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TUO15 Critical care myopathy: clinical, electrophysiological and pathological follow up study of 13 patients
S16
Abstracts of the 13th European Congress of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008), S1–S131
(testing GABAb-mediated inhibition), slightly reduced, was significantly prolonged by therapy. ICF (testing intracortical glutamate-mediated facilitation) decreased, and startle response normalized after treatment. Conclusions: TMS variables may help to unveil neurophysiological mechanisms of SPS symptoms and how these symptoms are improved by immunotherapy.
Tuesday, 6 May 2008
11:00–12:30
S10 Electrodiagnostics in myopathy Chairperson: A. Fuglsang-Frederiksen, Denmark Electrodiagnostics in myopathy A. Fuglsang-Frederiksen Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark In the diagnosis of myopathy EMG has an important role along with blood tests, muscle biopsies and genetic testing. Various needle EMG methods are helpful in the diagnosis of myopathy. These include manual analysis of individual motor unit potentials (MUPs) sampled at weak effort and analysis of averaged MUPs, e.g. the multi MUP analysis. At high effort, turns-amplitude analyses such as the peak-ratio analysis using the amplitude as an indication of force, have a high diagnostic yield. The EMG can only seldom be used to differentiate between different types of myopathy. Macro-EMG, single-fibre EMG and muscle fibre conduction velocity analysis have a limited role in detecting myopathy, but provide useful pathophysiological information. Analysis of the firing rate of motor units and power spectrum analysis may have diagnostic potential in myopathy in the future. Considerable variation has been found among European physicians regarding techniques used, number of muscles examined and number of abnormal EMG findings required for the diagnosis of myopathy. This variation indicates the need of international guidelines. Recommendations: In the diagnosis of patients with myopathy, a needle electrode and quantitative analyses should be used. A combination of a method at weak effort as well as a method at stronger effort seems optimal. In this way action potentials from motor units recruited at low effort as well as those recruited at high effort are evaluated.
TUO14 Neurophysiological examination of patients with myopathy. A European multicentre study Kirsten Pugdahl 1 , Hatice Tankisi 1 , Anders Fuglsang-Frederiksen 1 , Birger Johnsen 1 , Mamede de Carvalho 2 , Peter Fawcett 3 , Annick Labarre-Vila 4 , Rocco Liguori 5 , Wilfred Nix 6 , Ian Schofield 3 1 Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark; 2 Department of Neurology, Hospital de Santa Maria, Laboratory of Electromyography. Institute of Molecular Medicine-Faculty of Medicine, Lisbon, Portugal; 3 Department of Clinical Neurophysiology, Newcastle General Hospital, Newcastle upon Tyne, UK; 4 Unité ENMG et Pathologie neuromusculaire, Département de Neurologie, Centre Hospitalier Universitaire, Grenoble, France; 5 Department of Neurological Sciences, University of Bologna, Bologna Italy; 6 Department of Neurology University Clinics, Mainz, Germany Purpose: To examine differences in the neurophysiological examination of patients with myopathy among 7 neurophysiologists from 6 different European countries. Methods: A set of 84 cases consisting of 12 consecutively performed examinations from each of the 7 physicians was collected. The examinations were reviewed independently by each physician and discussed by the physicians as a peer review group with the aim of obtaining consensus on the diagnosis. The consensus diagnosis comprised an EMG diagnosis based solely on the electrodiagnostic findings and a final diagnosis based on all available information. Sixty-nine cases classified as definite or probable myopathy as the final consensus diagnosis were selected for analysis. Results: The average number of muscles examined per patient by each physician varied from 2.8 to 5.3 and the number of abnormal muscles varied from 2.6 to 5.0 (p < 0.001). The variation was mainly related to whether quantitative or qualitative EMG methods were used. Variations among the physicians were also found in the average number of examined (p<0.001) and abnormal (p<0.05) motor and sensory nerve segments and F-wave studies per patient. As expected an increase in the probability of the EMG consensus diagnosis was found with an increasing number of muscles with abnormalities interpreted as myopathic. A probable EMG diagnosis was obtained with an average of 2.5 myopathic muscles and a definite EMG diagnosis with 3.6 muscles per patient. Conclusions: The variations found among the physicians in the neurophysiological examination of myopathy indicate a lack of internationally accepted criteria for the neurophysiological examination and diagnosis of myopathy. Minimal criteria developed by a consensus group can be the first step towards evidence-based guidelines for the electrodiagnosis of myopathy.
