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P198 Effect of botulinum toxin a on ephaptic transmission in patients with idiopathic hemifacial spasm
Abstracts of the 13th European Congress of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008), S1–S131 creases cortical excitability more widely than the I-wave networks that it targets.
P196 A new test to increase diagnostic sensitivity in ulnar nerve entrapment at elbow Pietro Caliandro 1,2 , Mariangela Foschini 1 , Costanza Pazzaglia 1 , Irene Aprile 2 , Giuseppe Granata 1 , Pietro Tonali 1,2 , Luca Padua 1,2 1 Institute of Neurology, Università Cattolica, Roma, Italy; 2 Fondazione Don Carlo Gnocchi ONLUS, Roma, Italy Purpose: Motor conduction velocity may yield false-negative results in mild ulnar nerve entrapment at elbow (UNE). There is evidence that the clinical heterogeneity of UNE may be due to the different involvement of fascicles. We hypothesized that, if fibres to FDI are more damaged than fibres to ADM, a relative slowing of motor CV at the segment across the elbow recording from FDI (FDI-CV) versus CV at the same segment recording from ADM (ADM-CV) would occur. Method: We calculated the ratio between FDI-CV and ADM-CV (INRATIO) in 60 consecutive UNE patients, 40 norms, and 16 patients with lower cervical radiculopathy. The UNE sample consisted of: 1) patients with neurophysiological evidence (UNE+), 2) patients without neurophysiological evidence (UNE-). We evaluated the possible usefulness of the IN-RATIO to increase sensitivity in diagnosing UNE. Results: The IN-RATIO was lower in the UNE- than in norms (p<0.001) and cervicobrachialgia sample (p=0.02). We found that if the IN-RATIO is ?0.97, its sensitivity in diagnosing UNE- is 68%, specificity 91%. Conclusion: Fibres to FDI have a higher susceptibility to damage than fibres to ADM, and the IN-RATIO is a useful neurophysiological parameter to increase diagnostic sensitivity. Our results demonstrate the usefulness of a new neurophysiological parameter in improving diagnosis of UNE.
P197 Myotonic dystrophy type I: autonomic nervous system evaluation Nora Lebrato Rubio, Susana Palao Duarte, Jose Maria Vazquez Miralles, Adriano Jimenez Escrig, Gema de Blas Beorlegui Hospital Ramon y Cajal, Madrid, Spain Background: Myotonic dystrophy type I (DM I) is a hereditary muscular dystrophy characterized by myotonia and multisystemic involvement. Although these patients present clinical manifestations related to autonomic nervous system (ANS) dysfunction, few systematic studies have been published. Purpose: To evaluate the presence of ANS dysfunction in patients with DM I and to correlate these findings with CGT (19q13) repeat size, degree of clinical severity, age and presence of endocrine and cardiac involvement. Methods: 16 patients with genetic diagnosis of DM I, aged 19-71 years (mean 42 years), and with CGT repeat size mean 586 (range 98-2000) were prospectively evaluated for the presence of clinical dysautonomy, endocrine disorders (diabetes mellitus, insulin resistance and hypothyroidism), and cardiopathy. ANS was studied by means of: a) RR interval variability during spontaneous breathing, deep breathing and Valsalva maneuver; b) blood pressure response to standing; and c) sympathetic skin response. In addition, electroneurography was performed to exclude the presence of peripheral neuropathy as a reason for ANS dysfunction. Results: 3 patients were excluded because of the presence of diabetes mellitus, neuropathy and polyneuropathy. In the other 13 patients, electroneurography studies were normal, and only in one case a reduction of RR interval variability during spontaneous breathing was found. RR interval variability during Valsalva maneuver was altered in 6 patients (46%), but without correlation with CGT repeat size. Conclusion: There is no remarkable ANS dysfunction in DM 1 patients. The abnormalities detected with Valsalva maneuver may be due to the impossibility of these patients to perform the test correctly because of neuromuscular involvement.
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P198 Effect of botulinum toxin a on ephaptic transmission in patients with idiopathic hemifacial spasm Yaprak Seçil, Nevin Gürgör, Ye¸sim Beckmann, Mustafa Ba¸so˘glu, Cumhur Ertekin, Tülay Kurt Atatürk Education and Training Hospital, Izmir, Turkey Purpose: The lateral spreading response (LSR) (abnormal muscle responses [AMR] and synkinetic responses of blink reflexes [SR1 and SR2]) are used in the electrophysiological diagnosis of hemifacial spasm (HFS) and sign of an abnormal function of the facial nerve circuitry known as ephaptic transmission. The aim of this study was to evaluate the effect of botulinum toxin A (Btx A) on LSR and latencies of motor responses and blink reflexes in idiopathic HFS. Method: Thirty three patients with idiopathic HFS were investigated. Btx A was injected only into the affected orbicularis oculi (OC) muscle. Nerve conduction studies, blink reflexes, LSR and needle EMG were performed in affected and unaffected sides of patients before and 3 weeks after Btx A injection. Results: Before Btx A: The latencies of blink reflex and facial nerve motor responses were not significantly different between affected and unaffected sides. The LSR was performed in 19 of 33 patients. All of them had AMR at the affected side in the OC and orbicularis oris (OR) muscles. The SR1 responses were obtained in 10 of 19 (52.6%) patients, the SR2 responses were obtained in 11 of 19 (57.8%) patients at the affected side OR muscle. None of them had AMR and SR at unaffected side. After Btx A: The latencies of motor responses, R1, R2 and contralateral R2 responses obtained from the affected side of the OC muscle were significantly increased. While the AMR were not obtained in the OC muscle, responses obtained from the OR muscle were not changed. There were no significantly differences in SR. In needle EMG, reduced recruitment on maximal effort, increased amplitude of MUPs with short duration and chemodenervation were observed in the only OC muscle. Conclusion: It was demostrated that Btx A affects the neuromuscular junctions in the muscle performed injection, does not show any effect in the other near muscles or does no has any effect upon ephaptic transmission.
