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IntroductionDifferentiating between functional jerks (FJ) and organic myoclonus can be challenging. At present, the only advanced diagnostic biomarker to support FJ is the Bereitschaftspotential (BP). However, its sensitivity is limited and its evaluation subjective. Recently, event related desynchronisation in the broad beta range (13-45 Hz) prior to functional generalised axial (propriospinal) myoclonus was reported as a possible complementary diagnostic marker for FJ. Here we study the value of ERD together with a quantified BP in clinical practice.MethodsTwenty-nine patients with FJ and 16 patients with cortical myoclonus (CM) were included. Jerk-locked back-averaging for determination of the 'classical' and quantified BP, and time-frequency decomposition for the event related desynchronisation (ERD) were performed. Diagnostic gain, sensitivity and specificity were obtained for individual and combined techniques.ResultsWe detected a classical BP in 14/29, a quantitative BP in 15/29 and an ERD in 18/29 patients. At group level we demonstrate that ERD in the broad beta band preceding a jerk has significantly higher amplitude in FJ compared to CM (respectively -0.14 ± 0.13 and +0.04 ± 0.09 (p

Background: Increased 4-12 Hz oscillatory activity in the cortico-basal ganglia-thalamo-cortical (CBGTC) loop is reported in dystonia. Coherence analysis is a measure of linear coupling between two signals, revealing oscillatory activity drives that are common across motor units. By performing coherence analysis, activity of the CBGTC-loop can be measured with modalities like local field potentials (LFPs), electromyography (EMG), and electro-encephalography (EEG). The aim of this study is to perform a systematic review on the use of coherence analysis for clinical assessment and treatment of dystonia., Methods: A systematic review was performed on a search in Embase and PubMed on June 28th, 2023. All studies incorporating coherence analysis and an adult dystonia cohort were included. Three authors evaluated the eligibility of the articles. Quality was assessed using the QUADAS-2 checklist., Results: A total of 41 articles were included, with data of 395 adult dystonia patients. In the selected records, six different types of coherence were investigated: corticocortical, corticopallidal, corticomuscular, pallidopallidal, pallidomuscular, and intermuscular coherence. Various types of 4-12 coherence were found to be increased in all dystonia subtypes., Conclusion: There is increased 4-12 Hz coherence found between the cortex, basal ganglia, and affected muscles in all dystonia subtypes. However, the relationship between 4-12 Hz coherence and the dystonic clinical state has not been established. DBS treatment leads to a reduction of 4-12 Hz coherence. In combination with the results of this review, the 4-12 Hz frequency band can be used as a promising phenomenon for the development of a biomarker., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: SAJEA Lagerweij reports a grant from the Stichting Wetenschapsfonds Dystonie and a personal grant from the University of Groningen. The funder was not involved in the study. M Smit, LM Centen, JW Elting and JMC van Dijk report no disclosures. ME van Egmond participated in a training program sponsored by Medtronic and received a grant from the Stichting Wetenschapsfonds Dystonie. MAJ Tijssen reports grants from the Netherlands Organisation for Health Research and Development Domain: NWO-TTW (2022–9), ZonMW Topsubsidie (91218013) and ZonMW Program Translational Research(40–44,600–98-323). She also received two European Fund for Regional Development from the European Union (01492947 & DIMATIO (EFRO-0059) and a European Joint Programme on Rare Diseases (EJP RD) Networking Support Scheme. A grant from the Health Holland and the PPP allowance program (PPP-2023-00).Furthermore, from the the province of Friesland, the Stichting Wetenschapsfonds Dystonie and unrestricted grants from Ipsen, Actelion and Merz. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Cerebral Autoregulation (CA) is an important physiological mechanism stabilizing cerebral blood flow (CBF) in response to changes in cerebral perfusion pressure (CPP). By maintaining an adequate, relatively constant supply of blood flow, CA plays a critical role in brain function. Quantifying CA under different physiological and pathological states is crucial for understanding its implications. This knowledge may serve as a foundation for informed clinical decision-making, particularly in cases where CA may become impaired. The quantification of CA functionality typically involves constructing models that capture the relationship between CPP (or arterial blood pressure) and experimental measures of CBF. Besides describing normal CA function, these models provide a means to detect possible deviations from the latter. In this context, a recent white paper from the Cerebrovascular Research Network focused on Transfer Function Analysis (TFA), which obtains frequency domain estimates of dynamic CA. In the present paper, we consider the use of time-domain techniques as an alternative approach. Due to their increased flexibility, time-domain methods enable the mitigation of measurement/physiological noise and the incorporation of nonlinearities and time variations in CA dynamics. Here, we provide practical recommendations and guidelines to support researchers and clinicians in effectively utilizing these techniques to study CA., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We studied 30 healthy volunteers (60 arms), categorized into three age groups with equal numbers to verify if a 22 MHz compared with a 15 MHz ultrasound transducer has additional value for studying the intraneural architecture of the ulnar nerve throughout its course. At six sites, there were no differences in cross-sectional area measurements between the two transducers. With both, the cross-sectional area was significantly larger at the medial epicondyle compared with the other sites and smaller at the mid-forearm and Guyon's canal compared with the mid-upper arm. With higher age the cross-sectional area significantly increased. Significantly more fascicles were visible distal to the medial epicondyle compared with more proximal sites, as well as in men compared with women. Finally, higher body weight was related to a significantly smaller number of fascicles being seen. A 22 MHz transducer depicts more details of the intraneural architecture than a 15 MHz transducer. Our data can be used as normative data or reference values in analysing ulnar nerve pathology. Level of evidence: II., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: Skater's cramp is a movement disorder in speed skaters. We investigated whether affected skaters matched the disease profile of task-specific dystonia, specifically whether there was evidence of maladaptive muscle activity occurring simultaneously with aberrant movements (jerking). We further examined different skating intensities, positing no change would be more indicative of task-specific dystonia., Methods: We analyzed video, kinematic and muscle activity in 14 affected skaters. We measured the angular velocity and electromyographic activity of normalized speed skating strokes using one dimensional statistical non-parametric mapping. Skaters were matched with comparably skilled controls, and filled out a bespoke clinical questionnaire., Results: Skaters' impacted leg showed over-activation in the peroneus longus, tibialis anterior and gastrocnemius that coincided with higher foot movement compared to their healthy leg and controls. This pattern persisted regardless of skating intensity. Clinical features indicated it was task-specific and painless with common trigger factors including stress, equipment change, and falling., Conclusions: We showed aberrant muscular and kinematic activity in a movement disorder in speed skaters indicative of task-specific dystonia., Significance: Understanding skater's cramp as a task-specific dystonia could reduce the damage that misdiagnosis and unsuccessful invasive operations have caused. Our quantitative method has value in testing future treatment efficacy., (Copyright © 2023 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Introduction: Skater's cramp is a career-ending movement disorder in expert speed skaters noted to be a likely task-specific dystonia. In other movement disorders, including task-specific dystonia, studies have found evidence of central dysregulation expressed as higher inter-muscular coherence. We looked at whether inter-muscular coherence was higher in affected skaters as a possible indicator that it is centrally driven, and by extension further evidence it is a task-specific dystonia., Methods: In 14 affected and 14 control skaters we calculated inter-muscular coherence in the theta-band in a stationary task where tonic muscle activation was measured at 10%, 20% and 50% of maximum voluntary contraction. Additionally, we calculated wavelet coherence while skating at key moments in the stroke cycle., Results: Coherence did not differ in the stationary activation task. While skating, coherence was higher in the impacted leg of affected skaters compared to their non-impacted leg, p = .05, η 2  = 0.031, and amplitude of electromyography correlated with coherence in the impacted leg, p = .009, R 2 adjusted  = 0.41. A sub-group of severely affected skaters (n = 6) had higher coherence in the impacted leg compared to the left and right leg of controls, p = .02, Cohen's d = 1.59 and p = .01, Cohen's d = 1.63 respectively. Results were less clear across the entire affected cohort probably due to a diverse case-mix., Conclusion: Our results of higher coherence in certain severe cases of skater's cramp is preliminary evidence of a central dysregulation, making the likelihood it is a task-specific dystonia higher., Competing Interests: Declaration of competing interest None., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an established treatment in advanced Parkinson's disease (PD). However, the clinical outcome after STN-DBS is variable. The aim of this study was to explore the coherence of antagonistic muscles measured with electromyography (EMG) as novel biomarker of STN-DBS efficacy in PD., Methods: EMG of bilateral wrist and upper arm antagonistic muscles of 21 PD patients was recorded during three standardized motor tasks. Patients were measured one day prior to DBS surgery (pre-DBS) and 6 months afterwards (post-DBS). Coherence analyses were performed on the antagonistic muscle pairs. Pearson correlations between intermuscular coherence and clinical performance were calculated., Results: Intermuscular coherence during each of the different co-contraction tasks significantly correlated to UPDRS-III bradykinesia scores (p < 0.01). In other words, higher intermuscular coherence is associated with more severe PD symptoms. Moreover, coherence changes (pre-DBS - post-DBS coherence) correlated to clinical score changes after DBS (p < 0.01) and pre-DBS coherence correlated to this clinical score change as well (p < 0.01)., Conclusions: Higher pre-DBS coherence of antagonistic arm muscles is correlated to worsening of clinical PD state and higher intermuscular coherence predicts enhanced clinical improvement., Significance: We propose that pre-DBS intermuscular coherence could be developed into a predictor of STN-DBS clinical outcome. It could aid patient selection and adaptive stimulation algorithms for DBS., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background/objective: Current severe traumatic brain injury (TBI) outcome prediction models calculate the chance of unfavourable outcome after 6 months based on parameters measured at admission. We aimed to improve current models with the addition of continuously measured neuromonitoring data within the first 24 h after intensive care unit neuromonitoring., Methods: Forty-five severe TBI patients with intracranial pressure/cerebral perfusion pressure monitoring from two teaching hospitals covering the period May 2012 to January 2019 were analysed. Fourteen high-frequency physiological parameters were selected over multiple time periods after the start of neuromonitoring (0-6 h, 0-12 h, 0-18 h, 0-24 h). Besides systemic physiological parameters and extended Corticosteroid Randomisation after Significant Head Injury (CRASH) score, we added estimates of (dynamic) cerebral volume, cerebral compliance and cerebrovascular pressure reactivity indices to the model. A logistic regression model was trained for each time period on selected parameters to predict outcome after 6 months. The parameters were selected using forward feature selection. Each model was validated by leave-one-out cross-validation., Results: A logistic regression model using CRASH as the sole parameter resulted in an area under the curve (AUC) of 0.76. For each time period, an increased AUC was found using up to 5 additional parameters. The highest AUC (0.90) was found for the 0-6 h period using 5 parameters that describe mean arterial blood pressure and physiological cerebral indices., Conclusions: Current TBI outcome prediction models can be improved by the addition of neuromonitoring bedside parameters measured continuously within the first 24 h after the start of neuromonitoring. As these factors might be modifiable by treatment during the admission, testing in a larger (multicenter) data set is warranted.

