- Email: [email protected]
Basic principles of clinical neurophysiology in the operating room (OR) and intensive care unit (ICU)
Abstracts of the 13th European Congress of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008), S1–S131
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glycosylated hemoglobin (HbA1C) value was 8.56±2.07% (normal: 3-6.5%). There was a significant correlation between the total neuropathy score and diabetes duration, retinopathy, and HbA1C. Conclusion: The relationship between DSP and retinopathy was significant. The association of neuropathy with retinopathy was expected, reflecting disease duration and intensity of hyperglycemia.
Wednesday, 7 May 2008
TUO41 Brucella: a cause of peripheral neuropathy
W13 Neurophysiological monitoring in ICU and operating theater
Gulnihal Kutlu 1 , Gunay T Ertem 2 , Ozlem Coskun 1 , Ufuk Ergun 1 , Necla Tulek 2 , Levent E Inan 1 1 Ministry of Health, Ankara Training & Research Hospital, Department of Neurology; 2 Ministry of Health, Ankara Training & Research Hospital, Department of Infectious Diseases and Clinical Microbiology, Turkey Purpose: Brucellosis is a common infectious disease in Mediterranean country. We evaluated the peripheral nerve involvement in patients with brucellosis. Methods: Thirty-eight patients with brucellosis were evaluated. Four of them were excluded because of B12 deficiency and diabetes mellitus. Thirtyfour patients were included. Average age was 43.08±15.3. Patients were divided into two according to the abnormality in their peripheral nervous system (PNS) examination. All patients underwent nerve conduction and needle EMG studies. Twenty normal healthy subjects were used as a control group. Results: Axonal sensory-motor neuropathy was determined in twelve patients who had also abnormality in PNS examination. After six months of treatment, nerve conduction studies were nearly normal in these patients. The EMG findings of remaining twenty-two patients were normal just like the clinical examination. However the motor conduction velocities of median(p<0.001), peroneal(p<0.001), ulnar (p<0.05) nerve were decreased, F wave latencies were prolonged in posterior tibial and peroneal nerve, and distal latency was also prolonged in posterior tibial nerve (p<0.05) in them compared to healthy subject. Sensory conduction velocities of median (p<0.001), ulnar and sural (p<0.05) nerve was also decreased. Conclusion: Brucellosis may be considered as a cause of clinical or subclinical peripheral neuropathy and should be evaluated especially in endemic areas.
TUO42 Correlation of finger skin thickness and sensory nerve action potential amplitude in normal volunteers Shahriar Nafissi, Parissa Hassanzadeh, Nahid Sedighi, Shahram Oveis Gharan Shariati Hospital, Tehran University, Medical Sciences, Tehran, Iran Purpose: It has been shown that finger circumference has a negative correlation with sensory nerve action potential amplitude (SNAP-A). Also fat people have lower sensory nerve amplitudes. Factors that cause electrodes displaced more from underlying nerves will result in lower SNAP-A. Cutaneous and subcutaneous tissue are the major determinants of the distance between digital nerves and surface electrodes. This study was designed to evaluate correlation between skin thickness and SNAP amplitude, which has not been evaluated in previous published studies. Methods: 38 healthy 22-40 years old subjects were selected with different occupations. 19 (51.4%) were male and 18 (48.6%) were female. There was no significant difference between males and females regarding their ages. For all subjects, height and weight were measured. Anteroposterior and mediolateral diameters of the proximal phalanges of the index and little fingers and also finger circumferences were measured. Palmar digital skin thickness was measured in two ways: first with sonography machine, and second with skin fold caliper. Median and ulnar nerves sensory and motor conduction studies were performed. Results: In bivariate analysis, SNAP-A correlated negatively with female sex, height, anteroposterior diameter of the fingers, finger circumference and skin thickness measured by sonography, but in multiple regression analysis only skin thickness measured by sonography could predict SNAP-A. Conclusion: This study demonstrate that among physiological factors of sex, height, BMI and also finger size measures, skin thickness is the best
predictor of SNAP-A. In clinical practice, this effect must be taken into account when making determination of abnormality based on sensory nerve amplitude.
