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Evaluation of sleep apnea detection from a smartwatch in a pilot study. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Echogenität der Substantia nigra gesunder Probanden – eine vergleichende sonographische und kernspintomographische Untersuchung. KLIN NEUROPHYSIOL 2014. [DOI: 10.1055/s-0034-1371200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Echogenicity of the Substantia nigra in the brain parenchyma sonography in children and adolescents compared with adults. KLIN NEUROPHYSIOL 2010. [DOI: 10.1055/s-0030-1250902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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P2.196 STN high frequency stimulation is effective in Parkinson's disease with camptocormia: a case report. Parkinsonism Relat Disord 2009. [DOI: 10.1016/s1353-8020(09)70547-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Transkranielle Sonografiebefunde bei der corticobasalen Degeneration. AKTUELLE NEUROLOGIE 2009. [DOI: 10.1055/s-0029-1238877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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147. Diffusion tensor imaging of the corpus callosum distinguishes Parkinson‘s disease from corticobasal syndrome. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.07.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Bildung eines Quotienten aus den zentralen motorischen Latenzen von Hand- und Beinmuskelantworten zum Läsionsnachweis in thorakolumbalen Rückenmarksabschnitten. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Repetitive transkranielle magnetische Stimulation der Großhirnrinde - Experimentelle, diagnostische und therapeutische Anwendungen unter besonderer Berücksichtigung der Reizung des motorischen Kortex. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Normwerte visuell evozierter Strömungsgeschwindigkeitsänderungen in der A. cerebri posterior. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ipsilaterale Antworten im M. biceps brachii nach fokaler magnetischer Stimulation des motorischen Kortex. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Vegetative Effekte der repetitiven transkraniellen Magnetstimulation. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hypoechogenicity of the Substantia nigra in Restless-Legs-Syndrome: Does it depend on imaging quality? KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1072904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Is substantia nigra echogenicity related to the dopaminergic nigrostriatal impairment in Parkinson’s disease? Clin Neurophysiol 2007. [DOI: 10.1016/j.clinph.2006.11.184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Neuroimaging of midbrain structures with different phased-array ultrasound systems. Clin Neurophysiol 2007. [DOI: 10.1016/j.clinph.2006.11.171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Nigrostriatale Auffälligkeiten in der Hirnparenchymsonographie und im Dopamin-Transport-SPECT bei frontotemporaler Demenz. AKTUELLE NEUROLOGIE 2007. [DOI: 10.1055/s-2007-987942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Affektion motorischer Fasersysteme bei der kortikobasalen Degeneration. AKTUELLE NEUROLOGIE 2007. [DOI: 10.1055/s-2007-987576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Is substantia nigra echogenicity related to the dopaminergic nigrostriatal impairment in Parkinson's disease? KLIN NEUROPHYSIOL 2006. [DOI: 10.1055/s-2006-939246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Neuroimaging of midbrain structures with different phased-array ultrasound systems. KLIN NEUROPHYSIOL 2006. [DOI: 10.1055/s-2006-939233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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20
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Assessment of nigrostriatal damage in schizophrenia using transcranial sonography and dopamin transporter imaging. AKTUELLE NEUROLOGIE 2006. [DOI: 10.1055/s-2006-953368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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21
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Fußapraxie als Initialsymptom der corticobasalen Degeneration? AKTUELLE NEUROLOGIE 2005. [DOI: 10.1055/s-2005-919526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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MRI study of human brain exposed to weak direct current stimulation of the frontal cortex. Clin Neurophysiol 2004; 115:2419-23. [PMID: 15351385 DOI: 10.1016/j.clinph.2004.05.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To determine whether weak transcranial direct current stimulation (tDCS), which is an interesting new tool inducing prolonged cortical excitability shifts in humans, induces brain edema, disturbance of the blood-brain barrier or structural alterations of the brain detectable by magnetic resonance imaging (MRI). METHODS In 10 healthy individuals, tDCS, which is known to alter cortical excitability for about 1 h, was applied over motor and pre-frontal cortices. contrast-enhanced t1-, t2-, and diffusion-weighted mri was performed immediately before, 30 and 60 min after tdcs. RESULTS MRI performed 30 and 60 min after tDCS did not show pathological signal alterations in pre- and post-contrast-enhanced T1-weighted and diffusion-weighted MR sequences. CONCLUSIONS tDCS protocols which are known to result in cortical excitability changes persisting for an hour after stimulation do not induce brain edema or alterations of the blood-brain barrier or cerebral tissue detectable by MRI. SIGNIFICANCE These results deliver further evidence for the safety of the currently applied tDCS protocols in humans.
