Ute Gschwandtner

• University of Basel

Neurodegenerative diseases like Parkinson’s (PD) and Alzheimer’s (AD) exhibit considerable heterogeneity of functional brain features within patients, complicating diagnosis and treatment. Here, we use electroencephalography (EEG) and normative modeling to investigate neurophysiological mechanisms underpinning this heterogeneity. Resting-state EEG...

Neurodegenerative diseases such as Parkinson's (PD) and Alzheimer's (AD) exhibit considerable heterogeneity of functional brain features within patient populations, complicating diagnosis, treatment, prognosis, and drug discovery. Here, we use electroencephalography (EEG) and normative modeling to investigate neurophysiological oscillatory mechanis...

Background and objectives Cognitive decline is an important and common complication in patients with Parkinson’s disease (PD) since it significantly reduces the quality of life. A breakthrough in treating and preventing cognitive decline in PD remains to be achieved. This study aimed to evaluate the effectiveness of high-frequency and intensive mul...

Anxiety is a common non-motor symptom in Parkinson’s disease (PD) occurring in up to 31% of the patients and affecting their quality of life. Despite the high prevalence, anxiety symptoms in PD are often underdiagnosed and, therefore, undertreated. To date, functional and structural neuroimaging studies have contributed to our understanding of the...

Background: Parkinson's disease (PD) patients present with a heterogeneous clinical phenotype, including motor, cognitive, sleep, and affective disruptions. However, this heterogeneity is often either ignored or assessed using only clinical assessments. Objectives: We aimed to identify different PD sub-phenotypes in a longitudinal follow-up anal...

Anxiety is a common non-motor symptom in Parkinson's disease (PD) occurring in up to 31% of the patients and affecting their quality of life. Despite the high prevalence, anxiety symptoms in PD are often underdiagnosed and, therefore, undertreated. To date, functional and structural neuroimaging studies have contributed to our understanding of the...

The aim of the study is to identify the dynamic change pattern of EEG to predict cognitive decline in patients with Parkinson’s disease. Here we demonstrate that the quantification of synchrony-pattern changes across the scalp, measured using electroencephalography (EEG), offers an alternative approach of observing an individual’s functional brain...

Background Huntington’s disease (HD) has a significant impact on the Quality of Life (QoL) of the afflicted patients. However relatively few studies have been conducted to determine the most pertinent factors. Aims To analyse the impact of cognitive, motor, and emotional status on QoL measured by HD-Pro-Triad (Carlozzi 2014), HD-QoL (Hocaoglu 2012...

Over the last few decades, electroencephalography (EEG) has evolved from being a method that purely relies on visual inspection into a quantitative method. Quantitative EEG, or QEEG, enables the assessment of neurological disorders based on spectral features, dynamic characterizations of EEG resting-state activity, brain connectivity analyzes or qu...

Here we tested if the reactivity of posterior resting-state electroencephalographic (rsEEG) alpha rhythms from the eye-closed to eyes-open condition may differ in patients with dementia due to Lewy Bodies (DLB) and Alzheimer's disease (ADD), as a functional probe of the dominant cortical neural synchronization mechanisms regulating the vigilance in...

Background: Tracking longitudinal functional brain dysconnectivity in Parkinson's disease (PD) is a key element to decoding the underlying physiopathology and understanding PD progression. Objectives: The objectives of this follow-up study were to explore, for the first time, the longitudinal changes in the functional brain networks of PD patien...

Objective Anxiety, depression, and apathy are the most common neuropsychiatric symptoms in Parkinson's disease (PD) patients. They impair cognitive functioning and have a profound impact on quality of life. This follow-up study aims to investigate the predictive value of anxiety, depression, and apathy on the development of Mild Cognitive Impairmen...

Background Recent studies suggest movements of speech and gait in patients with Parkinson's Disease (PD) are impaired by a common underlying rhythmic dysfunction. If this being the case, motor deficits in speech and gait should equally benefit from rhythmic interventions regardless of whether it is a speech-specific or step-training-specific approa...

