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Ripellino P, Lascano AM, Scheidegger O, Schilg-Hafer L, Schreiner B, Tsouni P, Vicino A, Peyer AK, Humm AM, Décard BF, Pianezzi E, Zezza G, Sparasci D, Hundsberger T, Dietmann A, Jung H, Kuntzer T, Wilder-Smith E, Martinetti-Lucchini G, Petrini O, Fontana S, Gowland P, Niederhauser C, Gobbi C. Neuropathies related to hepatitis E virus infection: A prospective, matched case-control study. Eur J Neurol 2024; 31:e16030. [PMID: 37548584 DOI: 10.1111/ene.16030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/11/2023] [Accepted: 08/03/2023] [Indexed: 08/08/2023]
Abstract
BACKGROUND Acute hepatitis E virus (HEV) infection has recently emerged as a potential trigger for acute dysimmune neuropathies, but prospective controlled studies are lacking. AIMS To compare the frequency of concomitant acute HEV infection in patients with neuralgic amyotrophy (NA), Guillain-Barré syndrome (GBS), and Bell's palsy with a matched control population. METHODS Swiss multicenter, prospective, observational, matched case-control study over 3 years (September 2019-October 2022). Neurological cases with NA, GBS, or Bell's palsy were recruited within 1 month of disease onset. Healthy controls were matched for age, sex, geographical location, and timing of blood collection. Diagnostic criteria for acute hepatitis E were reactive serum anti-HEV IgM and IgG assays (ELISA test) and/or HEV RNA detection in serum by real-time polymerase chain reaction (RT-PCR). RT-PCR was performed on sera to confirm IgM positivity. RESULTS We included 180 patients (59 GBS, 51 NA, 70 Bell's palsy cases) and corresponding matched controls (blood donors) with median age 51 years for both groups and equal gender distribution. Six IgM+ cases were detected in the NA, two in the GBS, and none in the Bell's palsy group. Two controls were anti-HEV IgM-positive. At disease onset, most cases with acute HEV infection had increased liver enzymes. A moderate association (p = 0.027, Fisher's exact test; Cramér's V = -0.25) was observed only between acute HEV infection and NA. CONCLUSION This prospective observational study suggests an association between concomitant acute HEV infection and NA, but not with GBS or Bell's palsy.
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Affiliation(s)
- Paolo Ripellino
- Department of Neurology, Neurocenter of Southern Switzerland EOC, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Agustina Maria Lascano
- Neurology Division, Department of Clinical Neuroscience, University Hospitals of Geneva and Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Olivier Scheidegger
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | | | - Bettina Schreiner
- Department of Neurology, University and Hospital Zurich, Zurich, Switzerland
| | | | - Alex Vicino
- Nerve-Muscle Unit, Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Anne-Kathrin Peyer
- Cantonal Hospital, Lucerne, Switzerland
- Neuroliestal, Liestal, Switzerland
| | - Andrea Monika Humm
- Department of Medicine, Neurology Unit, HFR Fribourg Cantonal Hospital, Fribourg, Switzerland
| | | | - Enea Pianezzi
- Laboratory of Microbiology EOC, Bellinzona, Switzerland
| | - Giulia Zezza
- Laboratory of Microbiology EOC, Bellinzona, Switzerland
| | - Davide Sparasci
- Department of Neurology, Neurocenter of Southern Switzerland EOC, Lugano, Switzerland
| | | | - Anelia Dietmann
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Hans Jung
- Department of Neurology, University and Hospital Zurich, Zurich, Switzerland
| | - Thierry Kuntzer
- Nerve-Muscle Unit, Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Einar Wilder-Smith
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
- Cantonal Hospital, Lucerne, Switzerland
| | | | - Orlando Petrini
- University of Applied Sciences and Arts of Southern Switzerland, Bellinzona, Switzerland
| | - Stefano Fontana
- Blood Transfusion Service SRC Southern Switzerland, Lugano, Switzerland
- Interregional Blood Transfusion SRC, Bern, Switzerland
| | - Peter Gowland
- Interregional Blood Transfusion SRC, Bern, Switzerland
| | - Christoph Niederhauser
- Interregional Blood Transfusion SRC, Bern, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Claudio Gobbi
- Department of Neurology, Neurocenter of Southern Switzerland EOC, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
