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Enhanced functional reinnervation under direct electrical stimulation of regenerating nerve
S133 male, 24-30-months old). Animals were anesthetized with urethane (50 mg/kg) and chloralose (5 mg/kg). Blood pressure and end-tidal CO 2 level were monitored throughout the experiment. The MG muscle was carefully dissected so that good blood circulation to the muscle was maintained, and was covered with warmed mineral oil (36+_1°C). The ventral root was dissected until it was ensured that it contained only one motor fiber to MG muscle. Motor units were classified by using the same criteria as those previously employed for cat hindlimb muscles. The units in the aged animals were readily classified into the same groups (type F and S) as in younger animals (11-14 months old). When compared with a motor unit sample of the younger animals, there was a large increase in population and mean tetanic tension for type S motor units in aged animals, and a slight decrease for type F motor units. There was no aheration of twitch contraction times in any unit type. A significant decrease in the average conduction velocity of motor axons in the aged animals was noted; the more marked decrease was found among the type F units.
P17.08 EMG STUDY OF M O T O R UNIT RESHAPING IN NEUROMUSCULAR AFFECTIONS. A. Serbanescu and A. Serbanescu Jnr.
( Bucharest, Romania) The concept of reshaping of the motor unit (MU) was recently introduced into neurological pathology (Desmedt 1979) as completing the process of axonal regeneration. Its purpose is the study of dynamic interaction between the peripheral nerve and muscle fibre in different pathological situations. An EMG study of this subject has been made by coherent EMG (Desmedt 1973) and single fibre EMG (Stalberg 1963). 50 cases with different neuromuscular lesions had EMGs recorded. The cases have been selected in agreement with the topography and type of the MU lesion: neurogenic (neurono-axono-myelinopathies) and myogenic (myositis, myopathies). The basic phenomena of MU reshaping: fibrillation which means the disconnection of the muscle fibre from the axon and linked potentials which mean the reconnection of the muscle fibre to the axon were studied dynamically by the two EMG methods, and the results were correlated. The peculiarity of the succession of phenomena: fibrillation, linked potentials, reshaped potentials, is the key to the EMG diagnosis, no matter the type of evolution of the lesion.
P17.09 DIAGNOSTIC VALUE OF K I N E S I O L O G I C EMG OF SACROSPINAL MUSCLES IN LUMBAR SPINE DYSFUNCTIONS. Ana Bobinac-Georgieuski, B.S. Matej,Sic, P. Matek, M. Turk and M. Safar
(Zagreb, Yugoslavia) Because of the obvious clinical significance of sacrospinal muscle 'spasm' in low back pain, we have developed an electrokinesiologic method to record EMG activity of sacrospinal muscles simultaneously with the POLGON diagram of trunk and thigh movements in the sagittal plane. Kinesiologic EMG of the sacrospinal muscles studied in 300 low back pain patients and 40 normal volunteers could be divided into six groups: 1. normal pattern of bi-phasic activity, lower during flexion, higher during extension, with electrical silence in the positions of maximal flexion and extension. 2. the same as above with the only difference that electrical silence is absent in the position of maximal extension. 3. monophasic activity during flexion and extension, with the peak of activity in the position of maximal flexion, with or without electrical silence in hyperextension. 4. bi-phasic reversed activity, higher during flexion, lower during extension, without electrical silence in maximal flexion, and with electrical silence in hyperextension. 5. monophasic activity of equal level during all phases of flexion-extension movements, with electrical silence in hyperextension. 6. continuous activity without electrical silence in any phases of movements. The data suggest that kinesiologic EMG variations of sacrospinal muscles represent different degrees of low back dysfunction. The results indicate that kinesiologic EMG is valuable in the diagnosis of low back impairment due to different causal factors.
PI7.10 ENHANCED FUNCTIONAL REINNERVATION UNDER DIRECT ELECTRICAL STIMULATION OF REGENERATING NERVE. W.A. Nix
(Mainz, W.Germany) A controversial matter is how far electrical stimulation can retard atrophy in denervated muscle. Furthermore it is not known whether stimulation affects nerve regeneration within the treated muscle. To study this aspect, the motor nerve to the soleus muscle was crushed, 30 mm before entering the muscle. Proximal to the lesion a permanent nerve cuff for stimulation was implanted to monitor in vivo regeneration of twitch, tetanic force and muscle action potential until they had reached their preoperative values. Three groups were formed: a control group of 9 animals, a nerve stimulated group of 8 and a muscle stimulated group of 8 rabbits. Muscle stimulation was performed via an implanted muscle electrode. Continuous stimulation with 4 Hz for 24 h was performed for about 4 weeks. In all
S134 groups the measured parameters dropped after axonotmesis. Two weeks later the stimulated group presented with higher values than the control. While preoperative values were reached at the end of the third week in stimulated animals they took a week longer in the controls. Thus electrical stimulation proved to be effective in enhancing functional recovery.
