically a separate entity from other dystonic disorders. Polyphasic MEPs during the SICF protocol in M-D patients could reflect central neuron membrane instability. Application of the SICF protocol in other patient groups has to prove its value in movement disorders. (c) 2008 Elsevier Inc. All rights reserved.