Publications by authors named "Michel Rijntjes"

74 Publications

Approximation to pain-signaling network in humans by means of migraine.

Hum Brain Mapp 2021 Feb 28;42(3):766-779. Epub 2020 Oct 28.

Faculty of Medicine, Department of Neurology and Neuroscience, Medical Center - University of Freiburg, Freiburg, Germany.

Nociceptive signals are processed within a pain-related network of the brain. Migraine is a rather specific model to gain insight into this system. Brain networks may be described by white matter tracts interconnecting functionally defined gray matter regions. Here, we present an overview of the migraine-related pain network revealed by this strategy. Based on diffusion tensor imaging data from subjects in the Human Connectome Project (HCP) database, we used a global tractography approach to reconstruct white matter tracts connecting brain regions that are known to be involved in migraine-related pain signaling. This network includes an ascending nociceptive pathway, a descending modulatory pathway, a cortical processing system, and a connection between pain-processing and modulatory areas. The insular cortex emerged as the central interface of this network. Direct connections to visual and auditory cortical association fields suggest a potential neural basis of phono- or photophobia and aura phenomena. The intra-axonal volume (V ) as a measure of fiber integrity based on diffusion microstructure was extracted using an innovative supervised machine learning approach in form of a Bayesian estimator. Self-reported pain levels of HCP subjects were positively correlated with tract integrity in subcortical tracts. No correlation with pain was found for the cortical processing systems.
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http://dx.doi.org/10.1002/hbm.25261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7814755PMC
February 2021

Addition of Tolcapone in Intrajejunal Levodopa Infusion Therapy Requires a Pronounced Dose Reduction.

Mov Disord Clin Pract 2020 Oct 18;7(7):854-856. Epub 2020 Aug 18.

Clinic of Neurology and Neurophysiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg Freiburg Germany.

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http://dx.doi.org/10.1002/mdc3.13029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534000PMC
October 2020

The correlation between apraxia and neglect in the right hemisphere: A voxel-based lesion-symptom mapping study in 138 acute stroke patients.

Cortex 2020 Nov 2;132:166-179. Epub 2020 Sep 2.

Department of Neurology and Clinical Neuroscience, University Medical Center Freiburg, University of Freiburg, Freiburg i.Br., Germany; Freiburg Brain Imaging Center, University of Freiburg, Freiburg i.Br., Germany.

Apraxia is frequently described after left hemisphere stroke and results from lesions to a complex network for motor cognition with dorso-dorsal, ventro-dorsal and ventral processing streams. Apraxia also occurs after right hemisphere stroke, but lesion correlates and underlying mechanisms remain to be elucidated. To clarify the role of the right hemisphere in apraxic deficits and the influence of neglect, we prospectively examined apraxia (imitation of meaningless postures and pantomime of tool use) and neglect in 138 acute right hemisphere stroke patients with first-ever ischemic stroke in the middle cerebral artery territory and identified corresponding lesion correlates using voxel-based lesion-symptom mapping. Imitation of meaningless postures was impaired as frequently as after left hemisphere stroke (38.4%) and was significantly associated with neglect. Imitation of meaningless postures was related to temporal (middle temporal gyrus, temporoparietal junction, superior temporal gyrus and sulcus), parietal (angular gyrus, parieto-occpitpial sulcus), secondary sensorimotor cortex and (peri-)insular lesions. Presence of neglect dichotomized the results: a lesion correlate for isolated imitation without neglect was found in the right parieto-occipital cortex, while imitation deficits, when co-occurring with neglect, were related to lateral occipito-temporal, superior temporal sulcus and (peri-)insular lesions. Pantomime of tool use deficits, typical for apraxia after left hemisphere lesions, were found in only 5 cases (3.6%) and only in the context of neglect, and were associated with occipital lobe, ventral and anterior temporal lobe, and inferior frontal (areas 45/47) lesions. The syndrome of apraxia after right hemisphere stroke differs from apraxia after left hemisphere stroke. Imitation deficits are found in both hemispheres after dorso-dorsal stream lesions. Neglect also leads to and explains deficits in imitation and pantomime in patients with right ventral stream lesions. Therefore, in right hemisphere lesions, apraxia can either be explained as impaired visuomotor transformation or as a result of visuospatial deficits.
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http://dx.doi.org/10.1016/j.cortex.2020.07.017DOI Listing
November 2020

Parkinsonian Syndrome with Frontal Lobe Involvement and Anti-Glycine Receptor Antibodies.

Brain Sci 2020 Jun 23;10(6). Epub 2020 Jun 23.

Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany.