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Transcranial Sonography (TCS) of Brain Parenchyma in Corticobasal Degeneration. KLIN NEUROPHYSIOL 2004. [DOI: 10.1055/s-2004-832110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abnormalities of Inhibitory Neuronal Mechanisms in the Motor Cortex of Patients with Schizophrenia. PHARMACOPSYCHIATRY 2004; 37:74-80. [PMID: 15048615 DOI: 10.1055/s-2004-815529] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Focal transcranial magnetic stimulation (TMS) of the motor cortex was used to study two cortically activated inhibitory neuronal mechanisms that suppress ongoing tonic voluntary electromyographic activity in contralateral (postexcitatory inhibition [PI]) and ipsilateral (transcallosal inhibition [TI]) hand muscles. The PI follows the corticospinally mediated excitatory motor response (MEP) and is influenced by dopaminergic neurotransmission. TI reflects transcallosally mediated inhibition of the contralateral motor cortex, leading to motor inhibition in muscles ipsilateral to stimulation. PI and TI were studied to explore whether dopaminergic neurotransmission or interhemispheric transfers are altered in schizophrenia. METHODS TMS was performed in 16 patients with this disease and in 16 healthy control subjects. Surface electromyographic activity was recorded bilaterally from the first dorsal interosseous muscle during a sustained strong isometric contraction. RESULTS When compared with the findings in healthy subjects, patients with schizophrenia had a significantly longer PI and TI. The changes of the PI support the notion of an overactivity of the central dopaminergic system in schizophrenia. CONCLUSION The prolonged TI suggests an abnormal activation of interhemispheric connections between the motor cortices and may be related to previously reported pathology of the corpus callosum in schizophrenic patients.
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Bestimung der Exzitabilität des visuellen Kortex bei Migräne mit transkranieller Magnetstimulation - Ergebnisse mit Einzel- und Doppelreizen. AKTUELLE NEUROLOGIE 2004. [DOI: 10.1055/s-2004-833356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Evaluation of cortical excitability by motor and phosphene thresholds in transcranial magnetic stimulation. J Neurol Sci 2003; 215:75-8. [PMID: 14568132 DOI: 10.1016/s0022-510x(03)00228-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Motor threshold (MT), as determined by transcranial magnetic stimulation (TMS), is used as a parameter of cortex excitability. In TMS with single or repetitive pulses, stimulus intensities in general are referred to the individual MT, although it is unclear whether MT also reflects the excitability of nonmotor cortical areas such as the visual cortex. Visual cortex excitability can be assessed by thresholds for eliciting phosphenes (phosphene threshold, PT) following TMS over the occipital cortex. The question of a different efficacy of TMS pulses in distinct cortical areas was approached by comparing motor and phosphene thresholds using single-pulse TMS applied to the primary motor and visual cortex. The aim of the study was to clarify, whether MT and PT correlate with each other and whether MT possibly serves as a reasonable measure for the excitability of the visual cortex. In 32 healthy volunteers, TMS with biphasic single pulses was applied over the motor and visual cortex with a figure of eight-shaped coil connected to a Dantec MagPro stimulator. MT and PT were individually measured (percent of maximal stimulator output). Mean PT (61.4+/-11.7%) was significantly higher than mean MT (39.4+/-5.9%) (p=0.01). MT and PT did not correlate significantly (r=0.29, p>0.1). These findings suggest that the MT does not reflect the excitability of the visual cortex. Regarding excitatory effects, the efficacy of TMS may be different over the motor and visual cortex, likely related to a different excitability of these cortical areas. This should be considered in planning and execution of TMS studies of nonmotor cortical areas.