15:30 – 16:30
Chairperson: J.-M. Guerit, Belgium Basic principles of clinical neurophysiology in the operating room (OR) and intensive care unit (ICU) J.-M. Guerit Pain Clinic, Brussels, Belgium For more than 20 years, clinical neurophysiology (CN) has played a unique role in both OR and ICU. One reason of this success is that CN constitutes the only bedside tool for quantitative functional nervous assessment of patients who are unable to communicate. Another reason is that it is particularly aimed to detect at a reversible stage, and quantitatively follow up these pathophysiological processes whose evolution may be critical for patient outcome: alterations of anoxic and/or ischemic origin, alterations consecutive to an increase in intracranial pressure, nervous consequences of nerve compression, epilepsy. We will review the main EP and EEG changes, which can be detected, quantified, and followed up in these situations. Because patients in the OR and the ICU are often submitted to very extreme physiological conditions, CN efficiency also depends on its ability to differentiate these changes that are consecutive to the feared process from those that are merely the consequence of unusual physiological environments: body temperature, disturbances induced by neurotrophic drugs or metabolic disturbances. We will review how to disentangle physiological from pathological changes. Another essential condition for CN to be successful is to design decision algorithms, which must be defined before any collaboration between the clinical neurophysiologist and surgeon/intensivist. These algorithms must take into account both possibilities and limitations of CN. We will illustrate these by two types of algorithms that have been defined in the OR (carotid endarterectomy) and ICU (follow up of intracranial hypertension). This lecture will be only devoted to the detection of pathophysiological processes. Noteworthy, new applications of CN in the OR have emerged, like stimulation techniques for the localisation of critical brain structures or semimicroelectrode recordings for guidance in deep brain stimulation surgery.
WO24 Visual transformation of EEG in the ICU Michel J.A.M. van Putten 1 1 Department of Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, Netherlands; 2 Institute of Technical Medicine, University of Twente, Enschede, Netherlands Purpose: Although continuous EEG is considered highly relevant to be real-time informed about the status of the brain in comatose or sedated patients, routine use of continuous EEG (cEEG) in the Intensive Care Unit is still limited. A major contributing factor to this discrepancy is the expertise needed for the interpretation of the raw waveforms. In addition, even if an experienced physician is available, it is practically impossible to remain at the bedside during the monitoring procedure. Therefore, transformation of relevant EEG features to an alternative (visual) domain is needed, to assist in the interpretation by relatively non-trained personnel, in particular the intensive care staff and nurses, and to allow computer-assisted warning. Methods: We present a compact transform of the EEG, based on two symmetry measures (left-right and anterio-posterior), a measure for synchronization, and the mean frequency. Three of these features were recently proposed as a compact visual transform of the EEG background pattern in routine EEG recordings (MJAM van Putten, The Colorful Brain: visualisation of EEG background patterns, J Clin Neurophysiology (in press, 2008)). Here, we extend this analysis, displayed as four time-frequency representations. In
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glycosylated hemoglobin (HbA1C) value was 8.56±2.07% (normal: 3-6.5%). There was a significant correlation between the total neuropathy score and diabetes duration, retinopathy, and HbA1C. Conclusion: The relationship between DSP and retinopathy was significant. The association of neuropathy with retinopathy was expected, reflecting disease duration and intensity of hyperglycemia.
Wednesday, 7 May 2008
TUO41 Brucella: a cause of peripheral neuropathy
W13 Neurophysiological monitoring in ICU and operating theater
Gulnihal Kutlu 1 , Gunay T Ertem 2 , Ozlem Coskun 1 , Ufuk Ergun 1 , Necla Tulek 2 , Levent E Inan 1 1 Ministry of Health, Ankara Training & Research Hospital, Department of Neurology; 2 Ministry of Health, Ankara Training & Research Hospital, Department of Infectious Diseases and Clinical Microbiology, Turkey Purpose: Brucellosis is a common infectious disease in Mediterranean country. We evaluated the peripheral nerve involvement in patients with brucellosis. Methods: Thirty-eight patients with brucellosis were evaluated. Four of them were excluded because of B12 deficiency and diabetes mellitus. Thirtyfour patients were included. Average age was 43.08±15.3. Patients were divided into two according to the abnormality in their peripheral nervous system (PNS) examination. All patients underwent nerve conduction and needle EMG studies. Twenty normal healthy subjects were used as a control group. Results: Axonal sensory-motor neuropathy was determined in twelve patients who had also abnormality in PNS examination. After six months of treatment, nerve conduction studies were nearly normal in these patients. The EMG findings of remaining twenty-two patients were normal just like the clinical examination. However the motor conduction velocities of median(p<0.001), peroneal(p<0.001), ulnar (p<0.05) nerve were decreased, F wave latencies were prolonged in posterior tibial and peroneal nerve, and distal latency was also prolonged in posterior tibial nerve (p<0.05) in them compared to healthy subject. Sensory conduction velocities of median (p<0.001), ulnar and sural (p<0.05) nerve was also decreased. Conclusion: Brucellosis may be considered as a cause of clinical or subclinical peripheral neuropathy and should be evaluated especially in endemic areas.
