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Ramesh G, Didier PJ, England JD, Santana-Gould L, Doyle-Meyers LA, Martin DS, Jacobs MB, Philipp MT. Inflammation in the pathogenesis of lyme neuroborreliosis. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1344-60. [PMID: 25892509 DOI: 10.1016/j.ajpath.2015.01.024] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/20/2015] [Accepted: 01/23/2015] [Indexed: 01/03/2023]
Abstract
Lyme neuroborreliosis, caused by the spirochete Borrelia burgdorferi, affects both peripheral and central nervous systems. We assessed a causal role for inflammation in Lyme neuroborreliosis pathogenesis by evaluating the induced inflammatory changes in the central nervous system, spinal nerves, and dorsal root ganglia (DRG) of rhesus macaques that were inoculated intrathecally with live B. burgdorferi and either treated with dexamethasone or meloxicam (anti-inflammatory drugs) or left untreated. ELISA of cerebrospinal fluid showed significantly elevated levels of IL-6, IL-8, chemokine ligand 2, and CXCL13 and pleocytosis in all infected animals, except dexamethasone-treated animals. Cerebrospinal fluid and central nervous system tissues of infected animals were culture positive for B. burgdorferi regardless of treatment. B. burgdorferi antigen was detected in the DRG and dorsal roots by immunofluorescence staining and confocal microscopy. Histopathology revealed leptomeningitis, vasculitis, and focal inflammation in the central nervous system; necrotizing focal myelitis in the cervical spinal cord; radiculitis; neuritis and demyelination in the spinal roots; and inflammation with neurodegeneration in the DRG that was concomitant with significant neuronal and satellite glial cell apoptosis. These changes were absent in the dexamethasone-treated animals. Electromyography revealed persistent abnormalities in F-wave chronodispersion in nerve roots of a few infected animals; which were absent in dexamethasone-treated animals. These results suggest that inflammation has a causal role in the pathogenesis of acute Lyme neuroborreliosis.
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Affiliation(s)
- Geeta Ramesh
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, Louisiana
| | - Peter J Didier
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana
| | - John D England
- Department of Neurology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Lenay Santana-Gould
- Department of Neurology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Lara A Doyle-Meyers
- Division of Veterinary Medicine, Tulane National Primate Research Center, Covington, Louisiana
| | - Dale S Martin
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, Louisiana
| | - Mary B Jacobs
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, Louisiana
| | - Mario T Philipp
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, Louisiana.
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Gündüz A, Kiziltan ME. F-wave and motor-evoked potentials during motor imagery and observation in apraxia of Parkinson disease. Muscle Nerve 2015; 52:1072-7. [PMID: 25809124 DOI: 10.1002/mus.24663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2015] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The amplitudes of F-waves and motor-evoked potentials (MEPs) increase during imagination or active motor performance. The aim of this study was to investigate F-wave and MEP facilitation during assessment of apraxia. METHODS Eight Parkinson disease (PD) patients with apraxia, 11 patients without apraxia, and 8 healthy volunteers were enrolled. F-waves and MEPs were recorded during 4 states (resting, imagination, observation, and active movement). RESULTS The mean amplitude of the F-waves increased significantly during imagination and active movement as compared with at rest in healthy individuals (P = 0.028) and in the nonapraxia group (P = 0.005). PD patients with apraxia did not have similar facilitation. The mean amplitude of the MEPs also showed a similar loss of facilitation in PD with apraxia. CONCLUSIONS Loss of facilitation during the preparation for movement is closely related to the "gold standard" clinical praxis battery. This study provides additional support and a potential electrophysiological assessment method for apraxia in PD.
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Affiliation(s)
- Ayşegül Gündüz
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University, 34098, K.M. Pasa, Istanbul, Turkey
| | - Meral E Kiziltan
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University, 34098, K.M. Pasa, Istanbul, Turkey
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Shulga A, Lioumis P, Kirveskari E, Savolainen S, Mäkelä JP, Ylinen A. The use of F-response in defining interstimulus intervals appropriate for LTP-like plasticity induction in lower limb spinal paired associative stimulation. J Neurosci Methods 2015; 242:112-7. [DOI: 10.1016/j.jneumeth.2015.01.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/05/2015] [Accepted: 01/07/2015] [Indexed: 11/29/2022]
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Hirasawa S, Shimizu M, Marui Y, Kishimoto M, Okuno S. Establishment of a method to measure length of the ulnar nerve and standardize F-wave values in clinically normal beagles. J Vet Med Sci 2015; 76:1603-7. [PMID: 25649942 PMCID: PMC4300375 DOI: 10.1292/jvms.14-0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We designed a new method of
measuring the length of the ulnar nerve and determining standard values for F-wave
parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely
measured to determine F-wave latency and conduction velocity. The length of the forelimb
has served as the length of the ulnar nerve for F-wave assessments, but report indicates
that F-wave latency is proportional to the length of the pathway traveled by nerve
impulses. Therefore, we measured the surface distance from a stimulus point to the spinous
process of the first thoracic vertebra (nerve length 1) and the anterior horn of the
scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade
acromion. The correlation coefficients between the shortest F-wave latency and the length
of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the
highest value. Furthermore, the anterior horn of the scapula was easily palpated in any
dog regardless of well-fed body. We concluded that nerve length 2 was optimal for
measuring the length of the ulnar nerve.
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Affiliation(s)
- Shun Hirasawa
- Department of Veterinary Diagnostic Imaging, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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Mondelli M, Aretini A. Low sensitivity of F-wave in the electrodiagnosis of carpal tunnel syndrome. J Electromyogr Kinesiol 2014; 25:247-52. [PMID: 25561074 DOI: 10.1016/j.jelekin.2014.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/26/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE Previous studies showed "F-wave inversion" (F-INV) as a sensitive method in the electrodiagnosis of early stage of carpal tunnel syndrome (CTS). This study aimed at evaluating the sensitivity and specificity of F-wave and nerve conduction velocity (NCV) testing in CTS. METHODS We consecutively enrolled 244 cases and 108 controls. F-waves analysis included: Fwave minimum and mean latencies, F-wave persistence and chronodispersion, mean-F/CMAP amplitude ratio, F-INV. Specificity and sensitivity of F-waves parameters were calculated in the whole sample of CTS patients and by grouping the patients according to CTS severity. Multivariate logistic regression was also performed using F-INV as a dependent variable. RESULTS In the whole sample the sensitivity of F-mean-INV and of median-ulnar NCV comparative testing was 50.8% and 93.7%, respectively. F-INV sensitivity dropped to 8% in CTS early stage. F-INV could be predicted only by distal motor latency of the median nerve. The sensitivity of all F-wave parameters increased only in the most severe stages of CTS. CONCLUSIONS This study does not confirm the electrodiagnostic usefulness of F-INV in early stage of CTS. All F-wave parameters, including F-INV, are much less sensitive than conventional NCV in CTS electrodiagnosis. F-wave does not add further useful information specifically related to CTS.