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Transkranielle Sonographie der Substantia nigra bei Patienten mit essenziellem Tremor und idiopathischem Parkinson-Syndrom. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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28
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Verringerte kortikale Inhibition bei Patienten mit Major Depression. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Brain parenchyma sonography discriminates Parkinson's disease and atypical parkinsonian syndromes. Neurology 2003; 60:74-7. [PMID: 12525721 DOI: 10.1212/wnl.60.1.74] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To study the use of brain parenchyma sonography (BPS) in discriminating between patients with idiopathic PD (IPD) and atypical parkinsonian syndromes (APS). METHODS Twenty-five patients with APS, 9 with progressive supranuclear palsy (PSP) and 16 with multiple-system atrophy (MSA), and 25 age-matched patients with IPD were prospectively studied with BPS according to a standardized protocol. RESULTS Twenty-four of the 25 (96%) IPD patients exhibited hyperechogenicity of the substantia nigra (SN) but only 2 of 23 (9%) APS patients (Mann-Whitney U test, p < 0.001). In those two APS patients, SN hyperechogenicity was moderate only, whereas the remaining 21 APS patients had normal SN echogenicity. The specificity of SN hyperechogenicity in detection of clinically diagnosed IPD patients was 96%, and the sensitivity was 91%. If SN hyperechogenicity was marked, APS could be excluded because of a positive predictive value of 100% for IPD. Nucleus lentiformis hyperechogenicity was found in 17 of 22 (77%) APS patients but in only 5 of 22 (23%) IPD patients (Mann-Whitney U test, p < 0.001). Nucleus caudatus and thalamus echogenicity and widths of the third ventricle and of the frontal horns of the lateral ventricles did not discriminate between IPD and APS. Two patients with PSP could not be assessed because of an insufficient bone window. CONCLUSIONS BPS is a novel and noninvasive method to differentiate highly specifically between IPD and APS. Therefore, BPS might become a standard investigation in parkinsonian disorders.
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Vergleich von motorischen Schwellen und Phosphenschwellen zur Beurteilung kortikaler Erregbarkeit in der transkraniellen Magnetstimulation. KLIN NEUROPHYSIOL 2002. [DOI: 10.1055/s-2002-36003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
In patients with Idiopathic Parkinson's Disease (IPD) without a history of syncope the cardiovascular and cerebrovascular response to orthostatic stress was studied to search for subclinical impairment of autoregulatory mechanisms. Fifteen patients with IPD and 15 healthy age-matched controls were studied at rest and during head-up tilt (HUT). Heart rate, mean arterial blood pressure (MAP) and mean blood flow velocity (MBFV) in the middle cerebral artery were measured simultaneously. Changes of MAP and MBFV and the relationship between both were assessed. During HUT, heart rate increased less in patients than in healthy subjects (16.3% versus 24.2%, p=0.03). In the first minute of orthostasis MAP decreased more in patients than in healthy subjects (-4.0% versus -0.6%, p=0.04). MAP reached the pre-tilt values within 2 min in healthy subjects and 5 min in patients. Cerebral blood flow velocities fell to a similar degree and with similar time characteristics in patients and controls (-15.4% versus -16.7%, p=0.3). In both groups, patients and controls, changes of MAP did not correlate with changes of MBFV. It can be concluded that in IPD patients without symptoms of orthostatic dysregulation the autonomic circulatory control is impaired while the cerebral hemodynamic regulation during orthostasis is unaffected.