PI7.11 M A T U R A T I O N O F R E G E N E R A T E D M O T O R NERVE FIBERS IN C H I L D R E N W I T H O B S T E T R I C PARALYSIS. DISTAL LATENCIES O F M E D I A N AND U L N A R NERVE.
median nerves, in both forearms; ii) motor conduction velocity in peroneal and tibial nerves; iii) sensory conduction velocity in median and ulnar nerves; iv) EMG from m.deltoideus and m.tibialis ant. Results were compared with a control group. The correlations between lead level in serum, zinc level in serum and urine, c a d m i u m level in urine and electrophysiological findings were determined. The influence of individual metals and their joint effect on the degree of damage to peripheral nerves was estimated.
Olga Kwast and G. Krajewska
P17.13 S O M E C H A R A C T E R I S T I C S U N I T POTENTIALS.
(Warsaw, Poland)
1. Yletyinen and J. Partanen
Age related changes of distal latencies ( m s e c / c m ) (DL) of regenerated motor nerve fibres of median and ulnar nerves in children with obstetric plexus paralysis (OPP), aged from 4 m o n t h s to 15 years, were compared with developmental changes of these parameters in healthy children. The age when DL reaches its m i n i m u m value and m i n i m u m values of DL were computed using exponential functions and compared with a group of healthy children. It was found that the age of DL 'maturation' in both nerves was similar for children with OPP (25-26th months of age), while in healthy children it differed in median and ulnar nerves (24th and 38th m o n t h s respectively). The m i n i m u m values of DL in children with OPP were similar in median and ulnar nerves (0.54 and 0.58 m s e c / c m respectively) and similar to the average between the values obtained for median and ulnar nerve in healthy children (0.63 and 0.42 m s e c / c m respectively). The results obtained may indicate, not only that conduction properties of motor nerve fibers become similar, but that the whole motor units reach only intermediate type after a lesion at birth. Irreversible changes in muscles and a lack of specific afferent information, which is necessary for normal development of the motoneurone's final specific properties, and a lack of specific trophic influence from the regenerated motor neurones to muscle fibers during the early rapid period of development, may explain this phenomenon.
(Kuopio, Finland)
P17.12 LEAD, C A D M I U M A N D ZINC E L E C T R O M Y O G R A P H I C FINDINGS.
EXPOSURE
-
OF
FUSIMOTOR
End plate spikes in the EMG have been suggested to be caused by the activity of intrafusal muscle fibres driven by g a m m a motoneurones. Consequently, this kind of activity was renamed fusimotor unit potentials (FUPs) (Partanen and Nousiainen, Neurology 1983; 33: 1039). We have continued to analyze sequences of FUPs. In canine muscle, FUPs may be found for a limited time after denervation suggesting that the driving impulse may not always be spinal in origin. In h u m a n muscle, there seems to be a bimodal amplitude distribution of FUPs, corresponding possibly to gamma- and beta- efferent systems. A distinct alteration in the firing pattern of FUPs is often observed during passive lengthening or shortening of a muscle suggesting the effect of gamma-efferent control on length receptors. The firing pattern is often cyclic, presenting irregular bursts of activity with a general decline in the mean frequency. In the transition matrix of instantaneous frequencies, it is observed that transitions from a given high-frequency state to a given low-frequency state and vice versa occur in approximately equal numbers. These observations mostly support the original hypothesis and emphasize the role of peripheral, currently unresolved mechanisms contributing to F U P generation.