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Pre- and postoperative evaluation of patients with lumbosacral disc herniation by neurophysiological and clinical assessment. Spine (Phila Pa 1976) 2014; 39:1792-800. [PMID: 25010094 DOI: 10.1097/brs.0000000000000510] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN The application of complex neurophysiological examination including motor evoked potentials (MEP) for pre- and postoperative evaluation of patients experiencing acute sciatica. OBJECTIVE The assessment of sensitivity and specificity of needle electromyography, MEP, and H-reflex examinations. The comparative analysis of preoperative and postoperative neurophysiological examination. SUMMARY OF BACKGROUND DATA In spite of the fact that complex neurophysiological diagnostic tools seem to be important for interpretation of incompatible results of neuroimaging and clinical examination, especially in the patients qualified for surgical treatment, their application has never been completely analyzed and documented. METHODS Pre- and postoperative electromyography, electroneurography, F-waves, H-reflex, and MEP examination were performed in 23 patients with confirmed disc-root conflict at lumbosacral spine. Clinical evaluation included examination of sensory perception for L5-S1 dermatomes, muscles strength with Lovett's scale, deep tendon reflexes, pain intensity with visual analogue scale, and straight leg raising test. RESULTS Sensitivity of electromyography at rest and MEP examination for evaluation of L5-S1 roots injury was 22% to 63% and 31% to 56% whereas specificity was 71% to 83% and 57% to 86%, respectively. H-reflex sensitivity and specificity for evaluation of S1 root injury were 56% and 67%, respectively. A significant improvement of root latency parameter in postoperative MEP studies as compared with preoperative was recorded for L5 (P = 0.039) and S1 root's levels (P = 0.05). CONCLUSION The analysis of the results from neurophysiological tests together with neuroimaging and clinical examination allow for a precise preoperative indication of the lumbosacral roots injury and accurate postoperative evaluation of patients experiencing sciatica. LEVEL OF EVIDENCE 3.
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Derksen A, Ritter C, Athar P, Kieseier BC, Mancias P, Hartung HP, Sheikh KA, Lehmann HC. Sural sparing pattern discriminates Guillain-Barré syndrome from its mimics. Muscle Nerve 2014; 50:780-4. [PMID: 24616124 DOI: 10.1002/mus.24226] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/18/2014] [Accepted: 02/24/2014] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Electrodiagnostic features of demyelination are essential for establishing the diagnosis in demyelinating subtypes of Guillain-Barré syndrome (GBS), but they may also occur in disorders that mimic GBS clinically. Information about their frequency in GBS mimics is sparse. METHODS Evaluation of electrodiagnostic features from 38 patients with suspected GBS in whom the diagnosis was later refuted (GBS mimics). Their diagnostic accuracy was analyzed by comparison with nerve conduction studies (NCS) from 73 confirmed GBS patients. RESULTS Disorders that mimicked GBS clinically at the time of hospital admission included other inflammatory, metabolic, toxic, or infectious neuropathies and spinal cord disorders. The sural sparing pattern was the most specific electrodiagnostic feature for demyelinating GBS. CONCLUSIONS Common electrodiagnostic abnormalities in early demyelinating GBS do not usually exclude other rare differential diagnoses. An exception to this is the sural sparing pattern described here, which strongly supports the diagnosis of demyelinating GBS.
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Affiliation(s)
- Angelika Derksen
- Department of Neurology, University Düsseldorf, Medical Faculty, Düsseldorf, Germany
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58
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Kirimoto H, Tamaki H, Suzuki M, Matsumoto T, Sugawara K, Kojima S, Onishi H. Sensorimotor modulation differs with load type during constant finger force or position. PLoS One 2014; 9:e108058. [PMID: 25233353 PMCID: PMC4169486 DOI: 10.1371/journal.pone.0108058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/23/2014] [Indexed: 11/19/2022] Open
Abstract
During submaximal isometric contraction, there are two different load types: production of a constant force against a rigid restraint (force task), and maintenance of position against a constant load (position task). Previous studies reported that the time to task failure during a fatigue task was twice as long in the force task compared with the position task. Sensory feedback processing may contribute to these differences. The purpose of the current study was to determine the influence of load types during static muscle contraction tasks on the gating effect, i.e., attenuation of somatosensory-evoked potentials (SEPs) and the cortical silent period (cSP). Ten healthy subjects contracted their right first dorsal interosseus muscle by abducting their index finger for 90 s, to produce a constant force against a rigid restraint that was 20% of the maximum voluntary contraction (force task), or to maintain a constant position with 10° abduction of the metacarpophalangeal joint against the same load (position task). Somatosensory evoked potentials (SEPs) were recorded from C3' by stimulating either the right ulnar or median nerve at the wrist while maintaining contraction. The cortical silent period (cSP) was also elicited by transcranial magnetic stimulation. Reduction of the amplitude of the P45 component of SEPs was significantly larger during the position task than during the force task and under control rest conditions when the ulnar nerve, but not the median nerve, was stimulated. The position task had a significantly shorter cSP duration than the force task. These results suggest the need for more proprioceptive information during the position task than the force task. The shorter duration of the cSP during the position task may be attributable to larger amplitude of heteronymous short latency reflexes. Sensorimotor modulations may differ with load type during constant finger force or position tasks.
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Affiliation(s)
- Hikari Kirimoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hiroyuki Tamaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Makoto Suzuki
- School of Allied Health Sciences, Kitasato University, Kanagawa, Japan
| | - Takuya Matsumoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
- Graduate School of Health and Welfare, Niigata University of Health and Welfare, Niigata, Japan
| | - Kazuhiro Sugawara
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Syo Kojima
- Graduate School of Health and Welfare, Niigata University of Health and Welfare, Niigata, Japan
- Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
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Dai C, Tang S, Li J, Wang J, Xiao X. Effects of colistin on the sensory nerve conduction velocity and F-wave in mice. Basic Clin Pharmacol Toxicol 2014; 115:577-80. [PMID: 24861773 DOI: 10.1111/bcpt.12272] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/14/2014] [Indexed: 11/26/2022]
Abstract
The aim of this study was to examine the changes of sensory nerve conduction velocity (SNCV) and F-wave for colistin-induced peripheral neurotoxicity using a mouse model. Mice were administered with colistin 5, 7.5 and 15 mg/kg/day via a 3-min. intravenous infusion. The sensory nerve conduction velocity (SNCV) and F-wave were measured using the bipolar recording electrodes. The SNCV and F-wave latency changed in a dose- and time-dependent manner. The significant increase of F-wave latency and significant decrease of SNCV appeared on day 3 (p < 0.05 and 0.01, respectively) in the 15 mg/kg/day group, and they were markedly changed on day 7 in the 7.5 mg/kg/day (p < 0.01 and 0.05, respectively) and 15 mg/kg/day groups (both p < 0.01). In addition, F-wave latency also significantly increased on day 7 in the 5 mg/kg/day group (p < 0.05) without any clinical signs. These results indicate that SNCV and F-wave latency were more sensitive in colistin-induced neurotoxicity in mice, which highlights the early monitoring tool of polymyxins neurotoxicity in the clinic.
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Affiliation(s)
- Chongshan Dai
- College of Veterinary Medicine, China Agricultural University, Beijing, China
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60
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Bunno Y, Yurugi Y, Onigata C, Suzuki T, Iwatsuki H. Influence of motor imagery of isometric opponens pollicis activity on the excitability of spinal motor neurons: a comparison using different muscle contraction strengths. J Phys Ther Sci 2014; 26:1069-73. [PMID: 25140099 PMCID: PMC4135200 DOI: 10.1589/jpts.26.1069] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 01/23/2014] [Indexed: 12/05/2022] Open
Abstract
[Purpose] This study aimed to determine the differences in the excitability of spinal
motor neurons during motor imagery of a muscle contraction at different contraction
strengths. [Methods] We recorded the F-wave in 15 healthy subjects. First, in a trial at
rest, the muscle was relaxed during F-wave recording. Next, during motor imagery, subjects
were instructed to imagine maximum voluntary contractions of 10%, 30%, and 50% while
holding the sensor of a pinch meter, and F-waves were recorded for each contraction.