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Abstract
In 10 patients, reorganizational changes of the motor cortex contralateral to a replanted hand (MCreplant) were studied one to 14 years after complete traumatic amputation and consecutive successful replantation of the hand. The organizational state of MCreplant was assessed for the deafferentated and peripherally deefferentated hand-associated motor cortex and the adjacent motor representation of the proximal arm. For this, response maps were established for the first dorsal interosseus and biceps brachii muscle using focal transcranial magnetic stimulation (TMS) on a skull surface grid. Characteristics of the maps were center of gravity (COG), number of effective stimulation sites, amplitude sum, and amplitudes and response threshold at the optimal stimulation point. The COG is defined by the spatial distribution of response amplitudes on the map and lies over the cortex region with the most excitable corticospinal neurones supplying the recorded muscle. The COG of the biceps map in MCreplant was shifted laterally by 9.8 +/- 3.6 mm (range 5.0-15.7 mm). The extension of the biceps map in MCreplant was increased and the responses were enlarged and had lowered thresholds. For the muscles of the replanted hand, the pattern of reorganization was different: Response amplitudes were enlarged but thresholds, COG, and area of the cortical response map were normal. The different reorganizational phenomena observed for the motor cortical areas supplying the replanted hand and the biceps brachii of the same arm may be influenced by a different extent of deafferentation and by their different role in hand motor control.
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Abstract
A rare case of an osmotic demyelination syndrome in a 16-year-old girl is presented. MRI in the acute stage revealed a focal abnormal signal within the basis pontis and both caudate nuclei and putamina. Two years later brain lesions had disappeared on T1- and T2-weighted imaging, indicating that central pontine and extrapontine myelinolysis may be completely reversible.
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Abstract
In 22 healthy subjects, painless repetitive transcranial magnetic stimulation (rTMS) was used to investigate the role of the cortex in the regulation of pupil size and the influence of TMS on the central autonomic nervous system. RTMS was performed over three brain regions of each hemisphere (frontal, central, parieto-occipital), over cervical nerve roots and in front of the ear (sham stimulation) while the size of the pupil was measured by infrared oculography. rTMS always elicited a dilatation of both pupils, with its maximum after approximately 1.5 s and without significant R-L difference in latency or amplitude of pupillary response. No differential effects were observed for stimulation over different cortex regions of one hemisphere, but stimulation over the right central region evoked a larger dilatation of the pupil than stimulation over the left. Pupillary dilatation was larger for cervical nerve root stimulation (+13.2+/-8.3% (S.D.) of baseline) than for suprathreshold cortex stimulation (+8.4+/-4.5%, five 10-Hz stimuli). Pupillary dilatation in response to magnetic cortex stimulation appears to reflect a mainly unspecific activation of the sympathetic system rather than an activation of a cortical pupillomotor centre. Sympathetic activation following rTMS of the cortex does not limit its experimental and therapeutic application.
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Abstract
The influence of aging on photoreactive flow changes in the posterior cerebral artery (PCA) was investigated in 38 healthy volunteers aged 20-81 years. Mean blood flow velocity (MBFV) was measured at rest and during 10-Hz photic stimulation by transcranial Doppler sonography. The amplitude of the evoked flow response significantly decreased with age (r = -0.39; P < 0.001). In a group of elderly subjects (60-81 years), the evoked blood flow velocity increase was 10.8 +/- 2.7%, which is less than in young subjects aged 20-39 years (14.7 +/- 4.3%; P = 0.001). We conclude that normal aging affects photoreactive flow changes in the occipital lobe. This may limit the application of functional imaging studies based on measurements of blood flow changes in the elderly.