Atypical Parkinsonian syndromes with prominent frontal lobe involvement can occur in the 4R-taupathies progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Secondary forms of movement disorders may occur in the context of autoimmune encephalitis with antineuronal antibodies, such as anti-glycine receptor (anti-GlyR) antibodies, which are typically associated with Stiff-Person spectrum syndrome, or progressive encephalomyelitis with rigidity and myoclonus. Overlaps between neurodegenerative and immunological mechanisms have been recently suggested in anti-IgLON5 disease. In this case study, the authors describe a patient with a Parkinsonian syndrome with frontal lobe involvement and anti-GlyR antibodies. : The patient presented was a 63-year-old female. Her symptoms had begun with insomnia at the age of 60, after which, since the age of 61, increasing personality changes developed, leading to a diagnosis of depression with delusional symptoms. Severe cognitive deficits emerged, along with a left-side accentuated Parkinsonian syndrome with postural instability. The personality changes involved frontal systems. Magnetic resonance imaging (MRI) showed low-grade mesencephalon atrophy. [F]fluorodeoxyglucose positron emission tomography (FDG PET) depicted a moderate hypometabolism bilateral frontal and of the midbrain, while [I]FPCIT single-photon emission computed tomography (SPECT) revealed severely reduced dopamine transporter availability in both striata, indicating pronounced nigrostriatal degeneration. In addition, anti-GlyR antibodies were repeatedly found in the serum of the patient (max. titer of 1:640, reference: <1:20). Therefore, an anti-inflammatory treatment with steroids and azathioprine was administered; this resulted in a decrease of antibody titers (to 1:80) but no detectable clinical improvement. The cerebrospinal fluid (CSF) and electroencephalography diagnostics showed inconspicuous findings, and negative CSF anti-GlyR antibody results. : The patient presented here was suffering from a complex Parkinsonian syndrome with frontal lobe involvement. Because of the high anti-GlyR antibody titers, the presence of an autoimmune cause of the disorder was discussed. However, since no typical signs of autoimmune anti-GlyR antibody syndrome (e.g., hyperexcitability, anti-GlyR antibodies in CSF, or other inflammatory CSF changes) were detected, the possibility that the anti-GlyR antibodies might have been an unrelated bystander should be considered. Alternatively, the anti-GlyR antibodies might have developed secondarily to neurodegeneration (most likely a 4-repeat tauopathy, PSP or CBD) without exerting overt clinical effects, as in cases of anti-IgLON5 encephalopathy. In this case, such antibodies might also potentially modify the clinical course of classical movement disorders. Further research on the role of antineuronal antibodies in Parkinsonian syndromes is needed.
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http://dx.doi.org/10.3390/brainsci10060399DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7349831PMC
June 2020

Dissociation of visual extinction and neglect in the left hemisphere.

Cortex 2020 08 28;129:211-222. Epub 2020 Apr 28.

Department of Neurology and Neuroscience, University Medical Center Freiburg, Freiburg, Germany; Freiburg Brain Imaging Center, University Medical Center Freiburg, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University Medical Center Freiburg, Freiburg, Germany. Electronic address:

Visual neglect and extinction are two distinct visuospatial attention deficits that frequently occur after right hemisphere cerebral stroke. However, their different lesion profiles remain a matter of debate. In the left hemisphere, a domain-general dual-loop model with distinct computational abilities onto which several cognitive functions may project, has been proposed: a dorsal stream for sensori-motor mapping in time and space and a ventral stream for comprehension and representation of concepts. We wondered whether such a distinction may apply to visual extinction and neglect in left hemisphere lesions. Of 165 prospectively studied patients with acute left hemispheric ischemic stroke with a single lesion on MRI, 122 had no visuospatial attention deficit, 10 had extinction, 31 neglect and 2 had both, visual extinction and neglect. Voxel-based-lesion-symptom mapping (VLSM, FDR<.05) showed a clear anatomical dissociation. Extinction occurred after damage to the parietal cortex (anterior bank of the intraparietal sulcus, inferior parietal lobe, and supramarginal gyrus), while visual neglect occurred after damage mainly to the temporal lobe (superior and middle temporal lobe, anterior temporal pole), inferior ventral premotor cortex, frontal operculum, angular gyrus, and insula. Direct comparison of both conditions linked extinction to intraparietal sulcus and supramarginal gyrus (FDR<.05). Thus, in the left hemisphere extinction seems to be related to dorsal stream lesions, whereas neglect maps more on the ventral stream. These data cannot be generalized to the right hemisphere. However, a domain-general point-of-view may stimulate discussion on visuospatial attention processing also in the right hemisphere.
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http://dx.doi.org/10.1016/j.cortex.2020.04.010DOI Listing
August 2020

Musicians use speech-specific areas when processing tones: The key to their superior linguistic competence?

Behav Brain Res 2020 07 19;390:112662. Epub 2020 May 19.

Department of Neurology, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany. Electronic address:

It is known that musicians compared to non-musicians have some superior speech and language competence, yet the mechanisms how musical training leads to this advantage are not well specified. This event-related fMRI study confirmed that musicians outperformed non-musicians in processing not only of musical tones but also syllables and identified a network differentiating musicians from non-musicians during processing of linguistic sounds. Within this network, the activation of bilateral superior temporal gyrus was shared with all subjects during processing of the acoustically well-matched musical and linguistic sounds, and with the activation distinguishing tones with a complex harmonic spectrum (bowed tone) from a simpler one (plucked tone). These results confirm that better speech processing in musicians relies on improved cross-domain spectral analysis. Activation of left posterior superior temporal sulcus (pSTS), premotor cortex, inferior frontal and fusiform gyrus (FG) also distinguishing musicians from non-musicians during syllable processing overlapped with the activation segregating linguistic from musical sounds in all subjects. Since these brain-regions were not involved during tone processing in non-musicians, they could code for functions which are specialized for speech. Musicians recruited pSTS and FG during tone processing, thus these speech-specialized brain-areas processed musical sounds in the presence of musical training. This study shows that the linguistic advantage of musicians is linked not only to improved cross-domain spectral analysis, but also to the functional adaptation of brain resources that are specialized for speech, but accessible to the domain of music in the presence of musical training.
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http://dx.doi.org/10.1016/j.bbr.2020.112662DOI Listing
July 2020

Tau Imaging in the 4-Repeat-Tauopathies Progressive Supranuclear Palsy and Corticobasal Syndrome: A 11C-Pyridinyl-Butadienyl-Benzothiazole 3 PET Pilot Study.