F-waves were recorded immediately and at 5, 10, and 15 min after motor imagery. [Results]
Both persistence and F/M amplitude ratios during motor imagery under maximum voluntary
contractions of 10%, 30%, and 50% were significantly higher than that at rest. In
addition, persistence, F/M amplitude ratio, and latency were similar during motor imagery
under the three muscle contraction strengths. [Conclusion] Motor imagery under maximum
voluntary contractions of 10%, 30%, and 50% can increase the excitability of spinal motor
neurons. The results indicated that differences in muscle contraction strengths during
motor imagery are not involved in changes in the excitability of spinal motor neurons.
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Affiliation(s)
- Yoshibumi Bunno
- Graduate School of Health Sciences, Graduate School of Aomori University of Health and Welfare: 58-1 Mase, Hamadate, Aomori 030-8505, Japan
| | - Yuko Yurugi
- Graduate School of Health Sciences, Graduate School of Aomori University of Health and Welfare: 58-1 Mase, Hamadate, Aomori 030-8505, Japan
| | - Chieko Onigata
- Clinical Physical Therapy Laboratory, Faculty of Health Sciences, Kansai University of Health Sciences, Japan
| | - Toshiaki Suzuki
- Clinical Physical Therapy Laboratory, Faculty of Health Sciences, Kansai University of Health Sciences, Japan
| | - Hiroyasu Iwatsuki
- Graduate School of Health Sciences, Graduate School of Aomori University of Health and Welfare: 58-1 Mase, Hamadate, Aomori 030-8505, Japan
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Nowicki M, Baum P, Kosacka J, Stockinger M, Klöting N, Blüher M, Bechmann I, Toyka KV. Effects of isoflurane anesthesia on F-waves in the sciatic nerve of the adult rat. Muscle Nerve 2014; 50:257-61. [PMID: 24347162 DOI: 10.1002/mus.24150] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 12/10/2013] [Accepted: 12/11/2013] [Indexed: 11/07/2022]
Abstract
INTRODUCTION Nerve conduction studies provide insights into the functional consequences of axonal and myelin pathology in peripheral neuropathies. We investigated whether isoflurane inhalation anesthesia alters F-wave latencies and F-persistence in the sciatic nerve of adult rats. METHODS Ten rats were investigated at 3 different isoflurane concentrations followed by ketamine-xylazine injection anesthesia. To assess F-wave latencies, a stimulation paradigm was chosen to minimize H-reflex masking of F-waves. RESULTS F-wave persistence rates were reduced with 3.5% isoflurane concentration at 4 and 10 Hz supramaximal stimulation and marginally reduced with 2.5% isoflurane when compared with ketamine-xylazine. F-wave amplitudes decreased progressively with rising stimulus frequency in all types of anesthesia and most at 3.5% isoflurane concentration. CONCLUSIONS The type of anesthesia and the stimulus repetition rate have an impact on some F-wave parameters. Higher isoflurane concentrations and repetition rates are not recommended in experimental studies using rat neuropathy models where F-waves are of interest.
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Affiliation(s)
- Marcin Nowicki
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
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Kosacka J, Nowicki M, Blüher M, Baum P, Stockinger M, Toyka KV, Klöting I, Stumvoll M, Serke H, Bechmann I, Klöting N. Increased autophagy in peripheral nerves may protect Wistar Ottawa Karlsburg W rats against neuropathy. Exp Neurol 2013; 250:125-35. [PMID: 24095727 DOI: 10.1016/j.expneurol.2013.09.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/13/2013] [Accepted: 09/17/2013] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Wistar Ottawa Karlsburg W (RT1(u)) rats (WOKW) develop obesity, dyslipidemia, moderate hypertension, hyperinsulinemia and impaired glucose tolerance prone to induce peripheral neuropathy (PN). Autophagy has been shown to prevent neurodegeneration in the central and peripheral nervous system. We analyzed the potential protective role of autophagy in an established rat model in preventing PN. METHODS We examined electrophysiology (motor-and sensory/mixed afferent conduction velocities and the minimal F-wave latency) and morphology, including ultrathin sections, myelin sheath thickness (g-ratio) and immunohistochemical markers of autophagy and inflammation in the sciatic nerve of five-month-old, male WOKW as compared to Wistar derived, congenic LEW.1W control rats, characterized by the same major histocompatibility complex as WOKW rats (RT1(u)). Moreover, the expression of axonal and synaptic proteins (NF68, GAP43, MP0), autophagy- (Atg5, Atg7, LC3), and apoptosis (cleaved caspase-3)-related markers was measured using Western blot. RESULTS No abnormalities in nerve electrophysiology and morphology were found in WOKW compared to LEW.1W rats. However, autophagosomes were more frequently apparent in sciatic nerves of WOKW rats. In Western blot analyses no significant differences in expression of neuronal structural proteins were found, but autophagy markers were up-regulated in WOKW compared to LEW.1W sciatic nerves. Immunostaining revealed a greater infiltration of Iba1/ED-1-positive macrophages, CD-3-positive T-cells and LC3-expression in sciatic nerves of WOKW rats. CONCLUSIONS Our results indicate that WOKW rats show an up-regulated autophagy and a mild inflammatory response but do not develop overt neuropathy. We suggest that autophagy and inflammatory cells may exert a protective role in preventing neuropathy in this rat model of the metabolic syndrome but the mechanism of action is still unclear.
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Affiliation(s)
- J Kosacka
- Department of Medicine, University of Leipzig, Germany.
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Bianchi E, Biserni R, Gallucci A, Pisoni L, Menchetti M, Gandini G. Changes in electromyography and F wave responses in two cats with presumed local tetanus: implications for diagnosis and prognosis. J Feline Med Surg 2013; 15:927-31. [PMID: 23439760 PMCID: PMC11383150 DOI: 10.1177/1098612x13479599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two cases of focal tetanus in the cat are described. Clinical findings included severe muscular spasms of the pelvic limbs in one cat, and involvement of the thoracic limbs and muscles of the neck and face in the other. Electromyography in both cats showed spontaneous activity characterised by the presence of motor unit potentials. F waves, never previously reported in focal tetanus in animals, showed significantly increased F/M amplitude ratio in both cats and increased F wave duration in one cat. The electrodiagnostic findings provided relevant diagnostic and, possibly, prognostic information.
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Affiliation(s)
- Ezio Bianchi
- 1Department of Veterinary Medical Science, University of Parma, Parma, Italy
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Shields RK, Dudley-Javoroski S. Fatigue modulates synchronous but not asynchronous soleus activation during stimulation of paralyzed muscle. Clin Neurophysiol 2013; 124:1853-60. [PMID: 23673062 DOI: 10.1016/j.clinph.2013.03.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 03/07/2013] [Accepted: 03/15/2013] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Electrical stimulation over a motor nerve yields muscle force via a combination of direct and reflex-mediated activation. We determined the influence of fatigue on reflex-mediated responses induced during supra-maximal electrical stimulation in humans with complete paralysis. METHODS We analyzed soleus electromyographic (EMG) activity during repetitive stimulation (15 Hz, 125 contractions) in 22 individuals with complete paralysis. The bout of stimulation caused significant soleus muscle fatigue (53.1% torque decline). RESULTS Before fatigue, EMG at all latencies after the M-wave was less than 1% of the maximal M-wave amplitude (% MaxM). After fatigue there was a fourfold (p < 0.05) increase in EMG at the H-reflex latency; however, the overall magnitude remained low (< 2% change in % MaxM). There was no increase in "asynchronous" EMG ∼ 1 s after the stimulus train. CONCLUSIONS Fatigue enhanced the activation to the paralyzed soleus muscle, but primarily at the H-reflex latency. The overall influence of this reflex modulation was small. Soleus EMG was not elevated during fatigue at latencies consistent with asynchronous activation. SIGNIFICANCE These findings support synchronous reflex responses increase while random asynchronous reflex activation does not change during repetitive supra-maximal stimulation, offering a clinical strategy to consistently dose stress to paralyzed tissues.