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Abstract
Focal transcranial magnetic stimulation (TMS) of the motor cortex was used to study excitatory and inhibitory stimulation effects in 25 patients with writer's cramp and 25 healthy volunteers. We investigated excitatory and inhibitory corticospinally mediated motor effects in muscles contralateral to the stimulation side as well as interhemispheric inhibition of tonic motor activity in muscles ipsilateral to stimulation. Motor evoked potentials (MEPs) were recorded from both first dorsal interosseus muscles. Motor thresholds at rest and amplitudes and latencies of MEPs obtained during maximal contraction were always bilaterally normal. The duration of postexcitatory inhibition was significantly shortened (168+/-55 vs. 198+/-39 ms in normal subjects, P=0.001) and the duration of interhemispheric inhibition prolonged (30.3+/-6.6 vs. 26+/-3.9 ms in normal subjects, P < 0.001). Both observations would be compatible with a decreased inhibition of corticospinal and transcallosal outputs of the motor cortex. The results were not influenced by fatigue effects. Abnormal motor cortex inhibition seems to be a generalized phenomenon in writer's cramp since it was detected in both hemispheres and during a simple isometric motor task which did not evoke dystonic symptoms.
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Abstract
Changes in cerebral perfusion were studied during nine short-lasting simple partial motor seizures (SPS) in an 11-year-old girl. Blood flow velocity changes in both middle cerebral arteries (MCAs) were assessed by transcranial Doppler sonography during simultaneous EEG monitoring. Within 7.4 +/- 1.4 s after electroencephalographic seizure onset, flow velocity in the MCA ipsilateral to the electrical discharges started to increase and then gradually rose up to 70% above baseline values. Spread of the epileptic activity to the other hemisphere in the late stage of seizure was associated with a slight increase in blood flow velocity (<30%) in the contralateral MCA. After the end of the seizure, flow velocities returned to baseline within 47 +/- 7 s. Our findings indicate that focal epileptic seizures evoke asymmetric perfusion increases which are closely related to the onset and cessation of the electroencephalographic seizure activity.
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[Magnetic resonance imaging of hemorrhagic transformation in ischemic posterior infarction]. ROFO-FORTSCHR RONTG 2000; 172:675-9. [PMID: 11013608 DOI: 10.1055/s-2000-7170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
PURPOSE To describe the incidence, time course, and clinical correlates of hemorrhagic transformation (HT) of ischemic stroke in the posterior cerebral artery territory. METHODS Within 42 months 48 patients with 52 occipital lobe infarctions were examined by T1- and T2-weighted MR imaging. The extent and distribution of secondary hemorrhage were analysed at different intervals after stroke. Volume of ischemic and hemorrhagic infarction was measured planimetrically. RESULTS HT was observed in 71% of the infarcts between the 5th day and up to 1 year after stroke. HT was most frequently (88%) observed in the 2nd and 3rd month. HT was present in 55% of small infarcts (< 10 cm3), in 88% of medium size (10-50 cm3), and in all large (> 50 cm3) infarcts. In 92% HT presented with petechial bleedings within the cortex (64%) or less frequently (28%) in subcortical structures. The latter types of HT showed no progression and did not increase the clinical deficits. Space-occupying bleedings occurred in only two large defects. CONCLUSIONS In ischemic posterior infarction, HT can frequently be detected within the first three months after stroke and is predominantly of the petechial type and seems not to be relevant with regard to clinical deficits.
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Abstract
Pineal lesions are rare. Tumours in this location comprise 0.4-1% of intracranial tumours. They grow mainly as solid-mass lesions, and cystic tumours are not common. On MRI, a cystic configuration is associated usually with non-neoplastic pineal lesions rather than with a tumour, but analysis does not allow cystic pineal tumours to be distinguished from glial cysts with certainty. We compared neuroradiological and pathological data from 13 cystic pineal lesions, analysing preoperative MRI. Formalin-fixed, paraffin-embedded surgical specimens were stained routinely and immunocytochemically, using the streptavidin-biotin-complex method. Histology revealed six pineocytomas, four glial cysts, an arachnoid cyst, a low-grade astrocytoma and a teratoma. Signal characteristics of pineocytomas were similar in many respects to those of glial pineal cysts. Histomorphological analysis allowed unambiguous discrimination between pineocytomas and glial pineal cysts.