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Humm AM, Z'Graggen WJ. Venepuncture during head-up tilt testing in patients with suspected vasovagal syncope – implications for the test protocol. Eur J Neurol 2014; 22:389-94. [PMID: 25382753 DOI: 10.1111/ene.12590] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/10/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Head-up tilt (HUT) testing is a widely used diagnostic tool in patients with suspected vasovagal syncope (VVS). However, no gold standard exists for this examination and the various protocols used have a limited sensitivity and specificity. Our aim was to determine the sensitivity of a sequential HUT testing protocol including venepuncture (VP) and sublingual nitroglycerin application. METHODS This was a retrospective analysis of the diagnostic gain of a sequential HUT testing protocol including VP applied 10 min after the start of HUT testing and sublingual application of nitroglycerin 20 min after the start of the test protocol in 106 patients with a final diagnosis of VVS. The sensitivity of the test protocol was compared between patients with positive and negative history for VP induced VVS. RESULTS Overall, pre-syncope or syncope occurred in 68 patients (64.2%). Only 17% of all patients fainted spontaneously within 10 min of passive HUT. Another 39.6% fainted within 20 min. Application of nitroglycerin after 20 min of HUT evoked syncope in another 7.5% until the end of 45 min of HUT. The sensitivity of the test protocol for evoking (pre-)syncope was 94.4% in patients with a positive history for VP associated VVS and 58% in patients with a negative history (P < 0.01**); 85.7% of patients with a positive history and 42.9% of patients with a negative history fainted within 20 min of HUT testing (P < 0.01**). CONCLUSIONS Implementation of VP in sequential HUT testing protocols allows the sensitivity of HUT testing to be increased, especially in patients with a positive history for VP associated VVS.
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Affiliation(s)
- A M Humm
- Division of Neurology, Department of Internal Medicine, HFR Fribourg - Cantonal Hospital, Fribourg, Switzerland; Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
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Abstract
OBJECTIVE Patients with orthostatic hypotension may experience neck pain radiating to the occipital region of the skull and the shoulders while standing (so-called coat-hanger ache). This study assessed muscle membrane potential in the trapezius muscle of patients with orthostatic hypotension and healthy subjects during head-up tilt (HUT), by measuring velocity recovery cycles (VRCs) of muscle action potentials as an indicator of muscle membrane potential. METHODS Eight patients with multiple system atrophy (MSA), orthostatic hypotension and a positive history for coat-hanger pain and eight normal controls (NCs) were included in this study. Repeated VRCs were recorded from the trapezius muscle by direct muscle stimulation in the supine position and during HUT for 10 min. RESULTS Muscle VRC recordings did not differ between MSA patients and NCs in the supine position. During HUT, early supernormality decreased progressively and relative refractory period increased in MSA patients whereas VRC measures remained unchanged in NCs. Ten minutes after the start of HUT, early supernormality was reduced by 44% and relative refractory period was increased by 17%. CONCLUSIONS Muscle membranes in patients with orthostatic hypotension become progressively depolarised during standing. Membrane depolarisation is most likely the result of muscle ischaemia, related to the drop in perfusion pressure caused by orthostatic hypotension. Coat-hanger ache is most likely a consequence of this muscle ischaemia.
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Affiliation(s)
- Andrea Monika Humm
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
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Abstract
We report the case of a 17 year old male patient who presented with a history of orthostatic headache (present in the upright position only) for several months. The diagnostic investigations (MRI of the head and of the spine, lumbar puncture) revealed no signs of an intracranial hypotension or a CSF leak. In standing position, a significant raise of the heart rate (>40 bpm) without fall of the blood pressure occurred together with a bilateral, pressure-like headache. A diagnosis of postural tachycardia syndrome was made. Treatment with increase of fluid and salt intake, elastic compression stockings and regular exercise was successful.
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Affiliation(s)
- J Mathys
- Neurologische Universitätsklinik, Inselspital, Universitätsspital Bern.