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Affiliation(s)
- Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
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Short-latency afferent inhibition modulation during finger movement. PLoS One 2013; 8:e60496. [PMID: 23593228 PMCID: PMC3617156 DOI: 10.1371/journal.pone.0060496] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 02/26/2013] [Indexed: 11/19/2022] Open
Abstract
When somatosensory input via electrical stimulation of a peripheral nerve precedes a transcranial magnetic stimulation (TMS) pulse over the primary motor cortex (M1) the corticospinal output is substantially reduced, a phenomenon known as short-latency afferent inhibition (SAI). The present study investigated SAI during rest and during pre-movement, phasic and tonic components of movement. Participants were required to perform an index finger flexion reaction time task in response to an auditory cue. In a series of experiments, SAI was evoked from the mixed, median nerve at the wrist or the cutaneous, digital nerve stimulation of the index finger. To assess the spinal versus cortical origin of movement-related modulation of SAI, F-wave amplitudes were measured during rest and the three movement components. Results indicated that SAI was reduced during all movement components compared to rest, an effect that occurred for both nerves stimulated. Pre-movement SAI reduction was primarily attributed to reduced cortical inhibition, while increased spinal excitability additionally contributed to reduced SAI during tonic and phasic components of movement. SAI was differentially modulated across movement components with mixed but not cutaneous nerve stimulation. These findings reveal that SAI is reduced during movement and this reduction begins as early as the preparation to move. Further, these data suggest that the degree of SAI reduction during movement may be specific to the volume and/or composition of afferent input carried by each nerve.
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Wupuer S, Yamamoto T, Katayama Y, Motohiko H, Sekiguchi S, Matsumura Y, Kobayashi K, Obuchi T, Fukaya C. F-wave suppression induced by suprathreshold high-frequency repetitive trascranial magnetic stimulation in poststroke patients with increased spasticity. Neuromodulation 2012; 16:206-11; discussion 211. [PMID: 23094969 DOI: 10.1111/j.1525-1403.2012.00520.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/27/2012] [Accepted: 09/06/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVE High-intensity and high-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex was carried out in poststroke patients with increased spasticity, and the changes in F-wave parameters in comparison with M-wave parameters induced by rTMS were examined. METHODS Ten-hertz rTMS pulses were delivered to the primary motor cortex of the lesion side at 110% intensity of the resting motor threshold, and F-waves were obtained from the first dorsal interosseous muscle. F-waves were recorded before (pre-stim) and immediately after the end of rTMS (post-stim) in poststroke patients. RESULTS F-wave persistence and F/M Amp.Ratio increased significantly in patients with lesions in upper motor tract as compared with healthy subjects (Wilcoxon rank sum test, p = 0.00023 and p = 0.0073, respectively). After the rTMS application, both F-wave persistence and F/M Amp.Ratio decreased significantly (paired t-test, p = 0.0095 and p = 0.037, respectively). However, the F-wave amplitude did not show a statistically significant variance in poststroke patients. CONCLUSIONS High-frequency suprathreshold rTMS may suppress the F-waves by enhancing the inhibitory effect on spinal excitability through the corticospinal tract, and F-wave persistence and F/M Amp.Ratio can be used to determine the effect of rTMS on patients with increased spasticity.
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Affiliation(s)
- Sidikejiang Wupuer
- Division of Applied System Neuroscience, Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan
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Lapole T, Deroussen F, Pérot C, Petitjean M. Acute effects of Achilles tendon vibration on soleus and tibialis anterior spinal and cortical excitability. Appl Physiol Nutr Metab 2012; 37:657-63. [DOI: 10.1139/h2012-032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prolonged vibration is known to alter muscle performance. Attenuation of Ia afferent efficacy is the main mechanism suggested. However, changes in motor cortex excitability could also be hypothesized. The purpose of the present study was therefore to analyze the acute and outlasting effects of 1 h of Achilles tendon vibration (frequency, 50 Hz) on the soleus (SOL) and tibialis anterior (TA) neuromuscular excitability. Spinal excitability was investigated by means of H-reflexes and F-waves while cortical excitability was characterized by motor evoked potentials (MEPs) obtained by transcranial magnetic stimulation. Twelve subjects performed the experimental procedures 3 times: at the beginning of the testing session (PRE), immediately after 1 h of Achilles tendon vibration (POST), and 1 h after the end of vibration (POST-1H). Prolonged vibration led to acute reduced H-reflex amplitudes for SOL only (46.9% ± 7.7% vs. 32.8% ± 7%; p = 0.006). Mainly presynaptic inhibition mechanisms were thought to be involved because of unchanged F-wave persistence and amplitude mean values, suggesting unaffected motoneuronal excitability. While no acute effects were reported for SOL and TA cortical excitability, both muscles were characterized by an outlasting increase in their MEP amplitude (0.64 ± 0.2 mV vs. 0.43 ± 0.18 mV and 2.17 ± 0.56 mV vs. 1.26 ± 0.36 mV, respectively; p < 0.05). The high modulation of Ia afferent input by vibration led to changes in motor cortex excitability that could contribute to the enhancement in muscular activation capacities reported after chronic use of tendon vibration.
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Affiliation(s)
- Thomas Lapole
- EA 3300 Adaptations Physiologiques à l’Exercice et Réadaptation à l’Effort, UFR STAPS Amiens, Université de Picardie Jules Verne, Amiens, France
- Université de Technologie, Compiègne CNRS UMR 7338, Biomécanique et Bioingénierie, F-60205 Compiègne CEDEX, France
| | - François Deroussen
- Service de Chirurgie Orthopédique Pédiatrique, Centre Hospitalier Universitaire d’Amiens, France
| | - Chantal Pérot
- Université de Technologie, Compiègne CNRS UMR 7338, Biomécanique et Bioingénierie, F-60205 Compiègne CEDEX, France
| | - Michel Petitjean
- EA 2931 Centre de Recherche sur le Sport et le Mouvement, Université Paris Ouest, Nanterre, France
- Service d’Explorations Fonctionnelles du Système Nerveux, Centre Hospitalier Universitaire d’Amiens, France
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Understanding inhibitory mechanisms of lumbar spinal manipulation using H-reflex and F-wave responses: a methodological approach. J Neurosci Methods 2012; 210:169-77. [PMID: 22878176 DOI: 10.1016/j.jneumeth.2012.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 07/13/2012] [Accepted: 07/23/2012] [Indexed: 12/18/2022]
Abstract
The purpose of this research was to characterize unique neurophysiologic events following a high velocity, low amplitude (HVLA) spinal manipulation (SM) procedure. Descriptive time series analysis techniques of time plots, outlier detection and autocorrelation functions were applied to time series of tibial nerve H-reflexes that were evoked at 10-s intervals from 100 s before the event until 100 s after three distinct events L5-S1 HVLA SM, or a L5-S1 joint pre-loading procedure, or the control condition. Sixty-six subjects were randomly assigned to three procedures, i.e., 22 time series per group. If the detection of outliers and correlograms revealed a pattern of non-randomness that was only time-locked to a single, specific event in the normalized time series, then an experimental effect would be inferred beyond the inherent variability of H-reflex responses. Tibial nerve F-wave responses were included to determine if any new information about central nervous function following a HVLA SM procedure could be ascertained. Time series analyses of H(max)/M(max) ratios, pre-post L5-S1 HVLA SM, substantiated the hypothesis that the specific aspects of the manipulative thrust lead to a greater attenuation of the H(max)/M(max) ratio as compared to the non-specific aspects related to the postural perturbation and joint pre-loading. The attenuation of the H(max)/M(max) ratio following the HVLA SM procedure was reliable and may hold promise as a translational tool to measure the consistency and accuracy of protocol implementation involving SM in clinical trials research. F-wave responses were not sensitive to mechanical perturbations of the lumbar spine.