We present two cases with postural axial tremor predominantly involving the head, trunk, and shoulders. In the first patient, the postural tremor occurred in multiple attacks a day lasting approximately 10 min. The second patient developed a progressive tremor of his head and arms, worsened during sitting and standing. Electrophysiological supported the postural axial tremor in both patients with a varying 3-10 Hz tremor frequency between different muscles and within the same muscles at different times. Postural axial tremor is a rare and complex movement disorder. The majority of cases are caused by acquired cerebellar pathology. However, isolated cases with underlying genetic disorders are described in literature. Here, we illustrate how to differentiate paroxysmal axial tremor from other axial hyperkinetic movement disorders and extend the genetic heterogeneity of this intriguing movement disorder phenotype., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

We tested the influence of blood pressure variability on the reproducibility of dynamic cerebral autoregulation (DCA) estimates. Data were analyzed from the 2nd CARNet bootstrap initiative, where mean arterial blood pressure (MABP), cerebral blood flow velocity (CBFV) and end tidal CO2 were measured twice in 75 healthy subjects. DCA was analyzed by 14 different centers with a variety of different analysis methods. Intraclass Correlation (ICC) values increased significantly when subjects with low power spectral density MABP (PSD-MABP) values were removed from the analysis for all gain, phase and autoregulation index (ARI) parameters. Gain in the low frequency band (LF) had the highest ICC, followed by phase LF and gain in the very low frequency band. No significant differences were found between analysis methods for gain parameters, but for phase and ARI parameters, significant differences between the analysis methods were found. Alternatively, the Spearman-Brown prediction formula indicated that prolongation of the measurement duration up to 35 minutes may be needed to achieve good reproducibility for some DCA parameters. We conclude that poor DCA reproducibility (ICC<0.4) can improve to good (ICC > 0.6) values when cases with low PSD-MABP are removed, and probably also when measurement duration is increased., Competing Interests: The authors have declared that no competing interests exist.

