Selected
Abstracts Selected
Abstracts
Science 2004; 304 (Apr. 30): 700-703.
Galin V. Michailov 1, Michael W. Sereda 1,2, Bastian G. Brinkmann 1, Tobias M. Fischer 4, Bernhard A. Haug 3, Carmen Birchmeier 5, Lorna Role 6, Cary Lai 4, Markus H. Schwab 1, Klaus-Armin Nave 1,7
1 Dept. of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany; 2 Dept. of Neurology, 3 and Dept. of Clinical Neurophysiology, University of Goettingen, Germany; 4 Dept. of Neuropharmacology, Scripps Research Institute, La Jolla, California, USA; 5 Max Delbrueck Center for Molecular Medicine, Berlin, Germany; 6 Columbia University, New York, USA; 7 Hertie Institute of Multiple Sclerosis Research, Goettingen, Germany.
In the nervous system of vertebrates, myelination is essential for rapid and accurate impulse conduction. Myelin thickness depends on axon ?ber size. We use mutant and transgenic mouse lines to show that axonal Neuregulin-1 (Nrg1) signals information about axon size to Schwann cells. Reduced Nrg1 expression causes hypomyelination and reduced nerve conduction velocity. Neuronal overexpression of Nrg1 induces hypermyelination and demonstrates that Nrg1 type III is the responsible isoform. We suggest a model by which myelin-forming Schwann cells integrate axonal Nrg1 signals as a biochemical measure of axon size.
Tierärztl Prax 2002; 30 (K): 339-346.
Stefan Neumann 1, T. Bilzer 2, Bernhard A. Haug 3
1 Veterinary Institute, and 3 Dept. of Neurology and Clinical Neurophysiology, Georg August University, Göttingen, Germany; 2 Institute of Neuropathology, Heinrich Heine University, Düsseldorf, Germany.
Since 100 years muscle dystrophies have been well-known in man. Their meaning in veterinary medicine is rather low. We present a case report about a muscle dystrophy in a Doberman pinscher. The dog exhibited hypertrophy of some muscles of the trunk and the proximal legs. The activities of the muscle enzymes CK, AST and LDH were elevated. A histopathologic examination revealed many abnormal hypertrophic muscle fibres, some atrophic muscle fibres, as well as some regenerating fibres. In immunohistochemistry a decreased expression of dystrophin, gamma-sarcoglycane and beta-dystroglycane was found. The EMG showed typical changes of myotonic muscle dystrophy. We observed the course for one and a half year.
In: Ambler Z, Nevšímalová S, Kadañka Z, Rossini PM (eds.):
Clinical Neurophysiology at the Beginning of the 21st Century.
Elsevier Science B.V., Amsterdam.
Clin Neurophysiol 2000; Suppl 53: 312-322.
Bernhard A. Haug
Dept. of Neurology and Clinical Neurophysiology, Georg August University, Goettingen, Germany.
There are several ways to classify visual motion stimuli. One is considering the direction of motion: linear translation, rotation, expansion and contraction, and motion in depth. A special case are "random dot" kinematogrammes, where the overall motion is extracted from a set of coherently and/or incoherently moving subunits. Another classification distinguishes between real motion, apparent motion (stepwise dislocation) and illusionary motion (motion aftereffect, Leviant's enigma, etc.). All these kinds of stimuli have been applied in human volunteers to detect the cortical areas involved in the processing and perception of visual motion. Already the primary visual area V1 features retinotopically organised regions responsive to "motion boundaries" (Reppas, 1997). Ventral of area V3/V3A the kinetic occipital region (KO) has been identified (van Oostende, 1997). There is universal consense about the involvement of area V5 resp. middle temporal area (MT) in motion processing (Watson, 1993; Tootell, 1995; Uusitalo, 1997). The adjacent area V5A resp. medial superior temporal area (MST) is particularly responsive to rotation stimuli (Haug 1998; Brandt, 1998). The fundal area of the superior temporal sulcus (FST) has been identified in primates to be a further cortical region involved in motion processing (van Essen, 1981). The author's own studies using electroencephalography (EEG), magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) point to areas V5 and V5A as the predominant regions responsive to motion stimuli and involved in the generation of the motion aftereffect. MEG motion responses were used to further examine the influence of stimulus contrast, velocity and duration.
Clin Neurophysiol 1999; 110 (Suppl. 1): S133.
