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P181 Electrophysiology of hereditary motor & sensory neuropathy and hereditary spinocerebellar ataxia
Poster Session: EEG and EEG Related Techniques - Epilepsy" tude and frequency. These changes were in positive correlation with the increase of spastic muscle tone. The same changes, but less expressed, were registrated in Parkinson's disease, In patients with cerebellar lesions decreased F amplitude and frequency was found in positive correlation with reduction of the muscle tone. The increase of F amplitude and frequency in the early phase of ischemic stroke was correlated with good recovery of neurological deficit. It was concluded that the measurement of the F response parameters might be reliable marker of the ot motoneuron excitability and that might have predictive value in the early phase in ischemic stroke.
ELECTROPHYSlOLOGY OF HEREDITARY MOTOR & SENSORY NEUROPATHY AND HEREDITARY SPINOCEREBELLAR ATAXlA G. Kiteva-Trencevska, S. Vlaski-Jekic, R. Naumovski. Clinic of
Neurolog); Skopje, Macedonia The existence of ataxia in hereditary motor & sensory neuropathy (HMSN) and neuropathy in hereditary spinocerebellar ataxia (HSCA) are features connecting these two heterogeneous diseases. The aim is to show the electrophysiological findings in HMSN and HSCA. Electrophysiological examination included needle EMG of limb muscles, sensory and motor neurography and somatosensory evoked potentials (SSEP). 14 patients with HMSN, 10 of whom had HSMN type I, 2 type II and 2 type V and 10 patients with HSCA were examined, 4 of whom had Friedreich's ataxia (FA) and 6 HSCA with hyperreflexia, EMG showed reduction of the pattern of activity during maximal effort in muscles of upper and lower limbs in HMSN-1, HMSN-II, in lower limbs in HMSN-V, normal findings in 2 cases with HSCA and slight reduction in distal muscles of lower limbs in HSCA. Individual motor unit potentials were neurogenic. Motor conduction velocity (MCV) was decreased under 30 m/s in cases with HMSN-I in upper and lower limbs, slight reduction of MCV was registered in HMSN-II, normal MCV in HMSN-V and in patients with HSCA, MCV was normal in 5 and slightly reduced in the lower limbs in 5 cases. Sensory conduction velocity (SCV) of median and sural nerve was unmeasurable or reduced in HMSN-I and HMSN-I1. reduced of sural nerve in HMSN-V and in patients with HSCA, SCV was slightly reduced in 8 cases and normal in 2. SSEP registered affection of the peripheral somatosensory pathways in cases with HMSN, and affection of the central somatosensory pathways in HSCA as the dominant change. Electrophysiological evaluation of HMSN and HSCA reveals the severity of neuropathy and affection of the central somatosensory pathways and helps in differentiation of these diseases.
EEG and EEG Related Techniques - Epilepsy AUTOMATIC FOCUS DETECTION IN DIGITAL EEG BY A KNOWLEDGE-BASED SYSTEM
L. Schuster ~, C.S. Herrmann t H.P. Hundemer 2, H.C. Hopf 2. i TH Darmstadt, lntellektik, Neurologie, Germany; 2 Uniklinik Mainz, Neurologie, Germany
Question: Based on the adaptive frequency decomposition technique [1] combined with an expert system, we present a method for computer-aided detection of focal slow activity in the human EEG. Method: The incoming raw data are preprocessed by the adaptive frequency decomposition resulting in four linguistic fuzzy variables 3, 0, and ~ for frequency and four estimates high, medium, low and zero for amplitude. For the subsequent reasoning process, all data with high or medium 6- or 0-frequencies are selected, if their temporal occurrence within the EEG is higher than 10%. These data are analysed separately for each hemisphere and rules of the expert system determine, whether slow activity occurs in only one track (circumscribed focal activity) or in multiple adjacent tracks (large focal activity) or spreads over the whole hemisphere (generalised, lateralised activity). Results and Conclusion: Our method automatically detects various types of slow EEG-activity. The track showing maximal amplitude (the focus) can be determined as well as its spatial extent and duration.