Tremor and myoclonus are two common hyperkinetic movement disorders. Tremor is characterized by rhythmic oscillatory movements while myoclonic jerks are usually arrhythmic. Tremor can be classified into subtypes including the most common types: essential, enhanced physiological, and parkinsonian tremor. Myoclonus classification is based on its anatomic origin: cortical, subcortical, spinal, and peripheral myoclonus. The clinical presentations are unfortunately not always classic and electrophysiologic investigations can be helpful in making a phenotypic diagnosis. Video-polymyography is the main technique to (sub)classify the involuntary movements. In myoclonus, advanced electrophysiologic testing, such as back-averaging, coherence analysis, somatosensory-evoked potentials, and the C-reflex can be of additional value. Recent developments in tremor point toward a role for intermuscular coherence analysis to differentiate between tremor subtypes. Classification of the movement disorder based on clinical and electrophysiologic features is important, as it enables the search for an etiological diagnosis and guides tailored treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The presence of abnormal neural oscillations within the cortico-basal ganglia-thalamo-cortical (CBGTC) network has emerged as one of the current principal theories to explain the pathophysiology of movement disorders. In theory, these oscillations can be used as biomarkers and thereby serve as a feedback signal to control the delivery of deep brain stimulation (DBS). This new form of DBS, dependent on different characteristics of pathological oscillations, is called adaptive DBS (aDBS), and it has already been applied in patients with Parkinson's disease. In this review, the authors summarize the scientific research to date on pathological oscillations in dystonia and address potential biomarkers that might be used as a feedback signal for controlling aDBS in patients with dystonia.

Introduction: Differentiating between functional jerks (FJ) and organic myoclonus can be challenging. At present, the only advanced diagnostic biomarker to support FJ is the Bereitschaftspotential (BP). However, its sensitivity is limited and its evaluation subjective. Recently, event related desynchronisation in the broad beta range (13-45 Hz) prior to functional generalised axial (propriospinal) myoclonus was reported as a possible complementary diagnostic marker for FJ. Here we study the value of ERD together with a quantified BP in clinical practice., Methods: Twenty-nine patients with FJ and 16 patients with cortical myoclonus (CM) were included. Jerk-locked back-averaging for determination of the 'classical' and quantified BP, and time-frequency decomposition for the event related desynchronisation (ERD) were performed. Diagnostic gain, sensitivity and specificity were obtained for individual and combined techniques., Results: We detected a classical BP in 14/29, a quantitative BP in 15/29 and an ERD in 18/29 patients. At group level we demonstrate that ERD in the broad beta band preceding a jerk has significantly higher amplitude in FJ compared to CM (respectively -0.14 ± 0.13 and +0.04 ± 0.09 (p < 0.001)). Adding ERD to the classical BP achieved an additional diagnostic gain of 53%. Furthermore, when combining ERD with quantified and classical BP, an additional diagnostic gain of 71% was achieved without loss of specificity., Conclusion: Based on the current findings we propose to the use of combined beta ERD assessment and quantitative BP analyses in patients with a clinical suspicion for all types of FJ with a negative classical BP., (Copyright © 2018. Published by Elsevier Ltd.)

Objective: To determine the contribution of electrophysiologic testing in the diagnosis and anatomical classification of myoclonus., Methods: Participants with a clinical diagnosis of myoclonus were prospectively recruited, each undergoing a videotaped clinical examination and battery of electrophysiologic tests. The diagnosis of myoclonus and its subtype was reviewed after 6 months in the context of the electrophysiologic findings and specialist review of the videotaped clinical examination., Results: Seventy-two patients with myoclonus were recruited. Initial clinical anatomical classification included 25 patients with cortical myoclonus, 7 with subcortical myoclonus, 2 with spinal myoclonus, and 15 with functional myoclonic jerks. In 23 cases, clinical anatomical classification was not possible because of the complexity of the movement disorder. Electrophysiologic testing was completed in 66, with agreement of myoclonus in 60 (91%) and its subtype in 28 (47%) cases. Subsequent clinical review by a movement disorder specialist agreed with the electrophysiologic findings in 52 of 60; in the remaining 8, electrophysiologic testing was inconclusive., Conclusions: Electrophysiologic testing is an important additional tool in the diagnosis and anatomical classification of myoclonus, also aiding in decision-making regarding therapeutic management. Further development of testing criteria is necessary to optimize its use in clinical practice., (© 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: Optimal cerebral perfusion pressure (CPPopt) targeting in traumatic brain injury (TBI) patients constitutes an active and controversial area of research. It has been suggested that an autoregulation guided CPP therapy may improve TBI outcome. Prerequisites of a CPPopt intervention study would be objective criteria for the CPPopt detection. This study compared the agreement between automated and visual CPPopt detection., Methods: Twenty-five clinicians from 18 centers worldwide, familiar with brain monitoring and using dedicated software, reviewed ten 4-hour CPPopt screenshots at 48 hours after ictus in selected TBI patients. Each screenshot displayed the trends of cerebral perfusion pressure (CPP), intracranial pressure (ICP), cerebrovascular pressure reactivity (PRx) as well as the "CPP-optimal" curve and its associated value (automated CPPopt). The main objective was to evaluate the agreement between expert clinicians as well as the agreement between the clinicians and automated CPPopt., Results: Twenty-two clinicians responded to our call (88%). Three screenshots were judged as "CPPopt not determinable" by >45% of the clinicians. For the whole group, the consensus between automated CPPopt and clinicians' visual CPPopt was high. Three clinicians were identified as outliers. All clinicians recommended to modify CPP when patients differed >±5 mmHg from their CPPopt. The inter-observer consensus was highest in cases with current CPP below the optimal value., Conclusions: The overall agreement between automated CPPopt and visual CPPopt identified by autoregulation experts was high, except for those cases when the curve was deemed by the clinicians not reliable enough to yield a trustworthy CPPopt.

