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Objective: A downside of Deep Brain Stimulation (DBS) for Parkinson's Disease (PD) is that cognitive function may deteriorate postoperatively. Electroencephalography (EEG) was explored as biomarker of cognition using a Machine Learning (ML) pipeline., Methods: A fully automated ML pipeline was applied to 112 PD patients, taking EEG time-series as input and predicted class-labels as output. The most extreme cognitive scores were selected for class differentiation, i.e. best vs. worst cognitive performance (n = 20 per group). 16,674 features were extracted per patient; feature-selection was performed using a Boruta algorithm. A random forest classifier was modelled; 10-fold cross-validation with Bayesian optimization was performed to ensure generalizability. The predicted class-probabilities of the entire cohort were compared to actual cognitive performance., Results: Both groups were differentiated with a mean accuracy of 0.92; using only occipital peak frequency yielded an accuracy of 0.67. Class-probabilities and actual cognitive performance were negatively linearly correlated (β = -0.23 (95% confidence interval (-0.29, -0.18)))., Conclusions: Particularly high accuracies were achieved using a compound of automatically extracted EEG biomarkers to classify PD patients according to cognition, rather than a single spectral EEG feature., Significance: Automated EEG assessment may have utility for cognitive profiling of PD patients during the DBS screening., Competing Interests: Declaration of Competing Interest The authors 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 © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

As age and Parkinson's disease (PD) both play a role in the degeneration of brain white matter, we aimed to investigate a possible interaction effect of age and disease presence on white matter integrity in patients with PD. We studied white matter hyperintensity volume, global fractional anisotropy, mean diffusivity and mean magnetization transfer ratio of normal appearing white matter in 163 patients with PD and 218 age- and gender-matched healthy control subjects. We investigated the relationship between age and these parameters in both groups, and interaction between age and disease presence. Patients with PD had a higher load of white matter hyperintensities with a preferential periventricular and anterior distribution as compared with healthy control subjects. Visuospatial functioning was related to total and postural instability and gait difficulty was related to periventricular white matter hyperintensity volume in patients with PD. The age-related decline of white matter integrity was similar for both groups. Global microstructural integrity of the normal appearing white matter did not differ between patients and healthy control subjects, suggesting that PD-specific changes do not exceed normal age-associated change in white matter without lesions., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: In Parkinson's Disease (PD), measures of non-dopaminergic systems involvement may reflect disease severity and therefore contribute to patient-selection for Deep Brain Stimulation (DBS). There is currently no determinant for non-dopaminergic disease severity. In this exploratory study, we investigated whether quantitative EEG reflects non-dopaminergic disease severity in PD., Methods: Sixty-three consecutive PD patients screened for DBS were included (mean age 62.4 ± 7.2 years, 32% females). Relative spectral powers and the Phase-Lag-Index (PLI) reflecting functional connectivity were analysed on routine EEGs. Non-dopaminergic disease severity was quantified using the SENS-PD score and its subdomains; motor-severity was quantified using the MDS-UPDRS III., Results: The SENS-PD composite score correlated with a spectral ratio ((δ + θ)/(α1 + α2 + β) powers) (global spectral ratio Pearson's r = 0.4, 95% Confidence Interval (95%CI) 0.1-0.6), and PLI in the α2 band (10-13 Hz) (r = -0.3, 95%CI -0.5 to -0.1). These correlations seem driven by the subdomains cognition and psychotic symptoms. MDS-UPDRS III was not significantly correlated with EEG parameters., Conclusions: EEG slowing and reduced functional connectivity in the α2 band were associated with non-dopaminergic disease severity in PD., Significance: The described EEG parameters may have complementary utility as determinants of non-dopaminergic involvement in PD., (Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background: In Parkinson's disease (PD), the relation between cortical brain atrophy on MRI and clinical progression is not straightforward. Determination of changes in structural covariance networks - patterns of covariance in grey matter density - has shown to be a valuable technique to detect subtle grey matter variations. We evaluated how structural network integrity in PD is related to clinical data., Methods: 3 Tesla MRI was performed in 159 PD patients. We used nine standardized structural covariance networks identified in 370 healthy subjects as a template in the analysis of the PD data. Clinical assessment comprised motor features (Movement Disorder Society-Unified Parkinson's Disease Rating Scale; MDS-UPDRS motor scale) and predominantly non-dopaminergic features (SEverity of Non-dopaminergic Symptoms in Parkinson's Disease; SENS-PD scale: postural instability and gait difficulty, psychotic symptoms, excessive daytime sleepiness, autonomic dysfunction, cognitive impairment and depressive symptoms). Voxel-based analyses were performed within networks significantly associated with PD., Results: The anterior and posterior cingulate network showed decreased integrity, associated with the SENS-PD score, p = 0.001 (β = - 0.265, η p 2  = 0.070) and p = 0.001 (β = - 0.264, η p 2  = 0.074), respectively. Of the components of the SENS-PD score, cognitive impairment and excessive daytime sleepiness were associated with atrophy within both networks., Conclusions: We identified loss of integrity and atrophy in the anterior and posterior cingulate networks in PD patients. Abnormalities of both networks were associated with predominantly non-dopaminergic features, specifically cognition and excessive daytime sleepiness. Our findings suggest that (components of) the cingulate networks display a specific vulnerability to the pathobiology of PD and may operate as interfaces between networks involved in cognition and alertness.