P199 Auditory conflict processing: behavioral and electrophysiological manifestations of the Stroop effect Yifat Yaar Soffer, Yael Henkin, Chava Muchnik Department of Communication Disorders, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel Objective: To study auditory conflict processing by means of event-related potentials (ERPs) and behavioral measures during Stroop tasks. Secondary goals were to evaluate practice-related effects, and susceptibility to interference while processing different auditory dimensions (i.e. linguistic versus voice). Methods: ERPs and behavioral responses were recorded from sixteen adults while performing auditory Stroop tasks. Subjects were instructed to classify the linguistic (meaning) or voice (speaker’s gender) dimension, while ignoring the irrelevant voice or linguistic dimension, respectively. The words “father” and “mother” produced by a male or female speaker served as incongruent (conflictive) or congruent stimuli. Results: While a significant behavioral Stroop effect was evident (i.e. prolonged reaction time, reduced performance accuracy), the latencies of N1, P2, N2, and N4 were unaffected by the processing of incongruent versus congruent stimuli. N1 amplitude, on the other hand, was reduced during the processing of incongruent stimuli. Practice-related effects were manifested by shorter N4 latency and reaction time, and enhanced N1 amplitudes in the second half of Stroop trials (compared to the first), however, they were similar while processing congruent and incongruent stimuli. Lastly, classifying voice (versus linguistic) information resulted in reduced performance accuracy, diminished N1 and N2 amplitudes, and prolonged N4 latency. Conclusions: Conflict processing was manifested predominantly in postperceptual response selection and execution stages; however, an electrophysiological signature was evident at the early perceptual stages as well. Practice improved processing efficacy but did not alter the Stroop effect providing further support to its durability. Processing voice information was more susceptible to interference by linguistic content than vice versa. Utilization
P196 A new test to increase diagnostic sensitivity in ulnar nerve entrapment at elbow Pietro Caliandro 1,2 , Mariangela Foschini 1 , Costanza Pazzaglia 1 , Irene Aprile 2 , Giuseppe Granata 1 , Pietro Tonali 1,2 , Luca Padua 1,2 1 Institute of Neurology, Università Cattolica, Roma, Italy; 2 Fondazione Don Carlo Gnocchi ONLUS, Roma, Italy Purpose: Motor conduction velocity may yield false-negative results in mild ulnar nerve entrapment at elbow (UNE). There is evidence that the clinical heterogeneity of UNE may be due to the different involvement of fascicles. We hypothesized that, if fibres to FDI are more damaged than fibres to ADM, a relative slowing of motor CV at the segment across the elbow recording from FDI (FDI-CV) versus CV at the same segment recording from ADM (ADM-CV) would occur. Method: We calculated the ratio between FDI-CV and ADM-CV (INRATIO) in 60 consecutive UNE patients, 40 norms, and 16 patients with lower cervical radiculopathy. The UNE sample consisted of: 1) patients with neurophysiological evidence (UNE+), 2) patients without neurophysiological evidence (UNE-). We evaluated the possible usefulness of the IN-RATIO to increase sensitivity in diagnosing UNE. Results: The IN-RATIO was lower in the UNE- than in norms (p<0.001) and cervicobrachialgia sample (p=0.02). We found that if the IN-RATIO is ?0.97, its sensitivity in diagnosing UNE- is 68%, specificity 91%. Conclusion: Fibres to FDI have a higher susceptibility to damage than fibres to ADM, and the IN-RATIO is a useful neurophysiological parameter to increase diagnostic sensitivity. Our results demonstrate the usefulness of a new neurophysiological parameter in improving diagnosis of UNE.