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Abstract
BACKGROUND Rapid water ingestion improves orthostatic intolerance (OI) in multiple system atrophy (MSA) and postural tachycardia syndrome (PoTS). We compared haemodynamic changes after water and clear soup intake, the latter being a common treatment strategy for OI in daily practice. METHODS Seven MSA and seven PoTS patients underwent head-up tilt (HUT) without fluid intake and 30 min after drinking 450 ml of water and clear soup, respectively. All patients suffered from moderate to severe OI because of neurogenic orthostatic hypotension (OH) and excessive orthostatic heart rate (HR) increase, respectively. Beat-to-beat cardiovascular indices were measured non-invasively. RESULTS In MSA, HUT had to be terminated prematurely in 2/7 patients after water, but in 6/7 after clear soup. At 3 min of HUT, there was an increase in blood pressure of 15.7(8.2)/8.3(2.3) mmHg after water, but a decrease of 11.6(18.9)/8.1(9.2) mmHg after clear soup (P < 0.05). In PoTS, HUT could always be completed for 10 min, but OI subjectively improved after both water and clear soup. The attenuation of excessive orthostatic HR increase did not differ significantly after water and clear soup drinking. CONCLUSIONS In MSA, clear soup cannot substitute water for eliciting a pressor effect, but even worsens OI after rapid ingestion. In PoTS, acute water and clear soup intake both result in improvement of OI. These findings cannot solely be explained by difference in osmolarity but may reflect some degree of superimposed postprandial hypotension in widespread autonomic failure in MSA compared to the mild and limited autonomic dysfunction in PoTS.
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Affiliation(s)
- W J Z'Graggen
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland
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Z'Graggen WJ, Aregger F, Farese S, Humm AM, Baumann C, Uehlinger DE, Bostock H. Velocity recovery cycles of human muscle action potentials in chronic renal failure. Clin Neurophysiol 2010; 121:874-81. [PMID: 20181515 DOI: 10.1016/j.clinph.2010.01.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/20/2009] [Accepted: 01/08/2010] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To test the hypothesis that muscle fibers are depolarized in patients with chronic renal failure, by measuring velocity recovery cycles of muscle action potentials as indicators of muscle membrane potential. METHODS Velocity recovery cycles were recorded from brachioradialis muscle by direct muscle stimulation in 13 patients, before, immediately after, and 1h after haemodialysis, and compared with those from 10 age-matched controls. RESULTS In the patients, supernormality was reduced by 47%, and relative refractory period increased by 60.5% compared with controls (both P<0.001). Dialysis normalized the supernormality, but an hour later it was again reduced. These changes in supernormality were strongly correlated with the changes in serum potassium levels (P<0.0001). A late component of supernormality, attributed to potassium accumulation in the t-tubule system, was also reduced in the patients but remained abnormally low after dialysis. CONCLUSIONS Muscle membranes in the patients were chronically depolarized by hyperkalemia. Whereas dialysis transiently normalized muscle membrane potential, it was not adequate to normalize t-tubule function. SIGNIFICANCE Chronic muscle membrane depolarization by hyperkalemia may account for some of the functional deficits in uremic myopathy. Consistent normalization of membrane potential by avoiding hyperkalemia may therefore reduce symptoms of 'uremic myopathy'.
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Affiliation(s)
- W J Z'Graggen
- Department of Neurology, Inselspital, Bern University Hospital and University of Bern, Switzerland
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Humm AM, Mason LM, Mathias CJ. Effects of water drinking on cardiovascular responses to supine exercise and on orthostatic hypotension after exercise in pure autonomic failure. J Neurol Neurosurg Psychiatry 2008; 79:1160-4. [PMID: 18469030 DOI: 10.1136/jnnp.2008.147553] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Patients with pure autonomic failure (PAF) have an abnormal fall in blood pressure (BP) with supine exercise and exacerbation of orthostatic hypotension (OH) after exercise. This study assessed the pressor effect of water on the cardiovascular responses to supine exercise and on OH after exercise. METHODS 8 patients with PAF underwent a test protocol consisting of standing for 5 min, supine rest for 10 min, supine exercise by pedalling a cycle ergometer at workloads of 25, 50 and 75 W (each for 3 min), supine rest for 10 min and standing for 5 min. The test protocol was performed without water ingestion and on a separate occasion after 480 ml of distilled water immediately after pre-exercise standing. Beat to beat cardiovascular indices were measured with the Portapres II device with subsequent Modelflow analysis. RESULTS All patients had severe OH pre-exercise (BP fall systolic 65.0 (26.1) mm Hg, diastolic 22.7 (13.5) mm Hg), with prompt recovery of BP in the supine position. 5 min after water drinking, there was a significant rise in BP in the supine position. With exercise, there was a clear fall in BP (systolic 42.1 (24.4) mm Hg, diastolic 25.9 (10.0) mm Hg) with a modest rise in heart rate; this occurred even after water ingestion (BP fall systolic 49.8 (18.9) mm Hg, diastolic 26.0 (9.1) mm Hg). BP remained low after exercise but was significantly higher after water intake, resulting in better tolerance of post-exercise standing. CONCLUSIONS Water drinking did not change the abnormal cardiovascular responses to supine exercise. However, water drinking improved orthostatic tolerance post-exercise.