Background: North Sea Progressive Myoclonus Epilepsy is a rare and severe disorder caused by mutations in the GOSR2 gene. It is clinically characterized by progressive myoclonus, seizures, early-onset ataxia and areflexia. As in other progressive myoclonus epilepsies, the efficacy of antiepileptic drugs is disappointingly limited in North Sea Progressive Myoclonus Epilepsy. The ketogenic diet and the less restrictive modified Atkins diet have been proven to be effective in other drug-resistant epilepsy syndromes, including those with myoclonic seizures. Our aim was to evaluate the efficacy of the modified Atkins diet in patients with North Sea Progressive Myoclonus Epilepsy., Results: Four North Sea Progressive Myoclonus Epilepsy patients (aged 7-20 years) participated in an observational, prospective, open-label study on the efficacy of the modified Atkins diet. Several clinical parameters were assessed at baseline and again after participants had been on the diet for 3 months. The primary outcome measure was health-related quality of life, with seizure frequency and blinded rated myoclonus severity as secondary outcome measures. Ketosis was achieved within 2 weeks and all patients completed the 3 months on the modified Atkins diet. The diet was well tolerated by all four patients. Health-related quality of life improved considerably in one patient and showed sustained improvement during long-term follow-up, despite the progressive nature of the disorder. Health-related quality of life remained broadly unchanged in the other three patients and they did not continue the diet. Seizure frequency remained stable and blinded rating of their myoclonus showed improvement, albeit modest, in all patients., Conclusions: This observational, prospective study shows that some North Sea Progressive Myoclonus Epilepsy patients may benefit from the modified Atkins diet with sustained health-related quality of life improvement. Not all our patients continued on the diet, but nonetheless we show that the modified Atkins diet might be considered as a possible treatment in this devastating disorder.

Aims: Heart failure (HF) is associated with tissue hypoperfusion and congestion leading to organ dysfunction. Although cerebral blood flow (CBF) is preserved over a wide range of perfusion pressures in healthy subjects, it is impaired in end-stage HF. We aimed to compare CBF, autoregulation, and cognitive function in patients with mild non-ischaemic HF with healthy controls., Methods and Results: Fifteen patients with mild idiopathic dilated cardiomyopathy and 15 matched healthy controls were studied. Co-existing cerebrovascular disease was excluded. All subjects, except five patients with an implantable cardioverter defibrillator, underwent magnetic resonance imaging for measurements of both CBF by arterial spin labelling and quantitative volume flow entering the brain. Cardiocerebral vascular function was assessed with Doppler techniques testing cerebral dynamic autoregulation and vasomotor reactivity. Cognitive analysis was performed by neuropsychological testing. Global and regional CBF did not differ between HF patients (44.3 mL/100 g.min) and controls (42.1 mL/100 g.min). Basilar but not carotid artery inflow was reduced in patients (1.95 mL/s vs. 2.51 mL/s, P = 0.009). Testing autoregulation revealed fewer dampened blood flow fluctuations in HF patients vs. controls (0.96% vs. 0.67%, P < 0.001). Vasomotor reactivity in HF patients showed a reduced CBF velocity (48.4% vs. 61.0%, P = 0.05) and regional cerebral oxygen saturation (18.3% vs. 23.8%, P = 0.02). Cognitive function overall was not affected., Conclusion: Although global CBF was unaffected in patients with mild HF, significant changes in basilar inflow volume, cerebral autoregulation and vasomotor reactivity were observed. We describe a model of dynamic cerebral mechanisms required to compensate for the impaired haemodynamics in early-stage HF., (© 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.)

Objective: To evaluate the accuracy of clinical phenotyping of myoclonus patients and to determine differentiating clinical characteristics between cortical (CM), subcortical (SCM), spinal (SM), peripheral (PM) myoclonus, and functional jerks (FJ)., Methods: Clinical notes for all patients with myoclonus over an 8-year period (2006-2014) were reviewed retrospectively. We used the conclusion of electrophysiological testing as definite diagnosis of myoclonus or FJ., Results: 85 patients were identified suffering from CM (34%), SCM (11%), SM (6%), PM (2%), and 47% FJ. The clinical diagnosis of myoclonus was confirmed by electrophysiological testing in 74% and its subtype in 78% of cases. CM was characterized by an early age of onset, facial myoclonus, and provocation by action. Differentiating features of FJ were an abrupt onset, preceding contributing events and provocation by a supine position., Conclusion: The majority of clinical myoclonic jerk cases were functional in our heterogeneous tertiary clinic cohort. CM was the main anatomical myoclonic subtype. Clinical diagnosis was accurate in the majority of cases, although electrophysiological testing was important to verify the clinical classification., Significance: In patients with jerky movements a functional diagnosis should be considered. Determination of the myoclonic subtypes is important to initiate tailored treatment., (Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: Cerebrovascular reactivity can provide a continuously updated individualized target for management of cerebral perfusion pressure, termed optimal cerebral perfusion pressure. The objective of this project was to find a way of improving the optimal cerebral perfusion pressure methodology by introducing a new visualization method., Data Sources: Four severe traumatic brain injury patients with intracranial pressure monitoring., Data Extraction: Data were collected and pre-processed using ICM+ software., Data Synthesis: Sequential optimal cerebral perfusion pressure curves were used to create a color-coded maps of autoregulation - cerebral perfusion pressure relationship evolution over time., Conclusions: The visualization method addresses some of the main drawbacks of the original methodology and might bring the potential for its clinical application closer.

Background: Niemann-Pick type C (NP-C) is a rare autosomal recessive progressive neurodegenerative disorder caused by mutations in the NP-C 1 or 2 gene. Besides visceral symptoms, presentation in adolescent and adult onset variants is often with neurological symptoms. The most frequently reported presenting symptoms of NP-C in adulthood are psychiatric symptoms (38 %), cognitive decline (23 %) and ataxia (20 %). Myoclonus can be present, but its value in early diagnosis and the evolving clinical phenotype in NP-C is unclear. In this paper we present eight Dutch cases of NP-C of whom five with myoclonus., Methods: Eight patients with genetically confirmed NP-C were recruited from two Dutch University Medical Centers. A structured interview and neuropsychological tests (for working and verbal memory, attention and emotion recognition) were performed. Movement disorders were assessed using a standardized video protocol. Quality of life was evaluated by questionnaires (Rand-36, SIP-68, HAQ). In four of the five patients with myoclonic jerks simultaneous EEG with EMG was performed., Results: A movement disorder was the initial neurological symptom in six patients: three with myoclonus and three with ataxia. Two others presented with psychosis. Four experienced cognitive deficits early in the course of the disease. Patients showed cognitive deficits in all investigated domains. Five patients showed myoclonic jerks, including negative myoclonus. In all registered patients EEG-EMG coherence analysis and/or back-averaging proved a cortical origin of myoclonus. Patients with more severe movement disorders experienced significantly more physical disabilities., Conclusions: Presenting neurological symptoms of NP-C include movement disorders, psychosis and cognitive deficits. At current neurological examination movement disorders were seen in all patients. The incidence of myoclonus in our cohort was considerably higher (63 %) than in previous publications and it was the presenting symptom in 38 %. A cortical origin of myoclonus was demonstrated. Our data suggest that myoclonus may be overlooked in patients with NP-C. All patients scored significantly lower on physical domains of HRQoL. Symptomatic treatment of movement disorders may improve physical functioning and subsequently HRQoL.