P197 Myotonic dystrophy type I: autonomic nervous system evaluation Nora Lebrato Rubio, Susana Palao Duarte, Jose Maria Vazquez Miralles, Adriano Jimenez Escrig, Gema de Blas Beorlegui Hospital Ramon y Cajal, Madrid, Spain Background: Myotonic dystrophy type I (DM I) is a hereditary muscular dystrophy characterized by myotonia and multisystemic involvement. Although these patients present clinical manifestations related to autonomic nervous system (ANS) dysfunction, few systematic studies have been published. Purpose: To evaluate the presence of ANS dysfunction in patients with DM I and to correlate these findings with CGT (19q13) repeat size, degree of clinical severity, age and presence of endocrine and cardiac involvement. Methods: 16 patients with genetic diagnosis of DM I, aged 19-71 years (mean 42 years), and with CGT repeat size mean 586 (range 98-2000) were prospectively evaluated for the presence of clinical dysautonomy, endocrine disorders (diabetes mellitus, insulin resistance and hypothyroidism), and cardiopathy. ANS was studied by means of: a) RR interval variability during spontaneous breathing, deep breathing and Valsalva maneuver; b) blood pressure response to standing; and c) sympathetic skin response. In addition, electroneurography was performed to exclude the presence of peripheral neuropathy as a reason for ANS dysfunction. Results: 3 patients were excluded because of the presence of diabetes mellitus, neuropathy and polyneuropathy. In the other 13 patients, electroneurography studies were normal, and only in one case a reduction of RR interval variability during spontaneous breathing was found. RR interval variability during Valsalva maneuver was altered in 6 patients (46%), but without correlation with CGT repeat size. Conclusion: There is no remarkable ANS dysfunction in DM 1 patients. The abnormalities detected with Valsalva maneuver may be due to the impossibility of these patients to perform the test correctly because of neuromuscular involvement.
S121
P198 Effect of botulinum toxin a on ephaptic transmission in patients with idiopathic hemifacial spasm Yaprak Seçil, Nevin Gürgör, Ye¸sim Beckmann, Mustafa Ba¸so˘glu, Cumhur Ertekin, Tülay Kurt Atatürk Education and Training Hospital, Izmir, Turkey Purpose: The lateral spreading response (LSR) (abnormal muscle responses [AMR] and synkinetic responses of blink reflexes [SR1 and SR2]) are used in the electrophysiological diagnosis of hemifacial spasm (HFS) and sign of an abnormal function of the facial nerve circuitry known as ephaptic transmission. The aim of this study was to evaluate the effect of botulinum toxin A (Btx A) on LSR and latencies of motor responses and blink reflexes in idiopathic HFS. Method: Thirty three patients with idiopathic HFS were investigated. Btx A was injected only into the affected orbicularis oculi (OC) muscle. Nerve conduction studies, blink reflexes, LSR and needle EMG were performed in affected and unaffected sides of patients before and 3 weeks after Btx A injection. Results: Before Btx A: The latencies of blink reflex and facial nerve motor responses were not significantly different between affected and unaffected sides. The LSR was performed in 19 of 33 patients. All of them had AMR at the affected side in the OC and orbicularis oris (OR) muscles. The SR1 responses were obtained in 10 of 19 (52.6%) patients, the SR2 responses were obtained in 11 of 19 (57.8%) patients at the affected side OR muscle. None of them had AMR and SR at unaffected side. After Btx A: The latencies of motor responses, R1, R2 and contralateral R2 responses obtained from the affected side of the OC muscle were significantly increased. While the AMR were not obtained in the OC muscle, responses obtained from the OR muscle were not changed. There were no significantly differences in SR. In needle EMG, reduced recruitment on maximal effort, increased amplitude of MUPs with short duration and chemodenervation were observed in the only OC muscle. Conclusion: It was demostrated that Btx A affects the neuromuscular junctions in the muscle performed injection, does not show any effect in the other near muscles or does no has any effect upon ephaptic transmission.
P199 Auditory conflict processing: behavioral and electrophysiological manifestations of the Stroop effect Yifat Yaar Soffer, Yael Henkin, Chava Muchnik Department of Communication Disorders, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel Objective: To study auditory conflict processing by means of event-related potentials (ERPs) and behavioral measures during Stroop tasks. Secondary goals were to evaluate practice-related effects, and susceptibility to interference while processing different auditory dimensions (i.e. linguistic versus voice). Methods: ERPs and behavioral responses were recorded from sixteen adults while performing auditory Stroop tasks. Subjects were instructed to classify the linguistic (meaning) or voice (speaker’s gender) dimension, while ignoring the irrelevant voice or linguistic dimension, respectively. The words “father” and “mother” produced by a male or female speaker served as incongruent (conflictive) or congruent stimuli. Results: While a significant behavioral Stroop effect was evident (i.e. prolonged reaction time, reduced performance accuracy), the latencies of N1, P2, N2, and N4 were unaffected by the processing of incongruent versus congruent stimuli. N1 amplitude, on the other hand, was reduced during the processing of incongruent stimuli. Practice-related effects were manifested by shorter N4 latency and reaction time, and enhanced N1 amplitudes in the second half of Stroop trials (compared to the first), however, they were similar while processing congruent and incongruent stimuli. Lastly, classifying voice (versus linguistic) information resulted in reduced performance accuracy, diminished N1 and N2 amplitudes, and prolonged N4 latency. Conclusions: Conflict processing was manifested predominantly in postperceptual response selection and execution stages; however, an electrophysiological signature was evident at the early perceptual stages as well. Practice improved processing efficacy but did not alter the Stroop effect providing further support to its durability. Processing voice information was more susceptible to interference by linguistic content than vice versa. Utilization