TUO42 Correlation of finger skin thickness and sensory nerve action potential amplitude in normal volunteers Shahriar Nafissi, Parissa Hassanzadeh, Nahid Sedighi, Shahram Oveis Gharan Shariati Hospital, Tehran University, Medical Sciences, Tehran, Iran Purpose: It has been shown that finger circumference has a negative correlation with sensory nerve action potential amplitude (SNAP-A). Also fat people have lower sensory nerve amplitudes. Factors that cause electrodes displaced more from underlying nerves will result in lower SNAP-A. Cutaneous and subcutaneous tissue are the major determinants of the distance between digital nerves and surface electrodes. This study was designed to evaluate correlation between skin thickness and SNAP amplitude, which has not been evaluated in previous published studies. Methods: 38 healthy 22-40 years old subjects were selected with different occupations. 19 (51.4%) were male and 18 (48.6%) were female. There was no significant difference between males and females regarding their ages. For all subjects, height and weight were measured. Anteroposterior and mediolateral diameters of the proximal phalanges of the index and little fingers and also finger circumferences were measured. Palmar digital skin thickness was measured in two ways: first with sonography machine, and second with skin fold caliper. Median and ulnar nerves sensory and motor conduction studies were performed. Results: In bivariate analysis, SNAP-A correlated negatively with female sex, height, anteroposterior diameter of the fingers, finger circumference and skin thickness measured by sonography, but in multiple regression analysis only skin thickness measured by sonography could predict SNAP-A. Conclusion: This study demonstrate that among physiological factors of sex, height, BMI and also finger size measures, skin thickness is the best
predictor of SNAP-A. In clinical practice, this effect must be taken into account when making determination of abnormality based on sensory nerve amplitude.
15:30 – 16:30
Chairperson: J.-M. Guerit, Belgium Basic principles of clinical neurophysiology in the operating room (OR) and intensive care unit (ICU) J.-M. Guerit Pain Clinic, Brussels, Belgium For more than 20 years, clinical neurophysiology (CN) has played a unique role in both OR and ICU. One reason of this success is that CN constitutes the only bedside tool for quantitative functional nervous assessment of patients who are unable to communicate. Another reason is that it is particularly aimed to detect at a reversible stage, and quantitatively follow up these pathophysiological processes whose evolution may be critical for patient outcome: alterations of anoxic and/or ischemic origin, alterations consecutive to an increase in intracranial pressure, nervous consequences of nerve compression, epilepsy. We will review the main EP and EEG changes, which can be detected, quantified, and followed up in these situations. Because patients in the OR and the ICU are often submitted to very extreme physiological conditions, CN efficiency also depends on its ability to differentiate these changes that are consecutive to the feared process from those that are merely the consequence of unusual physiological environments: body temperature, disturbances induced by neurotrophic drugs or metabolic disturbances. We will review how to disentangle physiological from pathological changes. Another essential condition for CN to be successful is to design decision algorithms, which must be defined before any collaboration between the clinical neurophysiologist and surgeon/intensivist. These algorithms must take into account both possibilities and limitations of CN. We will illustrate these by two types of algorithms that have been defined in the OR (carotid endarterectomy) and ICU (follow up of intracranial hypertension). This lecture will be only devoted to the detection of pathophysiological processes. Noteworthy, new applications of CN in the OR have emerged, like stimulation techniques for the localisation of critical brain structures or semimicroelectrode recordings for guidance in deep brain stimulation surgery.
WO24 Visual transformation of EEG in the ICU Michel J.A.M. van Putten 1 1 Department of Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, Netherlands; 2 Institute of Technical Medicine, University of Twente, Enschede, Netherlands Purpose: Although continuous EEG is considered highly relevant to be real-time informed about the status of the brain in comatose or sedated patients, routine use of continuous EEG (cEEG) in the Intensive Care Unit is still limited. A major contributing factor to this discrepancy is the expertise needed for the interpretation of the raw waveforms. In addition, even if an experienced physician is available, it is practically impossible to remain at the bedside during the monitoring procedure. Therefore, transformation of relevant EEG features to an alternative (visual) domain is needed, to assist in the interpretation by relatively non-trained personnel, in particular the intensive care staff and nurses, and to allow computer-assisted warning. Methods: We present a compact transform of the EEG, based on two symmetry measures (left-right and anterio-posterior), a measure for synchronization, and the mean frequency. Three of these features were recently proposed as a compact visual transform of the EEG background pattern in routine EEG recordings (MJAM van Putten, The Colorful Brain: visualisation of EEG background patterns, J Clin Neurophysiology (in press, 2008)). Here, we extend this analysis, displayed as four time-frequency representations. In