Stephan Bohlhalter

Prof. Dr. Stephan Bohlhalter

orcid

Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
6 March 2006 in Brain
Verified
Journal Article
Open access
PDF file
SBStephan Bohlhalter
Stephan Bohlhalter
AGA. Goldfine
A. Goldfine
SMS. Matteson
S. Matteson
GGG. Garraux
G. Garraux
THT. Hanakawa
T. Hanakawa
MHMark Hallett
Mark Hallett
Little is known about the neural correlates of tics and associated urges. In the present study, we aimed to explore the neural basis of tics in patients with Tourette syndrome by using event-related functional MRI (fMRI). Ten patients (6 women, 4 men; age: mean ± SD = 31 ± 11.2) were studied while spontaneously exhibiting a variety of motor and vocal tics. On the basis of synchronized video/audio recordings, fMRI activities were analysed 2 s before and at tic onset irrespective of the clinical phenomenology. We identified a brain network of paralimbic areas such as anterior cingulate and insular cortex, supplementary motor area (SMA) and parietal operculum (PO) predominantly activated before tic onset (P < 0.05, corrected for multiple comparisons). In contrast, at the beginning of tic action, significant fMRI activities were found in sensorimotor areas including superior parietal lobule bilaterally and cerebellum. The results of this study indicate that paralimbic and sensory association areas are critically implicated in tic generation, similar to movements triggered internally by unpleasant sensations, as has been shown for pain or itching.

1 January 1996 in Journal of Neuroscience
Verified
Journal Article
Open access
PDF file
SBStephan Bohlhalter
Stephan Bohlhalter
OWO Weinmann
O Weinmann
HMH Mohler
H Mohler
JFJm Fritschy
Jm Fritschy
To assess the significance of GABAA-receptor heterogeneity, which is based on a family of at least 15 subunits, the cellular localization and subunit composition of GABAA-receptor subtypes were analyzed immunohistochemically in the rat spinal cord. The distribution of subunits alpha 1, alpha 2, alpha 3, alpha 5, beta 2,3, and gamma 2 was investigated with subunit-specific antibodies, and their colocalization within individual neurons was visualized by double-immunofluorescence staining. The results reveal a widespread expression of the subunits, alpha 3, beta 2,3, and gamma 2 in the spinal cord, whereas the three other alpha subunits displayed a more restricted, lamina-specific distribution. The alpha 1 and alpha 5 subunits were most abundant in the intermediate zone, whereas the alpha 2 subunit was predominant in the superficial layers of the dorsal horn and in somatic and preganglionic motoneurons. From colocalization studies, seven subunit combinations could be identified (alpha 3/beta 2,3/gamma 2; alpha 2/beta 2,3/gamma 2; alpha 1/beta 2,3/gamma 2; alpha 5/beta 2,3/gamma 2; alpha 1/alpha 5/beta 2,3/gamma 2; alpha 2/gamma 2; alpha 2/alpha 5/gamma 2) that correspond presumably to distinct receptor subtypes. Although most neurons expressed the subunit triplet alpha x/beta 2,3/gamma 2, the beta 2,3 subunits could not be detected in motoneurons that may thus possess “atypical” receptor subtypes (alpha 2/gamma 2 and alpha 2/alpha 5/gamma 2). ON the subcellular level, aggregates of immunoreactivity, suggestive of postsynaptic GABAA receptors, typically were seen on the surface of neuronal somata and proximal dendrites. In addition, an intense diffuse staining was observed in laminae I--III for the subunits alpha 2, alpha 3, beta 2,3, and gamma 2, presumably localized on primary afferent terminals. The localization of GABAA- receptor subtypes in distinct laminar compartments of the spinal cord suggests that GABAA-receptor heterogeneity is of relevance for the modulation of sensory inputs, nociception, and motor control at segmental levels.

1 December 2017 in Parkinsonism & Related Disorders
Verified
Journal Article
Open access
Angelo AntoniniAngelo Antonini
Angelo Antonini
WPWerner Poewe
Werner Poewe
Kallol (K) Chaudhuri also Ray-ChaudhuriKallol (K) Chaudhuri also Ray-Chaudhuri
Kallol (K) Chaudhuri also Ray-Chaudhuri
RJRobert Jech
Robert Jech
BPBarbara Pickut
Barbara Pickut
MZMichel Van Zandijcke
Michel Van Zandijcke
This registry evaluated the 24-month safety and efficacy of levodopa-carbidopa intestinal gel (LCIG) treatment in advanced Parkinson's disease (PD) patients under routine clinical care. Motor fluctuations, dyskinesia, non-motor symptoms, quality of life, and safety were evaluated. Observations were fully prospective for treatment-naïve patients (60% of patients) and partially retrospective for patients with ≤12 months of pre-treatment with LCIG (40% of patients). Hours of "On" and "Off" time were assessed with a modified version of the Unified Parkinson's Disease Rating Scale part IV items 32 and 39. Overall, 375 patients were enrolled by 75 movement disorder centers in 18 countries and 258 patients completed the registry. At 24 months LCIG treatment led to significant reductions from baseline in "Off" time (hours/day) (mean ± SD = -4.1 ± 3.5, P < 0.001), "On" time with dyskinesia (hours/day) (-1.1 ± 4.8, P = 0.006), Non-Motor Symptom Scale total (-16.7 ± 43.2, P < 0.001) and individual domains scores, and Parkinson's Disease Questionnaire-8 item total score (-7.1 ± 21.0, P < 0.001). Adverse events deemed to have a possible/probable causal relationship to treatment drug/device were reported in 194 (54%) patients; the most frequently reported were decreased weight (6.7%), device related infections (5.9%), device dislocations (4.8%), device issues (4.8%), and polyneuropathy (4.5%). LCIG treatment led to sustained improvements in motor fluctuations, non-motor symptoms particularly sleep/fatigue, mood/cognition and gastrointestinal domains, as well as quality of life in advanced PD patients over 24 months. Safety events were consistent with the established safety profile of LCIG.