Bernhard A. Haug 1,2, Shogo Yazawa 2, Xiaoping Xu 2,3, Takashi Nagamine 2, Hiroshi Shibasaki 2
1 Dept. of Clinical Neurophysiology, Georg August University, Goettingen, Germany; 2 Dept. of Brain Pathophysiology, Kyoto University School of Medicine, Kyoto, Japan; and 3 Dept. of Neurology, Loyola University and School of Medicine, Chicago, USA.
Six healthy volunteers aged 22–56 years with normal colour vision observed full field checkerboard pattern reversals at 2 Hz. Red/green stimuli of a series of luminance ratios placed across isoluminance were opposed to 95% and 12.5% contrast isochromatic grey stimuli, both with a spatial average luminance of 25 cd/m². Recording was performed by a 122 channel planar gradiometer and a 32 channel electroencephalographic (EEG) amplifier. The magnetoencephalograph (MEG) picked up the earliest occipital response at 41 ms. Peaks P1 (~88 ms) and P2 (~119 ms) were clearly identified both in EEG and MEG. However, dependence of P2 on colour balance was different between both techniques. In MEG, its latency increased from 115 ms to 129 ms, parallel to the increase of red/green ratio, and its amplitude remained constant at 65 to 67 fT/cm for all colour combinations. In EEG, there was a tendency to reach extremes at isoluminance of red and green, with a maximal latency of 145 ms and a reduction of amplitude from 3.0 µV to 1.6 µV. The configuration of EEG and magnetoencephalographic (MEG) responses to red/green and black/white stimuli with 95% contrast was similar, but with 12.5% contrast the early phase corresponding to P1 showed opposite polarity. A single equivalent current dipole model showed no consistent difference in dipole location within the occipital pole for the isochromatic and colour data. It is concluded, that colour responses were not fully accessible by MEG due to the deeper location of the colour-processing area V4.
In: Yoshimoto T, Kotani M, Kuriki S, Karibe H, Nakasato N (eds.):
Recent Advances in Biomagnetism. Tohoku University Press, Sendai 1999: 569-572.
Bernhard A. Haug 1,2, Shogo Yazawa 1, Xiaoping Xu 1,3, Takashi Nagamine 1, Hiroshi Shibasaki 1
1 Department of Brain Pathophysiology, Kyoto University School of Medicine, Sakyo-ku, Kyoto, Japan; 2 Department of Clinical Neurophysiology, Georg August University, Goettingen, Germany; and 3 Department of Neurology, Loyola University and School of Medicine, Chicago, Illinois, USA.
A windmill pattern with sinusoidal distribution of luminance, which is displayed rotating or stationary in alternating intervals of 1 s, appears to counter-rotate briefly during the resting phase, when the eyes maintain fixation to the centre.
For investigation by MEG in 10 healthy individuals, six angular velocities of 30–1200°/s and clockwise versus anticlockwise rotation were applied to record both START and STOP responses within the frequency range of 0.03–300 Hz. For each condition a minimum of 200 sweeps was averaged at a sampling rate of 900 Hz. Data were analysed by a model of two fixed equivalent current dipoles.
They were located in the temporo-parieto-occipital border regions, corresponding to area V5A. Dipole activities were characterised by a main peak latency of 120~160 ms, depending on the velocity of the stimulus, and irrespective of the START or STOP condition. Both showed identical polarity for the main component, and independence from rotation direction. The START response was initiated by a small peak of opposite polarity. The STOP response showed a slow second component peaking at a latency of ~240 ms, also of opposite polarity. Time course and amplitude of the latter were more independent from stimulus parameters than the main component. It shared these characteristics with the motion aftereffect, a psychophysical phenomenon which could be observed with equal intensity and speed for all stimulus velocities used.
It is concluded that the slow second peak of the STOP response might be the electrophysiological equivalent of the motion aftereffect.
In: Yoshimoto T, Kotani M,
Kuriki S, Karibe H, Nakasato N (eds.):
Recent Advances in Biomagnetism.
Tohoku University Press, Sendai 1999: 573-576.
Bernhard A. Haug 1,2, Jürgen Baudewig 2, Xiaoping Xu 1, Shogo Yazawa 1, Takashi Nagamine 1, Walter Paulus 2, Hiroshi Shibasaki 1
1 Department of Brain Pathophysiology, Kyoto University School of Medicine, Sakyo-ku, Kyoto, Japan. 2 Department of Clinical Neurophysiology, Georg August University, Goettingen, Germany.