Introduction: Distinguishing between different tremor disorders can be challenging. Some tremor disorders are thought to have typical tremor characteristics: the current study aims to provide sensitivity and specificity for five 'typical' tremor phenomena., Methods: Retrospectively, we examined 210 tremor patients referred for electrophysiological recordings between January 2008 and January 2014. The final clinical diagnosis was used as the gold standard. The first step was to determine whether patients met neurophysiological criteria for their type of tremor. Once established, we focused on 'typical' characteristics: tremor frequency decrease upon loading (enhanced physiological tremor (EPT)), amplitude increase upon loading, distractibility and entrainment (functional tremor (FT)), and intention tremor (essential tremor (ET)). The prevalence of these phenomena in the 'typical' group was compared to the whole group., Results: Most patients (87%) concurred with all core clinical neurophysiological criteria for their tremor type. We found a frequency decrease upon loading to be a specific (95%), but not a sensitive (42%) test for EPT. Distractibility and entrainment both scored high on sensitivity (92%, 91%) and specificity (94%, 91%) in FT, whereas a tremor amplitude increase was specific (92%), but not sensitive (22%). Intention tremor was a specific finding in ET (85%), but not a sensitive test (45%). Combination of characteristics improved sensitivity., Conclusion: In this study, we retrospectively determined sensitivity and specificity for five 'typical' tremor characteristics. Characteristics proved specific, but few were sensitive. These data on tremor phenomenology will help practicing neurologists to improve distinction between different tremor disorders., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A 42-year-old male was admitted for refractory status epilepticus. At the age of 25, he had been diagnosed with juvenile myoclonic epilepsy. He had a stable clinical course for over a decade until a recent deterioration of behavior and epilepsy. After exclusion of acquired disorders, diagnostic work-up included application of next-generation sequencing (NGS), with a gene panel targeting progressive myoclonic epilepsies. This resulted in the diagnosis Lafora disease resulting from compound heterozygous NHLRC1 pathogenic variants. Although these pathogenic variants may be associated with a variable phenotype, including both severe and mild clinical course, the clinical presentation of our patient at this age is very unusual for Lafora disease. Our case expands the phenotype spectrum of Lafora disease resulting from pathogenic NHLRC1 variants and illustrates the value of using NGS in clinical practice to lead to a rapid diagnosis and guide therapeutic options.

In the clinic, tremor is diagnosed during a time-limited process in which patients are observed and the characteristics of tremor are visually assessed. For some tremor disorders, a more detailed analysis of these characteristics is needed. Accelerometry and electromyography can be used to obtain a better insight into tremor. Typically, routine clinical assessment of accelerometry and electromyography data involves visual inspection by clinicians and occasionally computational analysis to obtain objective characteristics of tremor. However, for some tremor disorders these characteristics may be different during daily activity. This variability in presentation between the clinic and daily life makes a differential diagnosis more difficult. A long-term recording of tremor by accelerometry and/or electromyography in the home environment could help to give a better insight into the tremor disorder. However, an evaluation of such recordings using routine clinical standards would take too much time. We evaluated a range of techniques that automatically detect tremor segments in accelerometer data, as accelerometer data is more easily obtained in the home environment than electromyography data. Time can be saved if clinicians only have to evaluate the tremor characteristics of segments that have been automatically detected in longer daily activity recordings. We tested four non-parametric methods and five parametric methods on clinical accelerometer data from 14 patients with different tremor disorders. The consensus between two clinicians regarding the presence or absence of tremor on 3943 segments of accelerometer data was employed as reference. The nine methods were tested against this reference to identify their optimal parameters. Non-parametric methods generally performed better than parametric methods on our dataset when optimal parameters were used. However, one parametric method, employing the high frequency content of the tremor bandwidth under consideration (High Freq) performed similarly to non-parametric methods, but had the highest recall values, suggesting that this method could be employed for automatic tremor detection.

The physical examination findings of early posthypoxic myoclonus (PHM) are associated with poor prognosis. Recent findings indicate that patients with multifocal PHM, assumed to have a cortical origin, have a comparable outcome to resuscitated patients without PHM. Generalized PHM, assumed to have a subcortical myoclonus origin, is still associated with a bad clinical outcome. It is not known whether the electroencephalographic (EEG) findings differ between the multifocal and generalized myoclonus groups nor is the clinical significance clearly defined. Forty-three patients with PHM were retrospectively derived from an EEG database. Patients were categorized as having multifocal (i), generalized (ii), or undetermined (iii) PHM. Outcome was expressed in cerebral performance category scores. The EEG background was categorized into isoelectric (I), low voltage (II), burst suppression (III), status epilepticus (SE; IV), diffuse slowing (V), and mild encephalopathic or normal (VI). 17 patients had generalized PHM and 23 had multifocal PHM (3 undetermined). The EEG showed more SE in generalized compared to multifocal PHM (64% vs 13%, P< .001). Diffuse slowing was more often present in multifocal PHM (52% vs 17%, P < .05). Early-onset myoclonus occurred significantly more often in generalized PHM, and early generalized PHM was invariantly associated with poor outcome. In conclusion, patients with generalized PHM showed more SE. These EEG findings might be either subcortical corollaries or primarily cortical phenomena. Our retrospective results conflict with currently used clinical criteria for myoclonus classification, and we suggest that more refined difference may be needed for accurate assessment of PHM. To better understand PHM, prospective research with standardized clinical assessment and quantitative EEG analysis is needed., (© The Author(s) 2015.)