Clin Nucl Med 2020 Apr;45(4):283-287

Department of Nuclear Medicine.

Background And Objectives: To evaluate tau PET using C-pyridinyl-butadienyl-benzothiazole 3 (C-PBB3) in the 4-repeat (4R)-tauopathies progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS).

Methods: Retrospective analysis of C-PBB3 PET in 2, 7, and 2 patients with CBS, PSP, and Alzheimer dementia (AD), respectively. Normalized C-PBB3 uptake in clusters with significant hypometabolism on F-FDG-PET and corresponding atlas-based volumes of interest was compared between diagnostic groups.

Results: In accordance with visually appreciable group differences, C-PBB3 uptake was significantly higher in dorsolateral frontal and motor cortex in CBS patients and frontal and temporal cortices in AD patients as compared with PSP patients. Patients with PSP showed mildly but significantly higher uptake in midbrain compared with AD patients.

Conclusions: In line with known neuropathological changes, the spatial pattern and magnitude of C-PBB3 tau binding differ between CBS, PSP, and AD, which may be of diagnostic utility. Thus, C-PBB3 offers a promising lead structure for development of ligands for tau imaging, including 4R-tauopathies.
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http://dx.doi.org/10.1097/RLU.0000000000002949DOI Listing
April 2020

Anatomy of brain lesions after stroke predicts effectiveness of mirror therapy.

Eur J Neurosci 2020 09 25;52(6):3628-3641. Epub 2020 Feb 25.

Department of Neurology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

To improve clinical outcome, one longstanding goal in treating stroke patients has been an individual therapy based on functional and anatomical knowledge of the single patient. Therefore, in this study brain imaging of 36 chronic stroke patients was analyzed to identify parameters predicting clinical recovery. T1-weighted MRI was acquired to assess the lesion; functional MRI was used to visualize existing resources; DTI for the integrity of the corticospinal tract (CST) and long association tracts. These data were related to the clinical course. All patients were treated intensively with the mirror therapy (MT) only. After the training period, we analyzed which patient's feature would predict a beneficial course. Patients as a group improved after MT, but according to the fMRI activation of primary sensorimotor cortex (SMC), they could be divided in two groups with very diverging clinical outcome: those with ipsilesional SMC activation showed a noticeable increase of clinical scores, accompanied with ipsilesional activation in the frontal projection areas of the dorsal and ventral streams during action observation in fMRI. Those with contralesional SMC activation had lesions affecting both the dorsal and ventral stream and did not benefit from MT. The outcome for this therapy was not related to affection of CST. This study demonstrates that only in patients in which dorsal and ventral streams are not affected and therefore an interaction between these streams in post- and prerolandic regions is possible, MT can induce clinical improvement. Consequently, knowledge of the anatomical lesion can predict the beneficial course of MT.
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http://dx.doi.org/10.1111/ejn.14698DOI Listing
September 2020

Knowing Your Beans in Parkinson's Disease: A Critical Assessment of Current Knowledge about Different Beans and Their Compounds in the Treatment of Parkinson's Disease and in Animal Models.

Authors:
Michel Rijntjes

Parkinsons Dis 2019 30;2019:1349509. Epub 2019 Oct 30.

Dept. of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.

This review contains a critical appraisal of current knowledge about the use of beans in both animal models and patients with Parkinson's disease (PD). The potential beneficial effects of beans in PD are increasingly being touted, not only in scientific journals but also by the lay media. While there is a long tradition in Ayurvedic medicine of prescribing extracts from (MP), whose seeds contain 5% L-3,4-dihydroxyphenylalanin (L-DOPA), many other beans also contain L-DOPA (broad beans, common beans, and soybeans) or have other ingredients (coffee and cocoa) that may benefit PD patients. Indeed, bean-derived compounds can elicit neuroprotective effects in animal models of PD, while several studies in human PD patients have shown that motor performance can improve after ingestion of bean extracts. However, there are several arguments countering the view that beans serve as a natural therapy for PD: (i) the results from animal PD models are not necessarily directly applicable to humans; (ii) beans have many bioactive ingredients, some of which can be harmful in large doses; (iii) studies in human PD patients are scarce and only report on the effects of single doses or the administration of bean extract over short periods of time; and (iv) no data on long-term efficacy or side effects of bean therapy are available. Therefore, reservations about the use of beans as a "natural" therapy for PD seem to be justified.
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http://dx.doi.org/10.1155/2019/1349509DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875167PMC
October 2019

A novel longitudinal framework aimed at improving the teaching of the neurologic examination.

Neurology 2019 12 22;93(24):1046-1055. Epub 2019 Nov 22.

From the Department of Neurology and Neuroscience (K.B., M.R., J.B.), Medical Center, University of Freiburg; and Medical Clinic at the Health Center Tuttlingen (M.S.), Hospital of the District of Tuttlingen, Germany.

Objective: To develop an educational framework basis for improving the teaching of the neurologic examination (NE) by asking German neurologists to (1) identify the basic elements of the screening NE and (2) nominate the steps they would deem mandatory for medical students to master.

Methods: We conducted a questionnaire-based survey among neurologists working in a hospital or ambulatory setting in southwest Germany. To define the screening NE, neurologists were asked to list the NE components they normally use in clinical encounters with patients in whom neurologic findings are unlikely. Furthermore, they were asked to identify additional elements of the NE which they would consider mandatory for students to master.

Results: Our neurologists nominated a set of 23 elements as being essential for a screening NE. There was high consensus among the 2 groups, and the results were concordant with international data. Furthermore, nearly 60 additional maneuvers of the NE were deemed obligatory for students to master.