From monkey experiments the cortical area V5A/MST is known for its high specificity to process rotatory visual motion signals. We investigated its human homologue by magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) in 10 normal subjects each.
A windmill pattern with sinusoidal modulation of luminance along the rotation trajectories was presented foveally to both eyes. Rotation phases with angular velocities of 30–1200°/s alternated with stationary phases in 1 s intervals to record start and stop responses by 122 channel MEG. Two equivalent current dipoles were fitted to the data using temporospatial integration throughout 50–250 ms. For fMRI, blocks of this condition were compared to blocks of stationary presentation, and analysed by pixelwise calculation of correlation coefficients.
MEG indicated response latencies (onset ~60 ms, main peak 120~160 ms depending on stimulus parameters) and allowed to differentiate between start and stop responses. Both were in accord for bilateral dipole positions in area V5A within the temporo-parieto-occipital border region. By fMRI exclusive activation in corresponding locations was confirmed, without stimulus-related change in activity in primary visual areas as observed with other motion displays. The extent of activated region was 76.3 ± 67.5 mm³, with lateralisation in 6 of 10 subjects, but no general side dominance.
The human cortical area V5A could for the first time be visualised and functionally analysed by combining the non-invasive and innocuous techniques of fMRI and MEG. The described windmill stimulus proved to be highly selective for activation of area V5A and hence facilitates dipole analysis.
Neuroreport 1998; 9 (4): 611-614.
Bernhard A. Haug, Juergen Baudewig, Walter Paulus
Dept. of Neurology and Clinical Neurophysiology, Georg August University, Goettingen, Germany.
The human homologue of area V5A of rotation-selective cells in the monkey medial superior temporal area (MST) was identified using functional magnetic resonance imaging (fMRI). It was located within the border region of occipito-temporo-parietal cortex, in 4 of 10 subjects on both sides, and on the right or left side in 3 subjects each. The stimulus was a black-and-white sine-modulated windmill presented either stationary or in rotation phases of 1 s duration. Areas V1-V3 did not show up with this paradigm. Focusing attention by mentally counting the number of rotation phases ensured high signal intensity in V5A, whereas moving attention away by counting electric stimuli to the wrist diminished it despite persistent fixation of gaze to the centre of the windmill.
Pfluegers Archiv, Europ J Physiol 1998; Suppl. 435 (6): R 166.
Bernhard A. Haug 1,2, Juergen Baudewig 1, Hiroshi Shibasaki 2
1 Dept. of Neurology and Clinical Neurophysiology, Georg August University, Goettingen, Germany; and 2 Dept. of Brain Pathophysiology, Kyoto University, Kyoto, Japan.
Purpose: From monkey experiments using single cell recording the cortical area V5A is known for its high specificity to process rotatory visual motion signals. In the macaque it is localised in the medial superior temporal area (MST) and adjoins the inner and medial border of the more general motion area V5 or middle temporal area (MT). We intended to localise the human homologue of area V5A in 10 normal subjects and to characterise the time course of the evoked fields. Methods: A windmill pattern with sinusoidal modulation of luminance along the rotation trajectories was chosen as a specific stimulus presented to the fovea of both eyes. Rotation phases alternated with stationary phases in 1 s intervals to record both start and stop responses by MEG at a sampling rate of 900 Hz (angular velocities 30 to 1200°/s). Data were analysed by applying a model of 2 equivalent current dipoles with temporospatial integration throughout the interval of 50-250 ms. For fMRI, blocks of this condition were compared to blocks of mere stationary presentation of the stimulus, and analysed by pixelwise calculation of correlation coefficients. Results: Both methods were in accord for the localisation of area V5A within the temporo-parieto-occipital border region, with occasional lateralisation, but no general side dominance. In addition, fMRI showed the exact extent of the activated region along the individual cortical surface or sulcus (76.3 ± 67.5 mm3 bilaterally), whereas MEG allowed to indicate response latencies (onset ~60 ms, range of main peak 120~160 ms depending on stimulus parameters) and to differentiate between start and stop responses. The latter featured a slow second peak (latency ~240 ms) that might be related to the motion aftereffect. Conclusion: The human cortical area V5A could for the first time be visualised and functionally analysed by combining the non-invasive and innocuous techniques of fMRI and MEG.
In: Hashimoto I, Kakigi R (eds.):
Recent Advances in Human Neurophysiology. Elsevier, Amsterdam 1998: 374-381.