TUO13 Quantitative EMG of frontalis muscle in healthy and diseased states Zeliha Matur, Mehmet Bari¸s Baslo, Ali Emre Öge, Jale Yazici Istanbul University, Istanbul Medical Faculty, Department of Neurology Purpose: Diagnosis of myopathy in periocular muscles is difficult because the motor unit potentials (MUPs) of these muscles are already low in amplitude and short in duration. In this study, it is aimed to differentiate pathological processes affecting the periocular muscles by multi-MUP analysis. Method: Multi-MUP and interference pattern analysis (IP) from frontalis muscle was studied by using a concentric needle electrode. Thirty healthy subjects (aged 29 to 58), 20 patients with myopathy (aged 16 to 75), and 7 patients with facial palsy (aged 18 to 60) were included. MUP and IP parameters were compared among the groups by nonparametric tests. Results: Mean MUP amplitude was 343±226 µV (53–1729) in the normal subjects, 257±186 µV (46–1442) in patients with myopathy, and 544±374 µV (80–1929) in patients with facial palsy. Mean MUP duration was 3.3±1.4 ms (1–9.4) in the healthy controls, 2.5±1.1 ms (0.6–7.4) in myopathy group, and 5.3±2.2 ms (0.8–12.2) in the facial palsy group. Statistically significant difference of MUP and IP parameters was found between the groups (p<0.05). Conclusion: MUP and IP parameters were found significantly different between the groups. However, it is still tricky to differentiate myopathy patients from healthy controls according to patient based approach. Speaking for the MUP data; taking the outlier values of an individual patient into consideration rather than the mean values might help.
TUO15 Critical care myopathy: clinical, electrophysiological and pathological follow up study of 13 patients Alfredo Curras, Elena Vilas, Carina Diéguez, Jose Maria Fernandez University hospitals of Vigo Purpose: Patients in the ICU often develop difficulty of weaning from mechanical ventilation and a variable degree of weakness including quadriplegia. Often associated with steroid treatment, neuromuscular blocking agents and septic patients, the pathogenesis of CIM is still poorly understood. Originally thought to be neuropathic in nature, today myopathy is more often diagnosed. Methods: Between 1994 and 2002 a retrospective study was carried out on 13 patients diagnosed with CIM. In the clinical studies special attention was paid to the neuromuscular status APACHE II, CK and treatments with steroids, RMND, NPT and insulin. All patients underwent thorough electromyographic studies and muscle biopsy. Results: Of 13 patients, (4 women and 9 men all aged between 46 and 86); in three patients admission to the ICU was not necessary. All but two received prolonged high doses of steroids and two were on chronic treatment of steroids. Only one was treated with BMND.
Abstracts of the 13th European Congress of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008), S1–S131
(testing GABAb-mediated inhibition), slightly reduced, was significantly prolonged by therapy. ICF (testing intracortical glutamate-mediated facilitation) decreased, and startle response normalized after treatment. Conclusions: TMS variables may help to unveil neurophysiological mechanisms of SPS symptoms and how these symptoms are improved by immunotherapy.
Tuesday, 6 May 2008
11:00–12:30
S10 Electrodiagnostics in myopathy Chairperson: A. Fuglsang-Frederiksen, Denmark Electrodiagnostics in myopathy A. Fuglsang-Frederiksen Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark In the diagnosis of myopathy EMG has an important role along with blood tests, muscle biopsies and genetic testing. Various needle EMG methods are helpful in the diagnosis of myopathy. These include manual analysis of individual motor unit potentials (MUPs) sampled at weak effort and analysis of averaged MUPs, e.g. the multi MUP analysis. At high effort, turns-amplitude analyses such as the peak-ratio analysis using the amplitude as an indication of force, have a high diagnostic yield. The EMG can only seldom be used to differentiate between different types of myopathy. Macro-EMG, single-fibre EMG and muscle fibre conduction velocity analysis have a limited role in detecting myopathy, but provide useful pathophysiological information. Analysis of the firing rate of motor units and power spectrum analysis may have diagnostic potential in myopathy in the future. Considerable variation has been found among European physicians regarding techniques used, number of muscles examined and number of abnormal EMG findings required for the diagnosis of myopathy. This variation indicates the need of international guidelines. Recommendations: In the diagnosis of patients with myopathy, a needle electrode and quantitative analyses should be used. A combination of a method at weak effort as well as a method at stronger effort seems optimal. In this way action potentials from motor units recruited at low effort as well as those recruited at high effort are evaluated.