317
Reference
[ I ] C.S. Herrmann, H.P. Hundemer and H.C. Hopf, Adaptive Frequency Decomposition for EEG-Analysis, at the 40th Annual German Conference on Clinical Neurophysiology, Electroencephalography and Clinical Neurophysiology, 1995
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EEG DATA TRANSFER VIA ATM NETWORK
E. Rauhala i, M. Erkinjuntti i, E. R~ity 2, j. Koivisto 2, E Loula 2, V. H~ddnen 3.1 Satakunta Central Hospital, Pori, Finland; 2 Tampere University of Technology, Pori, Finland; 3 Tampere University Hospital, Tampere, Finland About 60 clinical neurophysiologists take care of all neurophysiological services (EEG, ENMG, evoked potentials, sleep studies) of the population of 5 million in Finland, Each central hospital has usually only one clinical neurophysiologist and distances between hospitals are quite long. The telecommunication infrastructure is modem and of high quality in Finland. Since at present most of the collected neurophysiological data is in digital, transferable form it is natural to develop telemedical applications for the needs of clinical neurophysiology. Telemedicine can be used e.g. for second opinion consulting, educational meetings and maintenance of data banks. Via neurophysiological networks it is possible to guarantee the availability of EEG analysis also daring holiday season and on-duty time. Telemedicine can be applied also for quality control and for standardizing the methods in different laboratories. We have developed a multimedia application for the consultation of EEG. The system is based on two Sun Sparcstation computers in UNIX environment. A video conference program 'Showme' is used both for sending video signal and sharing an EEG analysis application. Either of the conference partners can take control over the discussed data and move snaps on a whiteboard for further analysis. The system uses an ATM network with a capacity of 155 Mbytes per second which allows to transfer large amounts of EEG data and maintain a simultaneous video conference. This multimedia application makes possible a real-time interactive consultation and can be adapted to many kinds of data which is in digital form. ~P~-']
SOME ASPECTS OF CONTINUOUS EEG SOURCE IMAGING SOFTWARE'S UTILISATION IN CURRENT ACTIVITIES OF CHILDREN NEUROLOGY UNIT
M. zarowski, B. Galas-Zgorzalewicz. Department of Developmental Neurology at University of Medical Sciences, Poznah, Poland We received for testing Focus (MEGIS, Germany), an imaging technique transforming the traditional scalp EEG into an image of source activities of the different brain regions. Our research was based on 32-chanell EEG files recorded on CEEGRAPH SE, (Biologic, USA). Obtained from a group of 38 children and adolescents, both sexes, patients of the Department of Developmental Neurology at University of Medical Sciences in Poznafi. In order to test the usefulness of Focus in the Department's current activities, all EEG standard records obtained from children during the period of testing were subjected to an examination. All the records were marked by a physician, electroencephalographer. Digital EEG records were analysed by a continuous EEG source imaging Focus software. Only in those patients who underwent through seizures during EEG record was it possible to analyse the source activities just before a seizure. The seizure rhythms in temporal cortex, imagined by source montage channels, were revealed before they were apparent in traditional scalp EGG montage, in one patient. The utilisation of continuous-EEG source imaging analysis may be of a great importance as a non-invasively method providing additional information about seizure localisation in pre-surgical evaluations. ~ - ]
VISUALIZATION OF PHASE LAGS IN SINGLE FREQUENCY MAPS DERIVED FROM MULTI-CHANNEL EEG
N. Ille, M. Scherg. Div. of Biomagnetism, Dept. of Neurology, University of Heidelberg, Germany Continuous EEG or averaged segments were analyzed using Fast FourierTransformation (FFI', FOCUS program v.l.2). At distinct frequencies whole-head spherical spline maps were used to display the distribution
ELECTROPHYSlOLOGY OF HEREDITARY MOTOR & SENSORY NEUROPATHY AND HEREDITARY SPINOCEREBELLAR ATAXlA G. Kiteva-Trencevska, S. Vlaski-Jekic, R. Naumovski. Clinic of
Neurolog); Skopje, Macedonia The existence of ataxia in hereditary motor & sensory neuropathy (HMSN) and neuropathy in hereditary spinocerebellar ataxia (HSCA) are features connecting these two heterogeneous diseases. The aim is to show the electrophysiological findings in HMSN and HSCA. Electrophysiological examination included needle EMG of limb muscles, sensory and motor neurography and somatosensory evoked potentials (SSEP). 14 patients with HMSN, 10 of whom had HSMN type I, 2 type II and 2 type V and 10 patients with HSCA were examined, 4 of whom had Friedreich's ataxia (FA) and 6 HSCA with hyperreflexia, EMG showed reduction of the pattern of activity during maximal effort in muscles of upper and lower limbs in HMSN-1, HMSN-II, in lower limbs in HMSN-V, normal findings in 2 cases with HSCA and slight reduction in distal muscles of lower limbs in HSCA. Individual motor unit potentials were neurogenic. Motor conduction velocity (MCV) was decreased under 30 m/s in cases with HMSN-I in upper and lower limbs, slight reduction of MCV was registered in HMSN-II, normal MCV in HMSN-V and in patients with HSCA, MCV was normal in 5 and slightly reduced in the lower limbs in 5 cases. Sensory conduction velocity (SCV) of median and sural nerve was unmeasurable or reduced in HMSN-I and HMSN-I1. reduced of sural nerve in HMSN-V and in patients with HSCA, SCV was slightly reduced in 8 cases and normal in 2. SSEP registered affection of the peripheral somatosensory pathways in cases with HMSN, and affection of the central somatosensory pathways in HSCA as the dominant change. Electrophysiological evaluation of HMSN and HSCA reveals the severity of neuropathy and affection of the central somatosensory pathways and helps in differentiation of these diseases.