Background Alzheimer’s disease (AD) is the first‐most common neurodegenerative disorder due to an abnormal accumulation of amyloid and tau proteins in the brain and explains about 60‐70% of 50 million of patients with dementia worldwide (WHO report, www.who.int ). Disease with Lewy Bodies (DLB) is emerging as another important cause of dementia wit...

Objective: The objective of this study is to compare 2 different rhythmic, high-intensive interventions, that is, rhythmic speech-language therapy (rSLT) versus rhythmic balance-mobility training (rBMT), against a no-therapy (NT) condition in patients with Parkinson's disease and against healthy controls (HCs) with regard to the change in or enhan...

Objective: Deep brain stimulation (DBS) in Parkinson's disease (PD) is associated with an increased risk of post-operative cognitive deterioration. Preoperative neuropsychological testing can be affected and limited by the patient's collaboration in advanced disease. The purpose of this study was to determine whether preoperative quantitative elec...

An individual's brain functional organization is unique and can reliably be observed using modalities such as functional magnetic resonance imaging (fMRI). Here we demonstrate that a quantification of the dynamics of functional connectivity (FC) as measured using electroencephalography (EEG) offers an alternative means of observing an individual's...

Introduction. According to the Dual Syndrome Hypothesis cognitive impairment in Parkinson's disease (PD) patients can be divided into two subtypes: The frontal type versus the posterior type. The risk of progression to PD dementia was described to be higher in patients initially presenting with posterior deficits. Additionally, cognitive impairment...

Objective. Deep brain stimulation of the subthalamic nucleus (STN-DBS) improve motor functioning in Parkinson“s disease patients– Additionally it can also influence cognitive functioning. In most patients, a decline of verbal fluency test performance after STN-DBS is often reported. The purpose of this study was to determine whether preoperative qu...

Introduction. Mild cognitive impairment (MCI) in Parkinson“s disease (PD) has been recognized as a transitional state between normal cognition (PD-NC) and overt dementia (PD-D) and is associated with an increased risk of conversion toward PD-D. In a cross-sectional setting the combination of spectral band power and signal complexity for use as a di...

Background Parkinson’s disease (PD) is the second‐most common neurodegenerative disorder that affects 2–3% of the population ≥ 65 years of age and may belong to cognitive deficits and dementia in 50% of cases. Disease with Lewy Bodies (DLB) is emerging as another important cause of dementia in pathological aging. PD and DLB are both due to intra‐ne...

Background Parkinson’s disease (PD) is the second‐most common neurodegenerative disorder that affects 2–3% of the population ≥ 65 years of age and may belong to cognitive deficits and dementia in 50% of cases. Disease with Lewy Bodies (DLB) is emerging as another important cause of dementia in pathological aging. PD and DLB are both due to intra‐ne...

Parkinson’s disease is a neurodegenerative disorder requiring motor signs for diagnosis, but showing more widespread pathological alterations from its beginning. Compared to age-matched healthy individuals, patients with Parkinson’s disease bear a 6-fold lifetime risk of dementia. For individualized counselling and treatment, prognostic biomarkers...

Objective Here we tested if cortical sources of resting state electroencephalographic (rsEEG) rhythms may differ in sub-groups of patients with prodromal and overt dementia with Lewy bodies (DLB) as a function of relevant clinical symptoms. Methods We extracted clinical, demographic and rsEEG datasets in matched DLB patients (N = 60) and control A...

Objective: The first (primacy region) and last (recency region) items of a word list are generally better memorized than items from the middle region. The recency effect depends on short-term memory (STM) and the primacy effect on long-term memory (LTM), where verbal information is transferred from STM into LTM by maintenance rehearsal. We compare...

Objective: We aimed to determine whether the combination of two parameters: (a) score of axial impairment and limb rigidity (SAILR) with (b) EEG global relative median power in the frequency range theta 4–8 Hz (GRMPT) predicted cognitive outcome in patients with Parkinson's disease (PD) better than each of these measures alone. Methods: 47 non-deme...