Conclusion: Our results reinforce the international consensus for screening NE components and confirm a large set of additional examination steps that medical students should master, thereby indicating the need for an educational NE teaching concept. To solve this educational challenge, we propose a longitudinal curriculum that incorporates the "core + clusters" framework, thus combining the screening NE (core) with hypothesis-driven sets of maneuvers (clusters). Based on our data, we provide an initial proposal for the core and neurologic diagnostic clusters which is applicable to both novice and advanced learners across the continuum of training.
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http://dx.doi.org/10.1212/WNL.0000000000008628DOI Listing
December 2019

No Free Lunch With Herbal Preparations: Lessons From a Case of Parkinsonism and Depression Due to Herbal Medicine Containing Reserpine.

Front Neurol 2019 18;10:634. Epub 2019 Jun 18.

Department of Nuclear Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

The increasing use of herbal medicines calls for a heightened awareness of their potential side-effects. This especially pertains to western countries, where patients tend to use herbal medicine as self-medication, often alongside regular prescriptions, and physicians have less experience with their application. Here we report a case in which Parkinsonism, depression, and an atypical finding detected by dopamine transporter single-photon emission computed tomography were all belatedly recognized as side-effects of herbal medicine. This only occurred because one of its active ingredients, reserpine, has been extensively studied. For most other herbal medicines, however, knowledge about side-effects remains scarce or unavailable. Therefore, we suggest that physicians, when taking a medication history, should actively ask for the use of any herbal preparations.
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http://dx.doi.org/10.3389/fneur.2019.00634DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6591315PMC
June 2019

Neural correlates of acute apraxia: Evidence from lesion data and functional MRI in stroke patients.

Cortex 2019 11 18;120:1-21. Epub 2019 May 18.

Dept. of Neurology and Neuroscience, University Medical Center Freiburg, Freiburg, Germany; Freiburg Brain Imaging Center, University of Freiburg, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany.

Behavioral deficits after stroke like apraxia can be related to structural lesions and to a functional state of the underlying network - three factors, reciprocally influencing each other. Combining lesion data, behavioral performance and passive functional activation of the network-of-interest, this study aims to disentangle those mutual influences and to identify 1) activation patterns associated with the presence or absence of acute apraxia in tool-associated actions and 2) the specific impact of lesion location on those activation patterns. Brain activity of 48 patients (63.31 ± 13.68 years, 35 male) was assessed in a fMRI paradigm with observation of tool-related actions during the acute phase after first-ever left-hemispheric stroke (4.83 ± 2.04 days). Behavioral assessment of apraxia in tool-related tasks was obtained independently. Brain activation was compared between patients versus healthy controls and between patient with versus without apraxia. Interaction effects of lesion location (frontal vs parietal) and behavioral performance (apraxia vs no apraxia) were assessed in a 2 × 2 factorial design. Action observation activated the ventro-dorsal parts of the network for cognitive motor function; activation was globally downregulated after stroke. Apraxic compared to non-apraxic patients showed relatively increased activity in bilateral posterior middle temporal gyrus and middle frontal gyrus/superior frontal sulcus. Altered activation occurred in regions for tool-related cognition, corroborating known functions of the ventro-dorsal and ventral streams for praxis, and comprised domain-general areas, functionally related to cognitive control. The interaction analyses revealed different levels of activation in the left anterior middle temporal gyrus in the ventral stream in apraxic patients with frontal compared to parietal lesions, suggesting a modulation of network activation in relation to behavioral performance and lesion location as separate factors. By detecting apraxia-specific activation patterns modulated by lesion location, this study underlines the necessity to combine structural lesion information, behavioral parameters and functional activation to comprehensively examine cognitive functions in acute stroke patients.
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http://dx.doi.org/10.1016/j.cortex.2019.05.005DOI Listing
November 2019

Atypical Presentation of Rapid-onset Dystonia-parkinsonism (DYT12) Unresponsive to Deep Brain Stimulation of the Subthalamic Nucleus.

Mov Disord Clin Pract 2018 Jul-Aug;5(4):427-429. Epub 2018 Apr 1.

Department of Neurology and Neuroscience, Medical Center - University of Freiburg, Medical Faculty University of Freiburg, Breisacher Straße 64 D-79106, Freiburg Germany.

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http://dx.doi.org/10.1002/mdc3.12605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6336285PMC
April 2018

Chorea-Acanthocytosis Presenting as Autosomal Recessive Epilepsy in a Family With a Novel Mutation.

Front Neurol 2018 9;9:1168. Epub 2019 Jan 9.

Department of Neurology, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg, Germany.

Chorea-acanthocytosis (ChAc) is a rare, adult-onset disease usually characterized by, hence the name, a movement disorder and acanthocytosis in the blood. It is caused by mutations of the gene with an autosomal recessive transmission. We report a consanguineous Turkish family with a different and informative clinical and diagnostic course. Three siblings developed seizures and the index patient had been diagnosed with bilateral temporal lobe epilepsy. A key finding, however, was the basal ganglia involvement in neuroimaging although no movement disorder was present. [F]FDG-PET showed a prominent decline in striatal glucose metabolism at 31 years of age and [I]FP-CIT-SPECT revealed a moderate loss of striatal dopamine transporter availability. The family was referred for genetic testing and exome sequencing detected a homozygous novel truncating mutation c.4326 T>A (p.Tyr1442) in in all affected siblings. With this case, we present autosomal recessive epilepsy as the predominant phenotype of ChAc with a new homozygous mutation and provide pathological structural and molecular neuroimaging findings.
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http://dx.doi.org/10.3389/fneur.2018.01168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334619PMC
January 2019

Large Vessel Occlusion in Acute Stroke.