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Affiliation(s)
- A M Humm
- Neurovascular Medicine Unit, Imperial College London at St Mary's Hospital, London, UK
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Abstract
OBJECTIVE To determine the frequency, age distribution and clinical presentation of carotid sinus hypersensitivity (CSH) among 373 patients (age range 15-92 years) referred to two autonomic referral centres during a 10-year period. METHODS Carotid sinus massage (CSM) was performed both supine and during 60 degree head-up tilt. Beat-to-beat blood pressure, heart rate and a three-lead electrocardiography were recorded continuously. CSH was classified as cardioinhibitory (asystole > or = 3 s), vasodepressor (systolic blood pressure fall > or = 50 mm Hg) or mixed. All patients additionally underwent autonomic screening tests for orthostatic hypotension and autonomic failure. RESULTS CSH was observed in 13.7% of all patients. The diagnostic yield of CSM was nil in patients aged < 50 years (n = 65), 2.4% in those aged 50-59 years (n = 82), 9.1% in those aged 60-69 years (n = 77), 20.7% in those aged 70-79 years (n = 92) and reached 40.4% in those > 80 years (n = 57). Syncope was the leading clinical symptom in 62.8%. In 27.4% of patients falls without definite loss of consciousness was the main clinical symptom. Mild and mainly systolic orthostatic hypotension was recorded in 17.6%; evidence of sympathetic or parasympathetic dysfunction was found in none. CONCLUSIONS CSH was confirmed in patients > 50 years, the incidence steeply increasing with age. The current European Society of Cardiology guidelines that recommend testing for CSH in all patients > 40 years with syncope of unknown aetiology may need reconsideration. Orthostatic hypotension was noted in some patients with CSH, but evidence of sympathetic or parasympathetic failure was not found in any of them.
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Affiliation(s)
- A M Humm
- Neurovascular Medicine Unit, Imperial College London at St Mary's Hospital, London, UK.
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Humm AM, Z'Graggen WJ, Bühler R, Magistris MR, Rösler KM. Quantification of central motor conduction deficits in multiple sclerosis patients before and after treatment of acute exacerbation by methylprednisolone. J Neurol Neurosurg Psychiatry 2006; 77:345-50. [PMID: 16174651 PMCID: PMC2077708 DOI: 10.1136/jnnp.2005.065284] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To compare the effects of intravenous methylprednisolone (IVMP) in patients with relapsing-remitting (RR-MS), secondary progressive (SP-MS), and primary progressive multiple sclerosis (PP-MS). METHODS Clinical and neurophysiological follow up was undertaken in 24 RR-MS, eight SP-MS, and nine PP-MS patients receiving Solu-Medrol 500 mg/d over five days for exacerbations involving the motor system. Motor evoked potentials (MEPs) were used to measure central motor conduction time (CMCT) and the triple stimulation technique (TST) was applied to assess conduction deficits. The TST allows accurate quantification of the number of conducting central motor neurones, expressed by the TST amplitude ratio. RESULTS There was a significant increase in TST amplitude ratio in RR-MS (p<0.001) and SP-MS patients (p<0.02) at day 5, paralleling an increase in muscle force. TST amplitude ratio and muscle force remained stable at two months. In PP-MS, TST amplitude ratio and muscle force did not change. CMCT did not change significantly in any of the three groups. CONCLUSIONS In RR-MS and SP-MS, IVMP is followed by a prompt increase in conducting central motor neurones paralleled by improvement in muscle force, which most probably reflects partial resolution of central conduction block. The lack of similar clinical and neurophysiological changes in PP-MS corroborates previous clinical reports on limited IVMP efficacy in this patient group and points to pathophysiological differences underlying exacerbations in PP-MS.