Background: Parkinson's disease (PD) is associated with cognitive decline, progressing from subjective memory complaints (SMC) via mild cognitive impairment (MCI) to dementia. SMC are only measurable by an interview and thus rely on individuals reporting a subjectively perceived worsening of cognitive functioning. Cognitive decline is accompanied...

Compared with Alzheimer’s disease (AD), Parkinson’s disease (PD) shows peculiar clinical manifestations related to vigilance (i.e., executive cognitive deficits and visual hallucinations) that may be reflected in resting state electroencephalographic (rsEEG) rhythms. To test this hypothesis, clinical and rsEEG rhythms in age-, sex-, and education-m...

Background: Fatigue is a common non-motor symptom in Parkinson's disease (PD) and is typically assessed via self-reported questionnaires such as the Parkinson's Fatigue Scale (PFS). The PFS captures the presence of subjective experience of physical fatigue as well as its impact on daily functioning. Objectives: We aimed to investigate whether di...

Objectives: To identify quantitative EEG frequency and connectivity features (Phase Lag Index) characteristic of mild cognitive impairment (MCI) in Parkinson's disease (PD) patients and to investigate if these features correlate with cognitive measures of the patients. Methods: We recorded EEG data for a group of PD patients with MCI (n = 27) an...

Previous evidence has shown different resting-state eyes-closed electroencephalographic delta (<4 Hz) and alpha (8–10.5 Hz) source connectivity in subjects with dementia due to Alzheimer's (ADD) and Lewy body (DLB) diseases. The present study tested if the same differences may be observed in the prodromal stages of mild cognitive impairment (MCI)....

Introduction: Deep brain stimulation of the subthalamic nucleus (STN-DBS) ameliorates motor function in patients with Parkinson's disease and allows reducing dopaminergic therapy. Beside effects on motor function STN-DBS influences many non-motor symptoms, among which decline of verbal fluency test performance is most consistently reported. The sur...

Frequency spectra of single subject in DBS-off, DBS-on without artifact removal, and DBS-on after artifact removal (1 Hz highpass filter was applied before plotting).

Recordings of electrical brain activity carry information about a person's cognitive health. For recording EEG signals, a very common setting is for a subject to be at rest with its eyes closed. Analysis of these recordings often involve a dimensionality reduction step in which electrodes are grouped into 10 or more regions (depending on the number...

Introduction Quantitative EEG and motor assessment tools are among the techniques investigated as biomarkers of dementia in Parkinson’s disease (PD) (Aarsland et al., 2017). It is assumed that a combination of various markers has a better predictive capacity of dementia than a single technique. We aimed to check if items of Unified Parkinson’s Dise...

Aims To find the best EEG parameters to discriminate between Parkinson’s disease (PD) and Parkinson’s Disease Dementia (PDD) patients and to evaluate the significance of Phase Lag Index as a parameter for classification of PD and PDD patients, in contrast to the use of frequency-band power measures alone. The study also deals with the challenge of...

Literature Parkinson’s disease comprises postural instability, problems with gait, balance and mobility. Such deficits may lead to falls, which may further decrease quality of life, morbidity of PD and mortality in PD patients (Muslimovic et al., 2008). PD patients suffer from 3 times the risk of falls and 5 times the injuries when compared to age-...

Background Models have been constructed to estimate individual risk for global cognitive impairment in Parkinson’s disease (PD) using a small set of clinical predictor variables (age at disease onset, sex, education, MMSE, motor impairment, depression) (Liu et al., 2017). The prediction algorithm accurately forecast cognitive decline with a predefi...

The phase-lag-index (PLI) (Stam et al., 2007) is a commonly used method to quantify functional connectivity (FC) in EEG/MEG data. When calculated for short epochs in the order of several seconds, PLI varies considerably from epoch to epoch. Using resting-state EEG data from 105 healthy subjects, we demonstrate that the pattern of correlations betwe...

We hypothesized that dopamine neuromodulation might affect cortical excitability in Parkinson's disease (PD) patients set in quiet wakefulness, as revealed by resting state eyes-closed electroencephalographic (rsEEG) rhythms at alpha frequencies (8–12 Hz). Clinical and rsEEG rhythms in PD with dementia (N = 35), PD with mild cognitive impairment (N...