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Abstract
OBJECTIVE To study the diagnostic usefulness of transcallosal inhibition (TI) elicited by transcranial magnetic stimulation (TMS) in detecting central conduction deficits in early multiple sclerosis. Corticospinally mediated excitatory responses evoked by TMS are accepted as a sensitive diagnostic tool in multiple sclerosis. Recently, TI evoked by TMS has been introduced as a new paradigm to test the function of callosal fibres interconnecting both hand associated motor cortices. METHODS Focal TMS of the motor cortex was performed in 50 patients with early relapsing-remitting multiple sclerosis. Corticospinally mediated (central motor latencies, amplitudes) and transcallosally mediated (onset latency and duration of TI) stimulation effects were investigated. RESULTS TMS disclosed abnormalities of corticospinally mediated responses in 62% and of TI in 80% of the patients. CONCLUSION The assessment of TI allows the discovery of lesions within the periventricular white matter that were not accessible by neurophysiological techniques before. This new paradigm increases the sensitivity of TMS with which to detect central conduction deficits in early multiple sclerosis.
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Abstract
We report a 38-year-old woman with extreme hypophosphataemia in whom CT and MRI disclosed bilateral lesions within the basal ganglia, thalamus and occipital lobes. After adequate substitution of phosphate the lesions grossly resolved and the patient recovered. This case is the first to demonstrate that profound changes of serum phosphate may be associated with reversible brain lesions.
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MRI study of human brain exposed to high-dose repetitive magnetic stimulation of visual cortex. Neurology 2000; 54:256-8. [PMID: 10636165 DOI: 10.1212/wnl.54.1.256] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
T1-, T2-, and diffusion-weighted MRI was used to determine whether repetitive transcranial magnetic stimulation (rTMS) affects the blood-brain barrier or induces localized brain edema. In 11 healthy individuals, 1,200 to 3,800 stimuli were applied over the visual cortex of one hemisphere in series of 5-, 10-, or 20-Hz stimulus trains. MRI performed 6 minutes to 6 hours after rTMS did not show pathologic changes in conventional MRI sequences, after application of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), or by determining apparent diffusion coefficients.
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Influence of pulse configuration and direction of coil current on excitatory effects of magnetic motor cortex and nerve stimulation. Clin Neurophysiol 2000; 111:75-80. [PMID: 10656513 DOI: 10.1016/s1388-2457(99)00198-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED This paper describes the influence of pulse configuration and current direction on the excitation of the hand-associated motor cortex and the median nerve by magnetic stimulation. Monophasic and biphasic current pulses with the same peak rise time of 80 micros and a maximum rate of current change (dI/dt) were discharged through an eight-shaped coil of the stimulator used (Dantec MagPro). Two current directions with opposite orientation in the coil axis were studied. FINDINGS (1) for both, cortex and nerve stimulation, biphasic stimuli were more effective and elicited compound muscle action potentials (CMAPs) with lower thresholds and larger amplitudes. (2) Using biphasic pulses the direction of the currents in the first phase of the pulse did not influence the CMAP amplitude. (3) Using monophasic pulses induced currents oriented postero-anteriorly in the motor cortex or orthodromically along the nerve axis elicited larger CMAPs than currents in the opposite orientation. (4) Pulse configuration did not influence the CMAP-latencies and by this the stimulation site (cortex, nerve). CONCLUSION Monophasic stimuli are useful to investigate excitation effects which are dependent on the current direction. The application of biphasic stimuli with their stronger excitation effects might be advantageous when patients with high cortical thresholds or deep lying nerves shall be investigated.