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MESH Headings
- Adult
- Dose-Response Relationship, Drug
- Evoked Potentials, Motor/drug effects
- Evoked Potentials, Motor/physiology
- Female
- Humans
- Infusions, Intravenous
- Isometric Contraction/drug effects
- Isometric Contraction/physiology
- Male
- Methylprednisolone/adverse effects
- Methylprednisolone/therapeutic use
- Middle Aged
- Motor Neuron Disease/drug therapy
- Motor Neuron Disease/physiopathology
- Multiple Sclerosis, Chronic Progressive/diagnosis
- Multiple Sclerosis, Chronic Progressive/drug therapy
- Multiple Sclerosis, Chronic Progressive/physiopathology
- Multiple Sclerosis, Relapsing-Remitting/diagnosis
- Multiple Sclerosis, Relapsing-Remitting/drug therapy
- Multiple Sclerosis, Relapsing-Remitting/physiopathology
- Muscle, Skeletal/innervation
- Neural Conduction/drug effects
- Neural Conduction/physiology
- Optic Neuritis/drug therapy
- Optic Neuritis/physiopathology
- Pyramidal Tracts/drug effects
- Pyramidal Tracts/physiopathology
- Treatment Outcome
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Affiliation(s)
- A M Humm
- Department of Neurology, University of Berne, Switzerland
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Z'Graggen WJ, Humm AM, Durisch N, Magistris MR, Rösler KM. Repetitive spinal motor neuron discharges following single transcranial magnetic stimuli: a quantitative study. Clin Neurophysiol 2005; 116:1628-37. [PMID: 15908271 DOI: 10.1016/j.clinph.2005.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 03/01/2005] [Accepted: 03/25/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To quantify repetitive discharges of spinal motor neurons (repMNDs) in response to single transcranial magnetic stimuli (TMS). To assess their contribution to the size of motor evoked potentials (MEPs). METHODS We combined the triple stimulation technique (TST) with an additional nerve stimulus in the periphery (= quadruple stimulation; QuadS). The QuadS eliminates the first action potential descending on each axon after TMS, and eliminates effects on response size induced by desynchronization of these discharges, thereby allowing a quantification of motor neurons (MNs) discharging twice. In some instances, a quintuple stimulation (QuintS) was used, to quantify the number of MNs discharging three times. Recordings were from the abductor digiti minimi of 14 healthy subjects, using two different stimulation intensities and three different levels of facilitatory muscle pre-contractions. RESULTS The threshold to obtain repMNDs was high. Their maximal size differed markedly between subjects, ranging from 8 to 52% of all MNs. Stimulation intensity and facilitatory muscle contraction, but not resting motor threshold, correlated with the amount of repMNDs. QuintS never yielded discernible responses, hence all observed repMNDs were double discharges. RepMNDs contributed to the MEP areas, but did not influence MEP amplitudes. CONCLUSIONS QuadS and QuintS allow precise quantification of repMNDs. The threshold of repMNDs is high and varies considerably between subjects. SIGNIFICANCE repMNDs have to be considered when MEP areas are measured. Their analysis may be of interest in neurological disorders, but standardized stimulation parameters appear essential.
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Affiliation(s)
- W J Z'Graggen
- Department of Neurology, Inselspital, University of Berne, Freiburgstrasse, CH-3010 Bern, Switzerland
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Humm AM, Z'Graggen WJ, von Hornstein NE, Magistris MR, Rösler KM. Assessment of central motor conduction to intrinsic hand muscles using the triple stimulation technique: normal values and repeatability. Clin Neurophysiol 2004; 115:2558-66. [PMID: 15465445 DOI: 10.1016/j.clinph.2004.06.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2004] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To establish the triple stimulation technique (TST) for recordings from the first dorsal interosseus (FDI) and the abductor pollicis brevis muscles (APB), and to analyse the test-retest repeatability of the TST measurements in APB. METHODS The recently developed TST was slightly modified for recordings from small hand muscles to account for volume conducted activity from surrounding muscles. The TST combines transcranial magnetic stimulation (TMS) with a peripheral collision technique [Magistris et al. Brain 121 (1998) 437]. In contrast to conventional motor-evoked potentials (MEPs), it quantifies the number of conducting central motor neurons (expressed by the TST amplitude ratio, TST-AR). MEPs and TST were performed in 30 sides of 25 healthy subjects (target muscle FDI), and in 29 sides of 21 healthy subjects (target muscle APB). All APB recordings were repeated after 25+/-5.9 days. RESULTS The TST-AR averaged 97.4+/-2.5% in FDI and 95.9+/-4.7% in APB. There was a mean difference of the TST-AR ratio of 2.9+/-3.1% between the repeated APB recordings (95% limits of agreement+/-6.3%). CONCLUSIONS TMS allows activation of virtually all motor neurons supplying FDI and APB, when effects of volume conduction are eliminated. Its test-retest repeatability is excellent. SIGNIFICANCE The TST is well suited for follow-up examinations of central motor conduction failures. The greater number of established target muscles widens its clinical applicability.