Stroke 2018 10;49(10):2323-2329

From the Department of Neurology and Neuroscience (L.-A.B., M.H., C.P.K., K.N., J.B., C.W., M.R.), Medical Center, University of Freiburg, Germany.

Background and Purpose- To date, no clinical score has become widely accepted as an eligible prehospital marker for large vessel occlusion (LVO) and the need of mechanical thrombectomy (MT) in ischemic stroke. On the basis of pathophysiological considerations, we propose that cortical symptoms such as aphasia and neglect are more sensitive indicators for LVO and MT than motor deficits. Methods- We, thus, retrospectively evaluated a consecutive cohort of 543 acute stroke patients including patients with ischemia in the posterior circulation, hemorrhagic stroke, transient ischemic attack, and stroke mimics to best represent the prehospital setting. Results- Cortical symptoms alone showed to be a reliable indicator for LVO (sensitivity: 0.91; specificity: 0.70) and MT (sensitivity: 0.90; specificity: 0.60) in acute stroke patients, whereas motor deficits showed a sensitivity of 0.85 for LVO (specificity: 0.53) and 0.87 for MT (specificity: 0.48). Conclusions- We propose that in the prehospital setting, the presence of cortical symptoms is a reliable indicator for LVO and its presence justifies transportation to an MT-capable center.
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http://dx.doi.org/10.1161/STROKEAHA.118.022253DOI Listing
October 2018

Bilateral Globus Pallidus Internus Deep Brain Stimulation in a Case of Progressive Dystonia in Mohr-Tranebjaerg Syndrome with Bilateral Cochlear Implants.

J Neurol Surg A Cent Eur Neurosurg 2019 Jan 5;80(1):44-48. Epub 2018 Oct 5.

Department of Stereotactic and Functional Neurosurgery, University Hospital Freiburg, Freiburg, Germany.

Introduction:  A 28-year-old man presented with a history of sensorineural deafness since early childhood treated with bilateral cochlear implants (CIs). He showed signs of debilitating dystonia that had been present since puberty. Dystonic symptoms, especially a protrusion of the tongue and bilateral hand tremor, had not responded to botulinum toxin therapy. We diagnosed Mohr-Tranebjaerg syndrome (MTS).

Methods And Material:  Deep brain stimulation (DBS) of the bilateral globus pallidus internus was performed predominantly with stereotaxic computed tomography angiography guidance under general anesthesia. Electrophysiology was used to identify the target regions and to guide DBS electrode placement.

Results:  In the immediate postoperative course and stimulation, the patient showed marked improvement of facial, extremity, and cervical dystonia. More than 2 years after implantation, his dystonic symptoms had dramatically improved by 82%.

Discussion:  MTS is a rare genetic disorder leading to sensorineural deafness, dystonia, and other symptoms. The use of DBS for the dystonia in MTS was previously described but not in the presence of bilateral CIs.

Conclusion:  DBS in MTS may be a viable option to treat debilitating dystonic symptoms. We describe successful DBS surgery, despite the presence of bilateral CIs, and stimulation therapy over 2 years.
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http://dx.doi.org/10.1055/s-0038-1669472DOI Listing
January 2019

The essential neurological examination of the unconscious patient in the emergency room.

Brain Behav 2018 09 28;8(9):e01097. Epub 2018 Aug 28.

Department of Neurology and Neuroscience, Medical Center, University of Freiburg, Freiburg, Germany.

Objective: To determine whether neurologists with long-term experience in the emergency room are in general agreement about the essential components of the neurological examination (NE) used on unconscious patients in whom an obvious cause for coma is lacking.

Methods: We surveyed 31 board-certified practicing neurologists who regularly examine unconscious patients in the emergency room and asked them to list the specific components of the NE that they would normally choose to apply in at least 80% of cases.

Results: Twenty-seven neurologists rated 24 of 38 items as essential steps of the neurological examination of the unconscious patient, with a high level of agreement amongst survey participants.

Conclusions: There was a high degree of consensus amongst the neurologists surveyed about which steps are essential for the NE of the unconscious patient. These findings provide an important source of validation for teaching this particular NE to medical students, as well as nonneurologists working in an emergency setting.
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http://dx.doi.org/10.1002/brb3.1097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6160651PMC
September 2018

One Pass Thalamic and Subthalamic Stimulation for Patients with Tremor-Dominant Idiopathic Parkinson Syndrome (OPINION): Protocol for a Randomized, Active-Controlled, Double-Blinded Pilot Trial.

JMIR Res Protoc 2018 Jan 30;7(1):e36. Epub 2018 Jan 30.

Department of Stereotactic and Functional Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany.

Background: Besides fluctuations, therapy refractory tremor is one of the main indications of deep brain stimulation (DBS) in patients with idiopathic Parkinson syndrome (IPS). Although thalamic DBS (ventral intermediate nucleus [Vim] of thalamus) has been shown to reduce tremor in 85-95% of patients, bradykinesia and rigidity often are not well controlled. The dentato-rubro-thalamic tract (DRT) that can directly be targeted with special diffusion tensor magnetic resonance imaging sequences has been shown as an efficient target for thalamic DBS. The subthalamic nucleus (STN) is typically chosen in younger patients as the target for dopamine-responsive motor symptoms. This study investigates a one-path thalamic (Vim/DRT) and subthalamic implantation of DBS electrodes and possibly a combined stimulation strategy for both target regions.