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Hemodynamic response to repetitive magnetic stimulation of the motor and visual cortex. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY. SUPPLEMENT 1999; 51:41-7. [PMID: 10590934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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First diagnostic applications of transcallosal inhibition in diseases affecting callosal neurones (multiple sclerosis, hydrocephalus, Huntington's disease). ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY. SUPPLEMENT 1999; 51:233-42. [PMID: 10590955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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[Transient cortical blindness in EPH gestosis caused by cerebral vasospasm]. DER NERVENARZT 1999; 70:931-4. [PMID: 10554788 DOI: 10.1007/s001150050600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The pathogenesis of cortical blindness as a rare complication in severe preeclampsia is still unclear. The case of a women with postpartum blindness is reported in which CT and MRI initially showed cortical and subcortical edema in the parieto-occipital lobes. At this time cerebral angiography and transcranial color-coded sonography (TCCS) revealed widespread cerebral vasospasm. Mean blood flow velocities in the middle and posterior cerebral artery and carotid syphon initially reached 380 cm/s and normalized within 2 weeks. While the patient's vision improved rapidly, follow-up MRI disclosed ischemic lesions and petechial hemorrhage in the occipital cortex. This case provides rare documentation that transient blindness in patients with preeclampsia may result from parieto-occipital ischemia due to cerebral vasospasm. In such patients TCCS may be useful to detect vasospasm associated with preeclampsia/eclampsia.
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School and nursing service managers' ability to hold their own amidst daily demands. Curationis 1999; 22:36-45. [PMID: 11040627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Improving quality of life itself subsumes the experience, maintenance, and continuous enhancement of physical and psychological health. It is therefore important for the physical and psychological health of school and nursing service managers that they are able to hold their own successfully, both personally and professionally. Bearing this in mind, the question of the extent to which school and nursing service managers succeed in holding their own (coping) successfully remains. Does their profession (field of work) influence school and nursing service managers' personal beliefs, perceptions of their coping ability amidst daily demands and their use of different types of coping strategies. The purpose of this research project was to address these issues. An empirical investigation was undertaken with reference to a theoretical framework to assess school and nursing service managers' personal beliefs, perceptions of their coping ability amidst daily demands and the coping strategies they use. Consecutive factor analytical procedures, item analyses, Hotelling T2-tests and Student t-tests were conducted on the data. The results of the analyses indicated, inter alia, that nursing service managers and, especially school managers, do not quite perceive themselves capable enough to cope with interpersonal demands. School managers find it significantly more difficult than nursing service managers to cope with demands arising from professional and personal relationships.
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Abstract
OBJECTIVE To investigate the reorganization of the corticospinal system long after arm amputation at different levels. METHODS Focal transcranial magnetic stimulation (TMS) was performed in 15 patients 21 to 65 years after arm amputation at the level of the forearm, upper arm, or shoulder. Cortically elicited electromyographic responses were investigated in muscles immediately proximal to the stump. TMS was performed on a skull surface grid overlying the motor cortex. The response threshold, number of effective stimulation sites, and the sum of the amplitudes elicited at these sites were evaluated for slightly contracted muscles. RESULTS Seven of eight patients with forearm amputation had larger stimulation effects in the biceps supplied by the motor cortex contralateral to amputation, as indicated by variable patterns of lowered response thresholds, increased response amplitudes, or increased numbers of effective stimulation sites. In seven patients with a more proximal amputation, the motor responses were investigated in the deltoid and trapezoid muscle. In only two of them, the motor cortex contralateral to amputation showed an increased excitability. Three patients presented with a higher excitability of the motor cortex contralateral to the intact arm and two with a balanced type of excitability. CONCLUSION Reorganization of the motor system can be present more than 20 years after amputation. Furthermore, differential patterns of reorganized corticospinal output were found for different stump muscles, which might be due to varying amounts of ipsilateral corticospinal projections.
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Abstract
A 25-year-old drug abuser who developed an unusual pattern of cerebral ischemic lesions is presented. Cerebral magnetic resonance imaging revealed bilateral borderzone infarctions which were attributed to a heroin-associated vasculitis of the basal cerebral arteries. Under probatory corticosteroid medication the mild neurological deficits completely disappeared.
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