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Affiliation(s)
- A M Humm
- Department of Neurology, University of Berne, Inselspital, CH-3010 Berne, Switzerland.
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Affiliation(s)
- A M Humm
- Department of Neurology, University of Berne, Berne, Switzerland.
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Humm AM, Beer S, Kool J, Magistris MR, Kesselring J, Rösler KM. Quantification of Uhthoff's phenomenon in multiple sclerosis: a magnetic stimulation study. Clin Neurophysiol 2004; 115:2493-501. [PMID: 15465437 DOI: 10.1016/j.clinph.2004.06.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To quantify temperature induced changes (=Uhthoff phenomenon) in central motor conduction and their relation to clinical motor deficits in 20 multiple sclerosis (MS) patients. METHODS Self-assessment of vulnerability to temperature and clinical examination were performed. We used motor evoked potentials to measure central motor conduction time (CMCT) and applied the triple stimulation technique (TST) to assess conduction failure. The TST allows an accurate quantification of the proportion of conducting central motor neurons, expressed by the TST amplitude ratio (TST-AR). RESULTS Temperature induced changes of TST-AR were significantly more marked in patients with prolonged CMCT (P=0.037). There was a significant linear correlation between changes of TST-AR and walking velocity (P=0.0002). Relationships were found between pronounced subjective vulnerability to temperature and (i) abnormal CMCT (P=0.02), (ii) temperature induced changes in TST-AR (P=0.04) and (iii) temperature induced changes in walking velocity (P=0.04). CMCT remained virtually unchanged by temperature modification. CONCLUSIONS Uhthoff phenomena in the motor system are due to varying degrees of conduction block and associated with prolonged CMCT. In contrast to conduction block, CMCT is not importantly affected by temperature. SIGNIFICANCE This is the first study quantifying the Uhthoff phenomenon in the pyramidal tract of MS patients. The results suggest that patients with central conduction slowing are particularly vulnerable to develop temperature-dependent central motor conduction blocks.
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Affiliation(s)
- A M Humm
- Department of Neurology, University of Berne, Inselspital, Freiburgstrasse, CH-3010 Bern, Switzerland
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Humm AM, Magistris MR, Truffert A, Hess CW, Rösler KM. Central motor conduction differs between acute relapsing–remitting and chronic progressive multiple sclerosis. Clin Neurophysiol 2003; 114:2196-203. [PMID: 14580619 DOI: 10.1016/s1388-2457(03)00231-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To characterize central motor conduction in relation to the clinical deficits and to the disease duration in 90 patients with acute relapsing-remitting MS (RR-MS) and in 51 patients with chronic primary or secondary progressive MS (P-MS). METHODS The triple stimulation technique (TST) was used to quantify the central motor conduction failure (expressed by the TST amplitude ratio) and conventional motor evoked potentials (MEPs) were used to measure the central motor conduction time (CMCT). RESULTS The TST amplitude ratio was reduced in presence of a clinical motor deficit (p=0.02 for RR-MS, p<0.01 for P-MS), but did not significantly differ in RR-MS and P-MS (p>0.05) when patients with similar clinical motor deficit were compared. The CMCT was not related to the clinical motor deficit in both RR-MS and P-MS. However, the CMCT was markedly prolonged in P-MS, when patients with similar clinical motor deficit and with similar disease duration were compared (p<0.01). The differences were not attributable to differential involvement of the spinal cord, which was similar in RR-MS and P-MS. CONCLUSIONS Our results disclose differences between the central motor conduction in RR-MS and P-MS that are not related to disease severity, spinal cord involvement or disease duration.