Objective: Motor dysfunction in Complex Regional Pain Syndrome (CRPS) has been associated with bilateral changes in central motor processing, suggesting abnormal coupling between the affected and unaffected limb. We evaluated the occurrence of involuntary muscle activity in a limb during voluntary movements of the contralateral limb (i.e., mirror activity) in unilaterally affected patients to examine disinhibition of contralateral motor activity in CRPS., Methods: Mirror activity was examined during unimanual rhythmic flexion-extension movements of the wrist through in-depth analysis of electromyography recordings from the passive arm in 20 CRPS patients and 40 controls., Results: The number of mirror-epochs was comparable for both arms in both CRPS patients and controls. Mirror-epochs in the affected arm of patients were comparable to those in controls. Mirror-epochs in the unaffected arm were shorter and showed less resemblance (in terms of rhythm and timing) to activity of the homologous muscle in the moving arm compared to mirror-epochs in controls., Conclusions: No evidence for disinhibition of contralateral motor activity was found during unimanual movement., Significance: Although motor dysfunction in CRPS has been associated with bilateral changes in cortical motor processing, the present findings argue against disinhibition of interhemispheric projections to homologous muscles in the contralateral limb during unimanual movement., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: Motor abnormalities in Complex Regional Pain Syndrome (CRPS) are common and often characterized by a restricted active range of motion (AROM) and an increased resistance to passive movements, whereby the affected body part preferably adopts an abnormal posture. The objective of the present study was to obtain a better understanding of the factors that are associated with these abnormal postures and limitations of the AROM, and to investigate whether these motor impairments reflect dystonia., Methods: We evaluated characteristics of surface EMG of the flexor carpi radialis and extensor carpi radialis muscles during active maintenance of various flexion-extension postures of the wrist of the affected and unaffected side in 15 chronic CRPS patients, and in 15 healthy controls., Results: Deviant joint postures in chronic CRPS - at least in those patients with some range of active movement - were not characterized by sustained muscle contractions, and limitations of the AROM were not attributable to excessive co-contraction. Rather, the agonistic muscle and its antagonist were activated in normal proportions, albeit over a limited range., Conclusions: The AROM limitations and abnormal postures that are often observed in chronic CRPS patients are not associated with excessive muscle activity and hence do not exhibit the characteristics typical of dystonia., Significance: We hypothesize that structural alterations in skeletal muscle tissue and pain-induced adaptations of motor function may contribute to the observed motor impairments. Our findings may have important clinical implications, since commonly prescribed treatments are aimed at reducing excessive muscle contraction., (Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Mutations in TAR DNA-binding protein (TARDBP) are associated with heterogenic phenotypes, including amyotrophic lateral sclerosis, frontotemporal dementia, and Parkinson's disease. In this study, we investigated the presence of TARDBP mutations in a cohort of 429 Dutch patients with Parkinson's disease. Though we detected 1 silent mutation, p.S332S, no missense mutations were present in our cohort. Our findings, therefore, demonstrate that TARDBP mutations do not appear to contribute to the pathogenesis of Parkinson's disease in The Netherlands., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To evaluate if hyperreflexia (exaggerated reflexes) due to disinhibition is associated with dystonia in Complex Regional Pain Syndrome (CRPS)., Methods: Stretch reflexes at the wrist were assessed in healthy controls (n=10) and CRPS-patients with dystonia (n=10). Subjects exerted a wrist flexion torque of 5% of maximum voluntary contraction torque (T(MVC)) to a manipulandum which applied ramp-and-hold stretches to the wrist flexors. Since reflex responses scale with background contraction, controls additionally performed the task at 1% and 3% T(MVC) to attain similar torques as patients who have reduced T(MVC). The M1 onset and the magnitudes of the short latency M1 and long latency M2 were assessed using the electromyographic signals (EMG) of the flexor carpi radialis. EMG of the extensor carpi radialis was recorded to monitor cocontraction., Results: Compared to controls, patients had a substantially reduced T(MVC). Ramp velocity had a significant effect on M1 onset time and magnitude., Conclusions: Since M1 magnitude decreased with flexion torque, no significant difference was found between patients and controls at 5% T(MVC), while comparison at similar absolute torques (controls at 1% T(MVC)) resulted in significantly smaller M1 magnitudes for patients with dystonia., Significance: This study suggests that CRPS-patients with dystonia are not hyperreflexive., (Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