Objective: This study investigates a one path thalamic (Vim/DRT) and subthalamic implantation of DBS electrodes and a possibly combined stimulation strategy for both target regions.

Methods: This is a randomized, active-controlled, double-blinded (patient- and observer-blinded), monocentric trial with three treatments, three periods and six treatment sequences allocated according to a Williams design. Eighteen patients will undergo one-path thalamic (Vim/DRT) and STN implantation of DBS electrodes. After one month, a double-blinded and randomly-assigned stimulation of the thalamic target (Vim/DRT), the STN and a combined stimulation of both target regions will be performed for a period of three months each. The primary objective is to assess the quality of life obtained by the Parkinson's Disease Questionnaire (39 items) for each stimulation modality. Secondary objectives include tremor reduction (obtained by the Fahn-Tolosa-Marin tremor rating scale, video recordings, the Unified Parkinson's disease rating scale, and by tremor analysis), psychiatric assessment of patients, and to assess the safety of intervention.

Results: At the moment, the recruitment is stopped and 12 patients have been randomized and treated. A futility analysis is being carried out by means of a conditional power analysis.

Conclusions: The approach of the OPINION trial planned to make, for the first time, a direct comparison of the different stimulation conditions (Vim/DRT, compared to STN, compared to Vim/DRT+STN) in a homogeneous patient population and, furthermore, will allow for intraindividual comparison of each condition with the "quality of life" outcome parameter. We hypothesize that the combined stimulation of the STN and the thalamic (Vim/DRT) target will be superior with respect to the patients' quality of life as compared to the singular stimulation of the individual target regions. If this holds true, this work might change the standardized treatment described in the previous section.

Trial Registration: ClinicalTrials.gov: NCT02288468; https://clinicaltrials.gov/ct2/show/NCT02288468 (Archived by WebCite at http://www.webcitation.org/6wlKnt2pJ); and German Clinical Trials Register: DRKS00007526; https://www.drks.de/drks_ web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00007526 (Archived by WebCite at http://www.webcitation.org/6wlKyXZZL).
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http://dx.doi.org/10.2196/resprot.8341DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5811645PMC
January 2018

Severe camptocormia due to myositis of paraspinal muscles as an early manifestation of Parkinson's disease.

Parkinsonism Relat Disord 2018 01 20;46:95-97. Epub 2017 Nov 20.

Department of Neurology and Neuroscience, Medical Center - University of Freiburg, Breisacher Straße 64, D-79106 Freiburg, Germany.

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http://dx.doi.org/10.1016/j.parkreldis.2017.11.008DOI Listing
January 2018

Effects of additional team-based learning on students' clinical reasoning skills: a pilot study.

BMC Res Notes 2017 Jul 14;10(1):282. Epub 2017 Jul 14.

Department of Neurology and Neuroscience, Medical Center-University of Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany.

Background: In the field of Neurology good clinical reasoning skills are essential for successful diagnosing and treatment. Team-based learning (TBL), an active learning and small group instructional strategy, is a promising method for fostering these skills. The aim of this pilot study was to examine the effects of a supplementary TBL-class on students' clinical decision-making skills.

Methods: Fourth- and fifth-year medical students participated in this pilot study (static-group comparison design). The non-treatment group (n = 15) did not receive any additional training beyond regular teaching in the neurology course. The treatment group (n = 11) took part in a supplementary TBL-class optimized for teaching clinical reasoning in addition to the regular teaching in the neurology course. Clinical decision making skills were assessed using a key-feature problem examination. Factual and conceptual knowledge was assessed by a multiple-choice question examination.

Results: The TBL-group performed significantly better than the non-TBL-group (p = 0.026) in the key-feature problem examination. No significant differences between the results of the multiple-choice question examination of both groups were found.

Conclusions: In this pilot study participants of a supplementary TBL-class significantly improved clinical decision-making skills, indicating that TBL may be an appropriate method for teaching clinical decision making in neurology. Further research is needed for replication in larger groups and other clinical fields.
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http://dx.doi.org/10.1186/s13104-017-2614-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512944PMC
July 2017

Teaching neurology to medical students with a simplified version of team-based learning.

Neurology 2017 Aug 12;89(6):616-622. Epub 2017 Jul 12.

From the Department of Neurology and Neuroscience (J.B., M.J., M.R.), Medical Center, University of Freiburg; and Center of Competence for the Evaluation of Teaching in Medicine-Baden-Württemberg (P.B. M.G.), Albert-Ludwigs-University Freiburg, Germany.

Objective: To compare the effect of a simplified version of team-based learning (sTBL), an active learning/small group instructional strategy, with that of the traditionally used small group interactive seminars on the acquisition of knowledge and clinical reasoning (CR) skills.

Methods: Third- and fourth-year medical students (n = 122) were randomly distributed into 2 groups. A crossover design was used in which 2 neurologic topics were taught by sTBL and 2 by small group interactive seminars. Knowledge was assessed with a multiple-choice question examination (MCQE), CR skills with a key feature problem examination (KFPE). Questionnaires were used for further methodologic evaluation.

Results: No group differences were found in the MCQE results. sTBL instruction of the topic "acute altered mental status" was associated with a significantly better student performance in the KFPE ( = 0.008), with no differences in the other 3 topics covered. Although both teaching methods were highly rated by the students, a clear majority voted for sTBL as their preferred future teaching method.