Bernhard A. Haug 1,2, Xiaoping Xu 1,3, Takashi Nagamine 1, Shogo Yazawa 1, Hiroshi Shibasaki 1
1 Dept. of Brain Pathophysiology, Kyoto University School of Medicine, Sakyo-ku, Kyoto, Japan; 2 Dept. of Clinical Neurophysiology, Georg August University, Goettingen, Germany; and 3 Dept. of Neurology, Loyola University and School of Medicine, Chicago, USA.
A windmill with 6 black-and-white vanes modulated sinusoidally along the rotation trajectories was generated on a PC system using a VSG 2/3 card (Cambridge Research Systems Ltd., Rochester) operating at 130 Hz frame rate. The stimulus was applied at different angular velocities (30°/s to 1200°/s for 1000 ms, "fixed duration stimulus") and different durations (130 screen refreshment steps down to 1 step, 7.7 ms for a 30° luminance reversing rotation, "fixed angle stimulus") in order to trace the transition between the typical MOTION response in area V5/V5A and the responses to ON, OFF and REVERSAL stimuli in areas V1, V2 and V3. Magnetic responses were recorded from 13 volunteers by a whole-scalp planar gradiometer (Neuromag-122, Helsinki). Already the slowest of 1000 ms stimuli elicited clear responses. Equivalent current dipole analysis showed intraindividually identical sources for all velocities in the occipito-temporo-parietal border region of both hemispheres, often with marked asymmetry of dipole moments, but without general preference to one side. Even for the fastest 1000 ms stimulus there was not yet a transition to OFF and ON responses, which would be anticipated at maximal velocities (at motion START the pattern fades into homogeneous grey, at STOP it re-appears). However, with shortening of movement duration below 3 screen refreshments (fixed angle stimulus), the response pattern of REVERSAL stimuli was approximated showing more medial dipole sources within the occipital lobe. This indicates that apparent motion displays with a single displacement step do probably not adequately activate the motion area V5/V5A.
Electroencephalogr clin Neurophysiol 1997; 103 (1): 201.
Bernhard A. Haug 1,2, Takashi Nagamine 1, Shogo Yazawa 1, Xiaoping Xu 1,3 and Hiroshi Shibasaki 1.
1 Department of Brain Pathophysiology, Kyoto University School of Medicine, Kyoto, Japan; 2 Department of Clinical Neurophysiology, Georg August University, Goettingen, Germany; and 3 Dept. of Neurology, Loyola University and School of Medicine, Chicago, USA.
Visually evoked, transient responses to 4.6° semicircular hemifield black-and-white pattern stimuli presented on a computer screen were recorded in multiple sessions from 11 healthy volunteers using EEG and 122 channel MEG. All combinations of three different patterns (checkerboard with checksize 15 arcmin, vertically modulated sine wave grating with 2 cycles/°, and Gabor spot of the same frequency) and three different stimulus conditions (onset, offset and reversal) were examined. Onset responses displayed similar waveforms for all patterns, with decreasing amplitude in the above-named sequence. They could be modelled by two dipoles in the contralateral occipital lobe, the first one close to the calcarine fissure at approximately 100 ms, the second one 1-2 cm antero-latero-superiorly at 150 ms. Reversal responses showed a more complex waveform in the MEG with remarkable differences between stimulus patterns and a more inconsistent distribution of sources, when two dipoles were chosen. Three dipoles would be more adequate to explain reversal responses, but due to the limited signal/noise ratio a stable solution could not be achieved. Offset responses had two components like the onset responses, but their smaller amplitude did not allow us to go beyond a one dipole solution.
Vision Research 1997; 37 (24): 3535-3547. 118 (6): 771-778
Bernhard A. Haug 1, Eva-Maria Hermsteiner 1, Borwin Bandelow 2, and Walter Paulus 1
1 Department of Clinical Neurophysiology, and 2 Department of Psychiatry, Georg August University, Goettingen, Germany.
Following reports on a predominant loss of blue/yellow contrast sensitivity in Parkinson's disease, we revisited the physiological phenomenon of transient tritanopia. Normative data were collected from 33 healthy individuals using different colour and time combinations. Stimuli of 440 nm wavelength (blue) proved optimal, if flashed for 50 ms within the early phase of a 2 s pause in the 600 nm adaptation light. These conditions were then applied to 15 patients with Parkinson's disease. We found a parallel increase of increment threshold (p<0.001) and postadaptation thresholds (p<0.01), with little change in the extent of transient tritanopia. A same tendency at a lower significance level was found in 15 psychiatric patients under chronic treatment with depot neuroleptics. The possible mechanisms are discussed, by which a dopaminergic deficit and blockage of D1 and D2 receptors can affect the efficiency of the blue cone pathway.