Background: Cerebral autoregulation is increasingly recognized as a factor that requires evaluation when managing poor grade aneurysmal subarachnoidal hemorrhage (aSAH) patients. In this single center pilot study, we investigated whether intraventricular intracranial pressure (ICP) derived when extraventricular drain (EVD) is open can be used to calculate dynamic autoregulation estimates in ICU aSAH patients., Methods: Ten patients with the diagnosis of aSAH as confirmed by computed tomography (CT) and CT-angiography were enrolled. ICP was monitored via a transducer connected to the most proximal side exit of the EVD catheter. From at least 30 min periods of brain monitoring before, during, and after temporarily EVD closure, commonly used indexes of dynamic cerebral autoregulation were calculated., Results: Preserved pulsatile ICP signals were seen with open EVD. There were no significant changes in parameters describing cerebral autoregulation between EVD open and closed conditions. Power spectra of ABP and ICP showed no significant changes for the selected frequency ranges. There was a small significant increase in absolute ICP [2.4 (3.8) mmHg, p < 0.001] upon short-term EVD closure. Cerebral spinal reserve capacity (RAP index) worsened significantly by short-term EVD closure., Conclusions: Due to preserved slow fluctuations in the ICP signal, an open EVD system can be used to calculate dynamic autoregulation indices in aSAH patients requiring intensive care monitoring with the pressure measurement from the most proximal part of drain. If these results are confirmed in larger study, this technique can open the way for investigating the role of autoregulation disturbance in aSAH patients.

Myoclonus is a hyperkinetic movement disorder characterized by brief, involuntary muscular jerks. Recognition of myoclonus and determination of the underlying aetiology remains challenging given that both acquired and genetically determined disorders have varied manifestations. The diagnostic work-up in myoclonus is often time-consuming and costly, and a definitive diagnosis is reached in only a minority of patients. On the basis of a systematic literature review up to June 2015, we propose a novel diagnostic eight-step algorithm to help clinicians accurately, efficiently and cost-effectively diagnose myoclonus. The large number of genes implicated in myoclonus and the wide clinical variation of these genetic disorders emphasize the need for novel diagnostic techniques. Therefore, and for the first time, we incorporate next-generation sequencing (NGS) in a diagnostic algorithm for myoclonus. The initial step of the algorithm is to confirm whether the movement disorder phenotype is consistent with, myoclonus, and to define its anatomical subtype. The next steps are aimed at identification of both treatable acquired causes and those genetic causes of myoclonus that require a diagnostic approach other than NGS. Finally, other genetic diseases that could cause myoclonus can be investigated simultaneously by NGS techniques. To facilitate NGS diagnostics, we provide a comprehensive list of genes associated with myoclonus.

Background: In clinical practice, myoclonus in childhood-onset neurogenetic disorders frequently remains unrecognized, because it is often overshadowed by other neurological features. Since treatment can lead to significant functional improvement, accurate phenotyping is essential. To demonstrate the importance of early identification and treatment, we report on four patients with various childhood-onset neurogenetic disorders suffering from myoclonus., Methods: We evaluated four patients with established childhood-onset neurogenetic disorders and involuntary jerky movements, who visited our young-onset movement disorder outpatient clinic., Results: We present the clinical data of four patients (aged 8-21 years) with childhood-onset neurogenetic disorders, including ataxia-telangiectasia, Coffin-Lowry syndrome and epileptic encephalopathy due to SCN1A mutations. All four suffered from jerky movements that hampered normal daily activities and that had gone unrecognized for several years. The presence of multifocal myoclonus was confirmed by polymyography. In all patients, treatment resulted in marked improvement of both myoclonus and overall functioning., Conclusion: These cases highlight the relevance of actively searching for myoclonus in childhood-onset neurogenetic disorders, even when a molecular diagnosis has already been established. To further improve the awareness and recognition of myoclonus in children, we provide a list of childhood-onset neurogenetic disorders with myoclonus as important associated feature., (Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate the potential value of two advanced EMG measures as additional diagnostic measures in the polymyographic assessment of postural upper-limb tremor., Methods: We investigated coherence as a measure of dependency between two EMG signals, and cumulant analysis to reveal patterns of synchronicity in EMG activity in muscle pairs. Eighty datasets were analyzed retrospectively, obtained from four groups: essential tremor (ET), Parkinson's disease (PD), enhanced physiological tremor (EPT), and functional tremor (FT)., Results: Intermuscular coherence was highest in the PD group (0.58), intermediate in FT (0.43) and ET (0.40), and weakest in EPT (0.16) (p=0.002). EPT patients could be distinguished by low coherence: coherence <0.18 in the wrist+elbow extensors differentiates EPT in this sample with a sensitivity of 86% and specificity of 84%. Cumulant analysis showed predominantly alternating activity between wrist and elbow extensor in ET patients, while a more synchronous pattern was predominant in PD, EPT and FT (p=0.008). EMG activity in wrist and elbow flexors tended to be more synchronous in PD (p=0.059)., Conclusion: Our results suggest that coherence and cumulant analysis may be of additional value in the diagnostic work-up of postural tremor., Significance: These additional measures may be helpful in diagnosing difficult tremor cases., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objectives: Transcutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of neurogenic regulation of cerebral blood flow, which could be decreased by electrical modulation. We therefore assess the effects of TENS on cerebral blood flow velocities (CBFVs) and cerebral saturation in patients with cerebral vasospasm after subarachnoid hemorrhage (SAH)., Materials and Methods: Cervical TENS was applied in 10 SAH patients with transcranial Doppler (TCD)-proven cerebral vasospasm. Measurements included plethysmography, near-infrared spectroscopy, capnography, and CBFVs by TCD. After determining the optimal frequency and current, patients were treated with cervical TENS for two periods of three days, with a pause of one day in between., Results: The TENS electrodes were not always tolerated by the patients. Higher frequencies demonstrated the most prominent combined effects. ETCO2 was 0.19% lower with TENS off than with TENS on (p = 0.05). Mean arterial blood pressure and pulse were not significantly different over time. CBFV in MCA was decreased (p = 0.07) while cerebral oxygen saturation was increased (p = 0.01) after the use of TENS., Conclusions: Our data suggest improved cerebral blood flow when using cervical TENS in patients with cerebral vasospasm. Several factors could have attenuated the effects: the electrodes were poorly tolerated, ETCO2 increased during TENS, few vessels showed prolonged vasospasm, and overall flow velocities were low. Still, an on-off effect of TENS over time was detected., (© 2014 International Neuromodulation Society.)