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Affiliation(s)
- A M Humm
- Department of Neurology, University of Berne, Inselspital, CH-3010 Bern, Switzerland
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Humm AM, Z'Graggen WJ, Remonda L, Rösler KM. Bilaterale axonale Läsion des N. facialis nach sagittaler Splitosteotomie: Eine Patientenbeschreibung. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Z'Graggen WJ, Humm AM, Carruzzo A, Arnold M, Rösler KM. Elektrophysiologische Untersuchung des N. ulnaris im Bereich der Handwurzel. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Rösler KM, Z'Graggen WJ, Humm AM. Desynchronisation von Motoneuronentladungen nach transkranieller Magnetstimulation: Eine quantitative Analyse. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Radojevic V, Humm AM, Rösler KM, Lauterburg T, Burgunder JM. Abnormal trafficking of sarcolemmal proteins in alpha-glucosidase deficiency. Acta Neuropathol 2003; 105:373-80. [PMID: 12624791 DOI: 10.1007/s00401-002-0656-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2001] [Revised: 10/17/2002] [Accepted: 11/04/2002] [Indexed: 10/25/2022]
Abstract
The dystrophin-associated protein complex (DAP) plays an important role in the integrity and stability of the muscle membrane. Whereas much is known about the interaction between DAP members at the sarcolemmal location, intracellular DAP assembly and trafficking is still largely unknown. In alpha-glucosidase (acid maltase) deficiency (alphaGDD), accumulation of glycogen is accompanied by cytoarchitectural abnormalities impairing normal protein metabolism. In the present study, we took advantage of this fact to examine the consequences of impaired protein handling on the formation of DAP, with the aim of gaining indirect knowledge about its sarcoplasmic trafficking and a better understanding of mechanisms leading to myopathic changes found in alphaGDD. Histological examination of alphaGDD muscle confirmed a vacuolar myopathy with glycogen accumulation both in vacuoles and within the sarcoplasm. Sarcoplasmic accumulation of sarcolemmal proteins, including dystrophin and sarcoglycans, occurred around some vacuoles and within non-vacuolated fibres. Utrophin was up-regulated and found at extra-junctional sarcolemmal locations of many fibres. AlphaGDD muscle cells developed in a fashion similar to that of controls in culture. However, vacuoles were found in 2-week-old alphaGDD myotubes, and these subsequently increased in size and number. Substantial alterations in DAP handling were found, with accumulation close to the Golgi apparatus. Utrophin was not enriched in the sarcoplasm but was up-regulated along the whole sarcolemma. Our results demonstrate a close association of dystrophin and sarcoglycans during sarcoplasmic processing. Furthermore, they suggest that the myopathy found in alphaGDD is a secondary form of DAP deficiency.
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Affiliation(s)
- V Radojevic
- Department of Neurology, Faculty of Medicine, University of Bern, Bern, Switzerland
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Humm AM, Pabst C, Lauterburg T, Burgunder JM. Enkephalin and aFGF are differentially regulated in rat spinal motoneurons after chemodenervation with botulinum toxin. Exp Neurol 2000; 161:361-72. [PMID: 10683301 DOI: 10.1006/exnr.1999.7268] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Botulinum toxin is used to induce transient graded paresis by chemodenervation in the treatment of focal hyperkinetic movement disorders. While the molecular events occurring in motoneurons after mechanical nerve lesioning leading to muscle paresis are well known, they have been investigated to a lesser extent after chemodenervation. We therefore examined the expression of enkephalin (ENK), acidic fibroblast growth factor (aFGF), neurotensin (NT), galanin (GAL), substance P (SP), vasoactive intestinal polypeptide (VIP), and neuropeptide Y (NPY) in rat spinal motoneurons after chemodenervation of the gastrocnemius. In order to precisely localize the motoneurons targeting the injection site, retrograde tracing was performed in additional rats by using Fluorogold injections. ENK expression was upregulated in the region corresponding to the Fluorogold positive motoneurons, but also on the contralateral side and in more distant parts of the spinal cord. The highest upregulation occurred 7 to 14 days after injections and decreased over a period of three months. At 8 days, aFGF was slightly downregulated in all regions studied, single motoneurons showed NT expression, while expression of GAL, SP, VIP, and NPY could be detected neither in controls nor in toxin-treated animals. These alterations in gene expression were strikingly different from those described after axotomy. Our present findings give additional demonstration of the considerable plasticity of the adult spinal cord after botulinum toxin treatment.
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Affiliation(s)
- A M Humm
- Laboratory of Neuromorphology, University of Berne, Berne, CH3010, Switzerland
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