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69
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Peripheral neuropathy response to erythropoietin in type 2 diabetic patients with mild to moderate renal failure. Clin Neurol Neurosurg 2012; 114:663-7. [DOI: 10.1016/j.clineuro.2012.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 01/05/2012] [Accepted: 01/07/2012] [Indexed: 01/29/2023]
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Chroni E, Tendero IS, Punga AR, Stålberg E. Usefulness of assessing repeater F-waves in routine studies. Muscle Nerve 2012; 45:477-85. [DOI: 10.1002/mus.22333] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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71
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Kleine BU, Boekestein WA, Arts IM, Zwarts MJ, Jurgen Schelhaas H, Stegeman DF. Fasciculations and their F-response revisited: High-density surface EMG in ALS and benign fasciculations. Clin Neurophysiol 2012; 123:399-405. [DOI: 10.1016/j.clinph.2011.06.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 05/06/2011] [Accepted: 06/07/2011] [Indexed: 11/26/2022]
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Kado N, Ito M, Suzuki T, Ando H. Excitability of Spinal Motor Neurons in the Contralateral Arm during Voluntary Arm Movements of Various Difficulty Levels. J Phys Ther Sci 2012. [DOI: 10.1589/jpts.24.949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Naoki Kado
- Department of Physical Therapy, Kobe College of Rehabilitation and Welfare
- Kobe University Graduate School of Health Science
| | - Masanori Ito
- Department of Physical Therapy, Kobe College of Rehabilitation and Welfare
- Kobe University Graduate School of Health Science
| | - Toshiaki Suzuki
- Clinical Physical Therapy Laboratory, Kansai University of Health Sciences
| | - Hiroshi Ando
- Kobe University Graduate School of Health Science
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73
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Yuminaga H, Isaka M, Hasegawa O, Niimura C, Lee H, Kanei K, Nishimori T. Difference in Upper Extremity Spinal Motor Neuron Excitability and Function during Walking and Stepping in Place. J Phys Ther Sci 2012. [DOI: 10.1589/jpts.24.1033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Hisanori Yuminaga
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Michiko Isaka
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Osamu Hasegawa
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Chizuko Niimura
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Hanayo Lee
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Kazuaki Kanei
- Department of Physical Therapy, Kansai Vocational College of Medicine
| | - Takashi Nishimori
- Department of Physical Therapy, Kansai Vocational College of Medicine
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Agostinucci J. The effects of circumferential pressure on the soleus muscle F-wave in healthy subjects. J Electromyogr Kinesiol 2011; 22:223-7. [PMID: 22000482 DOI: 10.1016/j.jelekin.2011.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 09/13/2011] [Accepted: 09/13/2011] [Indexed: 11/29/2022] Open
Abstract
Circumferential pressure (CP) was shown to decrease muscle activity in subjects without neuromuscular disorders and in individuals with spinal cord injury and cerebrovascular accidents. The mechanism for this decrease is unknown although it is hypothesized to be spinal in origin. The purpose of this study was to investigate the effect CP has on the soleus F-wave. Results will help determine the mechanism CP uses to effect motoneuron reflex excitability. Thirty-seven healthy volunteers participated. A 16cm air-splint was placed around the calf and during the pressure phase of the experiment it was inflated to 40-45mm Hg. F-waves were evoked by supra maximally stimulating (20%>Mmax) the tibial nerve with a 0.1ms pulse at 0.2Hz using a bipolar surface electrode on the skin of the popliteal fossa. Fifty F-waves were recorded before (baseline), during, and 3) after CP was applied. F-waves were then identified and mean latency, persistence, and mean F/Mmax amplitude ratios were measured and calculated. Friedman Repeated Measures on Ranks tests were conducted on each of the three parameters (p⩽0.05). No statistically significant difference was found for any of the F-wave parameters evaluated. These results were contrary to previous CP studies that observed a significant decrease in muscle activity. Possible reasons for this discrepancy are discussed.
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Affiliation(s)
- James Agostinucci
- Physical Therapy Department, University of Rhode Island, Kingston, RI, USA.
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75
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A neurophysiological approach to the complex organisation of the spine: F-wave duration and the cutaneous silent period in restless legs syndrome. Clin Neurophysiol 2011; 122:383-90. [DOI: 10.1016/j.clinph.2010.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 07/03/2010] [Accepted: 07/06/2010] [Indexed: 11/20/2022]
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Pelkonen A, Yavich L. Neuromuscular pathology in mice lacking alpha-synuclein. Neurosci Lett 2010; 487:350-3. [PMID: 21029764 DOI: 10.1016/j.neulet.2010.10.054] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/19/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
Abstract
This work was undertaken in order to study the possible role of alpha-synuclein in the function of the neuro-muscular junction in skeletal muscles. Repeated stimulation of skeletal muscle motor neurons revealed signs of neuromuscular pathology in alpha-synuclein null mutated (C57Bl/6JOlaHsd) and knockout (B6;129X1-Snca(tm1Rosl)/J) mice. This stimulation produced repetitive compound muscle action potentials in both lines of alpha-synuclein deficient mice. Muscle strength and muscle coordination during ambulation were unaffected, though motor learning was slower in alpha-synuclein deficient mice in the Rotarod test. We conclude that alpha-synuclein may play a role in acetylcholine compartmentalization at the neuromuscular junction, and in the fine control of activity of skeletal muscles.
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Affiliation(s)
- Anssi Pelkonen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
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78
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de Andrade DC, Bendib B, Hattou M, Keravel Y, Nguyen JP, Lefaucheur JP. Neurophysiological assessment of spinal cord stimulation in failed back surgery syndrome. Pain 2010; 150:485-491. [DOI: 10.1016/j.pain.2010.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 03/27/2010] [Accepted: 06/03/2010] [Indexed: 10/19/2022]
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79
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Pastore-Olmedo C, González O, Geijo-Barrientos E. A study of F-waves in patients with unilateral lumbosacral radiculopathy. Eur J Neurol 2009; 16:1233-9. [DOI: 10.1111/j.1468-1331.2009.02764.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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80
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Baudry S, Jordan K, Enoka RM. Heteronymous reflex responses in a hand muscle when maintaining constant finger force or position at different contraction intensities. Clin Neurophysiol 2009; 120:210-7. [DOI: 10.1016/j.clinph.2008.10.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 10/06/2008] [Accepted: 10/12/2008] [Indexed: 10/21/2022]
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Blicher JU, Nielsen JF. Cortical and spinal excitability changes after robotic gait training in healthy participants. Neurorehabil Neural Repair 2008; 23:143-9. [PMID: 19047360 DOI: 10.1177/1545968308317973] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Recent studies have proposed a role for robotic gait training in participants with acquired brain injury, but the effects on the excitability of cortical and spinal neurons even in healthy participants are uncertain. OBJECTIVE To investigate changes in corticospinal excitability in healthy participants after active and passive robotic gait training in a driven gait orthosis (DGO), the Lokomat. METHODS Thirteen healthy participants took part in 2 experiments. Each participant performed 20 minutes of active and passive gait training in a DGO. Motor evoked potentials (MEP), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), F-wave frequency, and Mmax were measured in the right tibialis anterior muscle before and after training. RESULTS Active training led to a decline in MEP amplitude and F-wave frequency. The MEP decline was associated with subjective muscle fatigue. Passive training induced a decrease in SICI lasting for 20 minutes after training. CONCLUSIONS The decline in MEP after active training is most likely because of central fatigue, whereas the decreased F-wave frequency might represent short-term plastic changes in the spinal cord. The decrease in SICI after passive training probably reflects a decrease in intracortical GABA activity, which could benefit the acquisition of new motor skills.