Dynamic cerebral autoregulation (dCA) estimates require mean arterial blood pressure (MABP) fluctuations of sufficient amplitude. Current methods to induce fluctuations are not easily implemented or require patient cooperation. In search of an alternative method, we evaluated if MABP fluctuations could be increased by passive cyclic leg raising (LR) and tested if reproducibility and variability of dCA parameters could be improved. Middle cerebral artery cerebral blood flow velocity (CBFV), MABP and end tidal CO2 (PetCO2) were obtained at rest and during LR at 0.1 Hz in 16 healthy subjects. The MABP-CBFV phase difference and gain were determined at 0.1 Hz and in the low frequency (LF) range (0.06-0.14 Hz). In addition the autoregulation index (ARI) was calculated. The LR maneuver increased the power of MABP fluctuations at 0.1 Hz and across the LF range. Despite a clear correlation between both phase and gain reproducibility and MABP variability in the rest condition, only the reproducibility of gain increased significantly with the maneuver. During the maneuver patients were breathing faster and more irregularly, accompanied by increased PetCO2 fluctuations and increased coherence between PetCO2 and CBFV. Multiple regression analysis showed that these concomitant changes were negatively correlated with the MABP-CBFV phase difference at 0.1 Hz Variability was not reduced by LR for any of the dCA parameters. The clinical utility of cyclic passive leg raising is limited because of the concomitant changes in PetCO2. This limits reproducibility of the most important dCA parameters. Future research on reproducibility and variability of dCA parameters should incorporate PetCO2 variability or find methods to keep PetCO2 levels constant., (Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.)

Dynamic cerebral autoregulation (dCA) estimates show large between and within subject variability. Sources of variability include low coherence and influence of CO2 in the very low frequency (VLF) band, where dCA is active. This may lead to unreliable transfer function and autoregulation index (ARI) estimates. We tested whether variability of the ARI could be decreased by suppressing the effect of the VLF band through filtering. We also evaluated whether filtering had any effect on mean group differences between healthy subjects and acute stroke patients. Data from a recent mobilization stroke study were re-analyzed. Middle cerebral artery cerebral blood flow velocity (MCA-CBFV), mean arterial blood pressure (MABP) and end tidal PCO2 (PetCO2) were obtained in 16 healthy subjects and 27 acute ischemic stroke patients in the supine position. The ARI index was calculated from the transfer function (TF) by using spontaneous BP fluctuations. Three different filtering strategies were compared; no filtering (NF), a high pass filter at 0.04 Hz (Time Domain Filtering: TDF) and a high pass Transfer Function Filter (TFF) at 0.04 Hz. In addition, a simulation study was done to obtain further insight into the effects of the applied filters. The variability of the ARI index decreased significantly only with TFF in healthy subjects (standard deviation (left vs. right) after NF 2.28 vs. 2.36, after TDF 2.13 vs. 2.31 after TFF 1.09 vs. 1.19, p<0.001). Variability was not significantly reduced in stroke patients. The mean ARI was significantly lower in stroke patients compared to healthy subjects after TFF (affected hemisphere 5.85±1.96 vs. 7.13±1.09, non-affected hemisphere 5.96±1.64 vs. 7.31±1.19, p<0.01 for both hemispheres), but not after NF or TDF. The simulation study showed that TFF results in an overestimation of the ARI index at low ARI levels (0-3), but in correct estimates at higher ARI levels. Removing the effect of the VLF band with TFF results in less ARI variability in healthy subjects, and in more pronounced group differences between stroke patients and healthy subjects. This will improve diagnostic properties when using TFA for ARI calculation., (Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.)

Facial tics and spasms are socially incapacitating, but effective treatment is often available. The clinical picture is sufficient for distinguishing between the different diseases that cause this affliction.We describe three cases of patients with facial tics or spasms: one case of tics, which are familiar to many physicians; one case of blepharospasms; and one case of hemifacial spasms. We discuss the differential diagnosis and the treatment possibilities for facial tics and spasms. Early diagnosis and treatment is important, because of the associated social incapacitation. Botulin toxin should be considered as a treatment option for facial tics and a curative neurosurgical intervention should be considered for hemifacial spasms.

Background: Ramsay Hunt syndrome (progressive myoclonus ataxia) is a descriptive diagnosis characterized by myoclonus, ataxia, and infrequent seizures. Often the etiology cannot be determined. Recently, a mutation in the GOSR2 gene (c.430G>T, p.Gly144Trp) was reported in 6 patients with childhood-onset progressive ataxia and myoclonus., Methods: We evaluated 5 patients with cortical myoclonus, ataxia, and areflexia., Results: All 5 patients had the same homozygous mutation in GOSR2. Here we present their clinical and neurophysiological data. Our patients (aged 7-26 years) all originated from the northern Netherlands and showed a remarkably homogeneous phenotype. Myoclonus and ataxia were relentlessly progressive over the years. Electromyography revealed signs of sensory neuronopathy or anterior horn cell involvement, or both, in all patients with absent reflexes., Conclusions: Based on the presented phenotype, we would advise movement disorder specialists to consider mutation analysis of GOSR2 in patients with Ramsay Hunt syndrome, especially when they also have areflexia., (Copyright © 2013 Movement Disorder Society.)

Cerebral blood flow (CBF) is regulated by vasomotor, chemical, metabolic, and neurogenic mechanisms. Even though the innervation of cerebral arteries is quite extensively described and reviewed in the literature, its role in regulation of CBF in humans remains controversial. We believe that insufficient attention has so far been focused on the potential role of the innervation of the cerebral vasculature in cerebral autoregulation in humans. We have performed an extensive search and selection of available literature on electrical, chemical, and surgical manipulations of the sympathetic innervation of cerebral arteries, and the effects of circulation sympathetically active agents on CBF. Studies on (surgical) ganglion block show a role of sympathetic tone in preventing increases in CBF in humans, which are consistent with the view based on animal studies. Both direct innervation of the cerebral arteries from cervical ganglia and stimulation of adrenergic receptors by circulating sympathomimetics prevent sudden increases of CBF associated with hypertension and hypercapnia. We postulate that under normal physiological conditions neurogenic control has little influence on cerebral autoregulation as other methods of control (vasomotor, chemical, and metabolic) are dominant. In severely challenging circumstances, such as delayed cerebral ischaemia after subarachnoid haemorrhage, these methods might be overwhelmed, increasing the relative importance of neurogenic, sympathetic control of CBF. This insight might lead to future therapeutic possibilities.

Objectives: National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes significantly after upright positioning in bed in the acute stroke phase., Design: Observational study., Participants: 47 patients with acute ischaemic stroke measured in the subacute phase after symptom onset and 20 healthy controls., Primary and Secondary Outcome Measures: We recorded postural changes in bilateral transcranial Doppler (primary outcome) and simultaneously recorded near-infrared spectroscopy, end-tidal CO2, non-invasive blood pressure data and changes in neurological status (secondary outcomes)., Methods: Postures included the supine, half sitting (45°), sitting (70°) and Trendelenburg (-15°) positions. Using multilevel analyses, we compared postural changes between hemispheres, outcome groups (using modified Rankin Scale) as well as between patients and healthy controls., Results: The mean patient age was 62±15 years and median National Institute of Health Stroke Scale score on admission was 7 (IQR 5-14). Mean proportional CBFV changes on sitting were not significantly different between healthy controls and affected hemispheres in patients with stroke. No significant differences were found between affected and unaffected stroke hemispheres and between patients with unfavourable and favourable outcomes. During upright positioning, no neurological worsening or improvement was observed in any of the patients., Conclusions: No indications were found that upright positioning in bed in mild to moderately affected patients with stroke compromises flow and (frontal)oxygenation significantly during the subacute phase of stroke. Supine or Trendelenburg positioning does not seem to augment real-time flow variables.