Brain 1995; 118 (6): 771-778
Bernhard A. Haug 1, Renate U. Kolle 1, Claudia Trenkwalder 2, Wolfgang H. Oertel 3, Walter Paulus 1
1 Department of Clinical Neurophysiology, Georg August University, Goettingen, Germany; 2 Max Planck Institute for Psychiatry, Clinical Institute, Neurology, Munich; and 3 Department of Neurology, Ludwig Maximilians University, Munich, Germany.
Luminance contrast sensitivity and colour vision was determined in 26 Parkinson patients and 17 normal controls of comparable age. They were psychophysically tested with a colour monitor system. Stimuli consisted of Gaussian enveloped luminance modulated or colour modulated (protan and tritan axis) vertical sine wave gratings with a spatial frequency of 1 cycle/degree. The Gaussian subtended 4 degrees in diameter. Thresholds were determined at the eye using a 2 alternative forced choice method. Conditions were stationary gratings, horizontal square wave displacement of the gratings at a frequency of 5 Hz and continuous motion of the gratings at velocities of 0, 2.5 and 5.0 cycles/sec. Intergroup differences were evaluated using two-tailed t-tests with Satterthwaite corrections. Consistent and significant differences between normals and patients were found for tritan stimuli in the static and both dynamic conditions, and for luminance contrast stimuli in the displacement condition. Protan stimuli were much less apt to detect differences between the groups. It is believed, that the retinal deficit of dopamine in Parkinson's disease is reflected by diminished centre/surround inhibition and that these changes are primarily apparent when vision is tested along the tritan axis, because blue cones are sparsely distributed.
Movement Disorders 1994; 9: 563-570
Bernhard A. Haug 1, Claudia Trenkwalder 2, Geoffrey B. Arden 3, Wolfgang H. Oertel 4, Walter Paulus 1
1 Department of Clinical Neurophysiology, Georg August University, Goettingen, Germany; 2 Max Planck Institute for Psychiatry, Clinical Institute, Neurology, Munich; 3 Institute of Ophthalmology, Moorfields Eye Hospital, London, UK; and 4 Department of Neurology, Ludwig Maximilians University, Munich, Germany.
We used the computerized Moorfield Vision System to demonstrate specific increases in various perceptual visual thresholds in idiopathic Parkinson's syndrome. 15 patients were compared to 13 age matched normals. Motion detection was impaired maximally (2p < 0.01 and better in 2-tailed t-test) at luminance contrasts between 3 and 7%. Stimulus was an achromatic vertical 4 cycles/deg sine wave grating subtending 3 deg x 2 deg, centered 5 deg in the nasal field and oscillating at 5 Hz. In addition, stationary colour and luminance contrast thresholds were tested with flashed display of 5 deg x 6 deg random letters, which were presented for 200 msec (colour) and 50 msec (achromatic). Colour discrimination was impaired in the tritan axis only (2p < 0.05 in 2-tailed t-test). All achromatic stimuli - luminance increments, decrements and phase reversing stimuli - were equally well seen by patients and controls. We conclude, that the dopaminergic deficit of retinal amacrine cells in Parkinson patients can be monitored by combined low-contrast and motion (displacement) stimuli. Future studies will determine if moving coloured targets are more effective in discriminating patients from controls than are the achromatic gratings used in this work.
Zentralbl Pathol 1994; 140 (2): 155-160
Pilichowska ME, Schroeter P, Haug BA, Krygier-Stojalowska A
Department of Neuropathology, University of Rostock, Germany; University of Stettin, Poland; and Georg August University, D-37075 Goettingen, Germany.
DNA ploidy and S-phase percentage from nine malignant gliomas (four glioblastomas, four anaplastic astrocytomas grade 3 and one anaplastic oligoastrocytoma grade 3) have been estimated by single cell cytophotometry on biopsy and necropsy specimens. All gliomas from biopsy material showed, with the exception of two diploid tumours, a polyploid-aneuploid DNA-pattern and stem-lines of different ploidy. The most frequent stem-lines were diploid and hyperdiploid. In necropsy material following treatment i.e. operation and combined drug and radiation therapy, the heterogeneous nature of all malignant gliomas persisted. From seven aneuploid-polyploid gliomas four showed an elevation and three of them a decrease of DI values. Diploid tumours remained diploid. Because of marked heterogeneity of ploidy patterns and the small number of tumours investigated, ploidy changes could not be used for estimation of therapy efficacy and prognosis. Further studies will be necessary to answer this question.