The purpose of this study was to develop a short questionnaire for psychosocial functioning in patients with Parkinson's Disease (PD). The SCales for Outcomes in Parkinson's disease-PsychoSocial questionnaire (SCOPA-PS) was tested in a survey and compared with other instruments and with medical information. This survey was sent to 205 patents with idiopathic PD. Eighty-six percent of the questionnaires were returned. Cronbach's alpha was 0.83. Two-week test-retest reliability was 0.85 (intraclass correlation coefficient). Construct validity with other scales (Spearman's rho) was 0.82 for the Parkinson's Disease Questionnaire-39-item version (PDQ-39), 0.76 for the PDQ-8, 0.69 for the Hospital Anxiety and Depression Scale, -0.61 for the Euroqol, and -0.60 for a visual analogue scale evaluating Quality-of-Life. The summary index revealed a significant increase with increasing disease severity. The SCOPA-PS is a new, short psychosocial questionnaire for patients with PD with good clinimetric properties.

We report the case of a patient with a 16 year history of periodic (30 day cycle) fever attacks. The infradian cycle, associated clinical features, and the findings of electroencephalogram recorded during two fever attacks suggest a periodic hypothalamic syndrome.

The aim of this study was to evaluate the role of the site of attachment of activity monitors. We compared mean diurnal and nocturnal motor activity measures as well as the daily pattern of motor activity of dominant and non-dominant wrist recordings over 5 successive days of 10 healthy right-handed and 10 left-handed subjects. In a second study we evaluated the relationship between truncal motor activity and wrist motor activity. No differences emerged between the diurnal and nocturnal measures as well as the diurnal activity pattern of the dominant and the non-dominant wrist. Additionally, no differences were found in relation to handedness. Our results show that it is inaccurate to regard wrist motor activity measurements as representative of an invariable percentage of truncal motor activity; the relation between the measurements of these two recording sites varies across the daytime period. During the nocturnal period bilateral wrist motor activity occurred frequently in absence of truncal motor activity. The reverse situation, however, may occur sporadically. This finding most likely reflects that integrated generalized movements like postural shifts are measured at all recording sites, while the small movements that occur at the distal extremities are predominantly recorded by wrist-worn monitors. In conclusion, it is apparent that for both diurnal and nocturnal studies on the assessment of motor activity, either wrist can be chosen as the recording site. Across the diurnal period the relation between motor activity recorded at the wrist and waist is subject to considerable variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Ten patients with myotonic dystrophy (MyD) and excessive daytime sleepiness (EDS) were studied. Daytime sleepiness was assessed by means of a subjective alertness rating scale, multiple sleep latency tests and auditory event-related potentials. In addition, the diurnal pattern of daytime sleepiness and ultradian rhythm characteristics of nocturnal sleep were assessed. The multiple sleep latency tests and the P300 component of the auditory event-related potentials gave evidence of EDS, whereas the subjective alertness ratings did not. However, the alertness ratings showed a significantly reduced circadian periodicity as compared with controls. Consistent with this, no time-of-day effect was observed for the multiple sleep latency test outcomes. The ultradian rhythm characteristics of nocturnal sleep indicated a prolonged mean cycle duration and decreased stability of NREM/REM cycle. Moreover, the temporal structure of REM sleep showed a pattern similar to that of subjects who develop free-running rhythms when living in temporal isolation. These findings suggest that EDS in MyD reflects a complex and wide-spread malfunction of the circadian and ultradian timing system.

The role of the dopaminergic system in the pathogenesis of migraine was studied by evaluating the course of migraine after the onset of Parkinson's disease (PD) in 5 migraineurs. The course of migraine in patients with a family history of migraine was not changed after the onset of PD. On the other hand, in migraineurs without a family history, the migraine attacks either subsided or became shorter and less severe after the onset of PD. These findings may suggest a different role of the dopaminergic system in migraineurs with and without a family history of migraine, and call for a larger survey.

A patient with traumatic bifrontal hemorrhagic lesions developed hyperthermia associated with autonomic dysfunction shortly after admission. This case illustrates that posttraumatic hyperthermia may also occur at a markedly less disturbed baseline neurological level, possibly secondary to disruption of fronto-diencephalic pathways.