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Affiliation(s)
- Jakob U Blicher
- Hammel Neurorehabilitation and Research Centre, Aarhus University Hospital, Denmark.
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82
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Udby Blicher J, Nielsen JF. Evidence of Increased Motoneuron Excitability in Stroke Patients Without Clinical Spasticity. Neurorehabil Neural Repair 2008; 23:14-6. [DOI: 10.1177/1545968308317439] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction. The contribution of hyperreflexia to impairment after stroke is debated. Spinal motoneuron excitability in healthy subjects and stroke patients with and without spasticity was compared. Methods. Twenty-four patients with single stroke more than 6 months ago and 18 gender-matched healthy volunteers were included. Spasticity was assessed according to the Modified Ashworth Scale. Mmax amplitude and F wave frequency in the abductor pollicis brevis muscle were measured by electrical stimulation of the median nerve. Results . Mmax values were comparable between the groups. However, patients with (n = 7) and without (n = 17) clinically evident spasticity had a significant increase in F wave frequency when compared with healthy subjects. F wave frequency did not differ between spastic and nonspastic patients. Discussion. Increase in spinal motoneuron excitability after stroke is present in stroke patients with minor or no motor deficiencies and does not necessarily lead to spasticity.
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Affiliation(s)
- Jakob Udby Blicher
- Hammel Neurorehabilitation and Research Centre, Aarhus University Hospital, Hammel, Denmark,
| | - Jørgen Feldbæk Nielsen
- Hammel Neurorehabilitation and Research Centre, Aarhus University Hospital, Hammel, Denmark
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83
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The realistic yield of lower leg SNAP amplitudes and SRAR in the routine evaluation of chronic axonal polyneuropathies. J Neurol 2008; 255:1127-35. [DOI: 10.1007/s00415-008-0817-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 11/02/2007] [Accepted: 11/13/2007] [Indexed: 11/26/2022]
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84
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Taniguchi S, Kimura J, Yamada T, Ichikawa H, Hara M, Fujisawa R, Shimizu H, Tani T. Effect of motion imagery to counter rest-induced suppression of F-wave as a measure of anterior horn cell excitability. Clin Neurophysiol 2008; 119:1346-52. [PMID: 18396453 DOI: 10.1016/j.clinph.2007.11.179] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 11/11/2007] [Accepted: 11/23/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To test if motor imagery prevents the rest-induced suppression of anterior horn cell excitability. METHODS Ten healthy subjects underwent two separate experiments, each consisting of stimulating the median nerve 100 times and recording F-waves from abductor pollicis brevis (APB) in three consecutive sessions: (1) after muscle exercise to standardize the baseline, (2) after immobilization of APB for 3h and (3) after muscle exercise to check recovery. We instructed the subject to volitionally relax APB in experiment 1 (relaxation task), and to periodically simulate thumb abduction without actual movement in experiment 2 (imagery task). RESULTS F-wave persistence and amplitude declined after relaxation task and recovered quickly after exercise, but changed little with imagery task. F-wave latencies showed no change when analyzed individually. The frequency distribution of collective F-waves recorded from all subjects remained the same after relaxation task, but showed a shift toward longer latencies after imagery task. CONCLUSIONS Mental imagery without overt motor output suffices to counter the effect of sustained volitional muscle relaxation, which would, otherwise, cause a reversible reduction in anterior horn cell excitability. SIGNIFICANCE This finding documents the importance of central drive for spinal excitability, which affects F-wave studies of a paretic muscle.
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Affiliation(s)
- S Taniguchi
- Department of Orthopaedic Surgery, Kochi Medical School, Kohasu Oko-cho, Nankoku-shi, Kochi 783-8505, Japan.
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85
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Okuno S, Kobayashi T, Orito K. F-wave conduction velocity, persistence, and amplitude for the tibial nerve in clinically normal cats. Am J Vet Res 2008; 69:261-4. [PMID: 18241024 DOI: 10.2460/ajvr.69.2.261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To establish a method of F-wave evaluation and to determine normative values of F-wave parameters, including F-wave conduction velocity, persistence, and amplitude for the tibial nerve in cats. ANIMALS 30 clinically normal cats. PROCEDURES F-waves elicited in the interosseous muscles by stimulation of the tibial nerve were recorded, and linear regression analyses of the shortest latency versus the length of the tibial nerve and the limb length were performed. F-wave persistence was calculated by dividing the number of recorded F-waves by the number of stimuli. RESULTS The correlation coefficient between F-wave latency and nerve length was 0.92, and that between F-wave latency and limb length was 0.58. Mean +/- SD F-wave conduction velocity of the tibial nerve was calculated to be 97.1 +/- 5.0 m/s. Linear regression analysis yielded the regression equation as follows: F-wave latency (milliseconds) = 2.60 + (0.02 x nerve length [mm]). Mean F-wave persistence and amplitude were 98.7 +/- 2.3% and 1.01 +/- 0.62 mV, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that nerve length should be used for nerve conduction studies of F-waves in felids. The regression equation for F-wave latency, conduction velocity, persistence, and amplitude may contribute to the diagnosis of nervous system diseases or injury in cats, such as trauma to the spinal cord or diabetic neuropathy.
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Affiliation(s)
- Seiichi Okuno
- Animal Clinic Kobayashi, 715-1 Sakai Fukaya Saitama 366-0813, Japan
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86
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Argyriou AA, Tsolakis I, Papadoulas S, Polychronopoulos P, Gourzis P, Chroni E. Dynamic F wave study in patients suffering from peripheral arterial occlusive disease. Acta Neurol Scand 2007; 115:84-9. [PMID: 17212610 DOI: 10.1111/j.1600-0404.2006.00725.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To prospectively detect significant transient F wave abnormalities obtained after exercise in patients with peripheral arterial disease (PAD) and to assess the potential diagnostic sensitivity of dynamic F wave study in such a context. PATIENTS AND METHODS A series of 40 electrical stimuli were delivered to the peroneal and the posterior tibial nerves of 25 patients with PAD in order to obtain F waves at rest and post-exercise. The following variables were estimated and the obtained pre- and post-exercise data were compared: F persistence, F wave latency, amplitude, duration and F chronodispersion. For each nerve studied, the minimum, average and maximum values were calculated. Conventional electrophysiological data were also collected pre- and post-exercise and the data obtained were also compared. Twenty-five healthy age-, gender- and height-matched individuals served as controls. RESULTS No evidence of conventional nerve conduction abnormalities was recorded either pre- or post-exercise in the group of patients. As regards the peroneal nerve, the significantly reduced F wave persistence (P = 0.007) and maximum F wave amplitude post- as opposed to pre-exercise (P = 0.05)- were the main findings to emerge. The average (P = 0.017) and the minimum duration (P = 0.005) of tibial F waves were also significantly increased post- compared with pre-exercise. Insignificant differences were observed between pre- and post-exercise neurophysiological and F wave values in the group of controls. CONCLUSION Given the observed absence of conventional neurophysiological abnormalities, the detection of dynamic F wave changes supports the view of an increased diagnostic sensitivity of this method in patients with mild PAD.