Conclusions: sTBL served as an equivalent alternative to small group interactive seminars for imparting knowledge and teaching CR skills, and was particularly advantageous for teaching CR in the setting of a complex neurologic topic. Furthermore, students reported a strong preference for the sTBL approach, making it a promising tool for effectively teaching neurology.
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http://dx.doi.org/10.1212/WNL.0000000000004211DOI Listing
August 2017

Reliability of the Infraspinatus Test in Carpal Tunnel Syndrome: A Clinical Study.

J Clin Diagn Res 2017 May 1;11(5):YC01-YC04. Epub 2017 May 1.

Department of Neurology, Medical Center, University of Freiburg, Germany.

Introduction: Recently, a standardized provocation tests for the infraspinatus muscle, the Infraspinatus test (IsT), aimed at clinically confirming Carpal Tunnel Syndrome (CTS), was validated in a multiple-blind, controlled study.

Aim: The present study was conducted to investigate inter-rater reliability of the IsT under conditions as they occur in daily clinical practice, since this is essential for acceptance of any new test.

Materials And Methods: Two raters from different medical disciplines used the IsT in the same group of subjects at different localities and with an interval of two to four weeks. Arms with symptoms of CTS were examined and compared with a control group of arms without symptoms. Nerve conduction studies were performed in all the subjects. Statistical analysis was performed with Cohen's Kappa (for inter-rater reliability) and McNemar's test (for determining dependencies between arms and raters).

Results: A total of 34 subjects (age 35-86 years) were investigated with the IsT by two raters in a blinded fashion. There was a high agreement between raters with a Kappa statistic of κ=0.868, when performing this new provocation test. The McNemar test did not reveal dependencies between Rater A and Rater B (p=0.6171), nor between the left and right arms of subjects (Rater A: p=0.4533, Rater B: p=0.5023).

Conclusion: The new provocation test of the infraspinatus muscle is not only capable of confirming CTS, as was shown before, but is also a reliable method for use by different examiners under customary conditions.
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http://dx.doi.org/10.7860/JCDR/2017/25096.9831DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483796PMC
May 2017

Adult-Onset Niemann-Pick Disease Type C: Rapid Treatment Initiation Advised but Early Diagnosis Remains Difficult.

Front Neurol 2017 4;8:108. Epub 2017 Apr 4.

Department of Neurology, University Hospital Freiburg, Freiburg im Breisgau, Germany.

Niemann-Pick type C disease (NP-C) presents with heterogeneous neurological and psychiatric symptoms. Adult onset is rare and possibly underdiagnosed due to frequent lack of specific and obvious key symptoms. For both early and adolescent/adult onset, the available data from studies and case reports describe a positive effect of Miglustat (symptom relief or stabilization). However, due to the low frequency of NP-C, experience with this therapy is still limited. We describe two adult-onset cases of NP-C. In both cases, vertical supranuclear gaze palsy was not recognized at symptom onset. Correct diagnosis was delayed from onset of symptoms by more than 10 years. The video demonstrates the broad spectrum of symptoms in later stages of the disease. Compared with published data, the treatment outcome observed in our cases after delayed initiation of Miglustat therapy was disappointing, with continuing disease progression in both cases. Thus, early treatment initiation could be necessary to achieve a good symptomatic effect. Hence, early biochemical testing for NP-C should be considered in patients suffering from atypical neurological/neuropsychological and psychiatric symptoms, even in cases of uncertainty.
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http://dx.doi.org/10.3389/fneur.2017.00108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5378773PMC
April 2017

A formal analysis of alexia in persistent aura and a comparison to acquired pure alexia.

Neurocase 2017 Feb;23(1):60-64

a Klinik für Neurologie, Universitätsklinikum Freiburg, Medizinische Fakultät , Albert-Ludwigs-Universität Freiburg , Freiburg , Germany.

A patient is reported with reversible pure alexia in the context of migraine with aura. Following previous, anecdotal reports, the present study is the first to formally assess word reading, writing, and other linguistic and visual processing and to compare these to a patient with stroke-related pure alexia. The reading impairment, suggestive of letter-by-letter reading, was observed across 7 days but had remitted at a 3-month follow-up. The deficit also affected recognition of letters, suggesting a functional impairment at the level of letter recognition, not just word reading. It went along with reversible abnormalities in diffusion-weighted and fluid-attenuated inversion recovery imaging in areas known to be involved in word reading.
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http://dx.doi.org/10.1080/13554794.2017.1291840DOI Listing
February 2017

Distinct Contributions of Dorsal and Ventral Streams to Imitation of Tool-Use and Communicative Gestures.

Cereb Cortex 2018 02;28(2):474-492

Faculty of Medicine, Department of Neurology and Clinical Neurosciences, Medical Center - University of Freiburg, University of Freiburg,  Freiburg, Germany.

Imitation of tool-use gestures (transitive; e.g., hammering) and communicative emblems (intransitive; e.g., waving goodbye) is frequently impaired after left-hemispheric lesions. We aimed 1) to identify lesions related to deficient transitive or intransitive gestures, 2) to delineate regions associated with distinct error types (e.g., hand configuration, kinematics), and 3) to compare imitation to previous data on pantomimed and actual tool use. Of note, 156 patients (64.3 ± 14.6 years; 56 female) with first-ever left-hemispheric ischemic stroke were prospectively examined 4.8 ± 2.0 days after symptom onset. Lesions were delineated on magnetic resonance imaging scans for voxel-based lesion-symptom mapping. First, while inferior-parietal lesions affected both gesture types, specific associations emerged between intransitive gesture deficits and anterior temporal damage and between transitive gesture deficits and premotor and occipito-parietal lesions. Second, impaired hand configurations were related to anterior intraparietal damage, hand/wrist-orientation errors to premotor lesions, and kinematic errors to inferior-parietal/occipito-temporal lesions. Third, premotor lesions impacted more on transitive imitation compared with actual tool use, pantomimed and actual tool use were more susceptible to lesioned insular cortex and subjacent white matter. In summary, transitive and intransitive gestures differentially rely on ventro-dorsal and ventral streams due to higher demands on temporo-spatial processing (transitive) or stronger reliance on semantic information (intransitive), respectively.
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http://dx.doi.org/10.1093/cercor/bhw383DOI Listing
February 2018

Visual neglect after left-hemispheric lesions: a voxel-based lesion-symptom mapping study in 121 acute stroke patients.