Background Episodic memory encoding and working memory (WM) deficits are among the first cognitive signs and symptoms in the course of schizophrenia spectrum disorders. However, it is not clear whether the deficit pattern is generalized or specific in nature. We hypothesized that encoding deficits at an early stage of the disease might be due to th...

Learning curves of the CVLT word list for HC, ARMS, and FE as a function of trials 1 to 5. Abbreviations: ARMS, at-risk mental state for psychosis; CVLT, California Verbal Learning Test; FE, first-episode psychosis; HC, healthy control.

Introduction The aims of this study are to investigate the usage of Phase Lag Index and frequency-band power measures as parameters for classification of PD and PDD patients, and dealing with the challenge of handling imbalanced data for classification. Methods EEG data for a group of 81 PD patients and 19 PDD patients were collected from three ce...

The present study tested the hypothesis that cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms reveal different abnormalities in cortical neural synchronization in groups of patients with mild cognitive impairment due to Alzheimer’s disease (ADMCI) and dementia with Lewy bodies (DLBMCI) as compared to cognitively...

Objective: This study tested the hypothesis that markers of functional cortical source connectivity of resting state eyes-closed electroencephalographic (rsEEG) rhythms may be abnormal in subjects with mild cognitive impairment due to Alzheimer's (ADMCI) and Parkinson's (PDMCI) diseases compared to healthy elderly subjects (Nold). Methods: rsEEG...

Previous evidence showed abnormal posterior sources of resting-state delta (<4 Hz) and alpha (8-12 Hz) rhythms in patients with Alzheimer's disease with dementia (ADD), Parkinson's disease with dementia (PDD), and Lewy body dementia (DLB), as cortical neural synchronization markers in quiet wakefulness. Here, we tested the hypothesis of additional...

Olfactory decline is a frequent and early non-motor symptom in Parkinson’s disease (PD), which is increasingly used for diagnostic purposes. Another early appearing sign of PD consists in electroencephalographic (EEG) alterations. The combination of olfactory and EEG assessment may improve the identification of patients with early stages of PD. We...

Background The decline of olfactory capacity has been identified as an early symptom of Parkinson’s disease (PD) and can precede PD-related motor and non-motor impairment. Applying the olfactory tests in the assessment of PD may increase the accuracy of diagnosis and provide promising markers of the disease progression. Objectives We set the follo...

Background and bbjectives studies have shown that quantitative EEG (QEEG) and neuropsychological parameters are associated with Parkinson’s disease (PD). We investigated the differences between PD patients and healthy controls (HC) in high-resolution QEEG measures, and analyzed the prediction accuracy. We also wanted to see if a combination of QEEG...

Background Neuropsychiatric symptoms (NPS) and mild cognitive impairment (MCI) are common in Parkinson disease (PD) and have a negative impact on the patient's quality of life (QoL). We aim to describe the effect of NPS and MCI on each other and on QoL. Methods Sixteen MCI and 37 non-MCI PD patients completed different self-assessment questionnair...

Introduction: Quantitative electroencephalography (QEEG) brain frequency and network analyses are known to differentiate between disease stages in Parkinson's disease (PD) and are possible biomarkers. They correlate with cognitive decline. Little is known about changes in brain networks in relation to apathy. Objective/Aims: To analyze changes in b...

Calculation of msPLI. After phase transformation of signal A and B using Hilbert-transformation, the phase-difference over time is calculated, and the resulting vector segmented according to the previously calculated microstates. PLI values are calculated based on the resulting four different segments.

Twenty-two regions for connectivity analysis.

The aim of this retrospective and exploratory study was that the cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms might reveal different abnormalities in cortical neural synchronization in groups of patients with mild cognitive impairment due to Alzheimer’s disease (ADMCI) and Parkinson’s disease (PDMCI) as comp...