EEG and EEG Related Techniques - Epilepsy AUTOMATIC FOCUS DETECTION IN DIGITAL EEG BY A KNOWLEDGE-BASED SYSTEM
L. Schuster ~, C.S. Herrmann t H.P. Hundemer 2, H.C. Hopf 2. i TH Darmstadt, lntellektik, Neurologie, Germany; 2 Uniklinik Mainz, Neurologie, Germany
Question: Based on the adaptive frequency decomposition technique [1] combined with an expert system, we present a method for computer-aided detection of focal slow activity in the human EEG. Method: The incoming raw data are preprocessed by the adaptive frequency decomposition resulting in four linguistic fuzzy variables 3, 0, and ~ for frequency and four estimates high, medium, low and zero for amplitude. For the subsequent reasoning process, all data with high or medium 6- or 0-frequencies are selected, if their temporal occurrence within the EEG is higher than 10%. These data are analysed separately for each hemisphere and rules of the expert system determine, whether slow activity occurs in only one track (circumscribed focal activity) or in multiple adjacent tracks (large focal activity) or spreads over the whole hemisphere (generalised, lateralised activity). Results and Conclusion: Our method automatically detects various types of slow EEG-activity. The track showing maximal amplitude (the focus) can be determined as well as its spatial extent and duration.
317
Reference
[ I ] C.S. Herrmann, H.P. Hundemer and H.C. Hopf, Adaptive Frequency Decomposition for EEG-Analysis, at the 40th Annual German Conference on Clinical Neurophysiology, Electroencephalography and Clinical Neurophysiology, 1995
F
•
-
•
EEG DATA TRANSFER VIA ATM NETWORK
E. Rauhala i, M. Erkinjuntti i, E. R~ity 2, j. Koivisto 2, E Loula 2, V. H~ddnen 3.1 Satakunta Central Hospital, Pori, Finland; 2 Tampere University of Technology, Pori, Finland; 3 Tampere University Hospital, Tampere, Finland About 60 clinical neurophysiologists take care of all neurophysiological services (EEG, ENMG, evoked potentials, sleep studies) of the population of 5 million in Finland, Each central hospital has usually only one clinical neurophysiologist and distances between hospitals are quite long. The telecommunication infrastructure is modem and of high quality in Finland. Since at present most of the collected neurophysiological data is in digital, transferable form it is natural to develop telemedical applications for the needs of clinical neurophysiology. Telemedicine can be used e.g. for second opinion consulting, educational meetings and maintenance of data banks. Via neurophysiological networks it is possible to guarantee the availability of EEG analysis also daring holiday season and on-duty time. Telemedicine can be applied also for quality control and for standardizing the methods in different laboratories. We have developed a multimedia application for the consultation of EEG. The system is based on two Sun Sparcstation computers in UNIX environment. A video conference program 'Showme' is used both for sending video signal and sharing an EEG analysis application. Either of the conference partners can take control over the discussed data and move snaps on a whiteboard for further analysis. The system uses an ATM network with a capacity of 155 Mbytes per second which allows to transfer large amounts of EEG data and maintain a simultaneous video conference. This multimedia application makes possible a real-time interactive consultation and can be adapted to many kinds of data which is in digital form. ~P~-']
SOME ASPECTS OF CONTINUOUS EEG SOURCE IMAGING SOFTWARE'S UTILISATION IN CURRENT ACTIVITIES OF CHILDREN NEUROLOGY UNIT
M. zarowski, B. Galas-Zgorzalewicz. Department of Developmental Neurology at University of Medical Sciences, Poznah, Poland We received for testing Focus (MEGIS, Germany), an imaging technique transforming the traditional scalp EEG into an image of source activities of the different brain regions. Our research was based on 32-chanell EEG files recorded on CEEGRAPH SE, (Biologic, USA). Obtained from a group of 38 children and adolescents, both sexes, patients of the Department of Developmental Neurology at University of Medical Sciences in Poznafi. In order to test the usefulness of Focus in the Department's current activities, all EEG standard records obtained from children during the period of testing were subjected to an examination. All the records were marked by a physician, electroencephalographer. Digital EEG records were analysed by a continuous EEG source imaging Focus software. Only in those patients who underwent through seizures during EEG record was it possible to analyse the source activities just before a seizure. The seizure rhythms in temporal cortex, imagined by source montage channels, were revealed before they were apparent in traditional scalp EGG montage, in one patient. The utilisation of continuous-EEG source imaging analysis may be of a great importance as a non-invasively method providing additional information about seizure localisation in pre-surgical evaluations. ~ - ]
VISUALIZATION OF PHASE LAGS IN SINGLE FREQUENCY MAPS DERIVED FROM MULTI-CHANNEL EEG
N. Ille, M. Scherg. Div. of Biomagnetism, Dept. of Neurology, University of Heidelberg, Germany Continuous EEG or averaged segments were analyzed using Fast FourierTransformation (FFI', FOCUS program v.l.2). At distinct frequencies whole-head spherical spline maps were used to display the distribution