Exp Brain Res 2017 01 16;235(1):83-95. Epub 2016 Sep 16.

Department of Neurology and Neuroscience, University Medical Centre Freiburg, Breisacherstrasse 64, 79106, Freiburg, Germany.

Visual neglect after left-hemispheric lesion is thought to be less frequent, less severe, and shorter lived than visuospatial attention deficits resulting from right-hemispheric lesions. However, reports exist opposing this assumption, and it is unclear how these findings fit into the current theories of visuospatial processing. Furthermore, only little is known about the exact structure-function relationship between visuospatial attention deficits and left-hemispheric stroke. We investigated neglect in 121 patients with acute left-hemispheric ischemic stroke by following clinical development from within the first 24 h of stroke onset until hospital discharge. Visuospatial attention deficits occurred in 17.4 % (n = 21). Voxel-based lesion-symptom mapping associated visual neglect to the right with lesion in the left superior and middle temporal gyrus, temporal pole, frontal operculum, and insula. Neglect severity, captured by the Center of Cancellation Score of the Bells test, was associated with lesion in the left anterior temporal lobe and the left frontal operculum. The left-hemispheric lesion pattern of neglect thus involves areas of the ventral attention system and partly mirrors the critical regions of the right hemisphere known to be associated with neglect. Based on our prospective analysis on a large cohort of patients with left-hemispheric stroke, this study shows that in a remarkable number of patients, the left hemisphere essentially contributes to an intact representation of space and clarifies the impact of the distinct left-hemispheric structures involved in visuospatial processing.
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http://dx.doi.org/10.1007/s00221-016-4771-9DOI Listing
January 2017

Componential Network for the Recognition of Tool-Associated Actions: Evidence from Voxel-based Lesion-Symptom Mapping in Acute Stroke Patients.

Cereb Cortex 2017 08;27(8):4139-4152

Department of Neurology and Clinical Neurosciences, Medical Center, University of Freiburg, 79106 Freiburg im Breisgau, Germany.

The study aimed to elucidate areas involved in recognizing tool-associated actions, and to characterize the relationship between recognition and active performance of tool use.We performed voxel-based lesion-symptom mapping in a prospective cohort of 98 acute left-hemisphere ischemic stroke patients (68 male, age mean ± standard deviation, 65 ± 13 years; examination 4.4 ± 2 days post-stroke). In a video-based test, patients distinguished correct tool-related actions from actions with spatio-temporal (incorrect grip, kinematics, or tool orientation) or conceptual errors (incorrect tool-recipient matching, e.g., spreading jam on toast with a paintbrush). Moreover, spatio-temporal and conceptual errors were determined during actual tool use.Deficient spatio-temporal error discrimination followed lesions within a dorsal network in which the inferior parietal lobule (IPL) and the lateral temporal cortex (sLTC) were specifically relevant for assessing functional hand postures and kinematics, respectively. Conversely, impaired recognition of conceptual errors resulted from damage to ventral stream regions including anterior temporal lobe. Furthermore, LTC and IPL lesions impacted differently on action recognition and active tool use, respectively.In summary, recognition of tool-associated actions relies on a componential network. Our study particularly highlights the dissociable roles of LTC and IPL for the recognition of action kinematics and functional hand postures, respectively.
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http://dx.doi.org/10.1093/cercor/bhw226DOI Listing
August 2017

Coincidental cerebral venous thrombosis and subarachnoid haemorrhage related to ruptured anterior communicating artery aneurysm.

Neuroradiol J 2016 Aug 17;29(4):286-8. Epub 2016 May 17.

Department of Neuroradiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany

Aneurysmal subarachnoid haemorrhage (SAH) and cerebral venous thrombosis (CVT) are rare cerebrovascular pathologies. Here, we report the extremely rare coincidental presentation of both entities and discuss the likely relationship in aetiology and their optimal management. A female patient presented with headache and progressive neurological deficits. Cranial computed tomography and contrast-enhanced magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) revealed dural venous sinus thrombosis, left-sided frontal and parietal infarcts, and left middle and anterior cerebral artery stenosis. In addition, left hemispheric subarachnoid haemosiderosis was seen on MRI. Following standard anticoagulation therapy for CVT, she represented with acute SAH. Digital subtraction angiography revealed a ruptured anterior communicating artery aneurysm and left middle cerebral artery/anterior cerebral artery vasospasms that were responsive to intra-arterial nimodipine. The latter were already present on the previous MRI, and had most likely prevented the detection of the aneurysm initially. The aneurysm was successfully coil embolised, and the patient improved clinically. Despite this case being an extremely rare coincidence, a ruptured aneurysm should be excluded in the presence of CVT and non-sulcal SAH. A careful consideration of treatment of both pathologies is required, since anticoagulation may have a potentially negative impact on aneurysmal bleeding.
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http://dx.doi.org/10.1177/1971400916650456DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4978332PMC
August 2016