Neurology 1994; 44: 936-940
Bernhard A. Haug, Borries Kukowski
Department of Clinical Neurophysiology, Georg August University, D-37075 Goettingen, Germany.
In muscles with sustained voluntary contraction electromyographic activity is transiently inhibited after transcranial magnetic stimulation (TMS). We recorded this postexcitatory silent period (SP) at 1.5-times individual stimulus threshold level from the first dorsal interosseus muscle in 65 neurological patients aged 11 to 80 years. When compared with 20 healthy volunteers, and a subgroup of patients with peripheral neurological conditions not affecting the tested pathways, the SP was significantly longer on the paretic side in cerebral ischaemia (p < 0.001) and chronic inflammatory CNS diseases, such as multiple sclerosis or neurosarcoidosis (p < 0.01). There was a similar tendency in pyramidal tract lesions due to CNS tumours and spinal cord trauma. In lesser degrees of paresis, SP duration is more sensitive than central motor conduction time (CMCT), but its specificity awaits further evaluation. SP is dependent on the integration of motor excitatory and inhibitory pathways and, possibly, sensory-motor reflex systems. In contrast to SP duration, which proved to be an independent variable giving supplementary information over the usual CMCT measurement, SP onset latency correlates well with CMCT and peripheral nerve conduction slowing as in polyradiculoneuritis.
Invest Ophthalmol Visual Sci 1993; 34 (4): 1416.
Haug BA 1, Trenkwalder C 2, Arden GB 3, Oertel WH 2, Paulus W 1
1 Department of Clinical Neurophysiology, Georg August University, D-37075 Goettingen, Germany; 2 Department of Neurology, Klinikum Grosshadern, Ludwig Maximilians University, Munich, Germany; and Moorfields Eye Hospital, London, Great Britain.
Purpose. In order to enhance the sensitivity of psychophysical tests for the detection of a retinal dopaminergic deficit we have chosen a low contrast displacement stimulus in the parafovea. Our aim was to stimulate the dopaminergic amacrine cell, which is involved in retinal motion processing. Methods. We used the computerized Moorfield Vision System with a 90 Hz Barco monitor to generate a central achromatic 4 cycles/° vertical sine wave grating subtending 3° at a viewing distance of 4.0 m. One eye was covered and a red light emitting diode was used as a fixation point 5° off the centre. The pattern within the nasal visual field was displaced horizontally in square wave manner by 0-7.5 minutes of arc corresponding to 0°-180° of phase angle of the grating at a frequency of 5 Hz in order to assess the parafoveal motion threshold. The procedure has been repeated with stepwise increasing luminance modulation depths (Michelson contrast) between 2% and 20% after initial demonstration to the subjects at 50%. 12 out-patients with idiopathic Parkinson syndrome under medication and 9 healthy controls with a mean age of 64.5 and 63.6 years respectively were examined. All of them had a Snellen visual acuity of better than 0.8 and congenital colour vision abnormalities were excluded. Results. Normals reached single pixel displacement (0.6'arc) at a much lower contrast level than Parkinson patients.
Electroencephalogr clin Neurophysiol 1992; 85: 158-160.
Bernhard A. Haug, Paul W. Schoenle, Christian Knobloch, Martin Koehne
Department of Clinical Neurophysiology, Georg August University, D-37075 Goettingen, Germany.
Following magnetic transcranial stimulation (TCS) a post-excitatory pause can be observed in surface electromyographic (EMG) recordings from pre-innervated muscles. We studied the duration of this silent period (SP) in the abductor pollicis brevis muscle while varying the stimulus intensity (SI) and the amount of the voluntary tonic contraction in 23 normal adults aged 20 to 78 years. A multivariate linear regression analysis revealed a positive correlation of SP with SI and a slight negative correlation with age. In 11 hemiparetic patients a relative increase of the SP was found on the affected side despite normal central motor conduction time. A marked shortening of the SP in relation to controls was observed in 6 Parkinsonian patients.
Nervenarzt 1991; 62: 637-640.