TUO14 Neurophysiological examination of patients with myopathy. A European multicentre study Kirsten Pugdahl 1 , Hatice Tankisi 1 , Anders Fuglsang-Frederiksen 1 , Birger Johnsen 1 , Mamede de Carvalho 2 , Peter Fawcett 3 , Annick Labarre-Vila 4 , Rocco Liguori 5 , Wilfred Nix 6 , Ian Schofield 3 1 Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark; 2 Department of Neurology, Hospital de Santa Maria, Laboratory of Electromyography. Institute of Molecular Medicine-Faculty of Medicine, Lisbon, Portugal; 3 Department of Clinical Neurophysiology, Newcastle General Hospital, Newcastle upon Tyne, UK; 4 Unité ENMG et Pathologie neuromusculaire, Département de Neurologie, Centre Hospitalier Universitaire, Grenoble, France; 5 Department of Neurological Sciences, University of Bologna, Bologna Italy; 6 Department of Neurology University Clinics, Mainz, Germany Purpose: To examine differences in the neurophysiological examination of patients with myopathy among 7 neurophysiologists from 6 different European countries. Methods: A set of 84 cases consisting of 12 consecutively performed examinations from each of the 7 physicians was collected. The examinations were reviewed independently by each physician and discussed by the physicians as a peer review group with the aim of obtaining consensus on the diagnosis. The consensus diagnosis comprised an EMG diagnosis based solely on the electrodiagnostic findings and a final diagnosis based on all available information. Sixty-nine cases classified as definite or probable myopathy as the final consensus diagnosis were selected for analysis. Results: The average number of muscles examined per patient by each physician varied from 2.8 to 5.3 and the number of abnormal muscles varied from 2.6 to 5.0 (p < 0.001). The variation was mainly related to whether quantitative or qualitative EMG methods were used. Variations among the physicians were also found in the average number of examined (p<0.001) and abnormal (p<0.05) motor and sensory nerve segments and F-wave studies per patient. As expected an increase in the probability of the EMG consensus diagnosis was found with an increasing number of muscles with abnormalities interpreted as myopathic. A probable EMG diagnosis was obtained with an average of 2.5 myopathic muscles and a definite EMG diagnosis with 3.6 muscles per patient. Conclusions: The variations found among the physicians in the neurophysiological examination of myopathy indicate a lack of internationally accepted criteria for the neurophysiological examination and diagnosis of myopathy. Minimal criteria developed by a consensus group can be the first step towards evidence-based guidelines for the electrodiagnosis of myopathy.
TUO13 Quantitative EMG of frontalis muscle in healthy and diseased states Zeliha Matur, Mehmet Bari¸s Baslo, Ali Emre Öge, Jale Yazici Istanbul University, Istanbul Medical Faculty, Department of Neurology Purpose: Diagnosis of myopathy in periocular muscles is difficult because the motor unit potentials (MUPs) of these muscles are already low in amplitude and short in duration. In this study, it is aimed to differentiate pathological processes affecting the periocular muscles by multi-MUP analysis. Method: Multi-MUP and interference pattern analysis (IP) from frontalis muscle was studied by using a concentric needle electrode. Thirty healthy subjects (aged 29 to 58), 20 patients with myopathy (aged 16 to 75), and 7 patients with facial palsy (aged 18 to 60) were included. MUP and IP parameters were compared among the groups by nonparametric tests. Results: Mean MUP amplitude was 343±226 µV (53–1729) in the normal subjects, 257±186 µV (46–1442) in patients with myopathy, and 544±374 µV (80–1929) in patients with facial palsy. Mean MUP duration was 3.3±1.4 ms (1–9.4) in the healthy controls, 2.5±1.1 ms (0.6–7.4) in myopathy group, and 5.3±2.2 ms (0.8–12.2) in the facial palsy group. Statistically significant difference of MUP and IP parameters was found between the groups (p<0.05). Conclusion: MUP and IP parameters were found significantly different between the groups. However, it is still tricky to differentiate myopathy patients from healthy controls according to patient based approach. Speaking for the MUP data; taking the outlier values of an individual patient into consideration rather than the mean values might help.
TUO15 Critical care myopathy: clinical, electrophysiological and pathological follow up study of 13 patients Alfredo Curras, Elena Vilas, Carina Diéguez, Jose Maria Fernandez University hospitals of Vigo Purpose: Patients in the ICU often develop difficulty of weaning from mechanical ventilation and a variable degree of weakness including quadriplegia. Often associated with steroid treatment, neuromuscular blocking agents and septic patients, the pathogenesis of CIM is still poorly understood. Originally thought to be neuropathic in nature, today myopathy is more often diagnosed. Methods: Between 1994 and 2002 a retrospective study was carried out on 13 patients diagnosed with CIM. In the clinical studies special attention was paid to the neuromuscular status APACHE II, CK and treatments with steroids, RMND, NPT and insulin. All patients underwent thorough electromyographic studies and muscle biopsy. Results: Of 13 patients, (4 women and 9 men all aged between 46 and 86); in three patients admission to the ICU was not necessary. All but two received prolonged high doses of steroids and two were on chronic treatment of steroids. Only one was treated with BMND.