VISUAL EVOKED P O T E N T I A L S I1. PI8.01 PATI'ERN REVERSAL VEP AND ERG: SIMULTAN E O U S RECORDINGS. M. Basciani, M. Treviso, and D. Gambl
Zofia Kazibutowska and B. Stadnicka-Kossowska (Chieti, Italy) (Katowice, Poland) 120 workers, from the Nonferrous Metals Foundry in Katowice, exposed to toxic effects of lead, c a d m i u m and zinc, were examined. Examination included: 1) neurological state. 2) electrophysiological research; i) motor conduction velocity inulnar, radial,
Patterned stimuli were used in clinical screening of visual impairment to obtain the electroretinogram and visual evoked responses. Three types of recording electrodes have been used in different laboratories for PERG: gold foil, fiberglass and contact lens. Some disadvantages were pointed out: local discomfort, correct perception of the stimulus, cost of the elec-
P17.08 EMG STUDY OF M O T O R UNIT RESHAPING IN NEUROMUSCULAR AFFECTIONS. A. Serbanescu and A. Serbanescu Jnr.
( Bucharest, Romania) The concept of reshaping of the motor unit (MU) was recently introduced into neurological pathology (Desmedt 1979) as completing the process of axonal regeneration. Its purpose is the study of dynamic interaction between the peripheral nerve and muscle fibre in different pathological situations. An EMG study of this subject has been made by coherent EMG (Desmedt 1973) and single fibre EMG (Stalberg 1963). 50 cases with different neuromuscular lesions had EMGs recorded. The cases have been selected in agreement with the topography and type of the MU lesion: neurogenic (neurono-axono-myelinopathies) and myogenic (myositis, myopathies). The basic phenomena of MU reshaping: fibrillation which means the disconnection of the muscle fibre from the axon and linked potentials which mean the reconnection of the muscle fibre to the axon were studied dynamically by the two EMG methods, and the results were correlated. The peculiarity of the succession of phenomena: fibrillation, linked potentials, reshaped potentials, is the key to the EMG diagnosis, no matter the type of evolution of the lesion.
P17.09 DIAGNOSTIC VALUE OF K I N E S I O L O G I C EMG OF SACROSPINAL MUSCLES IN LUMBAR SPINE DYSFUNCTIONS. Ana Bobinac-Georgieuski, B.S. Matej,Sic, P. Matek, M. Turk and M. Safar
(Zagreb, Yugoslavia) Because of the obvious clinical significance of sacrospinal muscle 'spasm' in low back pain, we have developed an electrokinesiologic method to record EMG activity of sacrospinal muscles simultaneously with the POLGON diagram of trunk and thigh movements in the sagittal plane. Kinesiologic EMG of the sacrospinal muscles studied in 300 low back pain patients and 40 normal volunteers could be divided into six groups: 1. normal pattern of bi-phasic activity, lower during flexion, higher during extension, with electrical silence in the positions of maximal flexion and extension. 2. the same as above with the only difference that electrical silence is absent in the position of maximal extension. 3. monophasic activity during flexion and extension, with the peak of activity in the position of maximal flexion, with or without electrical silence in hyperextension. 4. bi-phasic reversed activity, higher during flexion, lower during extension, without electrical silence in maximal flexion, and with electrical silence in hyperextension. 5. monophasic activity of equal level during all phases of flexion-extension movements, with electrical silence in hyperextension. 6. continuous activity without electrical silence in any phases of movements. The data suggest that kinesiologic EMG variations of sacrospinal muscles represent different degrees of low back dysfunction. The results indicate that kinesiologic EMG is valuable in the diagnosis of low back impairment due to different causal factors.
PI7.10 ENHANCED FUNCTIONAL REINNERVATION UNDER DIRECT ELECTRICAL STIMULATION OF REGENERATING NERVE. W.A. Nix
(Mainz, W.Germany) A controversial matter is how far electrical stimulation can retard atrophy in denervated muscle. Furthermore it is not known whether stimulation affects nerve regeneration within the treated muscle. To study this aspect, the motor nerve to the soleus muscle was crushed, 30 mm before entering the muscle. Proximal to the lesion a permanent nerve cuff for stimulation was implanted to monitor in vivo regeneration of twitch, tetanic force and muscle action potential until they had reached their preoperative values. Three groups were formed: a control group of 9 animals, a nerve stimulated group of 8 and a muscle stimulated group of 8 rabbits. Muscle stimulation was performed via an implanted muscle electrode. Continuous stimulation with 4 Hz for 24 h was performed for about 4 weeks. In all
S134 groups the measured parameters dropped after axonotmesis. Two weeks later the stimulated group presented with higher values than the control. While preoperative values were reached at the end of the third week in stimulated animals they took a week longer in the controls. Thus electrical stimulation proved to be effective in enhancing functional recovery.