Haug BA, Botsch G, Felgenhauer K
Department of Neurology, Georg August University, D-37075
Goettingen, Germany
A 57-year-old man on long-term renal dialysis presented with speech dyspraxia, a symptom characteristic of early aluminium encephalopathy. Once fully developed, this condition has a poor prognosis despite deferoxamine (DFO) treatment.
Europ Neurol 1991; 31: 423-425.
Haug BA, Holzgraefe M
Department of Neurology, Georg August University, D-37075 Goettingen, Germany.
A case of essential tremor since early adultness is presented, which has been treated successfully with the acetylcholine precursor 2-dimethylaminoethanol (deanol) for 10 years. Development of a marked dyskinesia syndrome affecting predominantly orofacial and respiratory musculature has been noticed with this medication. Partial remission after discontinuation and a favorable response to anticholinergics are suggestive of an adverse drug effect.
J Neurol 1990; 237: 62-63.
Haug BA, Dressler D, Prange HW
Department of Neurology, Georg August University, D-37075 Goettingen, Germany.
The development of Guillain-Barre syndrome is reported in a patient, who had previously received botulinum toxin type A injections into both orbicularis oculi muscles to treat idiopathic blepharospasm. The possibility of a causal relationship is discussed with consideration of the literature on adverse effects of vaccinations and of Clostridium botulinum and its toxin.
Akt Neurol 1990; 17(1): 12-15.
Haug BA, Menck S, Prange HW
Department of Neurology, Georg August University, D-37075 Goettingen, Germany.
In many cases of Legionella infection pneumonia is associated with severe cerebral, cerebellar, brainstem and cranial nerve disturbance. The neurological deficit may be the presenting complaint out of keeping with the degree of systemic upset and it may precede or occur in the absence of pulmonary disease as in Pontiac fever. Multi-organ involvement seems to result from bacterial toxins. A typical case is used to illustrate the clinical features, and current diagnostic aids and treatment are discussed.
Clin Neurol Neurosurg 1989; 91(1): 53-9.
Haug BA 1, Schoenle PW 2, Karch BJ 1, Bardosi A 3, Holzgraefe M 1
1 Department of Neurology; 2 Department of Clinical Neurophysiology; and 3 Department of Neuropathology, Georg August University, D-37075 Goettingen, Germany.
The clinical picture of Morvan's fibrillary chorea includes
(a) spontaneous muscular activity resulting from repetitive motor
unit action potentials of peripheral origin (multiplets), (b)
autonomic dysregulation with profuse hyperhidrosis, and (c)
central nervous system involvement as shown by severe insomnia
and hallucinosis. A case featuring all these symptoms is
presented. Whereas known causative factors range from gold or
mercury poisoning to autoimmune disorders, the presented case is
the first one in which chronic manganese intoxication
(occupational exposure) seems to be implicated. Manganese has
been found to inhibit acetylcholine esterase, and, as a
consequence, may produce peripheral and central cholinergic
hyperactivity.
Z EEG EMG 1988; 19: 234-40.
Meyer BU, Benecke R, Dressler D, Haug B, Conrad B
Department of Clinical Neurophysiology, Georg August University, D-37075 Goettingen, Germany.
Two different approaches of determining central motor conduction times were investigated. Both methods were based on calculations of latency differences of muscle compound action potentials. First, using multilocal stimulation of the descending motor system at different levels (motor cortex, motor tracts at spinal level, motor roots) and recording from one reference muscle (Figs. 1 and 2). Second, using unilocal stimulation over the motor cortex and recording from a number of paravertebral muscles at levels from C7 to L5 (Figs. 3 and 4). With multilocal stimulation of the motor pathways, muscle response potentials are observed which differ in amplitude, duration and configuration depending on the site of stimulation (Figs. 1 and 2). This finding points to the incongruency of excited fibres within the descending motor pathways. The causes underlying this phenomenon and the resulting limitations for determining central motor conduction times are discussed. The new approach using recordings of cortically evoked responses on different levels in paravertebral muscles does not suffer from the methodical limitations of the multilocal stimulation and may be of higher clinical validity for the localization of circumscript spinal processes.
Lancet 1986-Jan-4; I: 43.
Baur X, Fruhmann G, Haug B, Rasche B, Reiher W, Weiss W
Department of Respiratory Disease, Medical Clinic I, Klinikum Grosshadern, Munich, Germany.
Letter to the Editor.
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