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Affiliation(s)
- A A Argyriou
- EMG Laboratory, Department of Neurology, University of Patras Medical School, Rion-Patras, Greece
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87
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Chroni E, Argyriou AA, Katsoulas G, Polychronopoulos P. Ulnar F wave generation assessed within 3 days after the onset of stroke in patients with relatively preserved level of consciousness. Clin Neurol Neurosurg 2006; 109:27-31. [PMID: 16759794 DOI: 10.1016/j.clineuro.2006.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 04/26/2006] [Accepted: 04/29/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The present study aimed to detect any significant changes of F wave variables associated with acute hemiparesis in a group of stroke patients with relatively preserved consciousness (Glascow Coma Scale (GCS) score 8 or higher) and to detect the possible clinical significance of F wave recording in acute stroke patients for diagnostic purposes. PATIENTS AND METHODS Thirty-two consecutive patients with mean age 65+/-10.6 years admitted with a diagnosis of acute ischemic or primary hemorrhagic stroke were studied. A series of 40 electrical stimuli were delivered to the ulnar nerve bilaterally in order to obtain F waves. F wave studies were performed within 3 days from stroke's onset. The following variables were estimated and then compared between affected and unaffected side: F persistence, F wave latency, amplitude, duration and chronodispersion. A group of 30 healthy age-matched subjects served as control. RESULTS F persistence was significantly lower in both affected and unaffected sides as compared to controls. There was no statistical differences of latency values between control and either side of the stroke' patients. A significant decrease of maximum F wave amplitude was detected in both affected and unaffected side as opposed to controls. Separate analysis of the subgroup of 15 patients with stroke and completely normal level of consciousness (GCS score 15) did not showed any significant differences of F wave variables in the affected or unaffected side compared with controls. CONCLUSION The F wave persistence is not expected to be suppressed in the first few days after stroke unless the level of consciousness is reduced. The routine F wave studies are not appropriate to evaluate the severity of motor deficit, at least in the immediate period after a stroke incident.
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Affiliation(s)
- Elisabeth Chroni
- Department of Neurology, University of Patras Medical School, Greece.
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88
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Kakinohana M, Sugahara K. Level of consciousness affects the excitability of spinal motor neurones during propofol sedation in humans. Br J Anaesth 2006; 96:742-6. [PMID: 16595617 DOI: 10.1093/bja/ael081] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND To investigate the relationship between the depression of spinal motor neuronal excitability and the sedative level induced by propofol infusion, we simultaneously analysed the suppressive effect of propofol on the F wave and the sedative level during propofol infusion. METHODS After spinal anaesthesia, sedation was achieved using a propofol target-controlled infusion (TCI) system to achieve a score of 4 on the Wilson sedation scale. The excitability of spinal motor neurones was determined by measuring the left median nerve F wave. F-wave persistence and the F/M ratio were recorded at pre-sedation as the control, during sedation, at arousal by mild physical stimulation and at post-sedation. RESULTS Wilson sedation scores increased significantly corresponding to the increase in the target propofol concentration (Cpt), and a Cpt-producing Wilson sedation scale 4 ranged between 1.2 and 1.8 microg ml(-1). The F-wave persistence and F/M ratio before propofol infusion were 80.7 (8.6)% and 9.5 (3.9)%, respectively. At Wilson sedation scale 4, F-wave persistence and F/M ratio were 17.6 (12.8)% (0-37.5%) and 4.3 (4.1)%, and, at return of consciousness by mild physical stimulation, significantly increased to 71.3 (7.9)% and 10.0 (5.0)%, respectively. CONCLUSION We demonstrated that the excitability of spinal motor neurones was suppressed during sedation by propofol TCI, but this suppressive effect vanished at return of consciousness by mild physical stimulation even at a constant Cpt. Our data suggested that the effect of propofol on the excitability of spinal motor neurones might be affected by consciousness level rather than propofol Cpt in humans.
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Affiliation(s)
- M Kakinohana
- Department of Anesthesiology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
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89
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Chroni E, Katsoulas G, Argyriou AA, Sakellaropoulos GC, Polychronopoulos P, Nikiforidis G. Level of consciousness as a conditioning factor of F wave generation in stroke patients. Clin Neurophysiol 2006; 117:315-9. [PMID: 16386953 DOI: 10.1016/j.clinph.2005.10.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 10/19/2005] [Accepted: 10/22/2005] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The current study aimed to investigate whether the level of consciousness influenced the F wave generation, as an independent factor. METHODS Forty three patients with acute stroke were divided according to their level of consciousness in two groups; to those with Glasgow scale (GCS) score 3-7 indicating coma (group I) and those with GCS score 8-15 (group II). A series of 40 electrical stimuli were delivered to the ulnar nerve bilaterally in order to obtain F waves. The following variables were estimated and then compared between groups: F persistence, F wave latency, amplitude and duration. All studies were performed within 3 days from the onset of the stroke symptoms. RESULTS The main finding to emerge was the significantly reduced F wave persistence in the group of patients with low GCS score as opposed to patients allocated in the group with GCS score 8-15. This result is referred to F waves obtained from both the affected and unaffected limb. F wave minimum latency was also prolonged in the group with low GCS score, whilst the comparison of all other F wave variables revealed no significant differences between groups I and II. F wave persistence measurements did not differ between the affected and unaffected sides. Stroke location and type (ischemic or hemorrhagic) were not associated with alterations of F wave measurements. CONCLUSIONS Our results on stroke patients suggest that generation of F waves, expressed by the F wave persistence is associated with the level of consciousness. SIGNIFICANCE F wave study may be useful as an objective measure in documenting the severity of consciousness impairment.
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Affiliation(s)
- Elisabeth Chroni
- Department of Neurology, University of Patras Medical School, P.O. Box 1045, 26504 Rion-Patras, Greece.
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Hirose H, Suzuki T, Shimada T. Excitability of Spinal Motor Neuron Function after the Transcutaneous Electrical Stimulation (TES) in Healthy Subjects -F-wave Study. JOURNAL OF THE JAPANESE PHYSICAL THERAPY ASSOCIATION 2006; 9:17-20. [PMID: 25792946 DOI: 10.1298/jjpta.9.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Accepted: 11/26/2005] [Indexed: 11/23/2022]
Abstract
To clarify the excitability of spinal motor neuron function after transcutaneous electrical stimulation (TES), we investigated the F-wave before and after TES. Fourteen healthy volunteers with a mean age of 23.4 years were studied. TES was applied to the flexor hallucis brevis (FHB) for 15 minutes. F-wave and M-wave were recorded from the FHB after tibial nerve stimulation at the ankle before TES, just after TES, 10, 20 and 30 minutes after TES. TES evoked full flexion of the great toe. F-wave was analyzed for the amplitude ratio of F/M, latency and duration. The amplitude ratio of F/ M was 3.1% before TES, 1.4% just after TES, 1.6% 10 minutes after, 1.9% 20 minutes after and 1.7% 30 minutes after TES. Each amplitude ratio of F/M after TES was significantly lower than that before TES (p<0.05). There was no statistically significant difference in the latency and the duration. These results suggest that the excitability of spinal motor neuron function after TES to muscles under this condition was reduced in healthy subjects.