Cerebral vessels can keep cerebral perfusion more or less constant. This process is called cerebral vasoregulation and can be measured using different neuromonitoring techniques, which will be discussed in this overview. Cerebral perfusion deficits after brain damage caused by a cerebrovascular accident (CVA), subarachnoid haemorrhage (SAH) or severe traumatic skull and brain injury (TSBI) can be detected early and better understood by using these techniques. In current clinical guidelines on the treatment of CVA, SAB and TSBI, impaired cerebral vasoregulation is often assumed. However, there is a need to measure cerebral vasoregulation status at the individual level, with follow-up over time. Some vasoregulation techniques inform the clinician about subtle local regulation disorders ('snapshot' assessment). Other techniques are suitable for the global long-term monitoring of vasoregulation ('monitoring' assessment) where the results could serve as feedback for treatment interventions. Appropriate use of the techniques in daily clinical practice requires standardisation of the methods available for the monitoring of cerebral vasoregulation. Presently, use is mostly restricted to the research setting.

Background: Blood pressure (BP) is one of the major vital parameters monitored in the stroke unit. The accuracy of indirect BP measurement is strongly influenced by the position of both patient and arm during the measurement. Acute stroke patients are often nursed in lateral decubitus positions. The effect of these alternating body positions in relation to affected body side on the outcome and reliability of BP readings in acute stroke patients is unknown., Methods: An automatic oscillometric BP device was used. BP was measured in both arms in the (back) supine and both lateral decubitus positions., Results: In total, 54 consecutive acute stroke patients were included. Thirty-five patients had right-sided deficits and 19 patients had left-sided deficits. Supine BP readings were similar in the right and left arms regardless of side of deficit. Measurements of BP in the lateral decubitus positions resulted in significantly lower BP readings in the uppermost arm (around 12 mm Hg in both arms) and significantly higher readings in the right lowermost arm (around 6 mm Hg) compared to the supine position. This effect seemed less pronounced when the left lowermost arm was measured. There was no relation between change of BP readings in various lateral positions and side of stroke., Conclusions: Alternating lateral decubitus positions according to nursing standards in acute stroke patients lead to a mean 18 mm Hg BP fluctuation. This may largely be explained by hydrostatic pressure effects, partly by anatomic factors in the left lowermost arm, but not by the side of stroke., (Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Background: Routine lateral turning of patients has become an accepted standard of care to prevent complications of immobility. The haemodynamic and oxygenation effects for patients in both lateral positions (45°) are still a matter of debate. We aimed to study the effect of these positions on blood pressure, heart rate and oxygenation in a general intensive care population., Design: Observational study., Method: Twenty stable intensive care unit patients had intra-arterial blood pressure recordings in the supine and lateral positions with the correction of hydrostatic height compared with a fixed reference point (phlebostatic level). A multilevel model was used to analyse the data., Results: Mean arterial pressure readings in the lateral positions were, on average, 5 mmHg higher than in the supine position (p < 0.001). There were no significant differences between mean arterial pressure recordings in the left and right lateral position (p = 1.0). No important differences in oxygenation and heart rate were observed. After correction for covariates, the effects persisted., Conclusion: Our study demonstrated an increase, albeit small, in blood pressure in the lateral positions. No major differences between the left and right lateral position were found. No important differences in oxygenation and heart rate were observed., Relevance to Clinical Practice: Turning haemodynamically stable patients in the intensive care unit has no important effects on blood pressure measurements when continuous hydrostatic height correction is applied., (© 2011 Blackwell Publishing Ltd.)

Background and Purpose: There is uncertainty whether bilateral near infrared spectroscopy (NIRS) can be used for monitoring of patients with acute stroke., Methods: The NIRS responsiveness to systemic and stroke-related changes was studied overnight by assessing the effects of brief peripheral arterial oxygenation and mean arterial pressure alterations in the affected versus nonaffected hemisphere in 9 patients with acute stroke., Results: Significantly more NIRS drops were registered in the affected compared with the nonaffected hemisphere (477 drops versus 184, P<0.001). In the affected hemispheres, nearly all peripheral arterial oxygenation drops (n=128; 96%) were detected by NIRS; in the nonaffected hemispheres only 23% (n=30; P=0.17). Only a few mean arterial pressure drops were followed by a significant NIRS drop. This was however significantly different between both hemispheres (32% versus 13%, P=0.01)., Conclusions: This pilot study found good responsiveness of NIRS signal to systemic and stroke-related changes at the bedside but requires confirmation in a larger sample.

Background and Purpose: The effects of early upright positioning in the acute phase of ischemic stroke on both blood pressure and functional outcome have not been previously examined., Methods: Prospective investigation of mean arterial pressure, heart rate, and peripheral oxygen saturation in the supine, sitting, and (if achievable) active standing position 1, 2, and 3 days after an acute stroke was performed. Also investigated was the presence of a significant postural blood pressure rise and fall using orthostatic definitions and the relation to functional outcome after 3 months., Results: One hundred sixty-seven patients were included (mean age, 68.5±15.2 years; median National Institutes of Health Stroke Scale, 7). Approximately 60% of the patients were able to stand. On average the mean arterial pressure increased when patients moved from the supine to sitting (Day 1: Δ 3.9 mm Hg; P<0.001) and from sitting to an active standing position (Day 1: Δ 4.6 mm Hg; P<0.001). Changes were most pronounced within the first 24 hours after a stroke. Blood pressure decreased significantly (fall) on standing in 13% of patients and increased significantly (rise) in 20% of the patients. The latter was independently associated with a favorable outcome (P=0.003). Moving to the standing position was accompanied by an increase of heart rate. No difference in oxygen saturation was observed in the various positions over the period of investigation., Conclusions: We found that a significant blood pressure rise during early upright positioning in patients with acute stroke was independently associated with a favorable outcome. No contraindication to early mobilization was found in this study.