The aim of this retrospective exploratory study was that resting state eyes-closed electroencephalographic (rsEEG) rhythms might reflect brain arousal in patients with dementia due to Alzheimer's disease dementia (ADD), Parkinson's disease dementia (PDD), and dementia with Lewy body (DLB). Clinical and rsEEG data of 42 ADD, 42 PDD, 34 DLB, and 40 h...

Background. Visuospatial dysfunction is among the first cognitive symptoms in Parkinson’s disease (PD) and is often predictive for PD-dementia. Furthermore, cognitive status in PD-patients correlates with quantitative EEG. This cross-sectional study aimed to investigate the correlation between EEG slowing and visuospatial ability in nondemented PD-...

Objectives: To find out which Quantitative EEG (QEEG) parameters could best distinguish patients with Parkinson's disease (PD) with and without Mild Cognitive Impairment from healthy individuals and to find an optimal method for feature selection. Background: Certain QEEG parameters have been seen to be associated with dementia in Parkinson's and A...

Objective: The aim of this study is to compare a cognitive behavioral group therapy (CBT) with a health enhancement program (HEP) for stress reduction and the impact on quality of life (QoL) in patients with Parkinson’s disease (PD). Method: Thirty patients with PD participated in the study: 16 received CBT including stress-reducing elements and 14...

Objective: We investigated quantitative electroencephalography (qEEG) and clinical parameters as potential risk factors of severe cognitive decline in Parkinson’s disease. Methods: We prospectively investigated 37 patients with Parkinson’s disease at baseline and follow-up (after 3 years). Patients had no severe cognitive impairment at baseline. We...

Aims: The objective of this study was to investigate the relation between impaired fine motor skills in Parkinson disease (PD) patients and their cognitive status, and to determine whether fine motor skills are more impaired in PD patients with mild cognitive impairment (MCI) than in non-MCI patients. Methods: Twenty PD MCI and 31 PD non-MCI pat...

Objective: The aim of the present study was to validate and provide a German version of the Scale for Evaluation of Neuropsychiatric Disorders in Parkinson's disease (SEND-PD) of Martínez-Martín et al. (2012). Method: The German version of the SEND-PD was evaluated in a sample consisting of 96 patients with Parkinson's disease (PD) (mean age: 65.3...

Objective: To investigate the incidence of serious adverse events (SAE) of subthalamic deep brain stimulation (STN-DBS) in elderly patients with Parkinson's disease (PD). Methods: We investigated a group of 26 patients with PD who underwent STN-DBS at mean age 63.2 ± 3.3 years. The operated patients from the EARLYSTIM study (mean age 52.9 ± 6.6)...

Non-motor symptoms in patients with Parkinson's disease (PD) are gaining more and more interest. Diagnosis of mental disorders in particular, such as anxiety and depression, are often not a part of the professional's diagnostic procedure in spite of the high prevalence rate. To provide these patients with comprehensive treatment, proper diagnosis a...

Background Deep brain stimulation (DBS) is commonly used in the treatment of Parkinson’s disease (PD). Various research groups have reported that DBS is associated with decreased verbal fluency. We investigated the possible confounding effects of patients’ age, disease duration and levodopa equivalent daily dose (LEDD) on verbal fluency performance...

Objectives: In chronic schizophrenic psychoses, oscillatory abnormalities predominantly occur in prefrontal cortical regions and are associated with reduced communication across cortical areas. Nevertheless, it remains unclear whether similar alterations can be observed in patients with a first episode of psychosis (FEP), a state characterised by...

Background DBS is commonly used to treat Parkinson's disease (PD). DBS is not considered to cause major cognitive side effects, but some research groups have reported that it can cause decreased verbal fluency. The influence of age on DBS cognitive outcome is unclear. We investigated the possible influence of patients' age, level of education, dise...

program. Both groups underwent weekly sessions of 2 hours for 9 weeks. The “Fragebogen zur krankheitsbezogenen Kommunikation” (FKK) and the “Belastungsfragebogen” (BELA) were primary outcome variables. Ratings were completed at baseline, after 9 weeks (right after the treatment) and after 6 months. Results: Both, FKK and BELA, showed a significant...