PI7.11 M A T U R A T I O N O F R E G E N E R A T E D M O T O R NERVE FIBERS IN C H I L D R E N W I T H O B S T E T R I C PARALYSIS. DISTAL LATENCIES O F M E D I A N AND U L N A R NERVE.
median nerves, in both forearms; ii) motor conduction velocity in peroneal and tibial nerves; iii) sensory conduction velocity in median and ulnar nerves; iv) EMG from m.deltoideus and m.tibialis ant. Results were compared with a control group. The correlations between lead level in serum, zinc level in serum and urine, c a d m i u m level in urine and electrophysiological findings were determined. The influence of individual metals and their joint effect on the degree of damage to peripheral nerves was estimated.
Olga Kwast and G. Krajewska
P17.13 S O M E C H A R A C T E R I S T I C S U N I T POTENTIALS.
(Warsaw, Poland)
1. Yletyinen and J. Partanen
Age related changes of distal latencies ( m s e c / c m ) (DL) of regenerated motor nerve fibres of median and ulnar nerves in children with obstetric plexus paralysis (OPP), aged from 4 m o n t h s to 15 years, were compared with developmental changes of these parameters in healthy children. The age when DL reaches its m i n i m u m value and m i n i m u m values of DL were computed using exponential functions and compared with a group of healthy children. It was found that the age of DL 'maturation' in both nerves was similar for children with OPP (25-26th months of age), while in healthy children it differed in median and ulnar nerves (24th and 38th m o n t h s respectively). The m i n i m u m values of DL in children with OPP were similar in median and ulnar nerves (0.54 and 0.58 m s e c / c m respectively) and similar to the average between the values obtained for median and ulnar nerve in healthy children (0.63 and 0.42 m s e c / c m respectively). The results obtained may indicate, not only that conduction properties of motor nerve fibers become similar, but that the whole motor units reach only intermediate type after a lesion at birth. Irreversible changes in muscles and a lack of specific afferent information, which is necessary for normal development of the motoneurone's final specific properties, and a lack of specific trophic influence from the regenerated motor neurones to muscle fibers during the early rapid period of development, may explain this phenomenon.
(Kuopio, Finland)
P17.12 LEAD, C A D M I U M A N D ZINC E L E C T R O M Y O G R A P H I C FINDINGS.
EXPOSURE
-
OF
FUSIMOTOR
End plate spikes in the EMG have been suggested to be caused by the activity of intrafusal muscle fibres driven by g a m m a motoneurones. Consequently, this kind of activity was renamed fusimotor unit potentials (FUPs) (Partanen and Nousiainen, Neurology 1983; 33: 1039). We have continued to analyze sequences of FUPs. In canine muscle, FUPs may be found for a limited time after denervation suggesting that the driving impulse may not always be spinal in origin. In h u m a n muscle, there seems to be a bimodal amplitude distribution of FUPs, corresponding possibly to gamma- and beta- efferent systems. A distinct alteration in the firing pattern of FUPs is often observed during passive lengthening or shortening of a muscle suggesting the effect of gamma-efferent control on length receptors. The firing pattern is often cyclic, presenting irregular bursts of activity with a general decline in the mean frequency. In the transition matrix of instantaneous frequencies, it is observed that transitions from a given high-frequency state to a given low-frequency state and vice versa occur in approximately equal numbers. These observations mostly support the original hypothesis and emphasize the role of peripheral, currently unresolved mechanisms contributing to F U P generation.
VISUAL EVOKED P O T E N T I A L S I1. PI8.01 PATI'ERN REVERSAL VEP AND ERG: SIMULTAN E O U S RECORDINGS. M. Basciani, M. Treviso, and D. Gambl
Zofia Kazibutowska and B. Stadnicka-Kossowska (Chieti, Italy) (Katowice, Poland) 120 workers, from the Nonferrous Metals Foundry in Katowice, exposed to toxic effects of lead, c a d m i u m and zinc, were examined. Examination included: 1) neurological state. 2) electrophysiological research; i) motor conduction velocity inulnar, radial,
Patterned stimuli were used in clinical screening of visual impairment to obtain the electroretinogram and visual evoked responses. Three types of recording electrodes have been used in different laboratories for PERG: gold foil, fiberglass and contact lens. Some disadvantages were pointed out: local discomfort, correct perception of the stimulus, cost of the elec-