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Affiliation(s)
- Hiroaki Hirose
- Department of Physical Therapy, Kansai Vocational College of Medicine, Osaka 558-0011, Japan
| | - Toshiaki Suzuki
- Research Center of Neurological Diseases, Kansai College of Oriental Medicine, Osaka 590-0482, Japan
| | - Tomoaki Shimada
- Division of Health Sciences, Kobe University Graduate School of Medicine, Hyogo 654-0142, Japan
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91
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Baars JH, Tas S, Herold KF, Hadzidiakos DA, Rehberg B. The suppression of spinal F-waves by propofol does not predict immobility to painful stimuli in humans †. Br J Anaesth 2006; 96:118-26. [PMID: 16317030 DOI: 10.1093/bja/aei283] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The immobilizing effects of volatile anaesthetics are primarily mediated at the spinal level. A suppression of recurrent spinal responses (F-waves), which reflect spinal excitability, has been shown for propofol. We have assessed the concentration-dependent F-wave suppression by propofol and related it to the logistic regression curve for suppression of movement to noxious stimuli and the effect on the bispectral index (BIS). The predictive power of drug effects on F-waves and BIS for movement responses to noxious stimuli was tested. METHODS In 24 patients anaesthesia was induced and maintained with propofol infused by a target controlled infusion pump at stepwise increasing and decreasing plasma concentrations between 0.5 and 4.5 mg litre(-1). The F-waves of the abductor hallucis muscle were recorded at a frequency of 0.2 Hz. BIS values were recorded continuously. Calculated propofol concentrations and F-wave amplitude and persistence were analyzed in terms of a pharmacokinetic-pharmacodynamic (PK/PD) model with a simple sigmoid concentration-response function. Motor responses to tetanic electrical stimulation (50 Hz, 60 mA, 5 s, volar forearm) were tested and the EC(50tetanus) was calculated using logistic regression. RESULTS For slowly increasing propofol concentrations, computer fits of the PK/PD model for the suppression by propofol yielded a median EC50 of 1.26 (0.4-2.3) and 1.9 (1.0-2.8) mg litre(-1) for the F-wave amplitude and persistence, respectively. These values are far lower than the calculated EC(50) for noxious electrical stimulation of 3.75 mg litre(-1). This difference results in a poor prediction probability of movement to noxious stimuli of 0.59 for the F-wave amplitude. CONCLUSIONS F-waves are almost completely suppressed at subclinical propofol concentrations and they are therefore not suitable for prediction of motor responses to noxious stimuli under propofol mono-anaesthesia.
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Affiliation(s)
- J H Baars
- Department of Anaesthesiology, Charité Campus Mitte, Berlin, Germany.
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92
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Baars JH, Kalisch D, Herold KF, Hadzidiakos DA, Rehberg B. Concentration-dependent suppression of F-waves by sevoflurane does not predict immobility to painful stimuli in humans †. Br J Anaesth 2005; 95:789-97. [PMID: 16199415 DOI: 10.1093/bja/aei252] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Decreased spinal excitability contributes to the immobilizing effects of halogenated ethers during general anaesthesia. Recurrent spinal responses such as F-waves reflect spinal excitability and are suppressed by volatile anaesthetics. To evaluate whether F-waves are suitable for monitoring immobility, the concentration-dependent effects of sevoflurane on F-waves were compared with effects on the Bispectral Index (BIS). The predictive power of all parameters for movement responses to noxious stimuli was tested. In addition, the effect of the noxious stimulus itself on F-waves was investigated. METHODS In 28 patients, F-waves were recorded during sevoflurane anaesthesia at a frequency of 0.2 Hz at the lower limb. To insert a laryngeal mask, the sevoflurane concentration was initially increased to approximately 4%, which caused a complete extinction of F-waves. The sevoflurane concentration was then reduced until the F-waves recovered. BIS and spectral edge frequency (SEF(95)) were recorded continuously. The t(1/2ke0) and EC(50) values of the F-wave persistence and amplitude were calculated using a standard pharmacokinetic-pharmacodynamic model. During decreasing sevoflurane concentration motor responses to tetanic electrical stimulation (50 Hz, 60 mA, 5 s, volar forearm) were tested in seven patients and MAC(tetanus) was calculated using logistic regression. RESULTS Sevoflurane reduces the F-wave amplitude with an EC(50) of 0.79 vol% at a far lower concentration than the calculated MAC(tetanus) (1.5 vol%), whereas the F-wave persistence yields an EC(50) of 1.4 vol%. Spinal and EEG parameters predicted the motor responses to movement better than chance alone, but did not differ significantly from each other. CONCLUSION F-waves, especially the F-wave amplitude, cannot be used to predict movement to noxious stimuli during sevoflurane anaesthesia because they are almost completely suppressed at subclinical sevoflurane concentrations. Either the particular motoneurone pool (the largest motoneurones) assessed by F-waves is not involved in generating movement to painful stimuli or direct effects on motoneurone excitability are not involved in the suppression of movement to painful stimuli by sevoflurane.
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Affiliation(s)
- J H Baars
- Department of Anaesthesiology, Charité Campus Mitte, Schumannstrasse 20/21, D-10098 Berlin, Germany.
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93
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Bamford JA, Putman CT, Mushahwar VK. Intraspinal microstimulation preferentially recruits fatigue-resistant muscle fibres and generates gradual force in rat. J Physiol 2005; 569:873-84. [PMID: 16239281 PMCID: PMC1464280 DOI: 10.1113/jphysiol.2005.094516] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Intraspinal microstimulation (ISMS), a novel rehabilitative therapy consisting of stimulation through fine, hair-like microwires targeted at the ventral spinal cord, has been proposed for restoring standing and walking following spinal cord injury. This study compared muscle recruitment characteristics of ISMS with those produced by peripheral nerve cuff stimulation (NCS). Thirty-three minutes of either ISMS or NCS at 1, 20 or 50 s(-1) and 1.2 x threshold (T) amplitude depleted glycogen from muscle fibres of vastus lateralis and rectus femoris. ISMS and NCS were also carried out at 20 s(-1) and 3.0T. Muscle serial sections were stained for glycogen and for myosin heavy chain (MHC)-based fibre types using a panel of monoclonal antibodies. The results of this study show that ISMS recruited fatigue-resistant (FR) fibres at 2.9, 1.9, 1.7 and 2.5 times their relative MHC content at 1, 20 and 50 s(-1) 1.2T and 20 s(-1) 3.0T, respectively. In contrast, NCS recruited FR fibres at 1.2, 1.0, 2.1 and 0.0 times their MHC content at 1, 20 and 50 s(-1) 1.2T and 20 s(-1) 3.0T, respectively. The proportion of FR fibres recruited by ISMS and NCS was significantly different in the 20 s(-1) 3.0T condition (P < 0.0001). We also report that force recruitment curves were 4.9-fold less steep (P < 0.019) for ISMS than NCS. The findings of this study provide evidence for the efficacy of ISMS and further our understanding of muscle recruitment properties of this novel rehabilitative therapy.
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Affiliation(s)
- J A Bamford
- Centre for Neuroscience and Department of Biomedical Engineering, Room 503, Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada
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