18 December 2009 in European Journal of Neurology
Verified
Journal Article
Closed access
PDF file
TVT. Vanbellingen
T. Vanbellingen
BKB. Kersten
B. Kersten
BHB. Van Hemelrijk
B. Van Hemelrijk
AWA. Van de Winckel
A. Van de Winckel
MBM. Bertschi
M. Bertschi
SBStephan Bohlhalter
Stephan Bohlhalter

14 July 2017 in Schizophrenia Bulletin
Verified
Journal Article
Closed access
PDF file
SWSebastian Walther
Sebastian Walther
KSKatharina Stegmayer
Katharina Stegmayer
AFAndrea Federspiel
Andrea Federspiel
SBStephan Bohlhalter
Stephan Bohlhalter
RWRoland Wiest
Roland Wiest
PVPetra V Viher
Petra V Viher
Motor abnormalities are frequently observed in schizophrenia and structural alterations of the motor system have been reported. The association of aberrant motor network function, however, has not been tested. We hypothesized that abnormal functional connectivity would be related to the degree of motor abnormalities in schizophrenia. In 90 subjects (46 patients) we obtained resting stated functional magnetic resonance imaging (fMRI) for 8 minutes 40 seconds at 3T. Participants further completed a motor battery on the scanning day. Regions of interest (ROI) were cortical motor areas, basal ganglia, thalamus and motor cerebellum. We computed ROI-to-ROI functional connectivity. Principal component analyses of motor behavioral data produced 4 factors (primary motor, catatonia and dyskinesia, coordination, and spontaneous motor activity). Motor factors were correlated with connectivity values. Schizophrenia was characterized by hyperconnectivity in 3 main areas: motor cortices to thalamus, motor cortices to cerebellum, and prefrontal cortex to the subthalamic nucleus. In patients, thalamocortical hyperconnectivity was linked to catatonia and dyskinesia, whereas aberrant connectivity between rostral anterior cingulate and caudate was linked to the primary motor factor. Likewise, connectivity between motor cortex and cerebellum correlated with spontaneous motor activity. Therefore, altered functional connectivity suggests a specific intrinsic and tonic neural abnormality in the motor system in schizophrenia. Furthermore, altered neural activity at rest was linked to motor abnormalities on the behavioral level. Thus, aberrant resting state connectivity may indicate a system out of balance, which produces characteristic behavioral alterations.

24 July 2012 in Brain
Verified
Journal Article
Open access
PDF file
DCDario Cazzoli
Dario Cazzoli
RMRené Müri
René Müri
RSRahel Schumacher
Rahel Schumacher
SASebastian von Arx
Sebastian von Arx
SCSilvia Chaves
Silvia Chaves
TNThomas Nyffeler
Thomas Nyffeler
Left-sided spatial neglect is a common neurological syndrome following right-hemispheric stroke. The presence of spatial neglect is a powerful predictor of poor rehabilitation outcome. In one influential account of spatial neglect, interhemispheric inhibition is impaired and leads to a pathological hyperactivity in the contralesional hemisphere, resulting in a biased attentional allocation towards the right hemifield. Inhibitory transcranial magnetic stimulation can reduce the hyperactivity of the contralesional, intact hemisphere and thereby improve spatial neglect symptoms. However, it is not known whether this improvement is also relevant to the activities of daily living during spontaneous behaviour. The primary aim of the present study was to investigate whether the repeated application of continuous theta burst stimulation trains could ameliorate spatial neglect on a quantitative measure of the activities of daily living during spontaneous behaviour. We applied the Catherine Bergego Scale, a standardized observation questionnaire that can validly and reliably detect the presence and severity of spatial neglect during the activities of daily living. Eight trains of continuous theta burst stimulation were applied over two consecutive days on the contralesional, left posterior parietal cortex in patients suffering from subacute left spatial neglect, in a randomized, double-blind, sham-controlled design, which also included a control group of neglect patients without stimulation. The results showed a 37% improvement in the spontaneous everyday behaviour of the neglect patients after the repeated application of continuous theta burst stimulation. Remarkably, the improvement persisted for at least 3 weeks after stimulation. The amelioration of spatial neglect symptoms in the activities of daily living was also generally accompanied by significantly better performance in the neuropsychological tests. No significant amelioration in symptoms was observed after sham stimulation or in the control group without stimulation. These results provide Class I evidence that continuous theta burst stimulation is a viable add-on therapy in neglect rehabilitation that facilitates recovery of normal everyday behaviour.